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KVM GICv3 emulation

PATCH Superseded Andre Przywara 2 participants 30 messages Jan 14, 2015 – Jan 19, 2015

Subsystems (7)
Documentation Arm (32-bit) KVM arm64 +3 more subsystems
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#0 lore raw

v7 cover KVM GICv3 emulation

This is version 7 of the GICv3 guest emulation series. As v6 this series is based on v3.19-rc3 plus Eric's explicit VGIC_CTRL_INIT patches.

Most visible change is that the v6 patch 18/20 (introduce kvm_check_device_type()) is now gone, instead the validity check for the GICv2 emulation is now done internally via a new member of struct vgic_params (see new 18/20 for the implementation). There is new patch (20/20) that checks the userland provided memory regions's address for the VGIC to be properly aligned. Since that is build upon a refactoring in the series, I put it at the end. If this should be one of the first patches, let me know and I will rework that.

The rest of the changes are smaller things spotted by Christoffer (many thanks for the repeated, surely tiresome reviews!).

For a changelog summary see below, also each patch carries a changelog.
Only patches 02, 05, 08, 15, 18 and 19 had actual changes, 20/20 is new.

A git repo hosting all these patches lives in the kvm-gicv3/v7 branch of [1]. The kvm-gicv3/v6 branch has been updated to hold the delta patches.
-----

GICv3 is the ARM generic interrupt controller designed to overcome some limits of the prevalent GICv2. Most notably it lifts the 8-CPU limit. Though with Linux-3.17 Marc introduced support for hosts to use a GICv3, the CPU limitation still applies to KVM guests, since the current code emulates a GICv2 only.
Also, GICv2 backward compatibility being optional in GICv3, a number of systems won't be able to run GICv2 guests.

This patch series provides code to emulate a GICv3 distributor and redistributor for any KVM guest. It requires a GICv3 in the host to work. With those patches one can run guests efficiently on any GICv3 host. It has the following features:
- Affinity routing (support for up to 255 VCPUs, more possible)
- System registers (as opposed to MMIO access)
- No ITS
- No priority support (as the GICv2 emulation)
- No save / restore support so far (will be added soon)
- Only Group1 interrupts support

The first patches actually refactor the current VGIC code to make room for a different VGIC model to be dropped in with Patch 15. The remaining patches connect the new model to the kernel backend and the userland facing code.

The series goes on top of v3.19-rc3 plus Eric's init rework patches. The necessary patches for kvmtool to enable the guest's GICv3 have been posted here before [2], an updated version will follow soon.

There was some testing on the fast model with some I/O and interrupt affinity shuffling in a Linux guest with a varying number of VCPUs as well as some testing on a Juno board (GICv2 only, to spot regressions).

Please review and test.
I would be grateful for people to test for GICv2 regressions also (so on a GICv2 host with current kvmtool/qemu), as there is quite some refactoring on that front.

Much of the code was inspired by MarcZ, also kudos to him for doing the rather painful rebase on top of v3.17-rc1.

Cheers,
Andre.

[1] https://github.com/apritzel/linux.git
[2] https://lists.cs.columbia.edu/pipermail/kvmarm/2014-June/010086.html

Andre Przywara (20):
arm/arm64: KVM: rework MPIDR assignment and add accessors arm/arm64: KVM: pass down user space provided GIC type into vGIC code arm/arm64: KVM: refactor vgic_handle_mmio() function arm/arm64: KVM: wrap 64 bit MMIO accesses with two 32 bit ones arm/arm64: KVM: introduce per-VM ops
arm/arm64: KVM: move kvm_register_device_ops() into vGIC probing arm/arm64: KVM: dont rely on a valid GICH base address arm/arm64: KVM: make the maximum number of vCPUs a per-VM value arm/arm64: KVM: make the value of ICC_SRE_EL1 a per-VM variable arm/arm64: KVM: refactor MMIO accessors
arm/arm64: KVM: refactor/wrap vgic_set/get_attr() arm/arm64: KVM: add vgic.h header file
arm/arm64: KVM: split GICv2 specific emulation code from vgic.c arm/arm64: KVM: add opaque private pointer to MMIO data arm/arm64: KVM: add virtual GICv3 distributor emulation
arm64: GICv3: introduce symbolic names for GICv3 ICC_SGI1R_EL1 fields
arm64: KVM: add SGI generation register emulation arm/arm64: KVM: enable kernel side of GICv3 emulation arm/arm64: KVM: allow userland to request a virtual GICv3 arm/arm64: KVM: force alignment of VGIC dist/CPU/redist addresses

 Documentation/virtual/kvm/api.txt              |   13 +-
 Documentation/virtual/kvm/devices/arm-vgic.txt |   26 +-
 arch/arm/include/asm/kvm_emulate.h             |    5 +-
 arch/arm/include/asm/kvm_host.h                |    3 +
 arch/arm/include/asm/kvm_mmio.h                |    1 +
 arch/arm/kvm/Makefile                          |    1 +
 arch/arm/kvm/arm.c                             |   23 +-
 arch/arm/kvm/psci.c                            |   17 +-
 arch/arm64/include/asm/kvm_emulate.h           |    5 +-
 arch/arm64/include/asm/kvm_host.h              |    5 +
 arch/arm64/include/asm/kvm_mmio.h              |    1 +
 arch/arm64/include/uapi/asm/kvm.h              |    7 +
 arch/arm64/kernel/asm-offsets.c                |    1 +
 arch/arm64/kvm/Makefile                        |    2 +
 arch/arm64/kvm/sys_regs.c                      |   40 +-
 arch/arm64/kvm/vgic-v3-switch.S                |   14 +-
 drivers/irqchip/irq-gic-v3.c                   |   14 +-
 include/kvm/arm_vgic.h                         |   43 +-
 include/linux/irqchip/arm-gic-v3.h             |   44 +
 include/linux/kvm_host.h                       |    2 +
 include/uapi/linux/kvm.h                       |    2 +
 virt/kvm/arm/vgic-v2-emul.c                    |  847 ++++++++++++++++++
 virt/kvm/arm/vgic-v2.c                         |    4 +
 virt/kvm/arm/vgic-v3-emul.c                    | 1036 ++++++++++++++++++++++
 virt/kvm/arm/vgic-v3.c                         |   82 +-
 virt/kvm/arm/vgic.c                            | 1121 ++++++------------------
 virt/kvm/arm/vgic.h                            |  123 +++
 27 files changed, 2566 insertions(+), 916 deletions(-)
 create mode 100644 virt/kvm/arm/vgic-v2-emul.c
 create mode 100644 virt/kvm/arm/vgic-v3-emul.c
 create mode 100644 virt/kvm/arm/vgic.h
Signature · 1 line
1.7.9.5
#1 lore raw

PATCH v7 1/20 arm/arm64: KVM: rework MPIDR assignment and add accessors

The virtual MPIDR registers (containing topology information) for the guest are currently mapped linearily to the vcpu_id. Improve this mapping for arm64 by using three levels to not artificially limit the number of vCPUs.
To help this, change and rename the kvm_vcpu_get_mpidr() function to mask off the non-affinity bits in the MPIDR register.
Also add an accessor to later allow easier access to a vCPU with a given MPIDR. Use this new accessor in the PSCI emulation.

---
Changelog v6...v7:
(none)

Changelog v5...v6:
(add Reviewed-by:)

Changelog v4...v5:
(add Reviewed-by:)

Changelog v3...v4:
- rename kvm_vcpu_get_mpidr() to kvm_vcpu_get_mpidr_aff()
- simplify kvm_mpidr_to_vcpu()
- fixup comment

 arch/arm/include/asm/kvm_emulate.h   |    5 +++--
 arch/arm/include/asm/kvm_host.h      |    2 ++
 arch/arm/kvm/arm.c                   |   13 +++++++++++++
 arch/arm/kvm/psci.c                  |   17 +++++------------
 arch/arm64/include/asm/kvm_emulate.h |    5 +++--
 arch/arm64/include/asm/kvm_host.h    |    2 ++
 arch/arm64/kvm/sys_regs.c            |   13 +++++++++++--
 7 files changed, 39 insertions(+), 18 deletions(-)
arch/arm/include/asm/kvm_emulate.h +3 -2
index 66ce176..c528615 100644
@@ -23,6 +23,7 @@
 #include <asm/kvm_asm.h>
 #include <asm/kvm_mmio.h>
 #include <asm/kvm_arm.h>
+#include <asm/cputype.h>
 
 unsigned long *vcpu_reg(struct kvm_vcpu *vcpu, u8 reg_num);
 unsigned long *vcpu_spsr(struct kvm_vcpu *vcpu);
@@ -167,9 +168,9 @@ static inline u32 kvm_vcpu_hvc_get_imm(struct kvm_vcpu *vcpu)
 	return kvm_vcpu_get_hsr(vcpu) & HSR_HVC_IMM_MASK;
 }
 
-static inline unsigned long kvm_vcpu_get_mpidr(struct kvm_vcpu *vcpu)
+static inline unsigned long kvm_vcpu_get_mpidr_aff(struct kvm_vcpu *vcpu)
 {
-	return vcpu->arch.cp15[c0_MPIDR];
+	return vcpu->arch.cp15[c0_MPIDR] & MPIDR_HWID_BITMASK;
 }
 
 static inline void kvm_vcpu_set_be(struct kvm_vcpu *vcpu)
arch/arm/include/asm/kvm_host.h +2 -0
index 254e065..a4e1155 100644
@@ -234,6 +234,8 @@ static inline void vgic_arch_setup(const struct vgic_params *vgic)
 int kvm_perf_init(void);
 int kvm_perf_teardown(void);
 
+struct kvm_vcpu *kvm_mpidr_to_vcpu(struct kvm *kvm, unsigned long mpidr);
+
 static inline void kvm_arch_hardware_disable(void) {}
 static inline void kvm_arch_hardware_unsetup(void) {}
 static inline void kvm_arch_sync_events(struct kvm *kvm) {}
arch/arm/kvm/arm.c +13 -0
index 2d6d910..d0fadd6 100644
@@ -1045,6 +1045,19 @@ static void check_kvm_target_cpu(void *ret)
 	*(int *)ret = kvm_target_cpu();
 }
 
+struct kvm_vcpu *kvm_mpidr_to_vcpu(struct kvm *kvm, unsigned long mpidr)
+{
+	struct kvm_vcpu *vcpu;
+	int i;
+
+	mpidr &= MPIDR_HWID_BITMASK;
+	kvm_for_each_vcpu(i, vcpu, kvm) {
+		if (mpidr == kvm_vcpu_get_mpidr_aff(vcpu))
+			return vcpu;
+	}
+	return NULL;
+}
+
 /**
  * Initialize Hyp-mode and memory mappings on all CPUs.
  */
arch/arm/kvm/psci.c +5 -12
index 58cb324..02fa8ef 100644
@@ -22,6 +22,7 @@
 #include <asm/cputype.h>
 #include <asm/kvm_emulate.h>
 #include <asm/kvm_psci.h>
+#include <asm/kvm_host.h>
 
 /*
  * This is an implementation of the Power State Coordination Interface
@@ -66,25 +67,17 @@ static void kvm_psci_vcpu_off(struct kvm_vcpu *vcpu)
 static unsigned long kvm_psci_vcpu_on(struct kvm_vcpu *source_vcpu)
 {
 	struct kvm *kvm = source_vcpu->kvm;
-	struct kvm_vcpu *vcpu = NULL, *tmp;
+	struct kvm_vcpu *vcpu = NULL;
 	wait_queue_head_t *wq;
 	unsigned long cpu_id;
 	unsigned long context_id;
-	unsigned long mpidr;
 	phys_addr_t target_pc;
-	int i;
 
-	cpu_id = *vcpu_reg(source_vcpu, 1);
+	cpu_id = *vcpu_reg(source_vcpu, 1) & MPIDR_HWID_BITMASK;
 	if (vcpu_mode_is_32bit(source_vcpu))
 		cpu_id &= ~((u32) 0);
 
-	kvm_for_each_vcpu(i, tmp, kvm) {
-		mpidr = kvm_vcpu_get_mpidr(tmp);
-		if ((mpidr & MPIDR_HWID_BITMASK) == (cpu_id & MPIDR_HWID_BITMASK)) {
-			vcpu = tmp;
-			break;
-		}
-	}
+	vcpu = kvm_mpidr_to_vcpu(kvm, cpu_id);
 
 	/*
 	 * Make sure the caller requested a valid CPU and that the CPU is
@@ -155,7 +148,7 @@ static unsigned long kvm_psci_vcpu_affinity_info(struct kvm_vcpu *vcpu)
 	 * then ON else OFF
 	 */
 	kvm_for_each_vcpu(i, tmp, kvm) {
-		mpidr = kvm_vcpu_get_mpidr(tmp);
+		mpidr = kvm_vcpu_get_mpidr_aff(tmp);
 		if (((mpidr & target_affinity_mask) == target_affinity) &&
 		    !tmp->arch.pause) {
 			return PSCI_0_2_AFFINITY_LEVEL_ON;
arch/arm64/include/asm/kvm_emulate.h +3 -2
index 8127e45..fc3459f 100644
@@ -27,6 +27,7 @@
 #include <asm/kvm_arm.h>
 #include <asm/kvm_mmio.h>
 #include <asm/ptrace.h>
+#include <asm/cputype.h>
 
 unsigned long *vcpu_reg32(const struct kvm_vcpu *vcpu, u8 reg_num);
 unsigned long *vcpu_spsr32(const struct kvm_vcpu *vcpu);
@@ -187,9 +188,9 @@ static inline u8 kvm_vcpu_trap_get_fault_type(const struct kvm_vcpu *vcpu)
 	return kvm_vcpu_get_hsr(vcpu) & ESR_EL2_FSC_TYPE;
 }
 
-static inline unsigned long kvm_vcpu_get_mpidr(struct kvm_vcpu *vcpu)
+static inline unsigned long kvm_vcpu_get_mpidr_aff(struct kvm_vcpu *vcpu)
 {
-	return vcpu_sys_reg(vcpu, MPIDR_EL1);
+	return vcpu_sys_reg(vcpu, MPIDR_EL1) & MPIDR_HWID_BITMASK;
 }
 
 static inline void kvm_vcpu_set_be(struct kvm_vcpu *vcpu)
arch/arm64/include/asm/kvm_host.h +2 -0
index 0b7dfdb..37c4ff1 100644
@@ -206,6 +206,8 @@ int handle_exit(struct kvm_vcpu *vcpu, struct kvm_run *run,
 int kvm_perf_init(void);
 int kvm_perf_teardown(void);
 
+struct kvm_vcpu *kvm_mpidr_to_vcpu(struct kvm *kvm, unsigned long mpidr);
+
 static inline void __cpu_init_hyp_mode(phys_addr_t boot_pgd_ptr,
 				       phys_addr_t pgd_ptr,
 				       unsigned long hyp_stack_ptr,
arch/arm64/kvm/sys_regs.c +11 -2
index 3d7c2df..136e679 100644
@@ -252,10 +252,19 @@ static void reset_amair_el1(struct kvm_vcpu *vcpu, const struct sys_reg_desc *r)
 
 static void reset_mpidr(struct kvm_vcpu *vcpu, const struct sys_reg_desc *r)
 {
+	u64 mpidr;
+
 	/*
-	 * Simply map the vcpu_id into the Aff0 field of the MPIDR.
+	 * Map the vcpu_id into the first three affinity level fields of
+	 * the MPIDR. We limit the number of VCPUs in level 0 due to a
+	 * limitation to 16 CPUs in that level in the ICC_SGIxR registers
+	 * of the GICv3 to be able to address each CPU directly when
+	 * sending IPIs.
 	 */
-	vcpu_sys_reg(vcpu, MPIDR_EL1) = (1UL << 31) | (vcpu->vcpu_id & 0xff);
+	mpidr = (vcpu->vcpu_id & 0x0f) << MPIDR_LEVEL_SHIFT(0);
+	mpidr |= ((vcpu->vcpu_id >> 4) & 0xff) << MPIDR_LEVEL_SHIFT(1);
+	mpidr |= ((vcpu->vcpu_id >> 12) & 0xff) << MPIDR_LEVEL_SHIFT(2);
+	vcpu_sys_reg(vcpu, MPIDR_EL1) = (1ULL << 31) | mpidr;
 }
 
 /* Silly macro to expand the DBG{BCR,BVR,WVR,WCR}n_EL1 registers in one go */
Signature · 1 line
1.7.9.5
#2 lore raw

PATCH v7 2/20 arm/arm64: KVM: pass down user space provided GIC type into vGIC code

In reply to Andre Przywara

With the introduction of a second emulated GIC model we need to let userspace specify the GIC model to use for each VM. Pass the userspace provided value down into the vGIC code and store it there to differentiate later.

---
Changelog v6...v7:
- only provide auto vgic init for a GICv2

Changelog v5...v6:
(add Acked-by)

Changelog v4...v5:
(none)

Changelog v3...v4:
(added Acked-by)

 arch/arm/kvm/arm.c     |    2 +-
 include/kvm/arm_vgic.h |    7 +++++--
 virt/kvm/arm/vgic.c    |   15 +++++++++++++--
 3 files changed, 19 insertions(+), 5 deletions(-)
arch/arm/kvm/arm.c +1 -1
index d0fadd6..dd1a689 100644
@@ -821,7 +821,7 @@ long kvm_arch_vm_ioctl(struct file *filp,
 	switch (ioctl) {
 	case KVM_CREATE_IRQCHIP: {
 		if (vgic_present)
-			return kvm_vgic_create(kvm);
+			return kvm_vgic_create(kvm, KVM_DEV_TYPE_ARM_VGIC_V2);
 		else
 			return -ENXIO;
 	}
include/kvm/arm_vgic.h +5 -2
index ac4888d..525ce42 100644
@@ -140,6 +140,9 @@ struct vgic_dist {
 	bool			in_kernel;
 	bool			ready;
 
+	/* vGIC model the kernel emulates for the guest (GICv2 or GICv3) */
+	u32			vgic_model;
+
 	int			nr_cpus;
 	int			nr_irqs;
 
@@ -275,7 +278,7 @@ struct kvm_exit_mmio;
 int kvm_vgic_addr(struct kvm *kvm, unsigned long type, u64 *addr, bool write);
 int kvm_vgic_hyp_init(void);
 int kvm_vgic_map_resources(struct kvm *kvm);
-int kvm_vgic_create(struct kvm *kvm);
+int kvm_vgic_create(struct kvm *kvm, u32 type);
 void kvm_vgic_destroy(struct kvm *kvm);
 void kvm_vgic_vcpu_destroy(struct kvm_vcpu *vcpu);
 void kvm_vgic_flush_hwstate(struct kvm_vcpu *vcpu);
@@ -327,7 +330,7 @@ static inline int kvm_vgic_map_resources(struct kvm *kvm)
 	return 0;
 }
 
-static inline int kvm_vgic_create(struct kvm *kvm)
+static inline int kvm_vgic_create(struct kvm *kvm, u32 type)
 {
 	return 0;
 }
virt/kvm/arm/vgic.c +13 -2
index c84f53df..283038e 100644
@@ -1698,6 +1698,16 @@ int kvm_vgic_inject_irq(struct kvm *kvm, int cpuid, unsigned int irq_num,
 	int vcpu_id;
 
 	if (unlikely(!vgic_initialized(kvm))) {
+		/*
+		 * We only provide the automatic initialization of the VGIC
+		 * for the legacy case of a GICv2. Any other type must
+		 * be explicitly initialized once setup with the respective
+		 * KVM device call.
+		 */
+		if (kvm->arch.vgic.vgic_model != KVM_DEV_TYPE_ARM_VGIC_V2) {
+			ret = -EBUSY;
+			goto out;
+		}
 		mutex_lock(&kvm->lock);
 		ret = vgic_init(kvm);
 		mutex_unlock(&kvm->lock);
@@ -1935,7 +1945,7 @@ out:
 	return ret;
 }
 
-int kvm_vgic_create(struct kvm *kvm)
+int kvm_vgic_create(struct kvm *kvm, u32 type)
 {
 	int i, vcpu_lock_idx = -1, ret;
 	struct kvm_vcpu *vcpu;
@@ -1967,6 +1977,7 @@ int kvm_vgic_create(struct kvm *kvm)
 
 	spin_lock_init(&kvm->arch.vgic.lock);
 	kvm->arch.vgic.in_kernel = true;
+	kvm->arch.vgic.vgic_model = type;
 	kvm->arch.vgic.vctrl_base = vgic->vctrl_base;
 	kvm->arch.vgic.vgic_dist_base = VGIC_ADDR_UNDEF;
 	kvm->arch.vgic.vgic_cpu_base = VGIC_ADDR_UNDEF;
@@ -2404,7 +2415,7 @@ static void vgic_destroy(struct kvm_device *dev)
 
 static int vgic_create(struct kvm_device *dev, u32 type)
 {
-	return kvm_vgic_create(dev->kvm);
+	return kvm_vgic_create(dev->kvm, type);
 }
 
 static struct kvm_device_ops kvm_arm_vgic_v2_ops = {
Signature · 1 line
1.7.9.5
#3 lore raw

PATCH v7 3/20 arm/arm64: KVM: refactor vgic_handle_mmio() function

In reply to Andre Przywara

Currently we only need to deal with one MMIO region for the GIC emulation (the GICv2 distributor), but we soon need to extend this. Refactor the existing code to allow easier addition of different ranges without code duplication.

---
Changelog v6...v7:
(none)

Changelog v5...v6:
(add Acked-by)

Changelog v4...v5:
(none)

Changelog v3...v4:
- simplify is_in_range()
(added Reviewed-by:)

 virt/kvm/arm/vgic.c |   73 +++++++++++++++++++++++++++++++++++++--------------
 1 file changed, 53 insertions(+), 20 deletions(-)
virt/kvm/arm/vgic.c +53 -20
index 283038e..b5aa821 100644
@@ -1034,36 +1034,27 @@ static bool vgic_validate_access(const struct vgic_dist *dist,
 }
 
 /**
- * vgic_handle_mmio - handle an in-kernel MMIO access
+ * vgic_handle_mmio_range - handle an in-kernel MMIO access
  * @vcpu:	pointer to the vcpu performing the access
  * @run:	pointer to the kvm_run structure
  * @mmio:	pointer to the data describing the access
+ * @ranges:	array of MMIO ranges in a given region
+ * @mmio_base:	base address of that region
  *
- * returns true if the MMIO access has been performed in kernel space,
- * and false if it needs to be emulated in user space.
+ * returns true if the MMIO access could be performed
  */
-bool vgic_handle_mmio(struct kvm_vcpu *vcpu, struct kvm_run *run,
-		      struct kvm_exit_mmio *mmio)
+static bool vgic_handle_mmio_range(struct kvm_vcpu *vcpu, struct kvm_run *run,
+			    struct kvm_exit_mmio *mmio,
+			    const struct mmio_range *ranges,
+			    unsigned long mmio_base)
 {
 	const struct mmio_range *range;
 	struct vgic_dist *dist = &vcpu->kvm->arch.vgic;
-	unsigned long base = dist->vgic_dist_base;
 	bool updated_state;
 	unsigned long offset;
 
-	if (!irqchip_in_kernel(vcpu->kvm) ||
-	    mmio->phys_addr < base ||
-	    (mmio->phys_addr + mmio->len) > (base + KVM_VGIC_V2_DIST_SIZE))
-		return false;
-
-	/* We don't support ldrd / strd or ldm / stm to the emulated vgic */
-	if (mmio->len > 4) {
-		kvm_inject_dabt(vcpu, mmio->phys_addr);
-		return true;
-	}
-
-	offset = mmio->phys_addr - base;
-	range = find_matching_range(vgic_dist_ranges, mmio, offset);
+	offset = mmio->phys_addr - mmio_base;
+	range = find_matching_range(ranges, mmio, offset);
 	if (unlikely(!range || !range->handle_mmio)) {
 		pr_warn("Unhandled access %d %08llx %d\n",
 			mmio->is_write, mmio->phys_addr, mmio->len);
@@ -1071,7 +1062,7 @@ bool vgic_handle_mmio(struct kvm_vcpu *vcpu, struct kvm_run *run,
 	}
 
 	spin_lock(&vcpu->kvm->arch.vgic.lock);
-	offset = mmio->phys_addr - range->base - base;
+	offset -= range->base;
 	if (vgic_validate_access(dist, range, offset)) {
 		updated_state = range->handle_mmio(vcpu, mmio, offset);
 	} else {
@@ -1089,6 +1080,48 @@ bool vgic_handle_mmio(struct kvm_vcpu *vcpu, struct kvm_run *run,
 	return true;
 }
 
+static inline bool is_in_range(phys_addr_t addr, unsigned long len,
+			       phys_addr_t baseaddr, unsigned long size)
+{
+	return (addr >= baseaddr) && (addr + len <= baseaddr + size);
+}
+
+static bool vgic_v2_handle_mmio(struct kvm_vcpu *vcpu, struct kvm_run *run,
+				struct kvm_exit_mmio *mmio)
+{
+	unsigned long base = vcpu->kvm->arch.vgic.vgic_dist_base;
+
+	if (!is_in_range(mmio->phys_addr, mmio->len, base,
+			 KVM_VGIC_V2_DIST_SIZE))
+		return false;
+
+	/* GICv2 does not support accesses wider than 32 bits */
+	if (mmio->len > 4) {
+		kvm_inject_dabt(vcpu, mmio->phys_addr);
+		return true;
+	}
+
+	return vgic_handle_mmio_range(vcpu, run, mmio, vgic_dist_ranges, base);
+}
+
+/**
+ * vgic_handle_mmio - handle an in-kernel MMIO access for the GIC emulation
+ * @vcpu:      pointer to the vcpu performing the access
+ * @run:       pointer to the kvm_run structure
+ * @mmio:      pointer to the data describing the access
+ *
+ * returns true if the MMIO access has been performed in kernel space,
+ * and false if it needs to be emulated in user space.
+ */
+bool vgic_handle_mmio(struct kvm_vcpu *vcpu, struct kvm_run *run,
+		      struct kvm_exit_mmio *mmio)
+{
+	if (!irqchip_in_kernel(vcpu->kvm))
+		return false;
+
+	return vgic_v2_handle_mmio(vcpu, run, mmio);
+}
+
 static u8 *vgic_get_sgi_sources(struct vgic_dist *dist, int vcpu_id, int sgi)
 {
 	return dist->irq_sgi_sources + vcpu_id * VGIC_NR_SGIS + sgi;
Signature · 1 line
1.7.9.5
#4 lore raw

PATCH v7 4/20 arm/arm64: KVM: wrap 64 bit MMIO accesses with two 32 bit ones

In reply to Andre Przywara

Some GICv3 registers can and will be accessed as 64 bit registers. Currently the register handling code can only deal with 32 bit accesses, so we do two consecutive calls to cover this.

---
Changelog v6...v7:
(none)

Changelog v5...v6:
(add Acked-by)

Changelog v4...v5:
(add Reviewed-by:)

Changelog v3...v4:
- add comment explaining little endian handling

 virt/kvm/arm/vgic.c |   53 ++++++++++++++++++++++++++++++++++++++++++++++++---
 1 file changed, 50 insertions(+), 3 deletions(-)
virt/kvm/arm/vgic.c +50 -3
index b5aa821..a1fda79 100644
@@ -1033,6 +1033,53 @@ static bool vgic_validate_access(const struct vgic_dist *dist,
 	return true;
 }
 
+/*
+ * Call the respective handler function for the given range.
+ * We split up any 64 bit accesses into two consecutive 32 bit
+ * handler calls and merge the result afterwards.
+ * We do this in a little endian fashion regardless of the host's
+ * or guest's endianness, because the GIC is always LE and the rest of
+ * the code (vgic_reg_access) also puts it in a LE fashion already.
+ * At this point we have already identified the handle function, so
+ * range points to that one entry and offset is relative to this.
+ */
+static bool call_range_handler(struct kvm_vcpu *vcpu,
+			       struct kvm_exit_mmio *mmio,
+			       unsigned long offset,
+			       const struct mmio_range *range)
+{
+	u32 *data32 = (void *)mmio->data;
+	struct kvm_exit_mmio mmio32;
+	bool ret;
+
+	if (likely(mmio->len <= 4))
+		return range->handle_mmio(vcpu, mmio, offset);
+
+	/*
+	 * Any access bigger than 4 bytes (that we currently handle in KVM)
+	 * is actually 8 bytes long, caused by a 64-bit access
+	 */
+
+	mmio32.len = 4;
+	mmio32.is_write = mmio->is_write;
+
+	mmio32.phys_addr = mmio->phys_addr + 4;
+	if (mmio->is_write)
+		*(u32 *)mmio32.data = data32[1];
+	ret = range->handle_mmio(vcpu, &mmio32, offset + 4);
+	if (!mmio->is_write)
+		data32[1] = *(u32 *)mmio32.data;
+
+	mmio32.phys_addr = mmio->phys_addr;
+	if (mmio->is_write)
+		*(u32 *)mmio32.data = data32[0];
+	ret |= range->handle_mmio(vcpu, &mmio32, offset);
+	if (!mmio->is_write)
+		data32[0] = *(u32 *)mmio32.data;
+
+	return ret;
+}
+
 /**
  * vgic_handle_mmio_range - handle an in-kernel MMIO access
  * @vcpu:	pointer to the vcpu performing the access
@@ -1064,10 +1111,10 @@ static bool vgic_handle_mmio_range(struct kvm_vcpu *vcpu, struct kvm_run *run,
 	spin_lock(&vcpu->kvm->arch.vgic.lock);
 	offset -= range->base;
 	if (vgic_validate_access(dist, range, offset)) {
-		updated_state = range->handle_mmio(vcpu, mmio, offset);
+		updated_state = call_range_handler(vcpu, mmio, offset, range);
 	} else {
-		vgic_reg_access(mmio, NULL, offset,
-				ACCESS_READ_RAZ | ACCESS_WRITE_IGNORED);
+		if (!mmio->is_write)
+			memset(mmio->data, 0, mmio->len);
 		updated_state = false;
 	}
 	spin_unlock(&vcpu->kvm->arch.vgic.lock);
Signature · 1 line
1.7.9.5
#5 lore raw

PATCH v7 5/20 arm/arm64: KVM: introduce per-VM ops

In reply to Andre Przywara

Currently we only have one virtual GIC model supported, so all guests use the same emulation code. With the addition of another model we end up with different guests using potentially different vGIC models, so we have to split up some functions to be per VM. Introduce a vgic_vm_ops struct to hold function pointers for those functions that are different and provide the necessary code to initialize them.
Also split up the vgic_init() function to separate out VGIC model specific functionality into a separate function, which will later be different for a GICv3 model.

---
Changelog v6...v7:
- switch vgic_v2_init_emulation() to return void
(add Reviewed-by)

Changelog v5...v6:
- replace vgic_init() and vgic_init_maps() with map_resources() and init_model() (due to 3.19-rc change)
- various adaptions to upstream changes

Changelog v4...v5:
- add vgic_init_maps() function pointer

Changelog v3...v4:
- add accessor functions for vm_ops members
- introduce init_vgic_model() to differentiate between guest GIC models
- simplify vgic_v2_init_emulation()
- help debugging by hinting on handle_mmio codeflow in comment

 include/kvm/arm_vgic.h |   11 +++++++
 virt/kvm/arm/vgic.c    |   86 ++++++++++++++++++++++++++++++++++++++++++------
 2 files changed, 87 insertions(+), 10 deletions(-)
include/kvm/arm_vgic.h +11 -0
index 525ce42..dd24396 100644
@@ -134,6 +134,15 @@ struct vgic_params {
 	void __iomem	*vctrl_base;
 };
 
+struct vgic_vm_ops {
+	bool	(*handle_mmio)(struct kvm_vcpu *, struct kvm_run *,
+			       struct kvm_exit_mmio *);
+	bool	(*queue_sgi)(struct kvm_vcpu *, int irq);
+	void	(*add_sgi_source)(struct kvm_vcpu *, int irq, int source);
+	int	(*init_model)(struct kvm *);
+	int	(*map_resources)(struct kvm *, const struct vgic_params *);
+};
+
 struct vgic_dist {
 #ifdef CONFIG_KVM_ARM_VGIC
 	spinlock_t		lock;
@@ -215,6 +224,8 @@ struct vgic_dist {
 
 	/* Bitmap indicating which CPU has something pending */
 	unsigned long		*irq_pending_on_cpu;
+
+	struct vgic_vm_ops	vm_ops;
 #endif
 };
 
virt/kvm/arm/vgic.c +76 -10

171 lines not on this page · raw message

Signature · 1 line
1.7.9.5
#6 lore raw

PATCH v7 6/20 arm/arm64: KVM: move kvm_register_device_ops() into vGIC probing

In reply to Andre Przywara

Currently we unconditionally register the GICv2 emulation device during the host's KVM initialization. Since with GICv3 support we may end up with only v2 or only v3 or both supported, we move the registration into the GIC probing function, where we will later know which combination is valid.

---
Changelog v6...v7:
(none)

Changelog v5...v6:
(add Acked-by)

Changelog v4...v5:
(none)

Changelog v3...v4:
(add Acked-by)

 include/linux/kvm_host.h |    1 +
 virt/kvm/arm/vgic-v2.c   |    2 ++
 virt/kvm/arm/vgic-v3.c   |    1 +
 virt/kvm/arm/vgic.c      |    5 ++---
 4 files changed, 6 insertions(+), 3 deletions(-)
include/linux/kvm_host.h +1 -0
index 26f1060..703eeed 100644
@@ -1042,6 +1042,7 @@ void kvm_unregister_device_ops(u32 type);
 
 extern struct kvm_device_ops kvm_mpic_ops;
 extern struct kvm_device_ops kvm_xics_ops;
+extern struct kvm_device_ops kvm_arm_vgic_v2_ops;
 
 #ifdef CONFIG_HAVE_KVM_CPU_RELAX_INTERCEPT
 
virt/kvm/arm/vgic-v2.c +2 -0
index 2935405..e1cd3cb 100644
@@ -229,6 +229,8 @@ int vgic_v2_probe(struct device_node *vgic_node,
 		goto out_unmap;
 	}
 
+	kvm_register_device_ops(&kvm_arm_vgic_v2_ops, KVM_DEV_TYPE_ARM_VGIC_V2);
+
 	vgic->vcpu_base = vcpu_res.start;
 
 	kvm_info("%s@%llx IRQ%d\n", vgic_node->name,
virt/kvm/arm/vgic-v3.c +1 -0
index 1c2c8ee..d14c75f 100644
@@ -230,6 +230,7 @@ int vgic_v3_probe(struct device_node *vgic_node,
 		ret = -ENXIO;
 		goto out;
 	}
+	kvm_register_device_ops(&kvm_arm_vgic_v2_ops, KVM_DEV_TYPE_ARM_VGIC_V2);
 
 	vgic->vcpu_base = vcpu_res.start;
 	vgic->vctrl_base = NULL;
virt/kvm/arm/vgic.c +2 -3
index 9b63141..69f6e7a 100644
@@ -2564,7 +2564,7 @@ static int vgic_create(struct kvm_device *dev, u32 type)
 	return kvm_vgic_create(dev->kvm, type);
 }
 
-static struct kvm_device_ops kvm_arm_vgic_v2_ops = {
+struct kvm_device_ops kvm_arm_vgic_v2_ops = {
 	.name = "kvm-arm-vgic",
 	.create = vgic_create,
 	.destroy = vgic_destroy,
@@ -2643,8 +2643,7 @@ int kvm_vgic_hyp_init(void)
 
 	on_each_cpu(vgic_init_maintenance_interrupt, NULL, 1);
 
-	return kvm_register_device_ops(&kvm_arm_vgic_v2_ops,
-				       KVM_DEV_TYPE_ARM_VGIC_V2);
+	return 0;
 
 out_free_irq:
 	free_percpu_irq(vgic->maint_irq, kvm_get_running_vcpus());
Signature · 1 line
1.7.9.5
#7 lore raw

PATCH v7 7/20 arm/arm64: KVM: dont rely on a valid GICH base address

In reply to Andre Przywara

To check whether the vGIC was already initialized, we currently check the GICH base address for not being NULL. Since with GICv3 we may get along without this address, lets use the irqchip_in_kernel() function to detect an already initialized vGIC.

---
Changelog v6...v7:
(none)

Changelog v5...v6:
(add Acked-by)

Changelog v4...v5:
(none)

Changelog v3...v4:
(add Acked-by)

 virt/kvm/arm/vgic.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
virt/kvm/arm/vgic.c +1 -1
index 69f6e7a..1c3b75e 100644
@@ -2094,7 +2094,7 @@ int kvm_vgic_create(struct kvm *kvm, u32 type)
 
 	mutex_lock(&kvm->lock);
 
-	if (kvm->arch.vgic.vctrl_base) {
+	if (irqchip_in_kernel(kvm)) {
 		ret = -EEXIST;
 		goto out;
 	}
Signature · 1 line
1.7.9.5
#8 lore raw

PATCH v7 8/20 arm/arm64: KVM: make the maximum number of vCPUs a per-VM value

In reply to Andre Przywara

Currently the maximum number of vCPUs supported is a global value limited by the used GIC model. GICv3 will lift this limit, but we still need to observe it for guests using GICv2.
So the maximum number of vCPUs is per-VM value, depending on the GIC model the guest uses.
Store and check the value in struct kvm_arch, but keep it down to 8 for now.

---
Changelog v6...v7:
- switch vgic_v2_init_emulation to return void
- remove pr_warn() when asking for too many VCPUs
- change error code for EINVAL to E2BIG if too many VCPUs

Changelog v5...v6:
- adapt to 3.19-rc changes and to changes due to new 05/20

Changelog v4...v5:
- add define for GIC_V2_MAX_CPUS
- rename max_hw_vcpus
- add prototype for ARM non-VGIC configs

Changelog v3...v4:
- initialize max_vcpus with limit based on host GIC
- remove *_init_emul_* from VGIC backend
- refine VCPU limit on VGIC creation
- print warning when userland tries to create more VCPUs than supported

 arch/arm/include/asm/kvm_host.h   |    1 +
 arch/arm/kvm/arm.c                |    8 ++++++++
 arch/arm64/include/asm/kvm_host.h |    3 +++
 include/kvm/arm_vgic.h            |    8 ++++++++
 virt/kvm/arm/vgic-v2.c            |    1 +
 virt/kvm/arm/vgic-v3.c            |    1 +
 virt/kvm/arm/vgic.c               |   16 ++++++++++++++++
 7 files changed, 38 insertions(+)
arch/arm/include/asm/kvm_host.h +1 -0
index a4e1155..60c52ad 100644
@@ -68,6 +68,7 @@ struct kvm_arch {
 
 	/* Interrupt controller */
 	struct vgic_dist	vgic;
+	int max_vcpus;
 };
 
 #define KVM_NR_MEM_OBJS     40
arch/arm/kvm/arm.c +8 -0
index dd1a689..c33e4ab 100644
@@ -132,6 +132,9 @@ int kvm_arch_init_vm(struct kvm *kvm, unsigned long type)
 	/* Mark the initial VMID generation invalid */
 	kvm->arch.vmid_gen = 0;
 
+	/* The maximum number of VCPUs is limited by the host's GIC model */
+	kvm->arch.max_vcpus = kvm_vgic_get_max_vcpus();
+
 	return ret;
 out_free_stage2_pgd:
 	kvm_free_stage2_pgd(kvm);
@@ -218,6 +221,11 @@ struct kvm_vcpu *kvm_arch_vcpu_create(struct kvm *kvm, unsigned int id)
 		goto out;
 	}
 
+	if (id >= kvm->arch.max_vcpus) {
+		err = -EINVAL;
+		goto out;
+	}
+
 	vcpu = kmem_cache_zalloc(kvm_vcpu_cache, GFP_KERNEL);
 	if (!vcpu) {
 		err = -ENOMEM;
arch/arm64/include/asm/kvm_host.h +3 -0
index 37c4ff1..544de35 100644
@@ -59,6 +59,9 @@ struct kvm_arch {
 	/* VTTBR value associated with above pgd and vmid */
 	u64    vttbr;
 
+	/* The maximum number of vCPUs depends on the used GIC model */
+	int max_vcpus;
+
 	/* Interrupt controller */
 	struct vgic_dist	vgic;
 
include/kvm/arm_vgic.h +8 -0
index dd24396..1c0e9db 100644
@@ -33,6 +33,7 @@
 #define VGIC_V2_MAX_LRS		(1 << 6)
 #define VGIC_V3_MAX_LRS		16
 #define VGIC_MAX_IRQS		1024
+#define VGIC_V2_MAX_CPUS	8
 
 /* Sanity checks... */
 #if (KVM_MAX_VCPUS > 8)
@@ -132,6 +133,7 @@ struct vgic_params {
 	unsigned int	maint_irq;
 	/* Virtual control interface base address */
 	void __iomem	*vctrl_base;
+	int		max_gic_vcpus;
 };
 
 struct vgic_vm_ops {
@@ -289,6 +291,7 @@ struct kvm_exit_mmio;
 int kvm_vgic_addr(struct kvm *kvm, unsigned long type, u64 *addr, bool write);
 int kvm_vgic_hyp_init(void);
 int kvm_vgic_map_resources(struct kvm *kvm);
+int kvm_vgic_get_max_vcpus(void);
 int kvm_vgic_create(struct kvm *kvm, u32 type);
 void kvm_vgic_destroy(struct kvm *kvm);
 void kvm_vgic_vcpu_destroy(struct kvm_vcpu *vcpu);
@@ -393,6 +396,11 @@ static inline bool vgic_ready(struct kvm *kvm)
 {
 	return true;
 }
+
+static inline int kvm_vgic_get_max_vcpus(void)
+{
+	return KVM_MAX_VCPUS;
+}
 #endif
 
 #endif
virt/kvm/arm/vgic-v2.c +1 -0
index e1cd3cb..e8b82b2 100644
@@ -237,6 +237,7 @@ int vgic_v2_probe(struct device_node *vgic_node,
 		 vctrl_res.start, vgic->maint_irq);
 
 	vgic->type = VGIC_V2;
+	vgic->max_gic_vcpus = VGIC_V2_MAX_CPUS;
 	*ops = &vgic_v2_ops;
 	*params = vgic;
 	goto out;
virt/kvm/arm/vgic-v3.c +1 -0
index d14c75f..ea39bad 100644
@@ -235,6 +235,7 @@ int vgic_v3_probe(struct device_node *vgic_node,
 	vgic->vcpu_base = vcpu_res.start;
 	vgic->vctrl_base = NULL;
 	vgic->type = VGIC_V3;
+	vgic->max_gic_vcpus = KVM_MAX_VCPUS;
 
 	kvm_info("%s@%llx IRQ%d\n", vgic_node->name,
 		 vcpu_res.start, vgic->maint_irq);
virt/kvm/arm/vgic.c +16 -0
index 1c3b75e..2126bf5 100644
@@ -1878,6 +1878,17 @@ static int vgic_vcpu_init_maps(struct kvm_vcpu *vcpu, int nr_irqs)
 	return 0;
 }
 
+/**
+ * kvm_vgic_get_max_vcpus - Get the maximum number of VCPUs allowed by HW
+ *
+ * The host's GIC naturally limits the maximum amount of VCPUs a guest
+ * can use.
+ */
+int kvm_vgic_get_max_vcpus(void)
+{
+	return vgic->max_gic_vcpus;
+}
+
 void kvm_vgic_destroy(struct kvm *kvm)
 {
 	struct vgic_dist *dist = &kvm->arch.vgic;
@@ -2072,6 +2083,8 @@ static void vgic_v2_init_emulation(struct kvm *kvm)
 	dist->vm_ops.add_sgi_source = vgic_v2_add_sgi_source;
 	dist->vm_ops.init_model = vgic_v2_init_model;
 	dist->vm_ops.map_resources = vgic_v2_map_resources;
+
+	kvm->arch.max_vcpus = VGIC_V2_MAX_CPUS;
 }
 
 static int init_vgic_model(struct kvm *kvm, int type)
@@ -2084,6 +2097,9 @@ static int init_vgic_model(struct kvm *kvm, int type)
 		return -ENODEV;
 	}
 
+	if (atomic_read(&kvm->online_vcpus) > kvm->arch.max_vcpus)
+		return -E2BIG;
+
 	return 0;
 }
 
Signature · 1 line
1.7.9.5
#9 lore raw

PATCH v7 8/20 arm/arm64: KVM: make the maximum number of vCPUs a per-VM value

Quoted 9 lines · Andre Przywara

Currently the maximum number of vCPUs supported is a global value limited by the used GIC model. GICv3 will lift this limit, but we still need to observe it for guests using GICv2.
So the maximum number of vCPUs is per-VM value, depending on the GIC model the guest uses.
Store and check the value in struct kvm_arch, but keep it down to 8 for now.

#10 lore raw

PATCH v7 9/20 arm/arm64: KVM: make the value of ICC_SRE_EL1 a per-VM variable

In reply to Andre Przywara

ICC_SRE_EL1 is a system register allowing msr/mrs accesses to the GIC CPU interface for EL1 (guests). Currently we force it to 0, but for proper GICv3 support we have to allow guests to use it (depending on their selected virtual GIC model).
So add ICC_SRE_EL1 to the list of saved/restored registers on a world switch, but actually disallow a guest to change it by only restoring a fixed, once-initialized value.
This value depends on the GIC model userland has chosen for a guest.

---
Changelog v6...v7:
(none)

Changelog v5...v6:
(add Acked-by)

Changelog v4...v5:
(none)

Changelog v3...v4:
- initialize variable on declaration

 arch/arm64/kernel/asm-offsets.c |    1 +
 arch/arm64/kvm/vgic-v3-switch.S |   14 +++++++++-----
 include/kvm/arm_vgic.h          |    1 +
 virt/kvm/arm/vgic-v3.c          |    8 ++++++--
 4 files changed, 17 insertions(+), 7 deletions(-)
arch/arm64/kernel/asm-offsets.c +1 -0
index 9a9fce0..9d34486 100644
@@ -140,6 +140,7 @@ int main(void)
   DEFINE(VGIC_V2_CPU_ELRSR,	offsetof(struct vgic_cpu, vgic_v2.vgic_elrsr));
   DEFINE(VGIC_V2_CPU_APR,	offsetof(struct vgic_cpu, vgic_v2.vgic_apr));
   DEFINE(VGIC_V2_CPU_LR,	offsetof(struct vgic_cpu, vgic_v2.vgic_lr));
+  DEFINE(VGIC_V3_CPU_SRE,	offsetof(struct vgic_cpu, vgic_v3.vgic_sre));
   DEFINE(VGIC_V3_CPU_HCR,	offsetof(struct vgic_cpu, vgic_v3.vgic_hcr));
   DEFINE(VGIC_V3_CPU_VMCR,	offsetof(struct vgic_cpu, vgic_v3.vgic_vmcr));
   DEFINE(VGIC_V3_CPU_MISR,	offsetof(struct vgic_cpu, vgic_v3.vgic_misr));
arch/arm64/kvm/vgic-v3-switch.S +9 -5
index d160469..617a012 100644
@@ -148,17 +148,18 @@
  * x0: Register pointing to VCPU struct
  */
 .macro	restore_vgic_v3_state
-	// Disable SRE_EL1 access. Necessary, otherwise
-	// ICH_VMCR_EL2.VFIQEn becomes one, and FIQ happens...
-	msr_s	ICC_SRE_EL1, xzr
-	isb
-
 	// Compute the address of struct vgic_cpu
 	add	x3, x0, #VCPU_VGIC_CPU
 
 	// Restore all interesting registers
 	ldr	w4, [x3, #VGIC_V3_CPU_HCR]
 	ldr	w5, [x3, #VGIC_V3_CPU_VMCR]
+	ldr	w25, [x3, #VGIC_V3_CPU_SRE]
+
+	msr_s	ICC_SRE_EL1, x25
+
+	// make sure SRE is valid before writing the other registers
+	isb
 
 	msr_s	ICH_HCR_EL2, x4
 	msr_s	ICH_VMCR_EL2, x5
@@ -244,9 +245,12 @@
 	dsb	sy
 
 	// Prevent the guest from touching the GIC system registers
+	// if SRE isn't enabled for GICv3 emulation
+	cbnz	x25, 1f
 	mrs_s	x5, ICC_SRE_EL2
 	and	x5, x5, #~ICC_SRE_EL2_ENABLE
 	msr_s	ICC_SRE_EL2, x5
+1:
 .endm
 
 ENTRY(__save_vgic_v3_state)
include/kvm/arm_vgic.h +1 -0
index 1c0e9db..ff04afd 100644
@@ -245,6 +245,7 @@ struct vgic_v3_cpu_if {
 #ifdef CONFIG_ARM_GIC_V3
 	u32		vgic_hcr;
 	u32		vgic_vmcr;
+	u32		vgic_sre;	/* Restored only, change ignored */
 	u32		vgic_misr;	/* Saved only */
 	u32		vgic_eisr;	/* Saved only */
 	u32		vgic_elrsr;	/* Saved only */
virt/kvm/arm/vgic-v3.c +6 -2
index ea39bad..5249048 100644
@@ -145,15 +145,19 @@ static void vgic_v3_set_vmcr(struct kvm_vcpu *vcpu, struct vgic_vmcr *vmcrp)
 
 static void vgic_v3_enable(struct kvm_vcpu *vcpu)
 {
+	struct vgic_v3_cpu_if *vgic_v3 = &vcpu->arch.vgic_cpu.vgic_v3;
+
 	/*
 	 * By forcing VMCR to zero, the GIC will restore the binary
 	 * points to their reset values. Anything else resets to zero
 	 * anyway.
 	 */
-	vcpu->arch.vgic_cpu.vgic_v3.vgic_vmcr = 0;
+	vgic_v3->vgic_vmcr = 0;
+
+	vgic_v3->vgic_sre = 0;
 
 	/* Get the show on the road... */
-	vcpu->arch.vgic_cpu.vgic_v3.vgic_hcr = ICH_HCR_EN;
+	vgic_v3->vgic_hcr = ICH_HCR_EN;
 }
 
 static const struct vgic_ops vgic_v3_ops = {
Signature · 1 line
1.7.9.5
#11 lore raw

PATCH v7 10/20 arm/arm64: KVM: refactor MMIO accessors

In reply to Andre Przywara

The MMIO accessors for GICD_I[CS]ENABLER, GICD_I[CS]PENDR and GICD_ICFGR behave very similar for GICv2 and GICv3, although the way the affected VCPU is determined differs.
Since we need them to access the registers from three different places in the future, we factor out a generic, backend-facing implementation and use small wrappers in the current GICv2 emulation. This will ease adding GICv3 accessors later.

---
Changelog v6...v7:
(none)

Changelog v5...v6:
(none)

Changelog v4...v5:
(none)

Changelog v3...v4:
- improve commit message
- add Reviewed-by

 virt/kvm/arm/vgic.c |  126 ++++++++++++++++++++++++++++++---------------------
 1 file changed, 74 insertions(+), 52 deletions(-)
virt/kvm/arm/vgic.c +74 -52
index 2126bf5..7589e2c 100644
@@ -492,64 +492,66 @@ static bool handle_mmio_raz_wi(struct kvm_vcpu *vcpu,
 	return false;
 }
 
-static bool handle_mmio_set_enable_reg(struct kvm_vcpu *vcpu,
-				       struct kvm_exit_mmio *mmio,
-				       phys_addr_t offset)
+static bool vgic_handle_enable_reg(struct kvm *kvm, struct kvm_exit_mmio *mmio,
+				   phys_addr_t offset, int vcpu_id, int access)
 {
-	u32 *reg = vgic_bitmap_get_reg(&vcpu->kvm->arch.vgic.irq_enabled,
-				       vcpu->vcpu_id, offset);
-	vgic_reg_access(mmio, reg, offset,
-			ACCESS_READ_VALUE | ACCESS_WRITE_SETBIT);
+	u32 *reg;
+	int mode = ACCESS_READ_VALUE | access;
+	struct kvm_vcpu *target_vcpu = kvm_get_vcpu(kvm, vcpu_id);
+
+	reg = vgic_bitmap_get_reg(&kvm->arch.vgic.irq_enabled, vcpu_id, offset);
+	vgic_reg_access(mmio, reg, offset, mode);
 	if (mmio->is_write) {
-		vgic_update_state(vcpu->kvm);
+		if (access & ACCESS_WRITE_CLEARBIT) {
+			if (offset < 4) /* Force SGI enabled */
+				*reg |= 0xffff;
+			vgic_retire_disabled_irqs(target_vcpu);
+		}
+		vgic_update_state(kvm);
 		return true;
 	}
 
 	return false;
 }
 
+static bool handle_mmio_set_enable_reg(struct kvm_vcpu *vcpu,
+				       struct kvm_exit_mmio *mmio,
+				       phys_addr_t offset)
+{
+	return vgic_handle_enable_reg(vcpu->kvm, mmio, offset,
+				      vcpu->vcpu_id, ACCESS_WRITE_SETBIT);
+}
+
 static bool handle_mmio_clear_enable_reg(struct kvm_vcpu *vcpu,
 					 struct kvm_exit_mmio *mmio,
 					 phys_addr_t offset)
 {
-	u32 *reg = vgic_bitmap_get_reg(&vcpu->kvm->arch.vgic.irq_enabled,
-				       vcpu->vcpu_id, offset);
-	vgic_reg_access(mmio, reg, offset,
-			ACCESS_READ_VALUE | ACCESS_WRITE_CLEARBIT);
-	if (mmio->is_write) {
-		if (offset < 4) /* Force SGI enabled */
-			*reg |= 0xffff;
-		vgic_retire_disabled_irqs(vcpu);
-		vgic_update_state(vcpu->kvm);
-		return true;
-	}
-
-	return false;
+	return vgic_handle_enable_reg(vcpu->kvm, mmio, offset,
+				      vcpu->vcpu_id, ACCESS_WRITE_CLEARBIT);
 }
 
-static bool handle_mmio_set_pending_reg(struct kvm_vcpu *vcpu,
+static bool vgic_handle_set_pending_reg(struct kvm *kvm,
 					struct kvm_exit_mmio *mmio,
-					phys_addr_t offset)
+					phys_addr_t offset, int vcpu_id)
 {
 	u32 *reg, orig;
 	u32 level_mask;
-	struct vgic_dist *dist = &vcpu->kvm->arch.vgic;
+	int mode = ACCESS_READ_VALUE | ACCESS_WRITE_SETBIT;
+	struct vgic_dist *dist = &kvm->arch.vgic;
 
-	reg = vgic_bitmap_get_reg(&dist->irq_cfg, vcpu->vcpu_id, offset);
+	reg = vgic_bitmap_get_reg(&dist->irq_cfg, vcpu_id, offset);
 	level_mask = (~(*reg));
 
 	/* Mark both level and edge triggered irqs as pending */
-	reg = vgic_bitmap_get_reg(&dist->irq_pending, vcpu->vcpu_id, offset);
+	reg = vgic_bitmap_get_reg(&dist->irq_pending, vcpu_id, offset);
 	orig = *reg;
-	vgic_reg_access(mmio, reg, offset,
-			ACCESS_READ_VALUE | ACCESS_WRITE_SETBIT);
+	vgic_reg_access(mmio, reg, offset, mode);
 
 	if (mmio->is_write) {
 		/* Set the soft-pending flag only for level-triggered irqs */
 		reg = vgic_bitmap_get_reg(&dist->irq_soft_pend,
-					  vcpu->vcpu_id, offset);
-		vgic_reg_access(mmio, reg, offset,
-				ACCESS_READ_VALUE | ACCESS_WRITE_SETBIT);
+					  vcpu_id, offset);
+		vgic_reg_access(mmio, reg, offset, mode);
 		*reg &= level_mask;
 
 		/* Ignore writes to SGIs */
@@ -558,31 +560,30 @@ static bool handle_mmio_set_pending_reg(struct kvm_vcpu *vcpu,
 			*reg |= orig & 0xffff;
 		}
 
-		vgic_update_state(vcpu->kvm);
+		vgic_update_state(kvm);
 		return true;
 	}
 
 	return false;
 }
 
-static bool handle_mmio_clear_pending_reg(struct kvm_vcpu *vcpu,
+static bool vgic_handle_clear_pending_reg(struct kvm *kvm,
 					  struct kvm_exit_mmio *mmio,
-					  phys_addr_t offset)
+					  phys_addr_t offset, int vcpu_id)
 {
 	u32 *level_active;
 	u32 *reg, orig;
-	struct vgic_dist *dist = &vcpu->kvm->arch.vgic;
+	int mode = ACCESS_READ_VALUE | ACCESS_WRITE_CLEARBIT;
+	struct vgic_dist *dist = &kvm->arch.vgic;
 
-	reg = vgic_bitmap_get_reg(&dist->irq_pending, vcpu->vcpu_id, offset);
+	reg = vgic_bitmap_get_reg(&dist->irq_pending, vcpu_id, offset);
 	orig = *reg;
-	vgic_reg_access(mmio, reg, offset,
-			ACCESS_READ_VALUE | ACCESS_WRITE_CLEARBIT);
+	vgic_reg_access(mmio, reg, offset, mode);
 	if (mmio->is_write) {
 		/* Re-set level triggered level-active interrupts */
 		level_active = vgic_bitmap_get_reg(&dist->irq_level,
-					  vcpu->vcpu_id, offset);
-		reg = vgic_bitmap_get_reg(&dist->irq_pending,
-					  vcpu->vcpu_id, offset);
+					  vcpu_id, offset);
+		reg = vgic_bitmap_get_reg(&dist->irq_pending, vcpu_id, offset);
 		*reg |= *level_active;
 
 		/* Ignore writes to SGIs */
@@ -593,17 +594,31 @@ static bool handle_mmio_clear_pending_reg(struct kvm_vcpu *vcpu,
 
 		/* Clear soft-pending flags */
 		reg = vgic_bitmap_get_reg(&dist->irq_soft_pend,
-					  vcpu->vcpu_id, offset);
-		vgic_reg_access(mmio, reg, offset,
-				ACCESS_READ_VALUE | ACCESS_WRITE_CLEARBIT);
+					  vcpu_id, offset);
+		vgic_reg_access(mmio, reg, offset, mode);
 
-		vgic_update_state(vcpu->kvm);
+		vgic_update_state(kvm);
 		return true;
 	}
-
 	return false;
 }
 
+static bool handle_mmio_set_pending_reg(struct kvm_vcpu *vcpu,
+					struct kvm_exit_mmio *mmio,
+					phys_addr_t offset)
+{
+	return vgic_handle_set_pending_reg(vcpu->kvm, mmio, offset,
+					   vcpu->vcpu_id);
+}
+
+static bool handle_mmio_clear_pending_reg(struct kvm_vcpu *vcpu,
+					  struct kvm_exit_mmio *mmio,
+					  phys_addr_t offset)
+{
+	return vgic_handle_clear_pending_reg(vcpu->kvm, mmio, offset,
+					     vcpu->vcpu_id);
+}
+
 static bool handle_mmio_priority_reg(struct kvm_vcpu *vcpu,
 				     struct kvm_exit_mmio *mmio,
 				     phys_addr_t offset)
@@ -726,14 +741,10 @@ static u16 vgic_cfg_compress(u32 val)
  * LSB is always 0. As such, we only keep the upper bit, and use the
  * two above functions to compress/expand the bits
  */
-static bool handle_mmio_cfg_reg(struct kvm_vcpu *vcpu,
-				struct kvm_exit_mmio *mmio, phys_addr_t offset)
+static bool vgic_handle_cfg_reg(u32 *reg, struct kvm_exit_mmio *mmio,
+				phys_addr_t offset)
 {
 	u32 val;
-	u32 *reg;
-
-	reg = vgic_bitmap_get_reg(&vcpu->kvm->arch.vgic.irq_cfg,
-				  vcpu->vcpu_id, offset >> 1);
 
 	if (offset & 4)
 		val = *reg >> 16;
@@ -762,6 +773,17 @@ static bool handle_mmio_cfg_reg(struct kvm_vcpu *vcpu,
 	return false;
 }
 
+static bool handle_mmio_cfg_reg(struct kvm_vcpu *vcpu,
+				struct kvm_exit_mmio *mmio, phys_addr_t offset)
+{
+	u32 *reg;
+
+	reg = vgic_bitmap_get_reg(&vcpu->kvm->arch.vgic.irq_cfg,
+				  vcpu->vcpu_id, offset >> 1);
+
+	return vgic_handle_cfg_reg(reg, mmio, offset);
+}
+
 static bool handle_mmio_sgi_reg(struct kvm_vcpu *vcpu,
 				struct kvm_exit_mmio *mmio, phys_addr_t offset)
 {
Signature · 1 line
1.7.9.5
#12 lore raw

PATCH v7 11/20 arm/arm64: KVM: refactor/wrap vgic_set/get_attr()

In reply to Andre Przywara

vgic_set_attr() and vgic_get_attr() contain both code specific for the emulated GIC as well as code for the userland facing, generic part of the GIC.
Split the guest GIC facing code of from the generic part to allow easier splitting later.

---
Changelog v6...v7:
(none)

Changelog v5...v6:
(none)

Changelog v4...v5:
(add Reviewed-by:)

Changelog v3...v4:
(none)

 virt/kvm/arm/vgic.c |   78 +++++++++++++++++++++++++++++++++++----------------
 1 file changed, 54 insertions(+), 24 deletions(-)
virt/kvm/arm/vgic.c +54 -24
index 7589e2c..06073fa 100644
@@ -2440,7 +2440,8 @@ out:
 	return ret;
 }
 
-static int vgic_set_attr(struct kvm_device *dev, struct kvm_device_attr *attr)
+static int vgic_set_common_attr(struct kvm_device *dev,
+				struct kvm_device_attr *attr)
 {
 	int r;
 
@@ -2456,17 +2457,6 @@ static int vgic_set_attr(struct kvm_device *dev, struct kvm_device_attr *attr)
 		r = kvm_vgic_addr(dev->kvm, type, &addr, true);
 		return (r == -ENODEV) ? -ENXIO : r;
 	}
-
-	case KVM_DEV_ARM_VGIC_GRP_DIST_REGS:
-	case KVM_DEV_ARM_VGIC_GRP_CPU_REGS: {
-		u32 __user *uaddr = (u32 __user *)(long)attr->addr;
-		u32 reg;
-
-		if (get_user(reg, uaddr))
-			return -EFAULT;
-
-		return vgic_attr_regs_access(dev, attr, &reg, true);
-	}
 	case KVM_DEV_ARM_VGIC_GRP_NR_IRQS: {
 		u32 __user *uaddr = (u32 __user *)(long)attr->addr;
 		u32 val;
@@ -2510,7 +2500,33 @@ static int vgic_set_attr(struct kvm_device *dev, struct kvm_device_attr *attr)
 	return -ENXIO;
 }
 
-static int vgic_get_attr(struct kvm_device *dev, struct kvm_device_attr *attr)
+static int vgic_set_attr(struct kvm_device *dev, struct kvm_device_attr *attr)
+{
+	int ret;
+
+	ret = vgic_set_common_attr(dev, attr);
+	if (ret != -ENXIO)
+		return ret;
+
+	switch (attr->group) {
+	case KVM_DEV_ARM_VGIC_GRP_DIST_REGS:
+	case KVM_DEV_ARM_VGIC_GRP_CPU_REGS: {
+		u32 __user *uaddr = (u32 __user *)(long)attr->addr;
+		u32 reg;
+
+		if (get_user(reg, uaddr))
+			return -EFAULT;
+
+		return vgic_attr_regs_access(dev, attr, &reg, true);
+	}
+
+	}
+
+	return -ENXIO;
+}
+
+static int vgic_get_common_attr(struct kvm_device *dev,
+				struct kvm_device_attr *attr)
 {
 	int r = -ENXIO;
 
@@ -2528,27 +2544,41 @@ static int vgic_get_attr(struct kvm_device *dev, struct kvm_device_attr *attr)
 			return -EFAULT;
 		break;
 	}
+	case KVM_DEV_ARM_VGIC_GRP_NR_IRQS: {
+		u32 __user *uaddr = (u32 __user *)(long)attr->addr;
+
+		r = put_user(dev->kvm->arch.vgic.nr_irqs, uaddr);
+		break;
+	}
+
+	}
+
+	return r;
+}
+
+static int vgic_get_attr(struct kvm_device *dev, struct kvm_device_attr *attr)
+{
+	int ret;
+
+	ret = vgic_get_common_attr(dev, attr);
+	if (ret != -ENXIO)
+		return ret;
 
+	switch (attr->group) {
 	case KVM_DEV_ARM_VGIC_GRP_DIST_REGS:
 	case KVM_DEV_ARM_VGIC_GRP_CPU_REGS: {
 		u32 __user *uaddr = (u32 __user *)(long)attr->addr;
 		u32 reg = 0;
 
-		r = vgic_attr_regs_access(dev, attr, &reg, false);
-		if (r)
-			return r;
-		r = put_user(reg, uaddr);
-		break;
-	}
-	case KVM_DEV_ARM_VGIC_GRP_NR_IRQS: {
-		u32 __user *uaddr = (u32 __user *)(long)attr->addr;
-		r = put_user(dev->kvm->arch.vgic.nr_irqs, uaddr);
-		break;
+		ret = vgic_attr_regs_access(dev, attr, &reg, false);
+		if (ret)
+			return ret;
+		return put_user(reg, uaddr);
 	}
 
 	}
 
-	return r;
+	return -ENXIO;
 }
 
 static int vgic_has_attr_regs(const struct mmio_range *ranges,
Signature · 1 line
1.7.9.5
#13 lore raw

PATCH v7 12/20 arm/arm64: KVM: add vgic.h header file

In reply to Andre Przywara

vgic.c is currently a mixture of generic vGIC emulation code and functions specific to emulating a GICv2. To ease the addition of GICv3 later, we create new header file vgic.h, which holds constants and prototypes of commonly used functions.
Rename some identifiers to avoid name space clutter.
I removed the long-standing comment about using the kvm_io_bus API to tackle the GIC register ranges, as it wouldn't be a win for us anymore.

-------
As the diff isn't always obvious here (and to aid eventual rebases), here is a list of high-level changes done to the code:
* moved definitions and prototypes from vgic.c to vgic.h:
- VGIC_ADDR_UNDEF
- ACCESS_{READ,WRITE}_*
- vgic_init()
- vgic_update_state()
- vgic_kick_vcpus()
- vgic_get_vmcr()
- vgic_set_vmcr()
- struct mmio_range {} (renamed to struct kvm_mmio_range)
* removed static keyword and exported prototype in vgic.h:
- vgic_bitmap_get_reg()
- vgic_bitmap_set_irq_val()
- vgic_bitmap_get_shared_map()
- vgic_bytemap_get_reg()
- vgic_dist_irq_set_pending()
- vgic_dist_irq_clear_pending()
- vgic_cpu_irq_clear()
- vgic_reg_access()
- handle_mmio_raz_wi()
- vgic_handle_enable_reg()
- vgic_handle_set_pending_reg()
- vgic_handle_clear_pending_reg()
- vgic_handle_cfg_reg()
- vgic_unqueue_irqs()
- find_matching_range() (renamed to vgic_find_range)
- vgic_handle_mmio_range()
- vgic_update_state()
- vgic_get_vmcr()
- vgic_set_vmcr()
- vgic_queue_irq()
- vgic_kick_vcpus()
- vgic_init()
- vgic_v2_init_emulation()
- vgic_has_attr_regs()
- vgic_set_common_attr()
- vgic_get_common_attr()
- vgic_destroy()
- vgic_create()
* moved functions to vgic.h (static inline):
- mmio_data_read()
- mmio_data_write()
- is_in_range()
---
Changelog v6...v7:
- adapting prototype of vgic_v2_init_emulation()

Changelog v5...v6:
- adapt to changes due to new 05/20

Changelog v4...v5:
- add vgic_init_common_maps (from changes in previous patches) (add Acked-by:)

Changelog v3...v4:
- rename struct mmio_range to struct kvm_mmio_range
- rename find_matching_range() to vgic_find_range()
- remove vgic_create() and vgic_destroy() from header

 virt/kvm/arm/vgic.c |  151 +++++++++++++++++----------------------------------
 virt/kvm/arm/vgic.h |  120 ++++++++++++++++++++++++++++++++++++++++
 2 files changed, 170 insertions(+), 101 deletions(-)
 create mode 100644 virt/kvm/arm/vgic.h
virt/kvm/arm/vgic.c +50 -101
index 06073fa..ce6c998 100644
@@ -75,33 +75,16 @@
  *   inactive as long as the external input line is held high.
  */
 
-#define VGIC_ADDR_UNDEF		(-1)
-#define IS_VGIC_ADDR_UNDEF(_x)  ((_x) == VGIC_ADDR_UNDEF)
+#include "vgic.h"
 
-#define PRODUCT_ID_KVM		0x4b	/* ASCII code K */
-#define IMPLEMENTER_ARM		0x43b
 #define GICC_ARCH_VERSION_V2	0x2
 
-#define ACCESS_READ_VALUE	(1 << 0)
-#define ACCESS_READ_RAZ		(0 << 0)
-#define ACCESS_READ_MASK(x)	((x) & (1 << 0))
-#define ACCESS_WRITE_IGNORED	(0 << 1)
-#define ACCESS_WRITE_SETBIT	(1 << 1)
-#define ACCESS_WRITE_CLEARBIT	(2 << 1)
-#define ACCESS_WRITE_VALUE	(3 << 1)
-#define ACCESS_WRITE_MASK(x)	((x) & (3 << 1))
-
-static int vgic_init(struct kvm *kvm);
 static void vgic_retire_disabled_irqs(struct kvm_vcpu *vcpu);
 static void vgic_retire_lr(int lr_nr, int irq, struct kvm_vcpu *vcpu);
-static void vgic_update_state(struct kvm *kvm);
-static void vgic_kick_vcpus(struct kvm *kvm);
 static u8 *vgic_get_sgi_sources(struct vgic_dist *dist, int vcpu_id, int sgi);
 static void vgic_dispatch_sgi(struct kvm_vcpu *vcpu, u32 reg);
 static struct vgic_lr vgic_get_lr(const struct kvm_vcpu *vcpu, int lr);
 static void vgic_set_lr(struct kvm_vcpu *vcpu, int lr, struct vgic_lr lr_desc);
-static void vgic_get_vmcr(struct kvm_vcpu *vcpu, struct vgic_vmcr *vmcr);
-static void vgic_set_vmcr(struct kvm_vcpu *vcpu, struct vgic_vmcr *vmcr);
 
 static const struct vgic_ops *vgic_ops;
 static const struct vgic_params *vgic;
@@ -175,8 +158,7 @@ static unsigned long *u64_to_bitmask(u64 *val)
 	return (unsigned long *)val;
 }
 
-static u32 *vgic_bitmap_get_reg(struct vgic_bitmap *x,
-				int cpuid, u32 offset)
+u32 *vgic_bitmap_get_reg(struct vgic_bitmap *x, int cpuid, u32 offset)
 {
 	offset >>= 2;
 	if (!offset)
@@ -194,8 +176,8 @@ static int vgic_bitmap_get_irq_val(struct vgic_bitmap *x,
 	return test_bit(irq - VGIC_NR_PRIVATE_IRQS, x->shared);
 }
 
-static void vgic_bitmap_set_irq_val(struct vgic_bitmap *x, int cpuid,
-				    int irq, int val)
+void vgic_bitmap_set_irq_val(struct vgic_bitmap *x, int cpuid,
+			     int irq, int val)
 {
 	unsigned long *reg;
 
@@ -217,7 +199,7 @@ static unsigned long *vgic_bitmap_get_cpu_map(struct vgic_bitmap *x, int cpuid)
 	return x->private + cpuid;
 }
 
-static unsigned long *vgic_bitmap_get_shared_map(struct vgic_bitmap *x)
+unsigned long *vgic_bitmap_get_shared_map(struct vgic_bitmap *x)
 {
 	return x->shared;
 }
@@ -244,7 +226,7 @@ static void vgic_free_bytemap(struct vgic_bytemap *b)
 	b->shared = NULL;
 }
 
-static u32 *vgic_bytemap_get_reg(struct vgic_bytemap *x, int cpuid, u32 offset)
+u32 *vgic_bytemap_get_reg(struct vgic_bytemap *x, int cpuid, u32 offset)
 {
 	u32 *reg;
 
@@ -341,14 +323,14 @@ static int vgic_dist_irq_is_pending(struct kvm_vcpu *vcpu, int irq)
 	return vgic_bitmap_get_irq_val(&dist->irq_pending, vcpu->vcpu_id, irq);
 }
 
-static void vgic_dist_irq_set_pending(struct kvm_vcpu *vcpu, int irq)
+void vgic_dist_irq_set_pending(struct kvm_vcpu *vcpu, int irq)
 {
 	struct vgic_dist *dist = &vcpu->kvm->arch.vgic;
 
 	vgic_bitmap_set_irq_val(&dist->irq_pending, vcpu->vcpu_id, irq, 1);
 }
 
-static void vgic_dist_irq_clear_pending(struct kvm_vcpu *vcpu, int irq)
+void vgic_dist_irq_clear_pending(struct kvm_vcpu *vcpu, int irq)
 {
 	struct vgic_dist *dist = &vcpu->kvm->arch.vgic;
 
@@ -364,7 +346,7 @@ static void vgic_cpu_irq_set(struct kvm_vcpu *vcpu, int irq)
 			vcpu->arch.vgic_cpu.pending_shared);
 }
 
-static void vgic_cpu_irq_clear(struct kvm_vcpu *vcpu, int irq)
+void vgic_cpu_irq_clear(struct kvm_vcpu *vcpu, int irq)
 {
 	if (irq < VGIC_NR_PRIVATE_IRQS)
 		clear_bit(irq, vcpu->arch.vgic_cpu.pending_percpu);
@@ -378,16 +360,6 @@ static bool vgic_can_sample_irq(struct kvm_vcpu *vcpu, int irq)
 	return vgic_irq_is_edge(vcpu, irq) || !vgic_irq_is_queued(vcpu, irq);
 }
 
-static u32 mmio_data_read(struct kvm_exit_mmio *mmio, u32 mask)
-{
-	return le32_to_cpu(*((u32 *)mmio->data)) & mask;
-}
-
-static void mmio_data_write(struct kvm_exit_mmio *mmio, u32 mask, u32 value)
-{
-	*((u32 *)mmio->data) = cpu_to_le32(value) & mask;
-}
-
 /**
  * vgic_reg_access - access vgic register
  * @mmio:   pointer to the data describing the mmio access
@@ -399,8 +371,8 @@ static void mmio_data_write(struct kvm_exit_mmio *mmio, u32 mask, u32 value)
  * modes defined for vgic register access
  * (read,raz,write-ignored,setbit,clearbit,write)
  */
-static void vgic_reg_access(struct kvm_exit_mmio *mmio, u32 *reg,
-			    phys_addr_t offset, int mode)
+void vgic_reg_access(struct kvm_exit_mmio *mmio, u32 *reg,
+		     phys_addr_t offset, int mode)
 {
 	int word_offset = (offset & 3) * 8;
 	u32 mask = (1UL << (mmio->len * 8)) - 1;
@@ -484,16 +456,16 @@ static bool handle_mmio_misc(struct kvm_vcpu *vcpu,
 	return false;
 }
 
-static bool handle_mmio_raz_wi(struct kvm_vcpu *vcpu,
-			       struct kvm_exit_mmio *mmio, phys_addr_t offset)
+bool handle_mmio_raz_wi(struct kvm_vcpu *vcpu, struct kvm_exit_mmio *mmio,
+			phys_addr_t offset)
 {
 	vgic_reg_access(mmio, NULL, offset,
 			ACCESS_READ_RAZ | ACCESS_WRITE_IGNORED);
 	return false;
 }
 
-static bool vgic_handle_enable_reg(struct kvm *kvm, struct kvm_exit_mmio *mmio,
-				   phys_addr_t offset, int vcpu_id, int access)
+bool vgic_handle_enable_reg(struct kvm *kvm, struct kvm_exit_mmio *mmio,
+			    phys_addr_t offset, int vcpu_id, int access)
 {
 	u32 *reg;
 	int mode = ACCESS_READ_VALUE | access;
@@ -530,9 +502,9 @@ static bool handle_mmio_clear_enable_reg(struct kvm_vcpu *vcpu,
 				      vcpu->vcpu_id, ACCESS_WRITE_CLEARBIT);
 }
 
-static bool vgic_handle_set_pending_reg(struct kvm *kvm,
-					struct kvm_exit_mmio *mmio,
-					phys_addr_t offset, int vcpu_id)
+bool vgic_handle_set_pending_reg(struct kvm *kvm,
+				 struct kvm_exit_mmio *mmio,
+				 phys_addr_t offset, int vcpu_id)
 {
 	u32 *reg, orig;
 	u32 level_mask;
@@ -567,9 +539,9 @@ static bool vgic_handle_set_pending_reg(struct kvm *kvm,
 	return false;
 }
 
-static bool vgic_handle_clear_pending_reg(struct kvm *kvm,
-					  struct kvm_exit_mmio *mmio,
-					  phys_addr_t offset, int vcpu_id)
+bool vgic_handle_clear_pending_reg(struct kvm *kvm,
+				   struct kvm_exit_mmio *mmio,
+				   phys_addr_t offset, int vcpu_id)
 {
 	u32 *level_active;
 	u32 *reg, orig;
@@ -741,8 +713,8 @@ static u16 vgic_cfg_compress(u32 val)
  * LSB is always 0. As such, we only keep the upper bit, and use the
  * two above functions to compress/expand the bits
  */
-static bool vgic_handle_cfg_reg(u32 *reg, struct kvm_exit_mmio *mmio,
-				phys_addr_t offset)
+bool vgic_handle_cfg_reg(u32 *reg, struct kvm_exit_mmio *mmio,
+			 phys_addr_t offset)
 {
 	u32 val;
 
@@ -818,7 +790,7 @@ static void vgic_v2_add_sgi_source(struct kvm_vcpu *vcpu, int irq, int source)
  * to the distributor but the active state stays in the LRs, because we don't
  * track the active state on the distributor side.
  */
-static void vgic_unqueue_irqs(struct kvm_vcpu *vcpu)
+void vgic_unqueue_irqs(struct kvm_vcpu *vcpu)
 {
 	struct vgic_cpu *vgic_cpu = &vcpu->arch.vgic_cpu;
 	int i;
@@ -943,21 +915,7 @@ static bool handle_mmio_sgi_clear(struct kvm_vcpu *vcpu,
 		return write_set_clear_sgi_pend_reg(vcpu, mmio, offset, false);
 }
 
-/*
- * I would have liked to use the kvm_bus_io_*() API instead, but it
- * cannot cope with banked registers (only the VM pointer is passed
- * around, and we need the vcpu). One of these days, someone please
- * fix it!
- */
-struct mmio_range {
-	phys_addr_t base;
-	unsigned long len;
-	int bits_per_irq;
-	bool (*handle_mmio)(struct kvm_vcpu *vcpu, struct kvm_exit_mmio *mmio,
-			    phys_addr_t offset);
-};
-
-static const struct mmio_range vgic_dist_ranges[] = {
+static const struct kvm_mmio_range vgic_dist_ranges[] = {
 	{
 		.base		= GIC_DIST_CTRL,
 		.len		= 12,
@@ -1042,12 +1000,12 @@ static const struct mmio_range vgic_dist_ranges[] = {
 	{}
 };
 
-static const
-struct mmio_range *find_matching_range(const struct mmio_range *ranges,
+const
+struct kvm_mmio_range *vgic_find_range(const struct kvm_mmio_range *ranges,
 				       struct kvm_exit_mmio *mmio,
 				       phys_addr_t offset)
 {
-	const struct mmio_range *r = ranges;
+	const struct kvm_mmio_range *r = ranges;
 
 	while (r->len) {
 		if (offset >= r->base &&
@@ -1060,7 +1018,7 @@ struct mmio_range *find_matching_range(const struct mmio_range *ranges,
 }
 
 static bool vgic_validate_access(const struct vgic_dist *dist,
-				 const struct mmio_range *range,
+				 const struct kvm_mmio_range *range,
 				 unsigned long offset)
 {
 	int irq;
@@ -1088,7 +1046,7 @@ static bool vgic_validate_access(const struct vgic_dist *dist,
 static bool call_range_handler(struct kvm_vcpu *vcpu,
 			       struct kvm_exit_mmio *mmio,
 			       unsigned long offset,
-			       const struct mmio_range *range)
+			       const struct kvm_mmio_range *range)
 {
 	u32 *data32 = (void *)mmio->data;
 	struct kvm_exit_mmio mmio32;
@@ -1132,18 +1090,18 @@ static bool call_range_handler(struct kvm_vcpu *vcpu,
  *
  * returns true if the MMIO access could be performed
  */
-static bool vgic_handle_mmio_range(struct kvm_vcpu *vcpu, struct kvm_run *run,
+bool vgic_handle_mmio_range(struct kvm_vcpu *vcpu, struct kvm_run *run,
 			    struct kvm_exit_mmio *mmio,
-			    const struct mmio_range *ranges,
+			    const struct kvm_mmio_range *ranges,
 			    unsigned long mmio_base)
 {
-	const struct mmio_range *range;
+	const struct kvm_mmio_range *range;
 	struct vgic_dist *dist = &vcpu->kvm->arch.vgic;
 	bool updated_state;
 	unsigned long offset;
 
 	offset = mmio->phys_addr - mmio_base;
-	range = find_matching_range(ranges, mmio, offset);
+	range = vgic_find_range(ranges, mmio, offset);
 	if (unlikely(!range || !range->handle_mmio)) {
 		pr_warn("Unhandled access %d %08llx %d\n",
 			mmio->is_write, mmio->phys_addr, mmio->len);
@@ -1169,12 +1127,6 @@ static bool vgic_handle_mmio_range(struct kvm_vcpu *vcpu, struct kvm_run *run,
 	return true;
 }
 
-static inline bool is_in_range(phys_addr_t addr, unsigned long len,
-			       phys_addr_t baseaddr, unsigned long size)
-{
-	return (addr >= baseaddr) && (addr + len <= baseaddr + size);
-}
-
 static bool vgic_v2_handle_mmio(struct kvm_vcpu *vcpu, struct kvm_run *run,
 				struct kvm_exit_mmio *mmio)
 {
@@ -1301,7 +1253,7 @@ static int compute_pending_for_cpu(struct kvm_vcpu *vcpu)
  * Update the interrupt state and determine which CPUs have pending
  * interrupts. Must be called with distributor lock held.
  */
-static void vgic_update_state(struct kvm *kvm)
+void vgic_update_state(struct kvm *kvm)
 {
 	struct vgic_dist *dist = &kvm->arch.vgic;
 	struct kvm_vcpu *vcpu;
@@ -1362,12 +1314,12 @@ static inline void vgic_disable_underflow(struct kvm_vcpu *vcpu)
 	vgic_ops->disable_underflow(vcpu);
 }
 
-static inline void vgic_get_vmcr(struct kvm_vcpu *vcpu, struct vgic_vmcr *vmcr)
+void vgic_get_vmcr(struct kvm_vcpu *vcpu, struct vgic_vmcr *vmcr)
 {
 	vgic_ops->get_vmcr(vcpu, vmcr);
 }
 
-static void vgic_set_vmcr(struct kvm_vcpu *vcpu, struct vgic_vmcr *vmcr)
+void vgic_set_vmcr(struct kvm_vcpu *vcpu, struct vgic_vmcr *vmcr)
 {
 	vgic_ops->set_vmcr(vcpu, vmcr);
 }
@@ -1417,7 +1369,7 @@ static void vgic_retire_disabled_irqs(struct kvm_vcpu *vcpu)
  * Queue an interrupt to a CPU virtual interface. Return true on success,
  * or false if it wasn't possible to queue it.
  */
-static bool vgic_queue_irq(struct kvm_vcpu *vcpu, u8 sgi_source_id, int irq)
+bool vgic_queue_irq(struct kvm_vcpu *vcpu, u8 sgi_source_id, int irq)
 {
 	struct vgic_cpu *vgic_cpu = &vcpu->arch.vgic_cpu;
 	struct vgic_dist *dist = &vcpu->kvm->arch.vgic;
@@ -1703,7 +1655,7 @@ int kvm_vgic_vcpu_pending_irq(struct kvm_vcpu *vcpu)
 	return test_bit(vcpu->vcpu_id, dist->irq_pending_on_cpu);
 }
 
-static void vgic_kick_vcpus(struct kvm *kvm)
+void vgic_kick_vcpus(struct kvm *kvm)
 {
 	struct kvm_vcpu *vcpu;
 	int c;
@@ -1956,7 +1908,7 @@ static int vgic_v2_init_model(struct kvm *kvm)
  * Allocate and initialize the various data structures. Must be called
  * with kvm->lock held!
  */
-static int vgic_init(struct kvm *kvm)
+int vgic_init(struct kvm *kvm)
 {
 	struct vgic_dist *dist = &kvm->arch.vgic;
 	struct kvm_vcpu *vcpu;
@@ -2096,7 +2048,7 @@ out:
 	return ret;
 }
 
-static void vgic_v2_init_emulation(struct kvm *kvm)
+void vgic_v2_init_emulation(struct kvm *kvm)
 {
 	struct vgic_dist *dist = &kvm->arch.vgic;
 
@@ -2326,7 +2278,7 @@ static bool handle_cpu_mmio_ident(struct kvm_vcpu *vcpu,
  * CPU Interface Register accesses - these are not accessed by the VM, but by
  * user space for saving and restoring VGIC state.
  */
-static const struct mmio_range vgic_cpu_ranges[] = {
+static const struct kvm_mmio_range vgic_cpu_ranges[] = {
 	{
 		.base		= GIC_CPU_CTRL,
 		.len		= 12,
@@ -2353,7 +2305,7 @@ static int vgic_attr_regs_access(struct kvm_device *dev,
 				 struct kvm_device_attr *attr,
 				 u32 *reg, bool is_write)
 {
-	const struct mmio_range *r = NULL, *ranges;
+	const struct kvm_mmio_range *r = NULL, *ranges;
 	phys_addr_t offset;
 	int ret, cpuid, c;
 	struct kvm_vcpu *vcpu, *tmp_vcpu;
@@ -2394,7 +2346,7 @@ static int vgic_attr_regs_access(struct kvm_device *dev,
 	default:
 		BUG();
 	}
-	r = find_matching_range(ranges, &mmio, offset);
+	r = vgic_find_range(ranges, &mmio, offset);
 
 	if (unlikely(!r || !r->handle_mmio)) {
 		ret = -ENXIO;
@@ -2440,8 +2392,7 @@ out:
 	return ret;
 }
 
-static int vgic_set_common_attr(struct kvm_device *dev,
-				struct kvm_device_attr *attr)
+int vgic_set_common_attr(struct kvm_device *dev, struct kvm_device_attr *attr)
 {
 	int r;
 
@@ -2525,8 +2476,7 @@ static int vgic_set_attr(struct kvm_device *dev, struct kvm_device_attr *attr)
 	return -ENXIO;
 }
 
-static int vgic_get_common_attr(struct kvm_device *dev,
-				struct kvm_device_attr *attr)
+int vgic_get_common_attr(struct kvm_device *dev, struct kvm_device_attr *attr)
 {
 	int r = -ENXIO;
 
@@ -2581,13 +2531,12 @@ static int vgic_get_attr(struct kvm_device *dev, struct kvm_device_attr *attr)
 	return -ENXIO;
 }
 
-static int vgic_has_attr_regs(const struct mmio_range *ranges,
-			      phys_addr_t offset)
+int vgic_has_attr_regs(const struct kvm_mmio_range *ranges, phys_addr_t offset)
 {
 	struct kvm_exit_mmio dev_attr_mmio;
 
 	dev_attr_mmio.len = 4;
-	if (find_matching_range(ranges, &dev_attr_mmio, offset))
+	if (vgic_find_range(ranges, &dev_attr_mmio, offset))
 		return 0;
 	else
 		return -ENXIO;
@@ -2622,12 +2571,12 @@ static int vgic_has_attr(struct kvm_device *dev, struct kvm_device_attr *attr)
 	return -ENXIO;
 }
 
-static void vgic_destroy(struct kvm_device *dev)
+void vgic_destroy(struct kvm_device *dev)
 {
 	kfree(dev);
 }
 
-static int vgic_create(struct kvm_device *dev, u32 type)
+int vgic_create(struct kvm_device *dev, u32 type)
 {
 	return kvm_vgic_create(dev->kvm, type);
 }
virt/kvm/arm/vgic.h new file +120 -0

120 lines not on this page · raw message

Signature · 1 line
1.7.9.5
#14 lore raw

PATCH v7 13/20 arm/arm64: KVM: split GICv2 specific emulation code from vgic.c

In reply to Andre Przywara

vgic.c is currently a mixture of generic vGIC emulation code and functions specific to emulating a GICv2. To ease the addition of GICv3, split off strictly v2 specific parts into a new file vgic-v2-emul.c.

-------
As the diff isn't always obvious here (and to aid eventual rebases), here is a list of high-level changes done to the code:
* added new file to respective arm/arm64 Makefiles
* moved GICv2 specific functions to vgic-v2-emul.c:
- handle_mmio_misc()
- handle_mmio_set_enable_reg()
- handle_mmio_clear_enable_reg()
- handle_mmio_set_pending_reg()
- handle_mmio_clear_pending_reg()
- handle_mmio_priority_reg()
- vgic_get_target_reg()
- vgic_set_target_reg()
- handle_mmio_target_reg()
- handle_mmio_cfg_reg()
- handle_mmio_sgi_reg()
- vgic_v2_unqueue_sgi()
- read_set_clear_sgi_pend_reg()
- write_set_clear_sgi_pend_reg()
- handle_mmio_sgi_set()
- handle_mmio_sgi_clear()
- vgic_v2_handle_mmio()
- vgic_get_sgi_sources()
- vgic_dispatch_sgi()
- vgic_v2_queue_sgi()
- vgic_v2_map_resources()
- vgic_v2_init()
- vgic_v2_add_sgi_source()
- vgic_v2_init_model()
- vgic_v2_init_emulation()
- handle_cpu_mmio_misc()
- handle_mmio_abpr()
- handle_cpu_mmio_ident()
- vgic_attr_regs_access()
- vgic_create() (renamed to vgic_v2_create())
- vgic_destroy() (renamed to vgic_v2_destroy())
- vgic_has_attr() (renamed to vgic_v2_has_attr())
- vgic_set_attr() (renamed to vgic_v2_set_attr())
- vgic_get_attr() (renamed to vgic_v2_get_attr())
- struct kvm_mmio_range vgic_dist_ranges[]
- struct kvm_mmio_range vgic_cpu_ranges[]
- struct kvm_device_ops kvm_arm_vgic_v2_ops {}
---
Changelog v6...v7:
- adapting prototype of vgic_v2_init_emulation()
- remove no longer needed GICC_ARCH_VERSION_V2 from vgic.c

Changelog v5...v6:
- adapt to 3.19-rc changes and to changes due to new 05/20

Changelog v4...v5:
(move adapted to changes in previous patches)

Changelog v3...v4:
- (move adapted to previous patches)
- moving vgic_create() and vgic_destroy() also

 arch/arm/kvm/Makefile       |    1 +
 arch/arm64/kvm/Makefile     |    1 +
 virt/kvm/arm/vgic-v2-emul.c |  847 +++++++++++++++++++++++++++++++++++++++++++
 virt/kvm/arm/vgic.c         |  806 +---------------------------------------
 4 files changed, 850 insertions(+), 805 deletions(-)
 create mode 100644 virt/kvm/arm/vgic-v2-emul.c
arch/arm/kvm/Makefile +1 -0
index f7057ed..443b8be 100644
@@ -22,4 +22,5 @@ obj-y += arm.o handle_exit.o guest.o mmu.o emulate.o reset.o
 obj-y += coproc.o coproc_a15.o coproc_a7.o mmio.o psci.o perf.o
 obj-$(CONFIG_KVM_ARM_VGIC) += $(KVM)/arm/vgic.o
 obj-$(CONFIG_KVM_ARM_VGIC) += $(KVM)/arm/vgic-v2.o
+obj-$(CONFIG_KVM_ARM_VGIC) += $(KVM)/arm/vgic-v2-emul.o
 obj-$(CONFIG_KVM_ARM_TIMER) += $(KVM)/arm/arch_timer.o
arch/arm64/kvm/Makefile +1 -0
index 32a0961..d957353 100644
@@ -21,6 +21,7 @@ kvm-$(CONFIG_KVM_ARM_HOST) += guest.o reset.o sys_regs.o sys_regs_generic_v8.o
 
 kvm-$(CONFIG_KVM_ARM_VGIC) += $(KVM)/arm/vgic.o
 kvm-$(CONFIG_KVM_ARM_VGIC) += $(KVM)/arm/vgic-v2.o
+kvm-$(CONFIG_KVM_ARM_VGIC) += $(KVM)/arm/vgic-v2-emul.o
 kvm-$(CONFIG_KVM_ARM_VGIC) += vgic-v2-switch.o
 kvm-$(CONFIG_KVM_ARM_VGIC) += $(KVM)/arm/vgic-v3.o
 kvm-$(CONFIG_KVM_ARM_VGIC) += vgic-v3-switch.o
virt/kvm/arm/vgic-v2-emul.c new file +847 -0

847 lines not on this page · raw message

virt/kvm/arm/vgic.c +1 -805

904 lines not on this page · raw message

Signature · 1 line
1.7.9.5
#15 lore raw

PATCH v7 14/20 arm/arm64: KVM: add opaque private pointer to MMIO data

In reply to Andre Przywara

For a GICv2 there is always only one (v)CPU involved: the one that does the access. On a GICv3 the access to a CPU redistributor is memory-mapped, but not banked, so the (v)CPU affected is determined by looking at the MMIO address region being accessed.
To allow passing the affected CPU into the accessors later, extend struct kvm_exit_mmio to add an opaque private pointer parameter. The current GICv2 emulation just does not use it.

---
Changelog v6...v7:
(none)

Changelog v5...v6:
(none)

Changelog v4...v5:
(add Acked-by:)

Changelog v3...v4:
- moving private parameter from each accessor into struct kvm_exit_mmio

 arch/arm/include/asm/kvm_mmio.h   |    1 +
 arch/arm64/include/asm/kvm_mmio.h |    1 +
 virt/kvm/arm/vgic.c               |    1 +
 3 files changed, 3 insertions(+)
arch/arm/include/asm/kvm_mmio.h +1 -0
index adcc0d7..3f83db2 100644
@@ -37,6 +37,7 @@ struct kvm_exit_mmio {
 	u8		data[8];
 	u32		len;
 	bool		is_write;
+	void		*private;
 };
 
 static inline void kvm_prepare_mmio(struct kvm_run *run,
arch/arm64/include/asm/kvm_mmio.h +1 -0
index fc2f689..9f52beb 100644
@@ -40,6 +40,7 @@ struct kvm_exit_mmio {
 	u8		data[8];
 	u32		len;
 	bool		is_write;
+	void		*private;
 };
 
 static inline void kvm_prepare_mmio(struct kvm_run *run,
virt/kvm/arm/vgic.c +1 -0
index 0e84292..b6e17c8 100644
@@ -709,6 +709,7 @@ static bool call_range_handler(struct kvm_vcpu *vcpu,
 
 	mmio32.len = 4;
 	mmio32.is_write = mmio->is_write;
+	mmio32.private = mmio->private;
 
 	mmio32.phys_addr = mmio->phys_addr + 4;
 	if (mmio->is_write)
Signature · 1 line
1.7.9.5
#16 lore raw

PATCH v7 15/20 arm/arm64: KVM: add virtual GICv3 distributor emulation

In reply to Andre Przywara

With everything separated and prepared, we implement a model of a GICv3 distributor and redistributors by using the existing framework to provide handler functions for each register group.

Currently we limit the emulation to a model enforcing a single security state, with SRE==1 (forcing system register access) and ARE==1 (allowing more than 8 VCPUs).

We share some of the functions provided for GICv2 emulation, but take the different ways of addressing (v)CPUs into account. Save and restore is currently not implemented.

Similar to the split-off of the GICv2 specific code, the new emulation code goes into a new file (vgic-v3-emul.c).

---
Changelog v6...v7:
- fix typo in comment
- change GICR_IGROUPR0 handling to RAO/WI
- map_resources: don't return without releasing the mutex
- map_resources: do not automatically init the VGIC, but return with an error
- change vgic_v3_init_emulation to return void

Changelog v5...v6:
- adapt to changes due to new 05/20

Changelog v4...v5:
- correct GICD_IROUTER region length
- adapt GICv3 specific memory allocation to new init_maps()
- minor styles changes and fixed comments

Changelog v3...v4:
- remove ICC_SGI1R_EL1 register handling (moved into later patch)
- add definitions for single security state
- document emulation limitations in vgic-v3-emul.c header
- move CTLR, TYPER and IIDR handling into separate functions
- add RAO/WI handling for IGROUPRn registers
- remove unneeded offset masking on calling vgic_reg_access()
- rework handle_mmio_route_reg() to only handle SPIs
- refine IROUTERn register range
- use non-atomic bitops functions (__clear_bit() and __set_bit())
- rename vgic_dist_ranges[] to vgic_v3_dist_ranges[]
- add (RAZ/WI) implementation of GICD_STATUSR
- add (RAZ/WI) implementations of MBI registers
- adapt to new private passing (in struct kvm_exit_mmio instead of a paramter)
- fix vcpu_id calculation bug in handle CFG registers
- always use hexadecimal numbers for .len member
- simplify vgic_v3_handle_mmio()
- add vgic_v3_create() and vgic_v3_destroy()
- swap vgic_v3_[sg]et_attr() code location
- add and improve comments
- (adaptions to changes from earlier patches)

 arch/arm64/kvm/Makefile            |    1 +
 include/kvm/arm_vgic.h             |    9 +-
 include/linux/irqchip/arm-gic-v3.h |   32 ++
 include/linux/kvm_host.h           |    1 +
 include/uapi/linux/kvm.h           |    2 +
 virt/kvm/arm/vgic-v3-emul.c        |  922 ++++++++++++++++++++++++++++++++++++
 virt/kvm/arm/vgic.c                |   11 +-
 virt/kvm/arm/vgic.h                |    3 +
 8 files changed, 978 insertions(+), 3 deletions(-)
 create mode 100644 virt/kvm/arm/vgic-v3-emul.c
arch/arm64/kvm/Makefile +1 -0
index d957353..4e6e09e 100644
@@ -24,5 +24,6 @@ kvm-$(CONFIG_KVM_ARM_VGIC) += $(KVM)/arm/vgic-v2.o
 kvm-$(CONFIG_KVM_ARM_VGIC) += $(KVM)/arm/vgic-v2-emul.o
 kvm-$(CONFIG_KVM_ARM_VGIC) += vgic-v2-switch.o
 kvm-$(CONFIG_KVM_ARM_VGIC) += $(KVM)/arm/vgic-v3.o
+kvm-$(CONFIG_KVM_ARM_VGIC) += $(KVM)/arm/vgic-v3-emul.o
 kvm-$(CONFIG_KVM_ARM_VGIC) += vgic-v3-switch.o
 kvm-$(CONFIG_KVM_ARM_TIMER) += $(KVM)/arm/arch_timer.o
include/kvm/arm_vgic.h +8 -1
index ff04afd..98c3016 100644
@@ -162,7 +162,11 @@ struct vgic_dist {
 
 	/* Distributor and vcpu interface mapping in the guest */
 	phys_addr_t		vgic_dist_base;
-	phys_addr_t		vgic_cpu_base;
+	/* GICv2 and GICv3 use different mapped register blocks */
+	union {
+		phys_addr_t		vgic_cpu_base;
+		phys_addr_t		vgic_redist_base;
+	};
 
 	/* Distributor enabled */
 	u32			enabled;
@@ -224,6 +228,9 @@ struct vgic_dist {
 	 */
 	struct vgic_bitmap	*irq_spi_target;
 
+	/* Target MPIDR for each IRQ (needed for GICv3 IROUTERn) only */
+	u32			*irq_spi_mpidr;
+
 	/* Bitmap indicating which CPU has something pending */
 	unsigned long		*irq_pending_on_cpu;
 
include/linux/irqchip/arm-gic-v3.h +32 -0
index 1e8b0cf..3fb4d85 100644
@@ -33,6 +33,7 @@
 #define GICD_SETSPI_SR			0x0050
 #define GICD_CLRSPI_SR			0x0058
 #define GICD_SEIR			0x0068
+#define GICD_IGROUPR			0x0080
 #define GICD_ISENABLER			0x0100
 #define GICD_ICENABLER			0x0180
 #define GICD_ISPENDR			0x0200
@@ -41,14 +42,37 @@
 #define GICD_ICACTIVER			0x0380
 #define GICD_IPRIORITYR			0x0400
 #define GICD_ICFGR			0x0C00
+#define GICD_IGRPMODR			0x0D00
+#define GICD_NSACR			0x0E00
 #define GICD_IROUTER			0x6000
+#define GICD_IDREGS			0xFFD0
 #define GICD_PIDR2			0xFFE8
 
+/*
+ * Those registers are actually from GICv2, but the spec demands that they
+ * are implemented as RES0 if ARE is 1 (which we do in KVM's emulated GICv3).
+ */
+#define GICD_ITARGETSR			0x0800
+#define GICD_SGIR			0x0F00
+#define GICD_CPENDSGIR			0x0F10
+#define GICD_SPENDSGIR			0x0F20
+
 #define GICD_CTLR_RWP			(1U << 31)
+#define GICD_CTLR_DS			(1U << 6)
 #define GICD_CTLR_ARE_NS		(1U << 4)
 #define GICD_CTLR_ENABLE_G1A		(1U << 1)
 #define GICD_CTLR_ENABLE_G1		(1U << 0)
 
+/*
+ * In systems with a single security state (what we emulate in KVM)
+ * the meaning of the interrupt group enable bits is slightly different
+ */
+#define GICD_CTLR_ENABLE_SS_G1		(1U << 1)
+#define GICD_CTLR_ENABLE_SS_G0		(1U << 0)
+
+#define GICD_TYPER_LPIS			(1U << 17)
+#define GICD_TYPER_MBIS			(1U << 16)
+
 #define GICD_TYPER_ID_BITS(typer)	((((typer) >> 19) & 0x1f) + 1)
 #define GICD_TYPER_IRQS(typer)		((((typer) & 0x1f) + 1) * 32)
 #define GICD_TYPER_LPIS			(1U << 17)
@@ -60,6 +84,8 @@
 #define GIC_PIDR2_ARCH_GICv3		0x30
 #define GIC_PIDR2_ARCH_GICv4		0x40
 
+#define GIC_V3_DIST_SIZE		0x10000
+
 /*
  * Re-Distributor registers, offsets from RD_base
  */
@@ -78,6 +104,7 @@
 #define GICR_SYNCR			0x00C0
 #define GICR_MOVLPIR			0x0100
 #define GICR_MOVALLR			0x0110
+#define GICR_IDREGS			GICD_IDREGS
 #define GICR_PIDR2			GICD_PIDR2
 
 #define GICR_CTLR_ENABLE_LPIS		(1UL << 0)
@@ -104,6 +131,7 @@
 /*
  * Re-Distributor registers, offsets from SGI_base
  */
+#define GICR_IGROUPR0			GICD_IGROUPR
 #define GICR_ISENABLER0			GICD_ISENABLER
 #define GICR_ICENABLER0			GICD_ICENABLER
 #define GICR_ISPENDR0			GICD_ISPENDR
@@ -112,11 +140,15 @@
 #define GICR_ICACTIVER0			GICD_ICACTIVER
 #define GICR_IPRIORITYR0		GICD_IPRIORITYR
 #define GICR_ICFGR0			GICD_ICFGR
+#define GICR_IGRPMODR0			GICD_IGRPMODR
+#define GICR_NSACR			GICD_NSACR
 
 #define GICR_TYPER_PLPIS		(1U << 0)
 #define GICR_TYPER_VLPIS		(1U << 1)
 #define GICR_TYPER_LAST			(1U << 4)
 
+#define GIC_V3_REDIST_SIZE		0x20000
+
 #define LPI_PROP_GROUP1			(1 << 1)
 #define LPI_PROP_ENABLED		(1 << 0)
 
include/linux/kvm_host.h +1 -0
index 703eeed..83d770e 100644
@@ -1043,6 +1043,7 @@ void kvm_unregister_device_ops(u32 type);
 extern struct kvm_device_ops kvm_mpic_ops;
 extern struct kvm_device_ops kvm_xics_ops;
 extern struct kvm_device_ops kvm_arm_vgic_v2_ops;
+extern struct kvm_device_ops kvm_arm_vgic_v3_ops;
 
 #ifdef CONFIG_HAVE_KVM_CPU_RELAX_INTERCEPT
 
include/uapi/linux/kvm.h +2 -0
index a37fd12..b4e6f1e 100644
@@ -952,6 +952,8 @@ enum kvm_device_type {
 #define KVM_DEV_TYPE_ARM_VGIC_V2	KVM_DEV_TYPE_ARM_VGIC_V2
 	KVM_DEV_TYPE_FLIC,
 #define KVM_DEV_TYPE_FLIC		KVM_DEV_TYPE_FLIC
+	KVM_DEV_TYPE_ARM_VGIC_V3,
+#define KVM_DEV_TYPE_ARM_VGIC_V3	KVM_DEV_TYPE_ARM_VGIC_V3
 	KVM_DEV_TYPE_MAX,
 };
 
virt/kvm/arm/vgic-v3-emul.c new file +922 -0

922 lines not on this page · raw message

virt/kvm/arm/vgic.c +9 -2
index b6e17c8..6d23e57 100644
@@ -1249,7 +1249,7 @@ static int vgic_update_irq_pending(struct kvm *kvm, int cpuid,
 	struct kvm_vcpu *vcpu;
 	int edge_triggered, level_triggered;
 	int enabled;
-	bool ret = true;
+	bool ret = true, can_inject = true;
 
 	spin_lock(&dist->lock);
 
@@ -1264,6 +1264,11 @@ static int vgic_update_irq_pending(struct kvm *kvm, int cpuid,
 
 	if (irq_num >= VGIC_NR_PRIVATE_IRQS) {
 		cpuid = dist->irq_spi_cpu[irq_num - VGIC_NR_PRIVATE_IRQS];
+		if (cpuid == VCPU_NOT_ALLOCATED) {
+			/* Pretend we use CPU0, and prevent injection */
+			cpuid = 0;
+			can_inject = false;
+		}
 		vcpu = kvm_get_vcpu(kvm, cpuid);
 	}
 
@@ -1286,7 +1291,7 @@ static int vgic_update_irq_pending(struct kvm *kvm, int cpuid,
 
 	enabled = vgic_irq_is_enabled(vcpu, irq_num);
 
-	if (!enabled) {
+	if (!enabled || !can_inject) {
 		ret = false;
 		goto out;
 	}
@@ -1439,6 +1444,7 @@ void kvm_vgic_destroy(struct kvm *kvm)
 	}
 	kfree(dist->irq_sgi_sources);
 	kfree(dist->irq_spi_cpu);
+	kfree(dist->irq_spi_mpidr);
 	kfree(dist->irq_spi_target);
 	kfree(dist->irq_pending_on_cpu);
 	dist->irq_sgi_sources = NULL;
@@ -1594,6 +1600,7 @@ int kvm_vgic_create(struct kvm *kvm, u32 type)
 	kvm->arch.vgic.vctrl_base = vgic->vctrl_base;
 	kvm->arch.vgic.vgic_dist_base = VGIC_ADDR_UNDEF;
 	kvm->arch.vgic.vgic_cpu_base = VGIC_ADDR_UNDEF;
+	kvm->arch.vgic.vgic_redist_base = VGIC_ADDR_UNDEF;
 
 out_unlock:
 	for (; vcpu_lock_idx >= 0; vcpu_lock_idx--) {
virt/kvm/arm/vgic.h +3 -0
index e363b93..1e83bdf 100644
@@ -35,6 +35,8 @@
 #define ACCESS_WRITE_VALUE	(3 << 1)
 #define ACCESS_WRITE_MASK(x)	((x) & (3 << 1))
 
+#define VCPU_NOT_ALLOCATED	((u8)-1)
+
 unsigned long *vgic_bitmap_get_shared_map(struct vgic_bitmap *x);
 
 void vgic_update_state(struct kvm *kvm);
@@ -116,5 +118,6 @@ int vgic_get_common_attr(struct kvm_device *dev, struct kvm_device_attr *attr);
 
 int vgic_init(struct kvm *kvm);
 void vgic_v2_init_emulation(struct kvm *kvm);
+void vgic_v3_init_emulation(struct kvm *kvm);
 
 #endif
Signature · 1 line
1.7.9.5
#17 lore raw

PATCH v7 15/20 arm/arm64: KVM: add virtual GICv3 distributor emulation

Quoted 8 lines · Andre Przywara

With everything separated and prepared, we implement a model of a GICv3 distributor and redistributors by using the existing framework to provide handler functions for each register group.

Currently we limit the emulation to a model enforcing a single security state, with SRE==1 (forcing system register access) and ARE==1 (allowing more than 8 VCPUs).

Quoted 8 lines

We share some of the functions provided for GICv2 emulation, but take the different ways of addressing (v)CPUs into account. Save and restore is currently not implemented.

Similar to the split-off of the GICv2 specific code, the new emulation code goes into a new file (vgic-v3-emul.c).

Drum roll....

#18 lore raw

PATCH v7 15/20 arm/arm64: KVM: add virtual GICv3 distributor emulation

Hi Christoffer,

Quoted 16 lines · Christoffer Dall
Quoted 15 lines · Andre Przywara

With everything separated and prepared, we implement a model of a GICv3 distributor and redistributors by using the existing framework to provide handler functions for each register group.

Currently we limit the emulation to a model enforcing a single security state, with SRE==1 (forcing system register access) and ARE==1 (allowing more than 8 VCPUs).

We share some of the functions provided for GICv2 emulation, but take the different ways of addressing (v)CPUs into account. Save and restore is currently not implemented.

Similar to the split-off of the GICv2 specific code, the new emulation code goes into a new file (vgic-v3-emul.c).

Quoted 6 lines
Quoted 1 line

Drum roll....

Awesome, many thanks for that!
If you need any help with any kind of merging/rebasing GIC related patches (the VFIO stuff for instance), please let me know.

Cheers,
Andre.

#19 lore raw

PATCH v7 15/20 arm/arm64: KVM: add virtual GICv3 distributor emulation

Quoted 22 lines · Andre Przywara

Hi Christoffer,

Quoted 19 lines · Christoffer Dall
Quoted 16 lines · Andre Przywara

With everything separated and prepared, we implement a model of a GICv3 distributor and redistributors by using the existing framework to provide handler functions for each register group.

Currently we limit the emulation to a model enforcing a single security state, with SRE==1 (forcing system register access) and ARE==1 (allowing more than 8 VCPUs).

We share some of the functions provided for GICv2 emulation, but take the different ways of addressing (v)CPUs into account. Save and restore is currently not implemented.

Similar to the split-off of the GICv2 specific code, the new emulation code goes into a new file (vgic-v3-emul.c).

Quoted 8 lines
Quoted 3 lines

Drum roll....

Awesome, many thanks for that!
If you need any help with any kind of merging/rebasing GIC related patches (the VFIO stuff for instance), please let me know.

Thanks, I'm still brewing on the remaining we-allow-some-dynamic-vgic-init stuff for gicv3 and whether we need to change that before merging this.

-Christoffer

#20 lore raw

PATCH v7 16/20 arm64: GICv3: introduce symbolic names for GICv3 ICC_SGI1R_EL1 fields

In reply to Andre Przywara

The gic_send_sgi() function used hardcoded bit shift values to generate the ICC_SGI1R_EL1 register value.
Replace this with symbolic names to allow reusing them later.

---
Changelog v6...v7:
(none)

Changelog v5...v6:
(none)

Changelog v4...v5:
(add Reviewed-by:)

Changelog v3...v4:
- (new patch)

 drivers/irqchip/irq-gic-v3.c       |   14 +++++++++-----
 include/linux/irqchip/arm-gic-v3.h |   12 ++++++++++++
 2 files changed, 21 insertions(+), 5 deletions(-)
drivers/irqchip/irq-gic-v3.c +9 -5
index 1a146cc..2ab290b 100644
@@ -481,15 +481,19 @@ out:
 	return tlist;
 }
 
+#define MPIDR_TO_SGI_AFFINITY(cluster_id, level) \
+	(MPIDR_AFFINITY_LEVEL(cluster_id, level) \
+		<< ICC_SGI1R_AFFINITY_## level ##_SHIFT)
+
 static void gic_send_sgi(u64 cluster_id, u16 tlist, unsigned int irq)
 {
 	u64 val;
 
-	val = (MPIDR_AFFINITY_LEVEL(cluster_id, 3) << 48	|
-	       MPIDR_AFFINITY_LEVEL(cluster_id, 2) << 32	|
-	       irq << 24			    		|
-	       MPIDR_AFFINITY_LEVEL(cluster_id, 1) << 16	|
-	       tlist);
+	val = (MPIDR_TO_SGI_AFFINITY(cluster_id, 3)	|
+	       MPIDR_TO_SGI_AFFINITY(cluster_id, 2)	|
+	       irq << ICC_SGI1R_SGI_ID_SHIFT		|
+	       MPIDR_TO_SGI_AFFINITY(cluster_id, 1)	|
+	       tlist << ICC_SGI1R_TARGET_LIST_SHIFT);
 
 	pr_debug("CPU%d: ICC_SGI1R_EL1 %llx\n", smp_processor_id(), val);
 	gic_write_sgi1r(val);
include/linux/irqchip/arm-gic-v3.h +12 -0
index 3fb4d85..800544b 100644
@@ -280,6 +280,18 @@
 #define ICC_SRE_EL2_SRE			(1 << 0)
 #define ICC_SRE_EL2_ENABLE		(1 << 3)
 
+#define ICC_SGI1R_TARGET_LIST_SHIFT	0
+#define ICC_SGI1R_TARGET_LIST_MASK	(0xffff << ICC_SGI1R_TARGET_LIST_SHIFT)
+#define ICC_SGI1R_AFFINITY_1_SHIFT	16
+#define ICC_SGI1R_AFFINITY_1_MASK	(0xff << ICC_SGI1R_AFFINITY_1_SHIFT)
+#define ICC_SGI1R_SGI_ID_SHIFT		24
+#define ICC_SGI1R_SGI_ID_MASK		(0xff << ICC_SGI1R_SGI_ID_SHIFT)
+#define ICC_SGI1R_AFFINITY_2_SHIFT	32
+#define ICC_SGI1R_AFFINITY_2_MASK	(0xffULL << ICC_SGI1R_AFFINITY_1_SHIFT)
+#define ICC_SGI1R_IRQ_ROUTING_MODE_BIT	40
+#define ICC_SGI1R_AFFINITY_3_SHIFT	48
+#define ICC_SGI1R_AFFINITY_3_MASK	(0xffULL << ICC_SGI1R_AFFINITY_1_SHIFT)
+
 /*
  * System register definitions
  */
Signature · 1 line
1.7.9.5
#21 lore raw

PATCH v7 17/20 arm64: KVM: add SGI generation register emulation

In reply to Andre Przywara

While the generation of a (virtual) inter-processor interrupt (SGI) on a GICv2 works by writing to a MMIO register, GICv3 uses the system register ICC_SGI1R_EL1 to trigger them.
Add a trap handler function that calls the new SGI register handler in the GICv3 code. As ICC_SRE_EL1.SRE at this point is still always 0, this will not trap yet, but will only be used later when all the data structures have been initialized properly.

---
Changelog v6...v7:
(none)

Changelog v5...v6:
- add sysreg trapping for 32-bit guests

Changelog v4...v5:
- fix merge conflict due to 3.18.0 rebase
- minor style changes and comments fixes

Changelog v3...v4:
- moved addition of vgic_v3_dispatch_sgi() from earlier patch into here
- move MPIDR comparison into extra function
- use new ICC_SGI1R_ field names
- improve readability of vgic_v3_dispatch_sgi()
- add and refine comments

 arch/arm64/kvm/sys_regs.c   |   27 +++++++++++
 include/kvm/arm_vgic.h      |    1 +
 virt/kvm/arm/vgic-v3-emul.c |  111 +++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 139 insertions(+)
arch/arm64/kvm/sys_regs.c +27 -0
index 136e679..8c30f26 100644
@@ -165,6 +165,27 @@ static bool access_sctlr(struct kvm_vcpu *vcpu,
 	return true;
 }
 
+/*
+ * Trap handler for the GICv3 SGI generation system register.
+ * Forward the request to the VGIC emulation.
+ * The cp15_64 code makes sure this automatically works
+ * for both AArch64 and AArch32 accesses.
+ */
+static bool access_gic_sgi(struct kvm_vcpu *vcpu,
+			   const struct sys_reg_params *p,
+			   const struct sys_reg_desc *r)
+{
+	u64 val;
+
+	if (!p->is_write)
+		return read_from_write_only(vcpu, p);
+
+	val = *vcpu_reg(vcpu, p->Rt);
+	vgic_v3_dispatch_sgi(vcpu, val);
+
+	return true;
+}
+
 static bool trap_raz_wi(struct kvm_vcpu *vcpu,
 			const struct sys_reg_params *p,
 			const struct sys_reg_desc *r)
@@ -434,6 +455,9 @@ static const struct sys_reg_desc sys_reg_descs[] = {
 	{ Op0(0b11), Op1(0b000), CRn(0b1100), CRm(0b0000), Op2(0b000),
 	  NULL, reset_val, VBAR_EL1, 0 },
 
+	/* ICC_SGI1R_EL1 */
+	{ Op0(0b11), Op1(0b000), CRn(0b1100), CRm(0b1011), Op2(0b101),
+	  access_gic_sgi },
 	/* ICC_SRE_EL1 */
 	{ Op0(0b11), Op1(0b000), CRn(0b1100), CRm(0b1100), Op2(0b101),
 	  trap_raz_wi },
@@ -666,6 +690,8 @@ static const struct sys_reg_desc cp14_64_regs[] = {
  * register).
  */
 static const struct sys_reg_desc cp15_regs[] = {
+	{ Op1( 0), CRn( 0), CRm(12), Op2( 0), access_gic_sgi },
+
 	{ Op1( 0), CRn( 1), CRm( 0), Op2( 0), access_sctlr, NULL, c1_SCTLR },
 	{ Op1( 0), CRn( 2), CRm( 0), Op2( 0), access_vm_reg, NULL, c2_TTBR0 },
 	{ Op1( 0), CRn( 2), CRm( 0), Op2( 1), access_vm_reg, NULL, c2_TTBR1 },
@@ -713,6 +739,7 @@ static const struct sys_reg_desc cp15_regs[] = {
 
 static const struct sys_reg_desc cp15_64_regs[] = {
 	{ Op1( 0), CRn( 0), CRm( 2), Op2( 0), access_vm_reg, NULL, c2_TTBR0 },
+	{ Op1( 0), CRn( 0), CRm(12), Op2( 0), access_gic_sgi },
 	{ Op1( 1), CRn( 0), CRm( 2), Op2( 0), access_vm_reg, NULL, c2_TTBR1 },
 };
 
include/kvm/arm_vgic.h +1 -0
index 98c3016..b9b2e05 100644
@@ -307,6 +307,7 @@ void kvm_vgic_flush_hwstate(struct kvm_vcpu *vcpu);
 void kvm_vgic_sync_hwstate(struct kvm_vcpu *vcpu);
 int kvm_vgic_inject_irq(struct kvm *kvm, int cpuid, unsigned int irq_num,
 			bool level);
+void vgic_v3_dispatch_sgi(struct kvm_vcpu *vcpu, u64 reg);
 int kvm_vgic_vcpu_pending_irq(struct kvm_vcpu *vcpu);
 bool vgic_handle_mmio(struct kvm_vcpu *vcpu, struct kvm_run *run,
 		      struct kvm_exit_mmio *mmio);
virt/kvm/arm/vgic-v3-emul.c +111 -0

117 lines not on this page · raw message

Signature · 1 line
1.7.9.5
#22 lore raw

PATCH v7 18/20 arm/arm64: KVM: enable kernel side of GICv3 emulation

In reply to Andre Przywara

With all the necessary GICv3 emulation code in place, we can now connect the code to the GICv3 backend in the kernel.
The LR register handling is different depending on the emulated GIC model, so provide different implementations for each. Also allow non-v2-compatible GICv3 implementations (which don't provide MMIO regions for the virtual CPU interface in the DT), but restrict those hosts to support GICv3 guests only.
If the device tree provides a GICv2 compatible GICV resource entry, but that one is faulty, just disable the GICv2 emulation and let the user use at least the GICv3 emulation for guests.
To provide proper support for the legacy KVM_CREATE_IRQCHIP ioctl, note virtual GICv2 compatibility in struct vgic_params and use it on creating a VGICv2.

---
Changelog v6...v7:
- introduce can_emulate_gicv2 to check KVM_CREATE_IRQCHIP
- adapt to new prototype of vgic_vx_init_emulation

Changelog v5...v6:
- allow GICv3 emulation in case of invalid GICv2 DT compat entries
- use new kvm_check_device_type()

Changelog v4...v5:
- minor whitespace and comments fixes

Changelog v3...v4:
- handle differences between GICv2-on-v3 and GICv3-on-v3 in existing functions
- remove init_*_emul() functions
- remove max_vcpus setting (done in earlier patches now)
- adapt to new vgic_v<n>_init_emulation behaviour

 include/kvm/arm_vgic.h |    2 ++
 virt/kvm/arm/vgic-v2.c |    1 +
 virt/kvm/arm/vgic-v3.c |   76 ++++++++++++++++++++++++++++++++----------------
 virt/kvm/arm/vgic.c    |   14 +++++++++
 4 files changed, 68 insertions(+), 25 deletions(-)
include/kvm/arm_vgic.h +2 -0
index b9b2e05..39039d5 100644
@@ -134,6 +134,8 @@ struct vgic_params {
 	/* Virtual control interface base address */
 	void __iomem	*vctrl_base;
 	int		max_gic_vcpus;
+	/* Only needed for the legacy KVM_CREATE_IRQCHIP */
+	bool		can_emulate_gicv2;
 };
 
 struct vgic_vm_ops {
virt/kvm/arm/vgic-v2.c +1 -0
index e8b82b2..a0a7b5d 100644
@@ -229,6 +229,7 @@ int vgic_v2_probe(struct device_node *vgic_node,
 		goto out_unmap;
 	}
 
+	vgic->can_emulate_gicv2 = true;
 	kvm_register_device_ops(&kvm_arm_vgic_v2_ops, KVM_DEV_TYPE_ARM_VGIC_V2);
 
 	vgic->vcpu_base = vcpu_res.start;
virt/kvm/arm/vgic-v3.c +51 -25

118 lines not on this page · raw message

virt/kvm/arm/vgic.c +14 -0
index 6d23e57..2efba82 100644
@@ -1550,6 +1550,11 @@ static int init_vgic_model(struct kvm *kvm, int type)
 	case KVM_DEV_TYPE_ARM_VGIC_V2:
 		vgic_v2_init_emulation(kvm);
 		break;
+#ifdef CONFIG_ARM_GIC_V3
+	case KVM_DEV_TYPE_ARM_VGIC_V3:
+		vgic_v3_init_emulation(kvm);
+		break;
+#endif
 	default:
 		return -ENODEV;
 	}
@@ -1573,6 +1578,15 @@ int kvm_vgic_create(struct kvm *kvm, u32 type)
 	}
 
 	/*
+	 * This function is also called by the KVM_CREATE_IRQCHIP handler,
+	 * which had no chance yet to check the availability of the GICv2
+	 * emulation. So check this here again. KVM_CREATE_DEVICE does
+	 * the proper checks already.
+	 */
+	if (type == KVM_DEV_TYPE_ARM_VGIC_V2 && !vgic->can_emulate_gicv2)
+		return -ENODEV;
+
+	/*
 	 * Any time a vcpu is run, vcpu_load is called which tries to grab the
 	 * vcpu->mutex.  By grabbing the vcpu->mutex of all VCPUs we ensure
 	 * that no other VCPUs are run while we create the vgic.
Signature · 1 line
1.7.9.5
#23 lore raw

PATCH v7 18/20 arm/arm64: KVM: enable kernel side of GICv3 emulation

Quoted 226 lines · Andre Przywara

With all the necessary GICv3 emulation code in place, we can now connect the code to the GICv3 backend in the kernel.
The LR register handling is different depending on the emulated GIC model, so provide different implementations for each. Also allow non-v2-compatible GICv3 implementations (which don't provide MMIO regions for the virtual CPU interface in the DT), but restrict those hosts to support GICv3 guests only.
If the device tree provides a GICv2 compatible GICV resource entry, but that one is faulty, just disable the GICv2 emulation and let the user use at least the GICv3 emulation for guests.
To provide proper support for the legacy KVM_CREATE_IRQCHIP ioctl, note virtual GICv2 compatibility in struct vgic_params and use it on creating a VGICv2.

---
Changelog v6...v7:
- introduce can_emulate_gicv2 to check KVM_CREATE_IRQCHIP
- adapt to new prototype of vgic_vx_init_emulation

Changelog v5...v6:
- allow GICv3 emulation in case of invalid GICv2 DT compat entries
- use new kvm_check_device_type()

Changelog v4...v5:
- minor whitespace and comments fixes

Changelog v3...v4:
- handle differences between GICv2-on-v3 and GICv3-on-v3 in existing functions
- remove init_*_emul() functions
- remove max_vcpus setting (done in earlier patches now)
- adapt to new vgic_v<n>_init_emulation behaviour

 include/kvm/arm_vgic.h |    2 ++
 virt/kvm/arm/vgic-v2.c |    1 +
 virt/kvm/arm/vgic-v3.c |   76 ++++++++++++++++++++++++++++++++----------------
 virt/kvm/arm/vgic.c    |   14 +++++++++
 4 files changed, 68 insertions(+), 25 deletions(-)
include/kvm/arm_vgic.h +2 -0
index b9b2e05..39039d5 100644
@@ -134,6 +134,8 @@ struct vgic_params {
 	/* Virtual control interface base address */
 	void __iomem	*vctrl_base;
 	int		max_gic_vcpus;
+	/* Only needed for the legacy KVM_CREATE_IRQCHIP */
+	bool		can_emulate_gicv2;
 };
 
 struct vgic_vm_ops {
virt/kvm/arm/vgic-v2.c +1 -0
index e8b82b2..a0a7b5d 100644
@@ -229,6 +229,7 @@ int vgic_v2_probe(struct device_node *vgic_node,
 		goto out_unmap;
 	}
 
+	vgic->can_emulate_gicv2 = true;
 	kvm_register_device_ops(&kvm_arm_vgic_v2_ops, KVM_DEV_TYPE_ARM_VGIC_V2);
 
 	vgic->vcpu_base = vcpu_res.start;
virt/kvm/arm/vgic-v3.c +51 -25
index 5249048..3a62d8a 100644
@@ -34,6 +34,7 @@
 #define GICH_LR_VIRTUALID		(0x3ffUL << 0)
 #define GICH_LR_PHYSID_CPUID_SHIFT	(10)
 #define GICH_LR_PHYSID_CPUID		(7UL << GICH_LR_PHYSID_CPUID_SHIFT)
+#define ICH_LR_VIRTUALID_MASK		(BIT_ULL(32) - 1)
 
 /*
  * LRs are stored in reverse order in memory. make sure we index them
@@ -48,12 +49,17 @@ static struct vgic_lr vgic_v3_get_lr(const struct kvm_vcpu *vcpu, int lr)
 	struct vgic_lr lr_desc;
 	u64 val = vcpu->arch.vgic_cpu.vgic_v3.vgic_lr[LR_INDEX(lr)];
 
-	lr_desc.irq	= val & GICH_LR_VIRTUALID;
-	if (lr_desc.irq <= 15)
-		lr_desc.source	= (val >> GICH_LR_PHYSID_CPUID_SHIFT) & 0x7;
+	if (vcpu->kvm->arch.vgic.vgic_model == KVM_DEV_TYPE_ARM_VGIC_V3)
+		lr_desc.irq = val & ICH_LR_VIRTUALID_MASK;
 	else
-		lr_desc.source = 0;
-	lr_desc.state	= 0;
+		lr_desc.irq = val & GICH_LR_VIRTUALID;
+
+	lr_desc.source = 0;
+	if (lr_desc.irq <= 15 &&
+	    vcpu->kvm->arch.vgic.vgic_model == KVM_DEV_TYPE_ARM_VGIC_V2)
+		lr_desc.source = (val >> GICH_LR_PHYSID_CPUID_SHIFT) & 0x7;
+
+	lr_desc.state = 0;
 
 	if (val & ICH_LR_PENDING_BIT)
 		lr_desc.state |= LR_STATE_PENDING;
@@ -68,8 +74,20 @@ static struct vgic_lr vgic_v3_get_lr(const struct kvm_vcpu *vcpu, int lr)
 static void vgic_v3_set_lr(struct kvm_vcpu *vcpu, int lr,
 			   struct vgic_lr lr_desc)
 {
-	u64 lr_val = (((u32)lr_desc.source << GICH_LR_PHYSID_CPUID_SHIFT) |
-		      lr_desc.irq);
+	u64 lr_val;
+
+	lr_val = lr_desc.irq;
+
+	/*
+	 * Currently all guest IRQs are Group1, as Group0 would result
+	 * in a FIQ in the guest, which it wouldn't expect.
+	 * Eventually we want to make this configurable, so we may revisit
+	 * this in the future.
+	 */
+	if (vcpu->kvm->arch.vgic.vgic_model == KVM_DEV_TYPE_ARM_VGIC_V3)
+		lr_val |= ICH_LR_GROUP;
+	else
+		lr_val |= (u32)lr_desc.source << GICH_LR_PHYSID_CPUID_SHIFT;
 
 	if (lr_desc.state & LR_STATE_PENDING)
 		lr_val |= ICH_LR_PENDING_BIT;
@@ -154,7 +172,15 @@ static void vgic_v3_enable(struct kvm_vcpu *vcpu)
 	 */
 	vgic_v3->vgic_vmcr = 0;
 
-	vgic_v3->vgic_sre = 0;
+	/*
+	 * If we are emulating a GICv3, we do it in an non-GICv2-compatible
+	 * way, so we force SRE to 1 to demonstrate this to the guest.
+	 * This goes with the spec allowing the value to be RAO/WI.
+	 */
+	if (vcpu->kvm->arch.vgic.vgic_model == KVM_DEV_TYPE_ARM_VGIC_V3)
+		vgic_v3->vgic_sre = ICC_SRE_EL1_SRE;
+	else
+		vgic_v3->vgic_sre = 0;
 
 	/* Get the show on the road... */
 	vgic_v3->vgic_hcr = ICH_HCR_EN;
@@ -209,34 +235,34 @@ int vgic_v3_probe(struct device_node *vgic_node,
 	 * maximum of 16 list registers. Just ignore bit 4...
 	 */
 	vgic->nr_lr = (ich_vtr_el2 & 0xf) + 1;
+	vgic->can_emulate_gicv2 = false;
 
 	if (of_property_read_u32(vgic_node, "#redistributor-regions", &gicv_idx))
 		gicv_idx = 1;
 
 	gicv_idx += 3; /* Also skip GICD, GICC, GICH */
 	if (of_address_to_resource(vgic_node, gicv_idx, &vcpu_res)) {
-		kvm_err("Cannot obtain GICV region\n");
-		ret = -ENXIO;
-		goto out;
-	}
-
-	if (!PAGE_ALIGNED(vcpu_res.start)) {
-		kvm_err("GICV physical address 0x%llx not page aligned\n",
+		kvm_info("GICv3: no GICV resource entry\n");
+		vgic->vcpu_base = 0;
+	} else if (!PAGE_ALIGNED(vcpu_res.start)) {
+		pr_warn("GICV physical address 0x%llx not page aligned\n",
 			(unsigned long long)vcpu_res.start);
-		ret = -ENXIO;
-		goto out;
-	}
-
-	if (!PAGE_ALIGNED(resource_size(&vcpu_res))) {
-		kvm_err("GICV size 0x%llx not a multiple of page size 0x%lx\n",
+		vgic->vcpu_base = 0;
+	} else if (!PAGE_ALIGNED(resource_size(&vcpu_res))) {
+		pr_warn("GICV size 0x%llx not a multiple of page size 0x%lx\n",
 			(unsigned long long)resource_size(&vcpu_res),
 			PAGE_SIZE);
-		ret = -ENXIO;
-		goto out;
+		vgic->vcpu_base = 0;
+	} else {
+		vgic->vcpu_base = vcpu_res.start;
+		vgic->can_emulate_gicv2 = true;
+		kvm_register_device_ops(&kvm_arm_vgic_v2_ops,
+					KVM_DEV_TYPE_ARM_VGIC_V2);
 	}
-	kvm_register_device_ops(&kvm_arm_vgic_v2_ops, KVM_DEV_TYPE_ARM_VGIC_V2);
+	if (vgic->vcpu_base == 0)
+		kvm_info("disabling GICv2 emulation\n");
+	kvm_register_device_ops(&kvm_arm_vgic_v3_ops, KVM_DEV_TYPE_ARM_VGIC_V3);
 
-	vgic->vcpu_base = vcpu_res.start;
 	vgic->vctrl_base = NULL;
 	vgic->type = VGIC_V3;
 	vgic->max_gic_vcpus = KVM_MAX_VCPUS;
virt/kvm/arm/vgic.c +14 -0
index 6d23e57..2efba82 100644
@@ -1550,6 +1550,11 @@ static int init_vgic_model(struct kvm *kvm, int type)
 	case KVM_DEV_TYPE_ARM_VGIC_V2:
 		vgic_v2_init_emulation(kvm);
 		break;
+#ifdef CONFIG_ARM_GIC_V3
+	case KVM_DEV_TYPE_ARM_VGIC_V3:
+		vgic_v3_init_emulation(kvm);
+		break;
+#endif
 	default:
 		return -ENODEV;
 	}
@@ -1573,6 +1578,15 @@ int kvm_vgic_create(struct kvm *kvm, u32 type)
 	}
 
 	/*
+	 * This function is also called by the KVM_CREATE_IRQCHIP handler,
+	 * which had no chance yet to check the availability of the GICv2
+	 * emulation. So check this here again. KVM_CREATE_DEVICE does
+	 * the proper checks already.
+	 */
+	if (type == KVM_DEV_TYPE_ARM_VGIC_V2 && !vgic->can_emulate_gicv2)
+		return -ENODEV;
+
+	/*
 	 * Any time a vcpu is run, vcpu_load is called which tries to grab the
 	 * vcpu->mutex.  By grabbing the vcpu->mutex of all VCPUs we ensure
 	 * that no other VCPUs are run while we create the vgic.
Signature · 1 line
1.7.9.5
#24 lore raw

PATCH v7 19/20 arm/arm64: KVM: allow userland to request a virtual GICv3

In reply to Andre Przywara

With all of the GICv3 code in place now we allow userland to ask the kernel for using a virtual GICv3 in the guest.
Also we provide the necessary support for guests setting the memory addresses for the virtual distributor and redistributors. This requires some userland code to make use of that feature and explicitly ask for a virtual GICv3.
Document that KVM_CREATE_IRQCHIP only works for GICv2, but is considered legacy and using KVM_CREATE_DEVICE is preferred.

---
Changelog v6...v7:
- clarify usage of KVM_CREATE_IRQCHIP

Changelog v5...v6:
(none)

Changelog v4...v5:
- improving documentation text

Changelog v3...v4:
- refine commit message
- add documentation of new GICv3 KVM device

 Documentation/virtual/kvm/api.txt              |   13 ++++---
 Documentation/virtual/kvm/devices/arm-vgic.txt |   22 ++++++++++--
 arch/arm64/include/uapi/asm/kvm.h              |    7 ++++
 include/kvm/arm_vgic.h                         |    4 +--
 virt/kvm/arm/vgic-v3-emul.c                    |    3 ++
 virt/kvm/arm/vgic.c                            |   46 +++++++++++++++++-------
 6 files changed, 73 insertions(+), 22 deletions(-)
Documentation/virtual/kvm/api.txt +8 -5
index 0007fef..f4b19d7 100644
@@ -612,11 +612,14 @@ Type: vm ioctl
 Parameters: none
 Returns: 0 on success, -1 on error
 
-Creates an interrupt controller model in the kernel.  On x86, creates a virtual
-ioapic, a virtual PIC (two PICs, nested), and sets up future vcpus to have a
-local APIC.  IRQ routing for GSIs 0-15 is set to both PIC and IOAPIC; GSI 16-23
-only go to the IOAPIC.  On ARM/arm64, a GIC is
-created. On s390, a dummy irq routing table is created.
+Creates an interrupt controller model in the kernel.
+On x86, creates a virtual ioapic, a virtual PIC (two PICs, nested), and sets up
+future vcpus to have a local APIC.  IRQ routing for GSIs 0-15 is set to both
+PIC and IOAPIC; GSI 16-23 only go to the IOAPIC.
+On ARM/arm64, a GICv2 is created. Any other GIC versions require the usage of
+KVM_CREATE_DEVICE, which also supports creating a GICv2.  Using
+KVM_CREATE_DEVICE is preferred over KVM_CREATE_IRQCHIP for GICv2.
+On s390, a dummy irq routing table is created.
 
 Note that on s390 the KVM_CAP_S390_IRQCHIP vm capability needs to be enabled
 before KVM_CREATE_IRQCHIP can be used.
Documentation/virtual/kvm/devices/arm-vgic.txt +20 -2
index 30f5427..5d4fd4b 100644
@@ -3,22 +3,38 @@ ARM Virtual Generic Interrupt Controller (VGIC)
 
 Device types supported:
   KVM_DEV_TYPE_ARM_VGIC_V2     ARM Generic Interrupt Controller v2.0
+  KVM_DEV_TYPE_ARM_VGIC_V3     ARM Generic Interrupt Controller v3.0
 
 Only one VGIC instance may be instantiated through either this API or the
 legacy KVM_CREATE_IRQCHIP api.  The created VGIC will act as the VM interrupt
 controller, requiring emulated user-space devices to inject interrupts to the
 VGIC instead of directly to CPUs.
 
+Creating a guest GICv3 device requires a host GICv3 as well.
+GICv3 implementations with hardware compatibility support allow a guest GICv2
+as well.
+
 Groups:
   KVM_DEV_ARM_VGIC_GRP_ADDR
   Attributes:
     KVM_VGIC_V2_ADDR_TYPE_DIST (rw, 64-bit)
       Base address in the guest physical address space of the GIC distributor
-      register mappings.
+      register mappings. Only valid for KVM_DEV_TYPE_ARM_VGIC_V2.
 
     KVM_VGIC_V2_ADDR_TYPE_CPU (rw, 64-bit)
       Base address in the guest physical address space of the GIC virtual cpu
-      interface register mappings.
+      interface register mappings. Only valid for KVM_DEV_TYPE_ARM_VGIC_V2.
+
+    KVM_VGIC_V3_ADDR_TYPE_DIST (rw, 64-bit)
+      Base address in the guest physical address space of the GICv3 distributor
+      register mappings. Only valid for KVM_DEV_TYPE_ARM_VGIC_V3.
+
+    KVM_VGIC_V3_ADDR_TYPE_REDIST (rw, 64-bit)
+      Base address in the guest physical address space of the GICv3
+      redistributor register mappings. There are two 64K pages for each
+      VCPU and all of the redistributor pages are contiguous.
+      Only valid for KVM_DEV_TYPE_ARM_VGIC_V3.
+
 
   KVM_DEV_ARM_VGIC_GRP_DIST_REGS
   Attributes:
@@ -36,6 +52,7 @@ Groups:
     the register.
   Limitations:
     - Priorities are not implemented, and registers are RAZ/WI
+    - Currently only implemented for KVM_DEV_TYPE_ARM_VGIC_V2.
   Errors:
     -ENODEV: Getting or setting this register is not yet supported
     -EBUSY: One or more VCPUs are running
@@ -68,6 +85,7 @@ Groups:
 
   Limitations:
     - Priorities are not implemented, and registers are RAZ/WI
+    - Currently only implemented for KVM_DEV_TYPE_ARM_VGIC_V2.
   Errors:
     -ENODEV: Getting or setting this register is not yet supported
     -EBUSY: One or more VCPUs are running
arch/arm64/include/uapi/asm/kvm.h +7 -0
index 480af34..3ef77a4 100644
@@ -78,6 +78,13 @@ struct kvm_regs {
 #define KVM_VGIC_V2_DIST_SIZE		0x1000
 #define KVM_VGIC_V2_CPU_SIZE		0x2000
 
+/* Supported VGICv3 address types  */
+#define KVM_VGIC_V3_ADDR_TYPE_DIST	2
+#define KVM_VGIC_V3_ADDR_TYPE_REDIST	3
+
+#define KVM_VGIC_V3_DIST_SIZE		SZ_64K
+#define KVM_VGIC_V3_REDIST_SIZE		(2 * SZ_64K)
+
 #define KVM_ARM_VCPU_POWER_OFF		0 /* CPU is started in OFF state */
 #define KVM_ARM_VCPU_EL1_32BIT		1 /* CPU running a 32bit VM */
 #define KVM_ARM_VCPU_PSCI_0_2		2 /* CPU uses PSCI v0.2 */
include/kvm/arm_vgic.h +2 -2
index 39039d5..7c55dd5 100644
@@ -36,8 +36,8 @@
 #define VGIC_V2_MAX_CPUS	8
 
 /* Sanity checks... */
-#if (KVM_MAX_VCPUS > 8)
-#error	Invalid number of CPU interfaces
+#if (KVM_MAX_VCPUS > 255)
+#error Too many KVM VCPUs, the VGIC only supports up to 255 VCPUs for now
 #endif
 
 #if (VGIC_NR_IRQS_LEGACY & 31)
virt/kvm/arm/vgic-v3-emul.c +3 -0
index 2d2199d..b3f1546 100644
@@ -1007,6 +1007,9 @@ static int vgic_v3_has_attr(struct kvm_device *dev,
 		case KVM_VGIC_V2_ADDR_TYPE_DIST:
 		case KVM_VGIC_V2_ADDR_TYPE_CPU:
 			return -ENXIO;
+		case KVM_VGIC_V3_ADDR_TYPE_DIST:
+		case KVM_VGIC_V3_ADDR_TYPE_REDIST:
+			return 0;
 		}
 		break;
 	case KVM_DEV_ARM_VGIC_GRP_DIST_REGS:
virt/kvm/arm/vgic.c +33 -13

69 lines not on this page · raw message

Signature · 1 line
1.7.9.5
#25 lore raw

PATCH v7 19/20 arm/arm64: KVM: allow userland to request a virtual GICv3

Quoted 10 lines · Andre Przywara

With all of the GICv3 code in place now we allow userland to ask the kernel for using a virtual GICv3 in the guest.
Also we provide the necessary support for guests setting the memory addresses for the virtual distributor and redistributors. This requires some userland code to make use of that feature and explicitly ask for a virtual GICv3.
Document that KVM_CREATE_IRQCHIP only works for GICv2, but is considered legacy and using KVM_CREATE_DEVICE is preferred.

#26 lore raw

PATCH v7 20/20 arm/arm64: KVM: force alignment of VGIC dist/CPU/redist addresses

In reply to Andre Przywara

Although the GIC architecture requires us to map the MMIO regions only at page aligned addresses, we currently do not enforce this from the kernel side.
Restrict any vGICv2 regions to be 4K aligned and any GICv3 regions to be 64K aligned. Document this requirement.

---
Changelog:
(new in v7)

 Documentation/virtual/kvm/devices/arm-vgic.txt |    4 ++++
 virt/kvm/arm/vgic.c                            |   16 +++++++++++++---
 2 files changed, 17 insertions(+), 3 deletions(-)
Documentation/virtual/kvm/devices/arm-vgic.txt +4 -0
index 5d4fd4b..3fb9054 100644
@@ -20,20 +20,24 @@ Groups:
     KVM_VGIC_V2_ADDR_TYPE_DIST (rw, 64-bit)
       Base address in the guest physical address space of the GIC distributor
       register mappings. Only valid for KVM_DEV_TYPE_ARM_VGIC_V2.
+      This address needs to be 4K aligned and the region covers 4 KByte.
 
     KVM_VGIC_V2_ADDR_TYPE_CPU (rw, 64-bit)
       Base address in the guest physical address space of the GIC virtual cpu
       interface register mappings. Only valid for KVM_DEV_TYPE_ARM_VGIC_V2.
+      This address needs to be 4K aligned and the region covers 4 KByte.
 
     KVM_VGIC_V3_ADDR_TYPE_DIST (rw, 64-bit)
       Base address in the guest physical address space of the GICv3 distributor
       register mappings. Only valid for KVM_DEV_TYPE_ARM_VGIC_V3.
+      This address needs to be 64K aligned and the region covers 64 KByte.
 
     KVM_VGIC_V3_ADDR_TYPE_REDIST (rw, 64-bit)
       Base address in the guest physical address space of the GICv3
       redistributor register mappings. There are two 64K pages for each
       VCPU and all of the redistributor pages are contiguous.
       Only valid for KVM_DEV_TYPE_ARM_VGIC_V3.
+      This address needs to be 64K aligned.
 
 
   KVM_DEV_ARM_VGIC_GRP_DIST_REGS
virt/kvm/arm/vgic.c +13 -3
index 184c6db..0cc6ab6 100644
@@ -1683,6 +1683,7 @@ int kvm_vgic_addr(struct kvm *kvm, unsigned long type, u64 *addr, bool write)
 	struct vgic_dist *vgic = &kvm->arch.vgic;
 	int type_needed;
 	phys_addr_t *addr_ptr, block_size;
+	phys_addr_t alignment;
 
 	mutex_lock(&kvm->lock);
 	switch (type) {
@@ -1690,22 +1691,26 @@ int kvm_vgic_addr(struct kvm *kvm, unsigned long type, u64 *addr, bool write)
 		type_needed = KVM_DEV_TYPE_ARM_VGIC_V2;
 		addr_ptr = &vgic->vgic_dist_base;
 		block_size = KVM_VGIC_V2_DIST_SIZE;
+		alignment = SZ_4K;
 		break;
 	case KVM_VGIC_V2_ADDR_TYPE_CPU:
 		type_needed = KVM_DEV_TYPE_ARM_VGIC_V2;
 		addr_ptr = &vgic->vgic_cpu_base;
 		block_size = KVM_VGIC_V2_CPU_SIZE;
+		alignment = SZ_4K;
 		break;
 #ifdef CONFIG_ARM_GIC_V3
 	case KVM_VGIC_V3_ADDR_TYPE_DIST:
 		type_needed = KVM_DEV_TYPE_ARM_VGIC_V3;
 		addr_ptr = &vgic->vgic_dist_base;
 		block_size = KVM_VGIC_V3_DIST_SIZE;
+		alignment = SZ_64K;
 		break;
 	case KVM_VGIC_V3_ADDR_TYPE_REDIST:
 		type_needed = KVM_DEV_TYPE_ARM_VGIC_V3;
 		addr_ptr = &vgic->vgic_redist_base;
 		block_size = KVM_VGIC_V3_REDIST_SIZE;
+		alignment = SZ_64K;
 		break;
 #endif
 	default:
@@ -1718,10 +1723,15 @@ int kvm_vgic_addr(struct kvm *kvm, unsigned long type, u64 *addr, bool write)
 		goto out;
 	}
 
-	if (write)
-		r = vgic_ioaddr_assign(kvm, addr_ptr, *addr, block_size);
-	else
+	if (write) {
+		if (!IS_ALIGNED(*addr, alignment))
+			r = -EINVAL;
+		else
+			r = vgic_ioaddr_assign(kvm, addr_ptr, *addr,
+					       block_size);
+	} else {
 		*addr = *addr_ptr;
+	}
 
 out:
 	mutex_unlock(&kvm->lock);
Signature · 1 line
1.7.9.5
#27 lore raw

PATCH v7 20/20 arm/arm64: KVM: force alignment of VGIC dist/CPU/redist addresses

Quoted 93 lines · Andre Przywara

Although the GIC architecture requires us to map the MMIO regions only at page aligned addresses, we currently do not enforce this from the kernel side.
Restrict any vGICv2 regions to be 4K aligned and any GICv3 regions to be 64K aligned. Document this requirement.

---
Changelog:
(new in v7)

 Documentation/virtual/kvm/devices/arm-vgic.txt |    4 ++++
 virt/kvm/arm/vgic.c                            |   16 +++++++++++++---
 2 files changed, 17 insertions(+), 3 deletions(-)
Documentation/virtual/kvm/devices/arm-vgic.txt +4 -0
index 5d4fd4b..3fb9054 100644
@@ -20,20 +20,24 @@ Groups:
     KVM_VGIC_V2_ADDR_TYPE_DIST (rw, 64-bit)
       Base address in the guest physical address space of the GIC distributor
       register mappings. Only valid for KVM_DEV_TYPE_ARM_VGIC_V2.
+      This address needs to be 4K aligned and the region covers 4 KByte.
 
     KVM_VGIC_V2_ADDR_TYPE_CPU (rw, 64-bit)
       Base address in the guest physical address space of the GIC virtual cpu
       interface register mappings. Only valid for KVM_DEV_TYPE_ARM_VGIC_V2.
+      This address needs to be 4K aligned and the region covers 4 KByte.
 
     KVM_VGIC_V3_ADDR_TYPE_DIST (rw, 64-bit)
       Base address in the guest physical address space of the GICv3 distributor
       register mappings. Only valid for KVM_DEV_TYPE_ARM_VGIC_V3.
+      This address needs to be 64K aligned and the region covers 64 KByte.
 
     KVM_VGIC_V3_ADDR_TYPE_REDIST (rw, 64-bit)
       Base address in the guest physical address space of the GICv3
       redistributor register mappings. There are two 64K pages for each
       VCPU and all of the redistributor pages are contiguous.
       Only valid for KVM_DEV_TYPE_ARM_VGIC_V3.
+      This address needs to be 64K aligned.
 
 
   KVM_DEV_ARM_VGIC_GRP_DIST_REGS
virt/kvm/arm/vgic.c +7 -3
index 184c6db..0cc6ab6 100644
@@ -1683,6 +1683,7 @@ int kvm_vgic_addr(struct kvm *kvm, unsigned long type, u64 *addr, bool write)
 	struct vgic_dist *vgic = &kvm->arch.vgic;
 	int type_needed;
 	phys_addr_t *addr_ptr, block_size;
+	phys_addr_t alignment;
 
 	mutex_lock(&kvm->lock);
 	switch (type) {
@@ -1690,22 +1691,26 @@ int kvm_vgic_addr(struct kvm *kvm, unsigned long type, u64 *addr, bool write)
 		type_needed = KVM_DEV_TYPE_ARM_VGIC_V2;
 		addr_ptr = &vgic->vgic_dist_base;
 		block_size = KVM_VGIC_V2_DIST_SIZE;
+		alignment = SZ_4K;
 		break;
 	case KVM_VGIC_V2_ADDR_TYPE_CPU:
 		type_needed = KVM_DEV_TYPE_ARM_VGIC_V2;
 		addr_ptr = &vgic->vgic_cpu_base;
 		block_size = KVM_VGIC_V2_CPU_SIZE;
+		alignment = SZ_4K;
 		break;
 #ifdef CONFIG_ARM_GIC_V3
 	case KVM_VGIC_V3_ADDR_TYPE_DIST:
 		type_needed = KVM_DEV_TYPE_ARM_VGIC_V3;
 		addr_ptr = &vgic->vgic_dist_base;
 		block_size = KVM_VGIC_V3_DIST_SIZE;
+		alignment = SZ_64K;
 		break;
 	case KVM_VGIC_V3_ADDR_TYPE_REDIST:
 		type_needed = KVM_DEV_TYPE_ARM_VGIC_V3;
 		addr_ptr = &vgic->vgic_redist_base;
 		block_size = KVM_VGIC_V3_REDIST_SIZE;
+		alignment = SZ_64K;
 		break;
 #endif
 	default:
@@ -1718,10 +1723,15 @@ int kvm_vgic_addr(struct kvm *kvm, unsigned long type, u64 *addr, bool write)
 		goto out;
 	}
 
-	if (write)
-		r = vgic_ioaddr_assign(kvm, addr_ptr, *addr, block_size);
-	else
+	if (write) {
+		if (!IS_ALIGNED(*addr, alignment))

virt/kvm/arm/vgic.c int kvm_vgic_addr(struct kvm *kvm, unsigned long type, u64 *addr, bool write) · line 1737

Quoted 10 lines
virt/kvm/arm/vgic.c +6 -0
+			r = -EINVAL;
+		else
+			r = vgic_ioaddr_assign(kvm, addr_ptr, *addr,
+					       block_size);
+	} else {
 		*addr = *addr_ptr;
+	}
 
 out:
 	mutex_unlock(&kvm->lock);
#28 lore raw

v7 cover KVM GICv3 emulation

In reply to Andre Przywara

Hi,

Quoted 3 lines · Andre Przywara

This is version 7 of the GICv3 guest emulation series. As v6 this series is based on v3.19-rc3 plus Eric's explicit VGIC_CTRL_INIT patches.

I've been told that there is some confusion about the above feature with vGICv3 and I just saw that I didn't mention it in the cover letter:

The GICv3 emulation does not support automatic init as the vGICv2 does. One needs to explicitly use the brand new VGIC_CTRL_INIT KVM device ioctl to finalise the GICv3 initialisation.

Among the three places the automatic VGIC init was done before now two are in vgic-v2-emul.c and don't apply to a virtual GICv3. The remaining place is in kvm_vgic_inject_irq() in vgic.c, where I explicitly added a check to only work with a virtual GICv2.
Removing the explicit VGIC_CTRL_INIT from kvmtool resulted in the desired effect: the VGICv3 didn't initialise and kvmtool returned with an error.
If there should be a codepath left which allows auto-init of a virtual GICv3, this is a bug and I'd be grateful for a report.

Thanks,
Andre.

Quoted 124 lines

Most visible change is that the v6 patch 18/20 (introduce kvm_check_device_type()) is now gone, instead the validity check for the GICv2 emulation is now done internally via a new member of struct vgic_params (see new 18/20 for the implementation). There is new patch (20/20) that checks the userland provided memory regions's address for the VGIC to be properly aligned. Since that is build upon a refactoring in the series, I put it at the end. If this should be one of the first patches, let me know and I will rework that.

The rest of the changes are smaller things spotted by Christoffer (many thanks for the repeated, surely tiresome reviews!).

For a changelog summary see below, also each patch carries a changelog.
Only patches 02, 05, 08, 15, 18 and 19 had actual changes, 20/20 is new.

A git repo hosting all these patches lives in the kvm-gicv3/v7 branch of [1]. The kvm-gicv3/v6 branch has been updated to hold the delta patches.
-----

GICv3 is the ARM generic interrupt controller designed to overcome some limits of the prevalent GICv2. Most notably it lifts the 8-CPU limit. Though with Linux-3.17 Marc introduced support for hosts to use a GICv3, the CPU limitation still applies to KVM guests, since the current code emulates a GICv2 only.
Also, GICv2 backward compatibility being optional in GICv3, a number of systems won't be able to run GICv2 guests.

This patch series provides code to emulate a GICv3 distributor and redistributor for any KVM guest. It requires a GICv3 in the host to work. With those patches one can run guests efficiently on any GICv3 host. It has the following features:
- Affinity routing (support for up to 255 VCPUs, more possible)
- System registers (as opposed to MMIO access)
- No ITS
- No priority support (as the GICv2 emulation)
- No save / restore support so far (will be added soon)
- Only Group1 interrupts support

The first patches actually refactor the current VGIC code to make room for a different VGIC model to be dropped in with Patch 15. The remaining patches connect the new model to the kernel backend and the userland facing code.

The series goes on top of v3.19-rc3 plus Eric's init rework patches. The necessary patches for kvmtool to enable the guest's GICv3 have been posted here before [2], an updated version will follow soon.

There was some testing on the fast model with some I/O and interrupt affinity shuffling in a Linux guest with a varying number of VCPUs as well as some testing on a Juno board (GICv2 only, to spot regressions).

Please review and test.
I would be grateful for people to test for GICv2 regressions also (so on a GICv2 host with current kvmtool/qemu), as there is quite some refactoring on that front.

Much of the code was inspired by MarcZ, also kudos to him for doing the rather painful rebase on top of v3.17-rc1.

Cheers,
Andre.

[1] https://github.com/apritzel/linux.git
[2] https://lists.cs.columbia.edu/pipermail/kvmarm/2014-June/010086.html

Andre Przywara (20):
arm/arm64: KVM: rework MPIDR assignment and add accessors arm/arm64: KVM: pass down user space provided GIC type into vGIC code arm/arm64: KVM: refactor vgic_handle_mmio() function arm/arm64: KVM: wrap 64 bit MMIO accesses with two 32 bit ones arm/arm64: KVM: introduce per-VM ops
arm/arm64: KVM: move kvm_register_device_ops() into vGIC probing arm/arm64: KVM: dont rely on a valid GICH base address arm/arm64: KVM: make the maximum number of vCPUs a per-VM value arm/arm64: KVM: make the value of ICC_SRE_EL1 a per-VM variable arm/arm64: KVM: refactor MMIO accessors
arm/arm64: KVM: refactor/wrap vgic_set/get_attr() arm/arm64: KVM: add vgic.h header file
arm/arm64: KVM: split GICv2 specific emulation code from vgic.c arm/arm64: KVM: add opaque private pointer to MMIO data arm/arm64: KVM: add virtual GICv3 distributor emulation
arm64: GICv3: introduce symbolic names for GICv3 ICC_SGI1R_EL1 fields
arm64: KVM: add SGI generation register emulation arm/arm64: KVM: enable kernel side of GICv3 emulation arm/arm64: KVM: allow userland to request a virtual GICv3 arm/arm64: KVM: force alignment of VGIC dist/CPU/redist addresses

 Documentation/virtual/kvm/api.txt              |   13 +-
 Documentation/virtual/kvm/devices/arm-vgic.txt |   26 +-
 arch/arm/include/asm/kvm_emulate.h             |    5 +-
 arch/arm/include/asm/kvm_host.h                |    3 +
 arch/arm/include/asm/kvm_mmio.h                |    1 +
 arch/arm/kvm/Makefile                          |    1 +
 arch/arm/kvm/arm.c                             |   23 +-
 arch/arm/kvm/psci.c                            |   17 +-
 arch/arm64/include/asm/kvm_emulate.h           |    5 +-
 arch/arm64/include/asm/kvm_host.h              |    5 +
 arch/arm64/include/asm/kvm_mmio.h              |    1 +
 arch/arm64/include/uapi/asm/kvm.h              |    7 +
 arch/arm64/kernel/asm-offsets.c                |    1 +
 arch/arm64/kvm/Makefile                        |    2 +
 arch/arm64/kvm/sys_regs.c                      |   40 +-
 arch/arm64/kvm/vgic-v3-switch.S                |   14 +-
 drivers/irqchip/irq-gic-v3.c                   |   14 +-
 include/kvm/arm_vgic.h                         |   43 +-
 include/linux/irqchip/arm-gic-v3.h             |   44 +
 include/linux/kvm_host.h                       |    2 +
 include/uapi/linux/kvm.h                       |    2 +
 virt/kvm/arm/vgic-v2-emul.c                    |  847 ++++++++++++++++++
 virt/kvm/arm/vgic-v2.c                         |    4 +
 virt/kvm/arm/vgic-v3-emul.c                    | 1036 ++++++++++++++++++++++
 virt/kvm/arm/vgic-v3.c                         |   82 +-
 virt/kvm/arm/vgic.c                            | 1121 ++++++------------------
 virt/kvm/arm/vgic.h                            |  123 +++
 27 files changed, 2566 insertions(+), 916 deletions(-)
 create mode 100644 virt/kvm/arm/vgic-v2-emul.c
 create mode 100644 virt/kvm/arm/vgic-v3-emul.c
 create mode 100644 virt/kvm/arm/vgic.h
#29 lore raw

v7 cover KVM GICv3 emulation

Hi Andre,

Quoted 14 lines · Andre Przywara

Hi,

Quoted 3 lines · Andre Przywara

This is version 7 of the GICv3 guest emulation series. As v6 this series is based on v3.19-rc3 plus Eric's explicit VGIC_CTRL_INIT patches.

I've been told that there is some confusion about the above feature with vGICv3 and I just saw that I didn't mention it in the cover letter:

The GICv3 emulation does not support automatic init as the vGICv2 does. One needs to explicitly use the brand new VGIC_CTRL_INIT KVM device ioctl to finalise the GICv3 initialisation.

Quoted 10 lines

Among the three places the automatic VGIC init was done before now two are in vgic-v2-emul.c and don't apply to a virtual GICv3. The remaining place is in kvm_vgic_inject_irq() in vgic.c, where I explicitly added a check to only work with a virtual GICv2.
Removing the explicit VGIC_CTRL_INIT from kvmtool resulted in the desired effect: the VGICv3 didn't initialise and kvmtool returned with an error.
If there should be a codepath left which allows auto-init of a virtual GICv3, this is a bug and I'd be grateful for a report.

No, I didn't realize when reading the patch for this specific issue that the set_attr code path was moved to the gicv2 specific files.

I think you nailed it, so we should be all good.

Will queue this once I get a chance to do a shallow test for regressions.

Thanks,
-Christoffer