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ARM: KVM: guest_didnt_mean_it()

PATCH In review Rusty Russell 1 participant 1 message Mar 9, 2012 Arm (32-bit)

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Rusty Russell

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PATCH 7/8 ARM: KVM: guest_didnt_mean_it()

From: Rusty Russell <[email protected]>

Conditional instructions may trap even if the condition isn't true, so a good hypervisor will check this. The same can happen with undefined instructions, so the kernel should be doing this dance already (it isn't).

(See p1206 of ARMv7-A ARM)

Signed-off-by Rusty Russell <[email protected]>
---
 arch/arm/include/asm/kvm_arm.h     |    4 +++
 arch/arm/include/asm/kvm_emulate.h |    2 +
 arch/arm/kvm/Makefile              |    2 +
 arch/arm/kvm/arm.c                 |    3 ++
 arch/arm/kvm/emulate.c             |   41 +++++++++++++++++++++++++++
 arch/arm/kvm/kvm_cond_match.S      |   54 ++++++++++++++++++++++++++++++++++++
 6 files changed, 105 insertions(+), 1 deletions(-)
 create mode 100644 arch/arm/kvm/kvm_cond_match.S
arch/arm/include/asm/kvm_arm.h +4 -0
index 1769187..156284a 100644
@@ -107,6 +107,10 @@
 #define HSR_ISS		(HSR_IL - 1)
 #define HSR_ISV_SHIFT	(24)
 #define HSR_ISV		(1U << HSR_ISV_SHIFT)
+#define HSR_CV_SHIFT	(24)
+#define HSR_CV		(1U << HSR_CV_SHIFT)
+#define HSR_COND_SHIFT	(20)
+#define HSR_COND	(0xfU << HSR_COND_SHIFT)
 
 #define HSR_EC_UNKNOWN	(0x00)
 #define HSR_EC_WFI	(0x01)
arch/arm/include/asm/kvm_emulate.h +2 -0
index fa54247..fe21e86 100644
@@ -49,6 +49,8 @@ int kvm_handle_cp15_64(struct kvm_vcpu *vcpu, struct kvm_run *run);
 int kvm_handle_wfi(struct kvm_vcpu *vcpu, struct kvm_run *run);
 int kvm_emulate_mmio_ls(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa,
 			unsigned long instr);
+bool kvm_should_not_have_trapped(struct kvm_vcpu *vcpu);
+bool kvm_cond_match(u32 flags, u32 cond);
 
 /*
  * Return the SPSR for the specified mode of the virtual CPU.
arch/arm/kvm/Makefile +1 -1
index e69a8e1..68f05b9 100644
@@ -12,6 +12,6 @@ obj-$(CONFIG_KVM_ARM_HOST) += init.o interrupts.o exports.o
 
 kvm-arm-y += $(addprefix ../../../virt/kvm/, kvm_main.o coalesced_mmio.o)
 
-kvm-arm-y += arm.o guest.o mmu.o emulate.o
+kvm-arm-y += arm.o guest.o mmu.o emulate.o kvm_cond_match.o
 
 obj-$(CONFIG_KVM) += kvm-arm.o
arch/arm/kvm/arm.c +3 -0
index a6cf02b..1724657 100644
@@ -414,6 +414,9 @@ static inline int handle_exit(struct kvm_vcpu *vcpu, struct kvm_run *run,
 		BUG();
 	}
 
+	if (kvm_should_not_have_trapped(vcpu))
+		return 0;
+
 	return arm_exit_handlers[hsr_ec](vcpu, run);
 }
arch/arm/kvm/emulate.c +41 -0

44 lines not on this page · raw message

arch/arm/kvm/kvm_cond_match.S new file +54 -0

54 lines not on this page · raw message