KVM/arm64: VM configuration enforcement

---
 arch/arm64/tools/sysreg | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

arch/arm64/tools/sysreg +7 -1

index fa3fe0856880..53daaaef46cb 100644
@@ -1366,6 +1366,7 @@ EndEnum
 UnsignedEnum	43:40	SPECRES
 	0b0000	NI
 	0b0001	IMP
+	0b0010	COSP_RCTX
 EndEnum
 UnsignedEnum	39:36	SB
 	0b0000	NI

@@ -1492,7 +1493,12 @@ EndEnum
 EndSysreg
 
 Sysreg	ID_AA64ISAR3_EL1	3	0	0	6	3
-Res0	63:12
+Res0	63:16
+UnsignedEnum	15:12	PACM
+	0b0000	NI
+	0b0001	TRIVIAL_IMP
+	0b0010	FULL_IMP
+EndEnum
 UnsignedEnum	11:8	TLBIW
 	0b0000	NI
 	0b0001	IMP

Signature · 1 line

2.39.2

Catalin Marinas

maintainer Acked-by on v4 1/26

2024-02-15 18:06 UTC #2 lore raw

Re: [PATCH v4 01/26] arm64: sysreg: Add missing ID_AA64ISAR[13]_EL1 fields and variants

Quoted 7 lines · Marc Zyngier

Despite having the control bits for FEAT_SPECRES and FEAT_PACM, the ID registers fields are either incomplete or missing.
Fix it.
Reviewed-by Mark Brown <[email protected]>
Signed-off-by Marc Zyngier <[email protected]>

In case you need another ack on this patch:

Acked-by Catalin Marinas <[email protected]>

Marc Zyngier

author maintainer

2024-02-14 13:18 UTC #3 lore raw

PATCH v4 2/26 KVM: arm64: Add feature checking helpers

In order to make it easier to check whether a particular feature is exposed to a guest, add a new set of helpers, with kvm_has_feat() being the most useful.

Let's start making use of them in the PMU code (courtesy of Oliver). Follow-up changes will introduce additional use patterns.

Reviewed-by Suzuki K Poulose <[email protected]>

Co-developed--by Oliver Upton <[email protected]>

Signed-off-by Oliver Upton <[email protected]>

---
 arch/arm64/include/asm/kvm_host.h | 44 +++++++++++++++++++++++++++++++
 arch/arm64/kvm/pmu-emul.c         | 11 ++++----
 arch/arm64/kvm/sys_regs.c         |  6 ++---
 include/kvm/arm_pmu.h             | 11 --------
 4 files changed, 52 insertions(+), 20 deletions(-)

arch/arm64/include/asm/kvm_host.h +44 -0

index 21c57b812569..527da3d2cedb 100644
@@ -1233,4 +1233,48 @@ static inline void kvm_hyp_reserve(void) { }
 void kvm_arm_vcpu_power_off(struct kvm_vcpu *vcpu);
 bool kvm_arm_vcpu_stopped(struct kvm_vcpu *vcpu);
 
+#define __expand_field_sign_unsigned(id, fld, val)			\
+	((u64)SYS_FIELD_VALUE(id, fld, val))
+
+#define __expand_field_sign_signed(id, fld, val)			\
+	({								\
+		u64 __val = SYS_FIELD_VALUE(id, fld, val);		\
+		sign_extend64(__val, id##_##fld##_WIDTH - 1);		\
+	})
+
+#define expand_field_sign(id, fld, val)					\
+	(id##_##fld##_SIGNED ?						\
+	 __expand_field_sign_signed(id, fld, val) :			\
+	 __expand_field_sign_unsigned(id, fld, val))
+
+#define get_idreg_field_unsigned(kvm, id, fld)				\
+	({								\
+		u64 __val = IDREG((kvm), SYS_##id);			\
+		FIELD_GET(id##_##fld##_MASK, __val);			\
+	})
+
+#define get_idreg_field_signed(kvm, id, fld)				\
+	({								\
+		u64 __val = get_idreg_field_unsigned(kvm, id, fld);	\
+		sign_extend64(__val, id##_##fld##_WIDTH - 1);		\
+	})
+
+#define get_idreg_field_enum(kvm, id, fld)				\
+	get_idreg_field_unsigned(kvm, id, fld)
+
+#define get_idreg_field(kvm, id, fld)					\
+	(id##_##fld##_SIGNED ?						\
+	 get_idreg_field_signed(kvm, id, fld) :				\
+	 get_idreg_field_unsigned(kvm, id, fld))
+
+#define kvm_has_feat(kvm, id, fld, limit)				\
+	(get_idreg_field((kvm), id, fld) >= expand_field_sign(id, fld, limit))
+
+#define kvm_has_feat_enum(kvm, id, fld, val)				\
+	(get_idreg_field_unsigned((kvm), id, fld) == __expand_field_sign_unsigned(id, fld, val))
+
+#define kvm_has_feat_range(kvm, id, fld, min, max)			\
+	(get_idreg_field((kvm), id, fld) >= expand_field_sign(id, fld, min) && \
+	 get_idreg_field((kvm), id, fld) <= expand_field_sign(id, fld, max))
+
 #endif /* __ARM64_KVM_HOST_H__ */

arch/arm64/kvm/pmu-emul.c +6 -5

index 3d9467ff73bc..925522470b2b 100644
@@ -64,12 +64,11 @@ u64 kvm_pmu_evtyper_mask(struct kvm *kvm)
 {
 	u64 mask = ARMV8_PMU_EXCLUDE_EL1 | ARMV8_PMU_EXCLUDE_EL0 |
 		   kvm_pmu_event_mask(kvm);
-	u64 pfr0 = IDREG(kvm, SYS_ID_AA64PFR0_EL1);
 
-	if (SYS_FIELD_GET(ID_AA64PFR0_EL1, EL2, pfr0))
+	if (kvm_has_feat(kvm, ID_AA64PFR0_EL1, EL2, IMP))
 		mask |= ARMV8_PMU_INCLUDE_EL2;
 
-	if (SYS_FIELD_GET(ID_AA64PFR0_EL1, EL3, pfr0))
+	if (kvm_has_feat(kvm, ID_AA64PFR0_EL1, EL3, IMP))
 		mask |= ARMV8_PMU_EXCLUDE_NS_EL0 |
 			ARMV8_PMU_EXCLUDE_NS_EL1 |
 			ARMV8_PMU_EXCLUDE_EL3;

@@ -83,8 +82,10 @@ u64 kvm_pmu_evtyper_mask(struct kvm *kvm)
  */
 static bool kvm_pmc_is_64bit(struct kvm_pmc *pmc)
 {
+	struct kvm_vcpu *vcpu = kvm_pmc_to_vcpu(pmc);
+
 	return (pmc->idx == ARMV8_PMU_CYCLE_IDX ||
-		kvm_pmu_is_3p5(kvm_pmc_to_vcpu(pmc)));
+		kvm_has_feat(vcpu->kvm, ID_AA64DFR0_EL1, PMUVer, V3P5));
 }
 
 static bool kvm_pmc_has_64bit_overflow(struct kvm_pmc *pmc)

@@ -556,7 +557,7 @@ void kvm_pmu_handle_pmcr(struct kvm_vcpu *vcpu, u64 val)
 		return;
 
 	/* Fixup PMCR_EL0 to reconcile the PMU version and the LP bit */
-	if (!kvm_pmu_is_3p5(vcpu))
+	if (!kvm_has_feat(vcpu->kvm, ID_AA64DFR0_EL1, PMUVer, V3P5))
 		val &= ~ARMV8_PMU_PMCR_LP;
 
 	/* The reset bits don't indicate any state, and shouldn't be saved. */

arch/arm64/kvm/sys_regs.c +2 -4

index 041b11825578..3c31f8cb9eef 100644
@@ -505,10 +505,9 @@ static bool trap_loregion(struct kvm_vcpu *vcpu,
 			  struct sys_reg_params *p,
 			  const struct sys_reg_desc *r)
 {
-	u64 val = IDREG(vcpu->kvm, SYS_ID_AA64MMFR1_EL1);
 	u32 sr = reg_to_encoding(r);
 
-	if (!(val & (0xfUL << ID_AA64MMFR1_EL1_LO_SHIFT))) {
+	if (!kvm_has_feat(vcpu->kvm, ID_AA64MMFR1_EL1, LO, IMP)) {
 		kvm_inject_undefined(vcpu);
 		return false;
 	}

@@ -2748,8 +2747,7 @@ static bool trap_dbgdidr(struct kvm_vcpu *vcpu,
 		return ignore_write(vcpu, p);
 	} else {
 		u64 dfr = IDREG(vcpu->kvm, SYS_ID_AA64DFR0_EL1);
-		u64 pfr = IDREG(vcpu->kvm, SYS_ID_AA64PFR0_EL1);
-		u32 el3 = !!SYS_FIELD_GET(ID_AA64PFR0_EL1, EL3, pfr);
+		u32 el3 = kvm_has_feat(vcpu->kvm, ID_AA64PFR0_EL1, EL3, IMP);
 
 		p->regval = ((SYS_FIELD_GET(ID_AA64DFR0_EL1, WRPs, dfr) << 28) |
 			     (SYS_FIELD_GET(ID_AA64DFR0_EL1, BRPs, dfr) << 24) |

include/kvm/arm_pmu.h +0 ~~-11~~

index 4b9d8fb393a8..eb4c369a79eb 100644
@@ -90,16 +90,6 @@ void kvm_vcpu_pmu_resync_el0(void);
 			vcpu->arch.pmu.events = *kvm_get_pmu_events();	\
 	} while (0)
 
-/*
- * Evaluates as true when emulating PMUv3p5, and false otherwise.
- */
-#define kvm_pmu_is_3p5(vcpu) ({						\
-	u64 val = IDREG(vcpu->kvm, SYS_ID_AA64DFR0_EL1);		\
-	u8 pmuver = SYS_FIELD_GET(ID_AA64DFR0_EL1, PMUVer, val);	\
-									\
-	pmuver >= ID_AA64DFR0_EL1_PMUVer_V3P5;				\
-})
-
 u8 kvm_arm_pmu_get_pmuver_limit(void);
 u64 kvm_pmu_evtyper_mask(struct kvm *kvm);
 int kvm_arm_set_default_pmu(struct kvm *kvm);

@@ -168,7 +158,6 @@ static inline u64 kvm_pmu_get_pmceid(struct kvm_vcpu *vcpu, bool pmceid1)
 }
 
 #define kvm_vcpu_has_pmu(vcpu)		({ false; })
-#define kvm_pmu_is_3p5(vcpu)		({ false; })
 static inline void kvm_pmu_update_vcpu_events(struct kvm_vcpu *vcpu) {}
 static inline void kvm_vcpu_pmu_restore_guest(struct kvm_vcpu *vcpu) {}
 static inline void kvm_vcpu_pmu_restore_host(struct kvm_vcpu *vcpu) {}

Signature · 1 line

2.39.2

Marc Zyngier

author maintainer

2024-02-14 13:18 UTC #4 lore raw

PATCH v4 3/26 KVM: arm64: nv: Add sanitising to VNCR-backed sysregs

VNCR-backed "registers" are actually only memory. Which means that there is zero control over what the guest can write, and that it is the hypervisor's job to actually sanitise the content of the backing store. Yeah, this is fun.

In order to preserve some form of sanity, add a repainting mechanism that makes use of a per-VM set of RES0/RES1 masks, one pair per VNCR register. These masks get applied on access to the backing store via __vcpu_sys_reg(), ensuring that the state that is consumed by KVM is correct.

So far, nothing populates these masks, but stay tuned.

---
 arch/arm64/include/asm/kvm_host.h | 22 ++++++++++++++++-
 arch/arm64/kvm/arm.c              |  1 +
 arch/arm64/kvm/nested.c           | 41 ++++++++++++++++++++++++++++++-
 3 files changed, 62 insertions(+), 2 deletions(-)

arch/arm64/include/asm/kvm_host.h +21 -1

index 527da3d2cedb..8cda003d6267 100644
@@ -238,6 +238,8 @@ static inline u16 kvm_mpidr_index(struct kvm_mpidr_data *data, u64 mpidr)
 	return index;
 }
 
+struct kvm_sysreg_masks;
+
 struct kvm_arch {
 	struct kvm_s2_mmu mmu;

@@ -312,6 +314,9 @@ struct kvm_arch {
 #define KVM_ARM_ID_REG_NUM	(IDREG_IDX(sys_reg(3, 0, 0, 7, 7)) + 1)
 	u64 id_regs[KVM_ARM_ID_REG_NUM];
 
+	/* Masks for VNCR-baked sysregs */
+	struct kvm_sysreg_masks	*sysreg_masks;
+
 	/*
 	 * For an untrusted host VM, 'pkvm.handle' is used to lookup
 	 * the associated pKVM instance in the hypervisor.

@@ -474,6 +479,13 @@ enum vcpu_sysreg {
 	NR_SYS_REGS	/* Nothing after this line! */
 };
 
+struct kvm_sysreg_masks {
+	struct {
+		u64	res0;
+		u64	res1;
+	} mask[NR_SYS_REGS - __VNCR_START__];
+};
+
 struct kvm_cpu_context {
 	struct user_pt_regs regs;	/* sp = sp_el0 */

@@ -868,7 +880,15 @@ static inline u64 *__ctxt_sys_reg(const struct kvm_cpu_context *ctxt, int r)
 
 #define ctxt_sys_reg(c,r)	(*__ctxt_sys_reg(c,r))
 
-#define __vcpu_sys_reg(v,r)	(ctxt_sys_reg(&(v)->arch.ctxt, (r)))
+u64 kvm_vcpu_sanitise_vncr_reg(const struct kvm_vcpu *, enum vcpu_sysreg);
+#define __vcpu_sys_reg(v,r)						\
+	(*({								\
+		const struct kvm_cpu_context *ctxt = &(v)->arch.ctxt;	\
+		u64 *__r = __ctxt_sys_reg(ctxt, (r));			\
+		if (vcpu_has_nv((v)) && (r) >= __VNCR_START__)		\
+			*__r = kvm_vcpu_sanitise_vncr_reg((v), (r));	\
+		__r;							\
+	}))
 
 u64 vcpu_read_sys_reg(const struct kvm_vcpu *vcpu, int reg);
 void vcpu_write_sys_reg(struct kvm_vcpu *vcpu, u64 val, int reg);

arch/arm64/kvm/arm.c +1 -0

index a25265aca432..c063e84fc72c 100644
@@ -206,6 +206,7 @@ void kvm_arch_destroy_vm(struct kvm *kvm)
 		pkvm_destroy_hyp_vm(kvm);
 
 	kfree(kvm->arch.mpidr_data);
+	kfree(kvm->arch.sysreg_masks);
 	kvm_destroy_vcpus(kvm);
 
 	kvm_unshare_hyp(kvm, kvm + 1);

arch/arm64/kvm/nested.c +40 -1

55 lines not on this page · raw message

Signature · 1 line

2.39.2

Marc Zyngier

author maintainer

2024-02-14 13:18 UTC #5 lore raw

PATCH v4 4/26 KVM: arm64: nv: Add sanitising to EL2 configuration registers

We can now start making use of our sanitising masks by setting them to values that depend on the guest's configuration.

First up are VTTBR_EL2, VTCR_EL2, VMPIDR_EL2 and HCR_EL2.

---
 arch/arm64/kvm/nested.c | 58 ++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 57 insertions(+), 1 deletion(-)

arch/arm64/kvm/nested.c +57 -1

index c976cd4b8379..29ed529681e2 100644
@@ -181,7 +181,7 @@ u64 kvm_vcpu_sanitise_vncr_reg(const struct kvm_vcpu *vcpu, enum vcpu_sysreg sr)
 	return v;
 }
 
-static void __maybe_unused set_sysreg_masks(struct kvm *kvm, int sr, u64 res0, u64 res1)
+static void set_sysreg_masks(struct kvm *kvm, int sr, u64 res0, u64 res1)
 {
 	int i = sr - __VNCR_START__;

@@ -191,6 +191,7 @@ static void __maybe_unused set_sysreg_masks(struct kvm *kvm, int sr, u64 res0, u
 
 int kvm_init_nv_sysregs(struct kvm *kvm)
 {
+	u64 res0, res1;
 	int ret = 0;
 
 	mutex_lock(&kvm->arch.config_lock);

@@ -209,6 +210,61 @@ int kvm_init_nv_sysregs(struct kvm *kvm)
 		kvm->arch.id_regs[i] = limit_nv_id_reg(IDX_IDREG(i),
 						       kvm->arch.id_regs[i]);
 
+	/* VTTBR_EL2 */
+	res0 = res1 = 0;
+	if (!kvm_has_feat_enum(kvm, ID_AA64MMFR1_EL1, VMIDBits, 16))
+		res0 |= GENMASK(63, 56);
+	if (!kvm_has_feat(kvm, ID_AA64MMFR2_EL1, CnP, IMP))
+		res0 |= VTTBR_CNP_BIT;
+	set_sysreg_masks(kvm, VTTBR_EL2, res0, res1);
+
+	/* VTCR_EL2 */
+	res0 = GENMASK(63, 32) | GENMASK(30, 20);
+	res1 = BIT(31);
+	set_sysreg_masks(kvm, VTCR_EL2, res0, res1);
+
+	/* VMPIDR_EL2 */
+	res0 = GENMASK(63, 40) | GENMASK(30, 24);
+	res1 = BIT(31);
+	set_sysreg_masks(kvm, VMPIDR_EL2, res0, res1);
+
+	/* HCR_EL2 */
+	res0 = BIT(48);
+	res1 = HCR_RW;
+	if (!kvm_has_feat(kvm, ID_AA64MMFR1_EL1, TWED, IMP))
+		res0 |= GENMASK(63, 59);
+	if (!kvm_has_feat(kvm, ID_AA64PFR1_EL1, MTE, MTE2))
+		res0 |= (HCR_TID5 | HCR_DCT | HCR_ATA);
+	if (!kvm_has_feat(kvm, ID_AA64MMFR2_EL1, EVT, TTLBxS))
+		res0 |= (HCR_TTLBIS | HCR_TTLBOS);
+	if (!kvm_has_feat(kvm, ID_AA64PFR0_EL1, CSV2, CSV2_2) &&
+	    !kvm_has_feat(kvm, ID_AA64PFR1_EL1, CSV2_frac, CSV2_1p2))
+		res0 |= HCR_ENSCXT;
+	if (!kvm_has_feat(kvm, ID_AA64MMFR2_EL1, EVT, IMP))
+		res0 |= (HCR_TOCU | HCR_TICAB | HCR_TID4);
+	if (!kvm_has_feat(kvm, ID_AA64PFR0_EL1, AMU, V1P1))
+		res0 |= HCR_AMVOFFEN;
+	if (!kvm_has_feat(kvm, ID_AA64PFR0_EL1, RAS, V1P1))
+		res0 |= HCR_FIEN;
+	if (!kvm_has_feat(kvm, ID_AA64MMFR2_EL1, FWB, IMP))
+		res0 |= HCR_FWB;
+	if (!kvm_has_feat(kvm, ID_AA64MMFR2_EL1, NV, NV2))
+		res0 |= HCR_NV2;
+	if (!kvm_has_feat(kvm, ID_AA64MMFR2_EL1, NV, IMP))
+		res0 |= (HCR_AT | HCR_NV1 | HCR_NV);
+	if (!(__vcpu_has_feature(&kvm->arch, KVM_ARM_VCPU_PTRAUTH_ADDRESS) &&
+	      __vcpu_has_feature(&kvm->arch, KVM_ARM_VCPU_PTRAUTH_GENERIC)))
+		res0 |= (HCR_API | HCR_APK);
+	if (!kvm_has_feat(kvm, ID_AA64ISAR0_EL1, TME, IMP))
+		res0 |= BIT(39);
+	if (!kvm_has_feat(kvm, ID_AA64PFR0_EL1, RAS, IMP))
+		res0 |= (HCR_TEA | HCR_TERR);
+	if (!kvm_has_feat(kvm, ID_AA64MMFR1_EL1, LO, IMP))
+		res0 |= HCR_TLOR;
+	if (!kvm_has_feat(kvm, ID_AA64MMFR4_EL1, E2H0, IMP))
+		res1 |= HCR_E2H;
+	set_sysreg_masks(kvm, HCR_EL2, res0, res1);
+
 out:
 	mutex_unlock(&kvm->arch.config_lock);

Signature · 1 line

2.39.2

Marc Zyngier

author maintainer

2024-02-14 13:18 UTC #6 lore raw

PATCH v4 5/26 KVM: arm64: nv: Add sanitising to VNCR-backed FGT sysregs

Fine Grained Traps are controlled by a whole bunch of features. Each one of them must be checked and the corresponding masks computed so that we don't let the guest apply traps it shouldn't be using.

This takes care of HFG[IRW]TR_EL2, HDFG[RW]TR_EL2, and HAFGRTR_EL2.

---
 arch/arm64/kvm/nested.c | 128 ++++++++++++++++++++++++++++++++++++++++
 1 file changed, 128 insertions(+)

arch/arm64/kvm/nested.c +128 -0

index 29ed529681e2..eda05eb16c0a 100644
@@ -265,6 +265,134 @@ int kvm_init_nv_sysregs(struct kvm *kvm)
 		res1 |= HCR_E2H;
 	set_sysreg_masks(kvm, HCR_EL2, res0, res1);
 
+	/* HFG[RW]TR_EL2 */
+	res0 = res1 = 0;
+	if (!(__vcpu_has_feature(&kvm->arch, KVM_ARM_VCPU_PTRAUTH_ADDRESS) &&
+	      __vcpu_has_feature(&kvm->arch, KVM_ARM_VCPU_PTRAUTH_GENERIC)))
+		res0 |= (HFGxTR_EL2_APDAKey | HFGxTR_EL2_APDBKey |
+			 HFGxTR_EL2_APGAKey | HFGxTR_EL2_APIAKey |
+			 HFGxTR_EL2_APIBKey);
+	if (!kvm_has_feat(kvm, ID_AA64MMFR1_EL1, LO, IMP))
+		res0 |= (HFGxTR_EL2_LORC_EL1 | HFGxTR_EL2_LOREA_EL1 |
+			 HFGxTR_EL2_LORID_EL1 | HFGxTR_EL2_LORN_EL1 |
+			 HFGxTR_EL2_LORSA_EL1);
+	if (!kvm_has_feat(kvm, ID_AA64PFR0_EL1, CSV2, CSV2_2) &&
+	    !kvm_has_feat(kvm, ID_AA64PFR1_EL1, CSV2_frac, CSV2_1p2))
+		res0 |= (HFGxTR_EL2_SCXTNUM_EL1 | HFGxTR_EL2_SCXTNUM_EL0);
+	if (!kvm_has_feat(kvm, ID_AA64PFR0_EL1, GIC, IMP))
+		res0 |= HFGxTR_EL2_ICC_IGRPENn_EL1;
+	if (!kvm_has_feat(kvm, ID_AA64PFR0_EL1, RAS, IMP))
+		res0 |= (HFGxTR_EL2_ERRIDR_EL1 | HFGxTR_EL2_ERRSELR_EL1 |
+			 HFGxTR_EL2_ERXFR_EL1 | HFGxTR_EL2_ERXCTLR_EL1 |
+			 HFGxTR_EL2_ERXSTATUS_EL1 | HFGxTR_EL2_ERXMISCn_EL1 |
+			 HFGxTR_EL2_ERXPFGF_EL1 | HFGxTR_EL2_ERXPFGCTL_EL1 |
+			 HFGxTR_EL2_ERXPFGCDN_EL1 | HFGxTR_EL2_ERXADDR_EL1);
+	if (!kvm_has_feat(kvm, ID_AA64ISAR1_EL1, LS64, LS64_ACCDATA))
+		res0 |= HFGxTR_EL2_nACCDATA_EL1;
+	if (!kvm_has_feat(kvm, ID_AA64PFR1_EL1, GCS, IMP))
+		res0 |= (HFGxTR_EL2_nGCS_EL0 | HFGxTR_EL2_nGCS_EL1);
+	if (!kvm_has_feat(kvm, ID_AA64PFR1_EL1, SME, IMP))
+		res0 |= (HFGxTR_EL2_nSMPRI_EL1 | HFGxTR_EL2_nTPIDR2_EL0);
+	if (!kvm_has_feat(kvm, ID_AA64PFR1_EL1, THE, IMP))
+		res0 |= HFGxTR_EL2_nRCWMASK_EL1;
+	if (!kvm_has_feat(kvm, ID_AA64MMFR3_EL1, S1PIE, IMP))
+		res0 |= (HFGxTR_EL2_nPIRE0_EL1 | HFGxTR_EL2_nPIR_EL1);
+	if (!kvm_has_feat(kvm, ID_AA64MMFR3_EL1, S1POE, IMP))
+		res0 |= (HFGxTR_EL2_nPOR_EL0 | HFGxTR_EL2_nPOR_EL1);
+	if (!kvm_has_feat(kvm, ID_AA64MMFR3_EL1, S2POE, IMP))
+		res0 |= HFGxTR_EL2_nS2POR_EL1;
+	if (!kvm_has_feat(kvm, ID_AA64MMFR3_EL1, AIE, IMP))
+		res0 |= (HFGxTR_EL2_nMAIR2_EL1 | HFGxTR_EL2_nAMAIR2_EL1);
+	set_sysreg_masks(kvm, HFGRTR_EL2, res0 | __HFGRTR_EL2_RES0, res1);
+	set_sysreg_masks(kvm, HFGWTR_EL2, res0 | __HFGWTR_EL2_RES0, res1);
+
+	/* HDFG[RW]TR_EL2 */
+	res0 = res1 = 0;
+	if (!kvm_has_feat(kvm, ID_AA64DFR0_EL1, DoubleLock, IMP))
+		res0 |= HDFGRTR_EL2_OSDLR_EL1;
+	if (!kvm_has_feat(kvm, ID_AA64DFR0_EL1, PMUVer, IMP))
+		res0 |= (HDFGRTR_EL2_PMEVCNTRn_EL0 | HDFGRTR_EL2_PMEVTYPERn_EL0 |
+			 HDFGRTR_EL2_PMCCFILTR_EL0 | HDFGRTR_EL2_PMCCNTR_EL0 |
+			 HDFGRTR_EL2_PMCNTEN | HDFGRTR_EL2_PMINTEN |
+			 HDFGRTR_EL2_PMOVS | HDFGRTR_EL2_PMSELR_EL0 |
+			 HDFGRTR_EL2_PMMIR_EL1 | HDFGRTR_EL2_PMUSERENR_EL0 |
+			 HDFGRTR_EL2_PMCEIDn_EL0);
+	if (!kvm_has_feat(kvm, ID_AA64DFR0_EL1, PMSVer, IMP))
+		res0 |= (HDFGRTR_EL2_PMBLIMITR_EL1 | HDFGRTR_EL2_PMBPTR_EL1 |
+			 HDFGRTR_EL2_PMBSR_EL1 | HDFGRTR_EL2_PMSCR_EL1 |
+			 HDFGRTR_EL2_PMSEVFR_EL1 | HDFGRTR_EL2_PMSFCR_EL1 |
+			 HDFGRTR_EL2_PMSICR_EL1 | HDFGRTR_EL2_PMSIDR_EL1 |
+			 HDFGRTR_EL2_PMSIRR_EL1 | HDFGRTR_EL2_PMSLATFR_EL1 |
+			 HDFGRTR_EL2_PMBIDR_EL1);
+	if (!kvm_has_feat(kvm, ID_AA64DFR0_EL1, TraceVer, IMP))
+		res0 |= (HDFGRTR_EL2_TRC | HDFGRTR_EL2_TRCAUTHSTATUS |
+			 HDFGRTR_EL2_TRCAUXCTLR | HDFGRTR_EL2_TRCCLAIM |
+			 HDFGRTR_EL2_TRCCNTVRn | HDFGRTR_EL2_TRCID |
+			 HDFGRTR_EL2_TRCIMSPECn | HDFGRTR_EL2_TRCOSLSR |
+			 HDFGRTR_EL2_TRCPRGCTLR | HDFGRTR_EL2_TRCSEQSTR |
+			 HDFGRTR_EL2_TRCSSCSRn | HDFGRTR_EL2_TRCSTATR |
+			 HDFGRTR_EL2_TRCVICTLR);
+	if (!kvm_has_feat(kvm, ID_AA64DFR0_EL1, TraceBuffer, IMP))
+		res0 |= (HDFGRTR_EL2_TRBBASER_EL1 | HDFGRTR_EL2_TRBIDR_EL1 |
+			 HDFGRTR_EL2_TRBLIMITR_EL1 | HDFGRTR_EL2_TRBMAR_EL1 |
+			 HDFGRTR_EL2_TRBPTR_EL1 | HDFGRTR_EL2_TRBSR_EL1 |
+			 HDFGRTR_EL2_TRBTRG_EL1);
+	if (!kvm_has_feat(kvm, ID_AA64DFR0_EL1, BRBE, IMP))
+		res0 |= (HDFGRTR_EL2_nBRBIDR | HDFGRTR_EL2_nBRBCTL |
+			 HDFGRTR_EL2_nBRBDATA);
+	if (!kvm_has_feat(kvm, ID_AA64DFR0_EL1, PMSVer, V1P2))
+		res0 |= HDFGRTR_EL2_nPMSNEVFR_EL1;
+	set_sysreg_masks(kvm, HDFGRTR_EL2, res0 | HDFGRTR_EL2_RES0, res1);
+
+	/* Reuse the bits from the read-side and add the write-specific stuff */
+	if (!kvm_has_feat(kvm, ID_AA64DFR0_EL1, PMUVer, IMP))
+		res0 |= (HDFGWTR_EL2_PMCR_EL0 | HDFGWTR_EL2_PMSWINC_EL0);
+	if (!kvm_has_feat(kvm, ID_AA64DFR0_EL1, TraceVer, IMP))
+		res0 |= HDFGWTR_EL2_TRCOSLAR;
+	if (!kvm_has_feat(kvm, ID_AA64DFR0_EL1, TraceFilt, IMP))
+		res0 |= HDFGWTR_EL2_TRFCR_EL1;
+	set_sysreg_masks(kvm, HFGWTR_EL2, res0 | HDFGWTR_EL2_RES0, res1);
+
+	/* HFGITR_EL2 */
+	res0 = HFGITR_EL2_RES0;
+	res1 = HFGITR_EL2_RES1;
+	if (!kvm_has_feat(kvm, ID_AA64ISAR1_EL1, DPB, DPB2))
+		res0 |= HFGITR_EL2_DCCVADP;
+	if (!kvm_has_feat(kvm, ID_AA64MMFR1_EL1, PAN, PAN2))
+		res0 |= (HFGITR_EL2_ATS1E1RP | HFGITR_EL2_ATS1E1WP);
+	if (!kvm_has_feat(kvm, ID_AA64ISAR0_EL1, TLB, OS))
+		res0 |= (HFGITR_EL2_TLBIRVAALE1OS | HFGITR_EL2_TLBIRVALE1OS |
+			 HFGITR_EL2_TLBIRVAAE1OS | HFGITR_EL2_TLBIRVAE1OS |
+			 HFGITR_EL2_TLBIVAALE1OS | HFGITR_EL2_TLBIVALE1OS |
+			 HFGITR_EL2_TLBIVAAE1OS | HFGITR_EL2_TLBIASIDE1OS |
+			 HFGITR_EL2_TLBIVAE1OS | HFGITR_EL2_TLBIVMALLE1OS);
+	if (!kvm_has_feat(kvm, ID_AA64ISAR0_EL1, TLB, RANGE))
+		res0 |= (HFGITR_EL2_TLBIRVAALE1 | HFGITR_EL2_TLBIRVALE1 |
+			 HFGITR_EL2_TLBIRVAAE1 | HFGITR_EL2_TLBIRVAE1 |
+			 HFGITR_EL2_TLBIRVAALE1IS | HFGITR_EL2_TLBIRVALE1IS |
+			 HFGITR_EL2_TLBIRVAAE1IS | HFGITR_EL2_TLBIRVAE1IS |
+			 HFGITR_EL2_TLBIRVAALE1OS | HFGITR_EL2_TLBIRVALE1OS |
+			 HFGITR_EL2_TLBIRVAAE1OS | HFGITR_EL2_TLBIRVAE1OS);
+	if (!kvm_has_feat(kvm, ID_AA64ISAR1_EL1, SPECRES, IMP))
+		res0 |= (HFGITR_EL2_CFPRCTX | HFGITR_EL2_DVPRCTX |
+			 HFGITR_EL2_CPPRCTX);
+	if (!kvm_has_feat(kvm, ID_AA64DFR0_EL1, BRBE, IMP))
+		res0 |= (HFGITR_EL2_nBRBINJ | HFGITR_EL2_nBRBIALL);
+	if (!kvm_has_feat(kvm, ID_AA64PFR1_EL1, GCS, IMP))
+		res0 |= (HFGITR_EL2_nGCSPUSHM_EL1 | HFGITR_EL2_nGCSSTR_EL1 |
+			 HFGITR_EL2_nGCSEPP);
+	if (!kvm_has_feat(kvm, ID_AA64ISAR1_EL1, SPECRES, COSP_RCTX))
+		res0 |= HFGITR_EL2_COSPRCTX;
+	if (!kvm_has_feat(kvm, ID_AA64ISAR2_EL1, ATS1A, IMP))
+		res0 |= HFGITR_EL2_ATS1E1A;
+	set_sysreg_masks(kvm, HFGITR_EL2, res0, res1);
+
+	/* HAFGRTR_EL2 - not a lot to see here */
+	res0 = HAFGRTR_EL2_RES0;
+	res1 = HAFGRTR_EL2_RES1;
+	if (!kvm_has_feat(kvm, ID_AA64PFR0_EL1, AMU, V1P1))
+		res0 |= ~(res0 | res1);
+	set_sysreg_masks(kvm, HAFGRTR_EL2, res0, res1);
 out:
 	mutex_unlock(&kvm->arch.config_lock);

Signature · 1 line

2.39.2

Marc Zyngier

author maintainer

2024-02-14 13:18 UTC #7 lore raw

PATCH v4 6/26 KVM: arm64: nv: Add sanitising to VNCR-backed HCRX_EL2

Just like its little friends, HCRX_EL2 gets the feature set treatment when backed by VNCR.

---
 arch/arm64/kvm/nested.c | 42 +++++++++++++++++++++++++++++++++++++++++
 1 file changed, 42 insertions(+)

arch/arm64/kvm/nested.c +42 -0

index eda05eb16c0a..ced30c90521a 100644
@@ -265,6 +265,48 @@ int kvm_init_nv_sysregs(struct kvm *kvm)
 		res1 |= HCR_E2H;
 	set_sysreg_masks(kvm, HCR_EL2, res0, res1);
 
+	/* HCRX_EL2 */
+	res0 = HCRX_EL2_RES0;
+	res1 = HCRX_EL2_RES1;
+	if (!kvm_has_feat(kvm, ID_AA64ISAR3_EL1, PACM, TRIVIAL_IMP))
+		res0 |= HCRX_EL2_PACMEn;
+	if (!kvm_has_feat(kvm, ID_AA64PFR2_EL1, FPMR, IMP))
+		res0 |= HCRX_EL2_EnFPM;
+	if (!kvm_has_feat(kvm, ID_AA64PFR1_EL1, GCS, IMP))
+		res0 |= HCRX_EL2_GCSEn;
+	if (!kvm_has_feat(kvm, ID_AA64ISAR2_EL1, SYSREG_128, IMP))
+		res0 |= HCRX_EL2_EnIDCP128;
+	if (!kvm_has_feat(kvm, ID_AA64MMFR3_EL1, ADERR, DEV_ASYNC))
+		res0 |= (HCRX_EL2_EnSDERR | HCRX_EL2_EnSNERR);
+	if (!kvm_has_feat(kvm, ID_AA64PFR1_EL1, DF2, IMP))
+		res0 |= HCRX_EL2_TMEA;
+	if (!kvm_has_feat(kvm, ID_AA64MMFR3_EL1, D128, IMP))
+		res0 |= HCRX_EL2_D128En;
+	if (!kvm_has_feat(kvm, ID_AA64PFR1_EL1, THE, IMP))
+		res0 |= HCRX_EL2_PTTWI;
+	if (!kvm_has_feat(kvm, ID_AA64MMFR3_EL1, SCTLRX, IMP))
+		res0 |= HCRX_EL2_SCTLR2En;
+	if (!kvm_has_feat(kvm, ID_AA64MMFR3_EL1, TCRX, IMP))
+		res0 |= HCRX_EL2_TCR2En;
+	if (!kvm_has_feat(kvm, ID_AA64ISAR2_EL1, MOPS, IMP))
+		res0 |= (HCRX_EL2_MSCEn | HCRX_EL2_MCE2);
+	if (!kvm_has_feat(kvm, ID_AA64MMFR1_EL1, CMOW, IMP))
+		res0 |= HCRX_EL2_CMOW;
+	if (!kvm_has_feat(kvm, ID_AA64PFR1_EL1, NMI, IMP))
+		res0 |= (HCRX_EL2_VFNMI | HCRX_EL2_VINMI | HCRX_EL2_TALLINT);
+	if (!kvm_has_feat(kvm, ID_AA64PFR1_EL1, SME, IMP) ||
+	    !(read_sysreg_s(SYS_SMIDR_EL1) & SMIDR_EL1_SMPS))
+		res0 |= HCRX_EL2_SMPME;
+	if (!kvm_has_feat(kvm, ID_AA64ISAR1_EL1, XS, IMP))
+		res0 |= (HCRX_EL2_FGTnXS | HCRX_EL2_FnXS);
+	if (!kvm_has_feat(kvm, ID_AA64ISAR1_EL1, LS64, LS64_V))
+		res0 |= HCRX_EL2_EnASR;
+	if (!kvm_has_feat(kvm, ID_AA64ISAR1_EL1, LS64, LS64))
+		res0 |= HCRX_EL2_EnALS;
+	if (!kvm_has_feat(kvm, ID_AA64ISAR1_EL1, LS64, LS64_ACCDATA))
+		res0 |= HCRX_EL2_EnAS0;
+	set_sysreg_masks(kvm, HCRX_EL2, res0, res1);
+
 	/* HFG[RW]TR_EL2 */
 	res0 = res1 = 0;
 	if (!(__vcpu_has_feature(&kvm->arch, KVM_ARM_VCPU_PTRAUTH_ADDRESS) &&

Signature · 1 line

2.39.2

Marc Zyngier

author maintainer

2024-02-14 13:18 UTC #8 lore raw

PATCH v4 7/26 KVM: arm64: nv: Drop sanitised_sys_reg() helper

Now that we have the infrastructure to enforce a sanitised register value depending on the VM configuration, drop the helper that only used the architectural RES0 value.

---
 arch/arm64/kvm/emulate-nested.c | 22 +++++++---------------
 1 file changed, 7 insertions(+), 15 deletions(-)

arch/arm64/kvm/emulate-nested.c +7 ~~-15~~

index 431fd429932d..7a4a886adb9d 100644
@@ -1897,14 +1897,6 @@ static bool check_fgt_bit(u64 val, const union trap_config tc)
 	return ((val >> tc.bit) & 1) == tc.pol;
 }
 
-#define sanitised_sys_reg(vcpu, reg)			\
-	({						\
-		u64 __val;				\
-		__val = __vcpu_sys_reg(vcpu, reg);	\
-		__val &= ~__ ## reg ## _RES0;		\
-		(__val);				\
-	})
-
 bool __check_nv_sr_forward(struct kvm_vcpu *vcpu)
 {
 	union trap_config tc;

@@ -1940,25 +1932,25 @@ bool __check_nv_sr_forward(struct kvm_vcpu *vcpu)
 
 	case HFGxTR_GROUP:
 		if (is_read)
-			val = sanitised_sys_reg(vcpu, HFGRTR_EL2);
+			val = __vcpu_sys_reg(vcpu, HFGRTR_EL2);
 		else
-			val = sanitised_sys_reg(vcpu, HFGWTR_EL2);
+			val = __vcpu_sys_reg(vcpu, HFGWTR_EL2);
 		break;
 
 	case HDFGRTR_GROUP:
 	case HDFGWTR_GROUP:
 		if (is_read)
-			val = sanitised_sys_reg(vcpu, HDFGRTR_EL2);
+			val = __vcpu_sys_reg(vcpu, HDFGRTR_EL2);
 		else
-			val = sanitised_sys_reg(vcpu, HDFGWTR_EL2);
+			val = __vcpu_sys_reg(vcpu, HDFGWTR_EL2);
 		break;
 
 	case HAFGRTR_GROUP:
-		val = sanitised_sys_reg(vcpu, HAFGRTR_EL2);
+		val = __vcpu_sys_reg(vcpu, HAFGRTR_EL2);
 		break;
 
 	case HFGITR_GROUP:
-		val = sanitised_sys_reg(vcpu, HFGITR_EL2);
+		val = __vcpu_sys_reg(vcpu, HFGITR_EL2);
 		switch (tc.fgf) {
 			u64 tmp;

@@ -1966,7 +1958,7 @@ bool __check_nv_sr_forward(struct kvm_vcpu *vcpu)
 			break;
 
 		case HCRX_FGTnXS:
-			tmp = sanitised_sys_reg(vcpu, HCRX_EL2);
+			tmp = __vcpu_sys_reg(vcpu, HCRX_EL2);
 			if (tmp & HCRX_EL2_FGTnXS)
 				tc.fgt = __NO_FGT_GROUP__;
 		}

Signature · 1 line

2.39.2

Marc Zyngier

author maintainer

2024-02-14 13:18 UTC #9 lore raw

PATCH v4 8/26 KVM: arm64: Unify HDFG[WR]TR_GROUP FGT identifiers

There is no reason to have separate FGT group identifiers for the debug fine grain trapping. The sole requirement is to provide the *names* so that the SR_FGF() macro can do its magic of picking the correct bit definition.

So let's alias HDFGWTR_GROUP and HDFGRTR_GROUP.

---
 arch/arm64/kvm/emulate-nested.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

arch/arm64/kvm/emulate-nested.c +1 -2

index 7a4a886adb9d..8a1cfcf553a2 100644
@@ -1010,7 +1010,7 @@ enum fgt_group_id {
 	__NO_FGT_GROUP__,
 	HFGxTR_GROUP,
 	HDFGRTR_GROUP,
-	HDFGWTR_GROUP,
+	HDFGWTR_GROUP = HDFGRTR_GROUP,
 	HFGITR_GROUP,
 	HAFGRTR_GROUP,

@@ -1938,7 +1938,6 @@ bool __check_nv_sr_forward(struct kvm_vcpu *vcpu)
 		break;
 
 	case HDFGRTR_GROUP:
-	case HDFGWTR_GROUP:
 		if (is_read)
 			val = __vcpu_sys_reg(vcpu, HDFGRTR_EL2);
 		else

Signature · 1 line

2.39.2

Marc Zyngier

author maintainer

2024-02-14 13:18 UTC #10 lore raw

PATCH v4 9/26 KVM: arm64: nv: Correctly handle negative polarity FGTs

Negative trap bits are a massive pain. They are, on the surface, indistinguishable from RES0 bits. Do you trap? or do you ignore?

Thankfully, we now have the right infrastructure to check for RES0 bits as long as the register is backed by VNCR, which is the case for the FGT registers.

Use that information as a discriminant when handling a trap that is potentially caused by a FGT.

---
 arch/arm64/kvm/emulate-nested.c | 59 +++++++++++++++++++++++++++++++--
 1 file changed, 56 insertions(+), 3 deletions(-)

arch/arm64/kvm/emulate-nested.c +56 -3

index 8a1cfcf553a2..ef46c2e45307 100644
@@ -1892,9 +1892,61 @@ static enum trap_behaviour compute_trap_behaviour(struct kvm_vcpu *vcpu,
 	return __compute_trap_behaviour(vcpu, tc.cgt, b);
 }
 
-static bool check_fgt_bit(u64 val, const union trap_config tc)
+static u64 kvm_get_sysreg_res0(struct kvm *kvm, enum vcpu_sysreg sr)
 {
-	return ((val >> tc.bit) & 1) == tc.pol;
+	struct kvm_sysreg_masks *masks;
+
+	/* Only handle the VNCR-backed regs for now */
+	if (sr < __VNCR_START__)
+		return 0;
+
+	masks = kvm->arch.sysreg_masks;
+
+	return masks->mask[sr - __VNCR_START__].res0;
+}
+
+static bool check_fgt_bit(struct kvm *kvm, bool is_read,
+			  u64 val, const union trap_config tc)
+{
+	enum vcpu_sysreg sr;
+
+	if (tc.pol)
+		return (val & BIT(tc.bit));
+
+	/*
+	 * FGTs with negative polarities are an absolute nightmare, as
+	 * we need to evaluate the bit in the light of the feature
+	 * that defines it. WTF were they thinking?
+	 *
+	 * So let's check if the bit has been earmarked as RES0, as
+	 * this indicates an unimplemented feature.
+	 */
+	if (val & BIT(tc.bit))
+		return false;
+
+	switch ((enum fgt_group_id)tc.fgt) {
+	case HFGxTR_GROUP:
+		sr = is_read ? HFGRTR_EL2 : HFGWTR_EL2;
+		break;
+
+	case HDFGRTR_GROUP:
+		sr = is_read ? HDFGRTR_EL2 : HDFGWTR_EL2;
+		break;
+
+	case HAFGRTR_GROUP:
+		sr = HAFGRTR_EL2;
+		break;
+
+	case HFGITR_GROUP:
+		sr = HFGITR_EL2;
+		break;
+
+	default:
+		WARN_ONCE(1, "Unhandled FGT group");
+		return false;
+	}
+
+	return !(kvm_get_sysreg_res0(kvm, sr) & BIT(tc.bit));
 }
 
 bool __check_nv_sr_forward(struct kvm_vcpu *vcpu)

@@ -1969,7 +2021,8 @@ bool __check_nv_sr_forward(struct kvm_vcpu *vcpu)
 		return false;
 	}
 
-	if (tc.fgt != __NO_FGT_GROUP__ && check_fgt_bit(val, tc))
+	if (tc.fgt != __NO_FGT_GROUP__ && check_fgt_bit(vcpu->kvm, is_read,
+							val, tc))
 		goto inject;
 
 	b = compute_trap_behaviour(vcpu, tc);

Signature · 1 line

2.39.2

Marc Zyngier

author maintainer

2024-02-14 13:18 UTC #11 lore raw

PATCH v4 10/26 KVM: arm64: nv: Turn encoding ranges into discrete XArray stores

In order to be able to store different values for member of an encoding range, replace xa_store_range() calls with discrete xa_store() calls and an encoding iterator.

We end-up using a bit more memory, but we gain some flexibility that we will make use of shortly.

Take this opportunity to tidy up the error handling path.

---
 arch/arm64/kvm/emulate-nested.c | 49 ++++++++++++++++++++++++---------
 1 file changed, 36 insertions(+), 13 deletions(-)

arch/arm64/kvm/emulate-nested.c +36 ~~-13~~

index ef46c2e45307..42f5b4483c80 100644
@@ -1757,6 +1757,28 @@ static __init void print_nv_trap_error(const struct encoding_to_trap_config *tc,
 		err);
 }
 
+static u32 encoding_next(u32 encoding)
+{
+	u8 op0, op1, crn, crm, op2;
+
+	op0 = sys_reg_Op0(encoding);
+	op1 = sys_reg_Op1(encoding);
+	crn = sys_reg_CRn(encoding);
+	crm = sys_reg_CRm(encoding);
+	op2 = sys_reg_Op2(encoding);
+
+	if (op2 < Op2_mask)
+		return sys_reg(op0, op1, crn, crm, op2 + 1);
+	if (crm < CRm_mask)
+		return sys_reg(op0, op1, crn, crm + 1, 0);
+	if (crn < CRn_mask)
+		return sys_reg(op0, op1, crn + 1, 0, 0);
+	if (op1 < Op1_mask)
+		return sys_reg(op0, op1 + 1, 0, 0, 0);
+
+	return sys_reg(op0 + 1, 0, 0, 0, 0);
+}
+
 int __init populate_nv_trap_config(void)
 {
 	int ret = 0;

@@ -1775,23 +1797,18 @@ int __init populate_nv_trap_config(void)
 			ret = -EINVAL;
 		}
 
-		if (cgt->encoding != cgt->end) {
-			prev = xa_store_range(&sr_forward_xa,
-					      cgt->encoding, cgt->end,
-					      xa_mk_value(cgt->tc.val),
-					      GFP_KERNEL);
-		} else {
-			prev = xa_store(&sr_forward_xa, cgt->encoding,
+		for (u32 enc = cgt->encoding; enc <= cgt->end; enc = encoding_next(enc)) {
+			prev = xa_store(&sr_forward_xa, enc,
 					xa_mk_value(cgt->tc.val), GFP_KERNEL);
 			if (prev && !xa_is_err(prev)) {
 				ret = -EINVAL;
 				print_nv_trap_error(cgt, "Duplicate CGT", ret);
 			}
-		}
 
-		if (xa_is_err(prev)) {
-			ret = xa_err(prev);
-			print_nv_trap_error(cgt, "Failed CGT insertion", ret);
+			if (xa_is_err(prev)) {
+				ret = xa_err(prev);
+				print_nv_trap_error(cgt, "Failed CGT insertion", ret);
+			}
 		}
 	}

@@ -1804,6 +1821,7 @@ int __init populate_nv_trap_config(void)
 	for (int i = 0; i < ARRAY_SIZE(encoding_to_fgt); i++) {
 		const struct encoding_to_trap_config *fgt = &encoding_to_fgt[i];
 		union trap_config tc;
+		void *prev;
 
 		if (fgt->tc.fgt >= __NR_FGT_GROUP_IDS__) {
 			ret = -EINVAL;

@@ -1818,8 +1836,13 @@ int __init populate_nv_trap_config(void)
 		}
 
 		tc.val |= fgt->tc.val;
-		xa_store(&sr_forward_xa, fgt->encoding,
-			 xa_mk_value(tc.val), GFP_KERNEL);
+		prev = xa_store(&sr_forward_xa, fgt->encoding,
+				xa_mk_value(tc.val), GFP_KERNEL);
+
+		if (xa_is_err(prev)) {
+			ret = xa_err(prev);
+			print_nv_trap_error(fgt, "Failed FGT insertion", ret);
+		}
 	}
 
 	kvm_info("nv: %ld fine grained trap handlers\n",

Signature · 1 line

2.39.2

Marc Zyngier

author maintainer

2024-02-14 13:18 UTC #12 lore raw

PATCH v4 11/26 KVM: arm64: Drop the requirement for XARRAY_MULTI

Now that we don't use xa_store_range() anymore, drop the added complexity of XARRAY_MULTI for KVM. It is likely still pulled in by other bits of the kernel though.

---
 arch/arm64/kvm/Kconfig | 1 -
 1 file changed, 1 deletion(-)

arch/arm64/kvm/Kconfig +0 -1

index 6c3c8ca73e7f..5c2a672c06a8 100644
@@ -39,7 +39,6 @@ menuconfig KVM
 	select HAVE_KVM_VCPU_RUN_PID_CHANGE
 	select SCHED_INFO
 	select GUEST_PERF_EVENTS if PERF_EVENTS
-	select XARRAY_MULTI
 	help
 	  Support hosting virtualized guest machines.

Signature · 1 line

2.39.2

Marc Zyngier

author maintainer

2024-02-14 13:18 UTC #13 lore raw

PATCH v4 12/26 KVM: arm64: nv: Move system instructions to their own sys_reg_desc array

As NV results in a bunch of system instructions being trapped, it makes sense to pull the system instructions into their own little array, where they will eventually be joined by AT, TLBI and a bunch of other CMOs.

Based on an initial patch by Jintack Lim.

---
 arch/arm64/kvm/sys_regs.c | 59 +++++++++++++++++++++++++++++----------
 1 file changed, 44 insertions(+), 15 deletions(-)

arch/arm64/kvm/sys_regs.c +44 ~~-15~~

index 3c31f8cb9eef..70043bd78cd4 100644
@@ -2196,16 +2196,6 @@ static u64 reset_hcr(struct kvm_vcpu *vcpu, const struct sys_reg_desc *r)
  * guest...
  */
 static const struct sys_reg_desc sys_reg_descs[] = {
-	{ SYS_DESC(SYS_DC_ISW), access_dcsw },
-	{ SYS_DESC(SYS_DC_IGSW), access_dcgsw },
-	{ SYS_DESC(SYS_DC_IGDSW), access_dcgsw },
-	{ SYS_DESC(SYS_DC_CSW), access_dcsw },
-	{ SYS_DESC(SYS_DC_CGSW), access_dcgsw },
-	{ SYS_DESC(SYS_DC_CGDSW), access_dcgsw },
-	{ SYS_DESC(SYS_DC_CISW), access_dcsw },
-	{ SYS_DESC(SYS_DC_CIGSW), access_dcgsw },
-	{ SYS_DESC(SYS_DC_CIGDSW), access_dcgsw },
-
 	DBG_BCR_BVR_WCR_WVR_EL1(0),
 	DBG_BCR_BVR_WCR_WVR_EL1(1),
 	{ SYS_DESC(SYS_MDCCINT_EL1), trap_debug_regs, reset_val, MDCCINT_EL1, 0 },

@@ -2737,6 +2727,18 @@ static const struct sys_reg_desc sys_reg_descs[] = {
 	EL2_REG(SP_EL2, NULL, reset_unknown, 0),
 };
 
+static struct sys_reg_desc sys_insn_descs[] = {
+	{ SYS_DESC(SYS_DC_ISW), access_dcsw },
+	{ SYS_DESC(SYS_DC_IGSW), access_dcgsw },
+	{ SYS_DESC(SYS_DC_IGDSW), access_dcgsw },
+	{ SYS_DESC(SYS_DC_CSW), access_dcsw },
+	{ SYS_DESC(SYS_DC_CGSW), access_dcgsw },
+	{ SYS_DESC(SYS_DC_CGDSW), access_dcgsw },
+	{ SYS_DESC(SYS_DC_CISW), access_dcsw },
+	{ SYS_DESC(SYS_DC_CIGSW), access_dcgsw },
+	{ SYS_DESC(SYS_DC_CIGDSW), access_dcgsw },
+};
+
 static const struct sys_reg_desc *first_idreg;
 
 static bool trap_dbgdidr(struct kvm_vcpu *vcpu,

@@ -3429,6 +3431,24 @@ static bool emulate_sys_reg(struct kvm_vcpu *vcpu,
 	return false;
 }
 
+static int emulate_sys_instr(struct kvm_vcpu *vcpu, struct sys_reg_params *p)
+{
+	const struct sys_reg_desc *r;
+
+	/* Search from the system instruction table. */
+	r = find_reg(p, sys_insn_descs, ARRAY_SIZE(sys_insn_descs));
+
+	if (likely(r)) {
+		perform_access(vcpu, p, r);
+	} else {
+		kvm_err("Unsupported guest sys instruction at: %lx\n",
+			*vcpu_pc(vcpu));
+		print_sys_reg_instr(p);
+		kvm_inject_undefined(vcpu);
+	}
+	return 1;
+}
+
 static void kvm_reset_id_regs(struct kvm_vcpu *vcpu)
 {
 	const struct sys_reg_desc *idreg = first_idreg;

@@ -3476,7 +3496,8 @@ void kvm_reset_sys_regs(struct kvm_vcpu *vcpu)
 }
 
 /**
- * kvm_handle_sys_reg -- handles a mrs/msr trap on a guest sys_reg access
+ * kvm_handle_sys_reg -- handles a system instruction or mrs/msr instruction
+ *			 trap on a guest execution
  * @vcpu: The VCPU pointer
  */
 int kvm_handle_sys_reg(struct kvm_vcpu *vcpu)

@@ -3493,12 +3514,19 @@ int kvm_handle_sys_reg(struct kvm_vcpu *vcpu)
 	params = esr_sys64_to_params(esr);
 	params.regval = vcpu_get_reg(vcpu, Rt);
 
-	if (!emulate_sys_reg(vcpu, &params))
+	/* System registers have Op0=={2,3}, as per DDI487 J.a C5.1.2 */
+	if (params.Op0 == 2 || params.Op0 == 3) {
+		if (!emulate_sys_reg(vcpu, &params))
+			return 1;
+
+		if (!params.is_write)
+			vcpu_set_reg(vcpu, Rt, params.regval);
+
 		return 1;
+	}
 
-	if (!params.is_write)
-		vcpu_set_reg(vcpu, Rt, params.regval);
-	return 1;
+	/* Hints, PSTATE (Op0 == 0) and System instructions (Op0 == 1) */
+	return emulate_sys_instr(vcpu, &params);
 }
 
 /******************************************************************************

@@ -3952,6 +3980,7 @@ int __init kvm_sys_reg_table_init(void)
 	valid &= check_sysreg_table(cp15_regs, ARRAY_SIZE(cp15_regs), true);
 	valid &= check_sysreg_table(cp15_64_regs, ARRAY_SIZE(cp15_64_regs), true);
 	valid &= check_sysreg_table(invariant_sys_regs, ARRAY_SIZE(invariant_sys_regs), false);
+	valid &= check_sysreg_table(sys_insn_descs, ARRAY_SIZE(sys_insn_descs), false);
 
 	if (!valid)
 		return -EINVAL;

Signature · 1 line

2.39.2

Marc Zyngier

author maintainer

2024-02-14 13:18 UTC #14 lore raw

PATCH v4 13/26 KVM: arm64: Always populate the trap configuration xarray

As we are going to rely more and more on the global xarray that contains the trap configuration, always populate it, even in the non-NV case.

---
 arch/arm64/kvm/sys_regs.c | 5 +----
 1 file changed, 1 insertion(+), 4 deletions(-)

arch/arm64/kvm/sys_regs.c +1 -4

index 70043bd78cd4..57f3d0c53fc3 100644
@@ -3995,8 +3995,5 @@ int __init kvm_sys_reg_table_init(void)
 	if (!first_idreg)
 		return -EINVAL;
 
-	if (kvm_get_mode() == KVM_MODE_NV)
-		return populate_nv_trap_config();
-
-	return 0;
+	return populate_nv_trap_config();
 }

Signature · 1 line

2.39.2

Marc Zyngier

author maintainer

2024-02-14 13:18 UTC #15 lore raw

PATCH v4 14/26 KVM: arm64: Register AArch64 system register entries with the sysreg xarray

In order to reduce the number of lookups that we have to perform when handling a sysreg, register each AArch64 sysreg descriptor with the global xarray. The index of the descriptor is stored as a 10 bit field in the data word.

Subsequent patches will retrieve and use the stored index.

---
 arch/arm64/include/asm/kvm_host.h |  3 +++
 arch/arm64/kvm/emulate-nested.c   | 39 +++++++++++++++++++++++++++++--
 arch/arm64/kvm/sys_regs.c         | 11 ++++++++-
 3 files changed, 50 insertions(+), 3 deletions(-)

arch/arm64/include/asm/kvm_host.h +3 -0

index 8cda003d6267..914fd54179bb 100644
@@ -1078,6 +1078,9 @@ int kvm_handle_cp10_id(struct kvm_vcpu *vcpu);
 void kvm_reset_sys_regs(struct kvm_vcpu *vcpu);
 
 int __init kvm_sys_reg_table_init(void);
+struct sys_reg_desc;
+int __init populate_sysreg_config(const struct sys_reg_desc *sr,
+				  unsigned int idx);
 int __init populate_nv_trap_config(void);
 
 bool lock_all_vcpus(struct kvm *kvm);

arch/arm64/kvm/emulate-nested.c +37 -2

index 42f5b4483c80..ddf760b4dda5 100644
@@ -427,12 +427,14 @@ static const complex_condition_check ccc[] = {
  * [19:14]	bit number in the FGT register (6 bits)
  * [20]		trap polarity (1 bit)
  * [25:21]	FG filter (5 bits)
- * [62:26]	Unused (37 bits)
+ * [35:26]	Main SysReg table index (10 bits)
+ * [62:36]	Unused (27 bits)
  * [63]		RES0 - Must be zero, as lost on insertion in the xarray
  */
 #define TC_CGT_BITS	10
 #define TC_FGT_BITS	4
 #define TC_FGF_BITS	5
+#define TC_SRI_BITS	10
 
 union trap_config {
 	u64	val;

@@ -442,7 +444,8 @@ union trap_config {
 		unsigned long	bit:6;		 /* Bit number */
 		unsigned long	pol:1;		 /* Polarity */
 		unsigned long	fgf:TC_FGF_BITS; /* Fine Grained Filter */
-		unsigned long	unused:37;	 /* Unused, should be zero */
+		unsigned long	sri:TC_SRI_BITS; /* SysReg Index */
+		unsigned long	unused:27;	 /* Unused, should be zero */
 		unsigned long	mbz:1;		 /* Must Be Zero */
 	};
 };

@@ -1868,6 +1871,38 @@ int __init populate_nv_trap_config(void)
 	return ret;
 }
 
+int __init populate_sysreg_config(const struct sys_reg_desc *sr,
+				  unsigned int idx)
+{
+	union trap_config tc;
+	u32 encoding;
+	void *ret;
+
+	/*
+	 * 0 is a valid value for the index, but not for the storage.
+	 * We'll store (idx+1), so check against an offset'd limit.
+	 */
+	if (idx >= (BIT(TC_SRI_BITS) - 1)) {
+		kvm_err("sysreg %s (%d) out of range\n", sr->name, idx);
+		return -EINVAL;
+	}
+
+	encoding = sys_reg(sr->Op0, sr->Op1, sr->CRn, sr->CRm, sr->Op2);
+	tc = get_trap_config(encoding);
+
+	if (tc.sri) {
+		kvm_err("sysreg %s (%d) duplicate entry (%d)\n",
+			sr->name, idx - 1, tc.sri);
+		return -EINVAL;
+	}
+
+	tc.sri = idx + 1;
+	ret = xa_store(&sr_forward_xa, encoding,
+		       xa_mk_value(tc.val), GFP_KERNEL);
+
+	return xa_err(ret);
+}
+
 static enum trap_behaviour get_behaviour(struct kvm_vcpu *vcpu,
 					 const struct trap_bits *tb)
 {

arch/arm64/kvm/sys_regs.c +10 -1

index 57f3d0c53fc3..a410e99f827e 100644
@@ -3972,6 +3972,7 @@ int __init kvm_sys_reg_table_init(void)
 	struct sys_reg_params params;
 	bool valid = true;
 	unsigned int i;
+	int ret = 0;
 
 	/* Make sure tables are unique and in order. */
 	valid &= check_sysreg_table(sys_reg_descs, ARRAY_SIZE(sys_reg_descs), false);

@@ -3995,5 +3996,13 @@ int __init kvm_sys_reg_table_init(void)
 	if (!first_idreg)
 		return -EINVAL;
 
-	return populate_nv_trap_config();
+	ret = populate_nv_trap_config();
+
+	for (i = 0; !ret && i < ARRAY_SIZE(sys_reg_descs); i++)
+		ret = populate_sysreg_config(sys_reg_descs + i, i);
+
+	for (i = 0; !ret && i < ARRAY_SIZE(sys_insn_descs); i++)
+		ret = populate_sysreg_config(sys_insn_descs + i, i);
+
+	return ret;
 }

Signature · 1 line

2.39.2

Marc Zyngier

author maintainer

2024-02-14 13:18 UTC #16 lore raw

PATCH v4 15/26 KVM: arm64: Use the xarray as the primary sysreg/sysinsn walker

Since we always start sysreg/sysinsn handling by searching the xarray, use it as the source of the index in the correct sys_reg_desc array.

This allows some cleanup, such as moving the handling of unknown sysregs in a single location.

---
 arch/arm64/include/asm/kvm_nested.h |  2 +-
 arch/arm64/kvm/emulate-nested.c     | 40 +++++++++++++-----
 arch/arm64/kvm/sys_regs.c           | 63 +++++++++--------------------
 3 files changed, 50 insertions(+), 55 deletions(-)

arch/arm64/include/asm/kvm_nested.h +1 -1

index 4882905357f4..68465f87d308 100644
@@ -60,7 +60,7 @@ static inline u64 translate_ttbr0_el2_to_ttbr0_el1(u64 ttbr0)
 	return ttbr0 & ~GENMASK_ULL(63, 48);
 }
 
-extern bool __check_nv_sr_forward(struct kvm_vcpu *vcpu);
+extern bool __check_nv_sr_forward(struct kvm_vcpu *vcpu, int *sr_idx);
 
 int kvm_init_nv_sysregs(struct kvm *kvm);

arch/arm64/kvm/emulate-nested.c +30 ~~-10~~

index ddf760b4dda5..5aeaa688755f 100644
@@ -2007,7 +2007,7 @@ static bool check_fgt_bit(struct kvm *kvm, bool is_read,
 	return !(kvm_get_sysreg_res0(kvm, sr) & BIT(tc.bit));
 }
 
-bool __check_nv_sr_forward(struct kvm_vcpu *vcpu)
+bool __check_nv_sr_forward(struct kvm_vcpu *vcpu, int *sr_index)
 {
 	union trap_config tc;
 	enum trap_behaviour b;

@@ -2015,9 +2015,6 @@ bool __check_nv_sr_forward(struct kvm_vcpu *vcpu)
 	u32 sysreg;
 	u64 esr, val;
 
-	if (!vcpu_has_nv(vcpu) || is_hyp_ctxt(vcpu))
-		return false;
-
 	esr = kvm_vcpu_get_esr(vcpu);
 	sysreg = esr_sys64_to_sysreg(esr);
 	is_read = (esr & ESR_ELx_SYS64_ISS_DIR_MASK) == ESR_ELx_SYS64_ISS_DIR_READ;

@@ -2028,13 +2025,16 @@ bool __check_nv_sr_forward(struct kvm_vcpu *vcpu)
 	 * A value of 0 for the whole entry means that we know nothing
 	 * for this sysreg, and that it cannot be re-injected into the
 	 * nested hypervisor. In this situation, let's cut it short.
-	 *
-	 * Note that ultimately, we could also make use of the xarray
-	 * to store the index of the sysreg in the local descriptor
-	 * array, avoiding another search... Hint, hint...
 	 */
 	if (!tc.val)
-		return false;
+		goto local;
+
+	/*
+	 * If we're not nesting, immediately return to the caller, with the
+	 * sysreg index, should we have it.
+	 */
+	if (!vcpu_has_nv(vcpu) || is_hyp_ctxt(vcpu))
+		goto local;
 
 	switch ((enum fgt_group_id)tc.fgt) {
 	case __NO_FGT_GROUP__:

@@ -2076,7 +2076,7 @@ bool __check_nv_sr_forward(struct kvm_vcpu *vcpu)
 	case __NR_FGT_GROUP_IDS__:
 		/* Something is really wrong, bail out */
 		WARN_ONCE(1, "__NR_FGT_GROUP_IDS__");
-		return false;
+		goto local;
 	}
 
 	if (tc.fgt != __NO_FGT_GROUP__ && check_fgt_bit(vcpu->kvm, is_read,

@@ -2089,6 +2089,26 @@ bool __check_nv_sr_forward(struct kvm_vcpu *vcpu)
 	    ((b & BEHAVE_FORWARD_WRITE) && !is_read))
 		goto inject;
 
+local:
+	if (!tc.sri) {
+		struct sys_reg_params params;
+
+		params = esr_sys64_to_params(esr);
+
+		/*
+		 * Check for the IMPDEF range, as per DDI0487 J.a,
+		 * D18.3.2 Reserved encodings for IMPLEMENTATION
+		 * DEFINED registers.
+		 */
+		if (!(params.Op0 == 3 && (params.CRn & 0b1011) == 0b1011))
+			print_sys_reg_msg(&params,
+					  "Unsupported guest access at: %lx\n",
+					  *vcpu_pc(vcpu));
+		kvm_inject_undefined(vcpu);
+		return true;
+	}
+
+	*sr_index = tc.sri - 1;
 	return false;
 
 inject:

arch/arm64/kvm/sys_regs.c +19 ~~-44~~

106 lines not on this page · raw message

Signature · 1 line

2.39.2

Marc Zyngier

author maintainer

2024-02-14 13:18 UTC #17 lore raw

PATCH v4 16/26 KVM: arm64: Rename __check_nv_sr_forward() to triage_sysreg_trap()

__check_nv_sr_forward() is not specific to NV anymore, and does a lot more. Rename it to triage_sysreg_trap(), making it plain that its role is to handle where an exception is to be handled.

---
 arch/arm64/include/asm/kvm_nested.h | 1 -
 arch/arm64/kvm/emulate-nested.c     | 2 +-
 arch/arm64/kvm/sys_regs.c           | 2 +-
 arch/arm64/kvm/sys_regs.h           | 2 ++
 4 files changed, 4 insertions(+), 3 deletions(-)

arch/arm64/include/asm/kvm_nested.h +0 -1

index 68465f87d308..c77d795556e1 100644
@@ -60,7 +60,6 @@ static inline u64 translate_ttbr0_el2_to_ttbr0_el1(u64 ttbr0)
 	return ttbr0 & ~GENMASK_ULL(63, 48);
 }
 
-extern bool __check_nv_sr_forward(struct kvm_vcpu *vcpu, int *sr_idx);
 
 int kvm_init_nv_sysregs(struct kvm *kvm);

arch/arm64/kvm/emulate-nested.c +1 -1

index 5aeaa688755f..4f2a32a8f247 100644
@@ -2007,7 +2007,7 @@ static bool check_fgt_bit(struct kvm *kvm, bool is_read,
 	return !(kvm_get_sysreg_res0(kvm, sr) & BIT(tc.bit));
 }
 
-bool __check_nv_sr_forward(struct kvm_vcpu *vcpu, int *sr_index)
+bool triage_sysreg_trap(struct kvm_vcpu *vcpu, int *sr_index)
 {
 	union trap_config tc;
 	enum trap_behaviour b;

arch/arm64/kvm/sys_regs.c +1 -1

index bc076ef8440b..938df5dc3684 100644
@@ -3482,7 +3482,7 @@ int kvm_handle_sys_reg(struct kvm_vcpu *vcpu)
 
 	trace_kvm_handle_sys_reg(esr);
 
-	if (__check_nv_sr_forward(vcpu, &sr_idx))
+	if (triage_sysreg_trap(vcpu, &sr_idx))
 		return 1;
 
 	params = esr_sys64_to_params(esr);

arch/arm64/kvm/sys_regs.h +2 -0

index c65c129b3500..997eea21ba2a 100644
@@ -233,6 +233,8 @@ int kvm_sys_reg_get_user(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg,
 int kvm_sys_reg_set_user(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg,
 			 const struct sys_reg_desc table[], unsigned int num);
 
+bool triage_sysreg_trap(struct kvm_vcpu *vcpu, int *sr_index);
+
 #define AA32(_x)	.aarch32_map = AA32_##_x
 #define Op0(_x) 	.Op0 = _x
 #define Op1(_x) 	.Op1 = _x

Signature · 1 line

2.39.2

Marc Zyngier

author maintainer

2024-02-14 13:18 UTC #18 lore raw

PATCH v4 17/26 KVM: arm64: Add Fine-Grained UNDEF tracking information

In order to efficiently handle system register access being disabled, and this resulting in an UNDEF exception being injected, we introduce the (slightly dubious) concept of Fine-Grained UNDEF, modeled after the architectural Fine-Grained Traps.

For each FGT group, we keep a 64 bit word that has the exact same bit assignment as the corresponding FGT register, where a 1 indicates that trapping this register should result in an UNDEF exception being reinjected.

So far, nothing populates this information, nor sets the corresponding trap bits.

---
 arch/arm64/include/asm/kvm_host.h | 21 +++++++++++++++++++++
 arch/arm64/kvm/emulate-nested.c   | 12 ------------
 2 files changed, 21 insertions(+), 12 deletions(-)

arch/arm64/include/asm/kvm_host.h +21 -0

index 914fd54179bb..c69b258fc989 100644
@@ -240,9 +240,30 @@ static inline u16 kvm_mpidr_index(struct kvm_mpidr_data *data, u64 mpidr)
 
 struct kvm_sysreg_masks;
 
+enum fgt_group_id {
+	__NO_FGT_GROUP__,
+	HFGxTR_GROUP,
+	HDFGRTR_GROUP,
+	HDFGWTR_GROUP = HDFGRTR_GROUP,
+	HFGITR_GROUP,
+	HAFGRTR_GROUP,
+
+	/* Must be last */
+	__NR_FGT_GROUP_IDS__
+};
+
 struct kvm_arch {
 	struct kvm_s2_mmu mmu;
 
+	/*
+	 * Fine-Grained UNDEF, mimicking the FGT layout defined by the
+	 * architecture. We track them globally, as we present the
+	 * same feature-set to all vcpus.
+	 *
+	 * Index 0 is currently spare.
+	 */
+	u64 fgu[__NR_FGT_GROUP_IDS__];
+
 	/* Interrupt controller */
 	struct vgic_dist	vgic;

arch/arm64/kvm/emulate-nested.c +0 ~~-12~~

index 4f2a32a8f247..b67078b8271b 100644
@@ -1009,18 +1009,6 @@ static const struct encoding_to_trap_config encoding_to_cgt[] __initconst = {
 
 static DEFINE_XARRAY(sr_forward_xa);
 
-enum fgt_group_id {
-	__NO_FGT_GROUP__,
-	HFGxTR_GROUP,
-	HDFGRTR_GROUP,
-	HDFGWTR_GROUP = HDFGRTR_GROUP,
-	HFGITR_GROUP,
-	HAFGRTR_GROUP,
-
-	/* Must be last */
-	__NR_FGT_GROUP_IDS__
-};
-
 enum fg_filter_id {
 	__NO_FGF__,
 	HCRX_FGTnXS,

Signature · 1 line

2.39.2

Marc Zyngier

author maintainer

2024-02-14 13:18 UTC #19 lore raw

PATCH v4 18/26 KVM: arm64: Propagate and handle Fine-Grained UNDEF bits

In order to correctly honor our FGU bits, they must be converted into a set of FGT bits. They get merged as part of the existing FGT setting.

Similarly, the UNDEF injection phase takes place when handling the trap.

This results in a bit of rework in the FGT macros in order to help with the code generation, as burying per-CPU accesses in macros results in a lot of expansion, not to mention the vcpu->kvm access on nvhe (kern_hyp_va() is not optimisation-friendly).

---
 arch/arm64/kvm/emulate-nested.c         | 11 ++++
 arch/arm64/kvm/hyp/include/hyp/switch.h | 81 +++++++++++++++++++------
 2 files changed, 72 insertions(+), 20 deletions(-)

arch/arm64/kvm/emulate-nested.c +11 -0

index b67078b8271b..4697ba41b3a9 100644
@@ -2017,6 +2017,17 @@ bool triage_sysreg_trap(struct kvm_vcpu *vcpu, int *sr_index)
 	if (!tc.val)
 		goto local;
 
+	/*
+	 * If a sysreg can be trapped using a FGT, first check whether we
+	 * trap for the purpose of forbidding the feature. In that case,
+	 * inject an UNDEF.
+	 */
+	if (tc.fgt != __NO_FGT_GROUP__ &&
+	    (vcpu->kvm->arch.fgu[tc.fgt] & BIT(tc.bit))) {
+		kvm_inject_undefined(vcpu);
+		return true;
+	}
+
 	/*
 	 * If we're not nesting, immediately return to the caller, with the
 	 * sysreg index, should we have it.

arch/arm64/kvm/hyp/include/hyp/switch.h +61 ~~-20~~

130 lines not on this page · raw message

Signature · 1 line

2.39.2

Marc Zyngier

author maintainer

2024-02-14 13:18 UTC #20 lore raw

PATCH v4 19/26 KVM: arm64: Move existing feature disabling over to FGU infrastructure

We already trap a bunch of existing features for the purpose of disabling them (MAIR2, POR, ACCDATA, SME...).

Let's move them over to our brand new FGU infrastructure.

---
 arch/arm64/include/asm/kvm_host.h       |  4 ++++
 arch/arm64/kvm/arm.c                    |  6 ++++++
 arch/arm64/kvm/hyp/include/hyp/switch.h | 17 +++--------------
 arch/arm64/kvm/sys_regs.c               | 23 +++++++++++++++++++++++
 4 files changed, 36 insertions(+), 14 deletions(-)

arch/arm64/include/asm/kvm_host.h +4 -0

index c69b258fc989..968a997b3f02 100644
@@ -297,6 +297,8 @@ struct kvm_arch {
 #define KVM_ARCH_FLAG_TIMER_PPIS_IMMUTABLE		6
 	/* Initial ID reg values loaded */
 #define KVM_ARCH_FLAG_ID_REGS_INITIALIZED		7
+	/* Fine-Grained UNDEF initialised */
+#define KVM_ARCH_FLAG_FGU_INITIALIZED			8
 	unsigned long flags;
 
 	/* VM-wide vCPU feature set */

@@ -1107,6 +1109,8 @@ int __init populate_nv_trap_config(void);
 bool lock_all_vcpus(struct kvm *kvm);
 void unlock_all_vcpus(struct kvm *kvm);
 
+void kvm_init_sysreg(struct kvm_vcpu *);
+
 /* MMIO helpers */
 void kvm_mmio_write_buf(void *buf, unsigned int len, unsigned long data);
 unsigned long kvm_mmio_read_buf(const void *buf, unsigned int len);

arch/arm64/kvm/arm.c +6 -0

index c063e84fc72c..9f806c9b7d5d 100644
@@ -675,6 +675,12 @@ int kvm_arch_vcpu_run_pid_change(struct kvm_vcpu *vcpu)
 			return ret;
 	}
 
+	/*
+	 * This needs to happen after NV has imposed its own restrictions on
+	 * the feature set
+	 */
+	kvm_init_sysreg(vcpu);
+
 	ret = kvm_timer_enable(vcpu);
 	if (ret)
 		return ret;

arch/arm64/kvm/hyp/include/hyp/switch.h +3 ~~-14~~

index a09149fd91ed..245f9c1ca666 100644
@@ -157,7 +157,7 @@ static inline void __activate_traps_hfgxtr(struct kvm_vcpu *vcpu)
 {
 	struct kvm_cpu_context *hctxt = &this_cpu_ptr(&kvm_host_data)->host_ctxt;
 	struct kvm *kvm = kern_hyp_va(vcpu->kvm);
-	u64 r_clr = 0, w_clr = 0, r_set = 0, w_set = 0, tmp;
+	u64 r_clr = 0, w_clr = 0, r_set = 0, w_set = 0;
 	u64 r_val, w_val;
 
 	CHECK_FGT_MASKS(HFGRTR_EL2);

@@ -174,13 +174,6 @@ static inline void __activate_traps_hfgxtr(struct kvm_vcpu *vcpu)
 	ctxt_sys_reg(hctxt, HFGRTR_EL2) = read_sysreg_s(SYS_HFGRTR_EL2);
 	ctxt_sys_reg(hctxt, HFGWTR_EL2) = read_sysreg_s(SYS_HFGWTR_EL2);
 
-	if (cpus_have_final_cap(ARM64_SME)) {
-		tmp = HFGxTR_EL2_nSMPRI_EL1_MASK | HFGxTR_EL2_nTPIDR2_EL0_MASK;
-
-		r_clr |= tmp;
-		w_clr |= tmp;
-	}
-
 	/*
 	 * Trap guest writes to TCR_EL1 to prevent it from enabling HA or HD.
 	 */

@@ -195,15 +188,11 @@ static inline void __activate_traps_hfgxtr(struct kvm_vcpu *vcpu)
 	compute_undef_clr_set(vcpu, kvm, HFGRTR_EL2, r_clr, r_set);
 	compute_undef_clr_set(vcpu, kvm, HFGWTR_EL2, w_clr, w_set);
 
-	/* The default to trap everything not handled or supported in KVM. */
-	tmp = HFGxTR_EL2_nAMAIR2_EL1 | HFGxTR_EL2_nMAIR2_EL1 | HFGxTR_EL2_nS2POR_EL1 |
-	      HFGxTR_EL2_nPOR_EL1 | HFGxTR_EL2_nPOR_EL0 | HFGxTR_EL2_nACCDATA_EL1;
-
-	r_val = __HFGRTR_EL2_nMASK & ~tmp;
+	r_val = __HFGRTR_EL2_nMASK;
 	r_val |= r_set;
 	r_val &= ~r_clr;
 
-	w_val = __HFGWTR_EL2_nMASK & ~tmp;
+	w_val = __HFGWTR_EL2_nMASK;
 	w_val |= w_set;
 	w_val &= ~w_clr;

arch/arm64/kvm/sys_regs.c +23 -0

index 938df5dc3684..39e7c7f74717 100644
@@ -3942,6 +3942,29 @@ int kvm_vm_ioctl_get_reg_writable_masks(struct kvm *kvm, struct reg_mask_range *
 	return 0;
 }
 
+void kvm_init_sysreg(struct kvm_vcpu *vcpu)
+{
+	struct kvm *kvm = vcpu->kvm;
+
+	mutex_lock(&kvm->arch.config_lock);
+
+	if (test_bit(KVM_ARCH_FLAG_FGU_INITIALIZED, &kvm->arch.flags))
+		goto out;
+
+	kvm->arch.fgu[HFGxTR_GROUP] = (HFGxTR_EL2_nAMAIR2_EL1		|
+				       HFGxTR_EL2_nMAIR2_EL1		|
+				       HFGxTR_EL2_nS2POR_EL1		|
+				       HFGxTR_EL2_nPOR_EL1		|
+				       HFGxTR_EL2_nPOR_EL0		|
+				       HFGxTR_EL2_nACCDATA_EL1		|
+				       HFGxTR_EL2_nSMPRI_EL1_MASK	|
+				       HFGxTR_EL2_nTPIDR2_EL0_MASK);
+
+	set_bit(KVM_ARCH_FLAG_FGU_INITIALIZED, &kvm->arch.flags);
+out:
+	mutex_unlock(&kvm->arch.config_lock);
+}
+
 int __init kvm_sys_reg_table_init(void)
 {
 	struct sys_reg_params params;

Signature · 1 line

2.39.2

Marc Zyngier

author maintainer

2024-02-14 13:18 UTC #21 lore raw

PATCH v4 20/26 KVM: arm64: Streamline save/restore of HFG[RW]TR_EL2

The way we save/restore HFG[RW]TR_EL2 can now be simplified, and the Ampere erratum hack is the only thing that still stands out.

---
 arch/arm64/kvm/hyp/include/hyp/switch.h | 42 ++++++-------------------
 1 file changed, 9 insertions(+), 33 deletions(-)

arch/arm64/kvm/hyp/include/hyp/switch.h +9 ~~-33~~

index 245f9c1ca666..2d5891518006 100644
@@ -157,8 +157,6 @@ static inline void __activate_traps_hfgxtr(struct kvm_vcpu *vcpu)
 {
 	struct kvm_cpu_context *hctxt = &this_cpu_ptr(&kvm_host_data)->host_ctxt;
 	struct kvm *kvm = kern_hyp_va(vcpu->kvm);
-	u64 r_clr = 0, w_clr = 0, r_set = 0, w_set = 0;
-	u64 r_val, w_val;
 
 	CHECK_FGT_MASKS(HFGRTR_EL2);
 	CHECK_FGT_MASKS(HFGWTR_EL2);

@@ -171,34 +169,10 @@ static inline void __activate_traps_hfgxtr(struct kvm_vcpu *vcpu)
 	if (!cpus_have_final_cap(ARM64_HAS_FGT))
 		return;
 
-	ctxt_sys_reg(hctxt, HFGRTR_EL2) = read_sysreg_s(SYS_HFGRTR_EL2);
-	ctxt_sys_reg(hctxt, HFGWTR_EL2) = read_sysreg_s(SYS_HFGWTR_EL2);
-
-	/*
-	 * Trap guest writes to TCR_EL1 to prevent it from enabling HA or HD.
-	 */
-	if (cpus_have_final_cap(ARM64_WORKAROUND_AMPERE_AC03_CPU_38))
-		w_set |= HFGxTR_EL2_TCR_EL1_MASK;
-
-	if (vcpu_has_nv(vcpu) && !is_hyp_ctxt(vcpu)) {
-		compute_clr_set(vcpu, HFGRTR_EL2, r_clr, r_set);
-		compute_clr_set(vcpu, HFGWTR_EL2, w_clr, w_set);
-	}
-
-	compute_undef_clr_set(vcpu, kvm, HFGRTR_EL2, r_clr, r_set);
-	compute_undef_clr_set(vcpu, kvm, HFGWTR_EL2, w_clr, w_set);
-
-	r_val = __HFGRTR_EL2_nMASK;
-	r_val |= r_set;
-	r_val &= ~r_clr;
-
-	w_val = __HFGWTR_EL2_nMASK;
-	w_val |= w_set;
-	w_val &= ~w_clr;
-
-	write_sysreg_s(r_val, SYS_HFGRTR_EL2);
-	write_sysreg_s(w_val, SYS_HFGWTR_EL2);
-
+	update_fgt_traps(hctxt, vcpu, kvm, HFGRTR_EL2);
+	update_fgt_traps_cs(hctxt, vcpu, kvm, HFGWTR_EL2, 0,
+			    cpus_have_final_cap(ARM64_WORKAROUND_AMPERE_AC03_CPU_38) ?
+			    HFGxTR_EL2_TCR_EL1_MASK : 0);
 	update_fgt_traps(hctxt, vcpu, kvm, HFGITR_EL2);
 	update_fgt_traps(hctxt, vcpu, kvm, HDFGRTR_EL2);
 	update_fgt_traps(hctxt, vcpu, kvm, HDFGWTR_EL2);

@@ -223,9 +197,11 @@ static inline void __deactivate_traps_hfgxtr(struct kvm_vcpu *vcpu)
 	if (!cpus_have_final_cap(ARM64_HAS_FGT))
 		return;
 
-	write_sysreg_s(ctxt_sys_reg(hctxt, HFGRTR_EL2), SYS_HFGRTR_EL2);
-	write_sysreg_s(ctxt_sys_reg(hctxt, HFGWTR_EL2), SYS_HFGWTR_EL2);
-
+	__deactivate_fgt(hctxt, vcpu, kvm, HFGRTR_EL2);
+	if (cpus_have_final_cap(ARM64_WORKAROUND_AMPERE_AC03_CPU_38))
+		write_sysreg_s(ctxt_sys_reg(hctxt, HFGWTR_EL2), SYS_HFGWTR_EL2);
+	else
+		__deactivate_fgt(hctxt, vcpu, kvm, HFGWTR_EL2);
 	__deactivate_fgt(hctxt, vcpu, kvm, HFGITR_EL2);
 	__deactivate_fgt(hctxt, vcpu, kvm, HDFGRTR_EL2);
 	__deactivate_fgt(hctxt, vcpu, kvm, HDFGWTR_EL2);

Signature · 1 line

2.39.2

Marc Zyngier

author maintainer

2024-02-14 13:18 UTC #22 lore raw

PATCH v4 21/26 KVM: arm64: Make TLBI OS/Range UNDEF if not advertised to the guest

Outer Shareable and Range TLBI instructions shouldn't be made available to the guest if they are not advertised. Use FGU to disable those, and set HCR_EL2.TLBIOS in the case the host doesn't have FGT. Note that in that later case, we cannot efficiently disable TLBI Range instructions, as this would require to trap all TLBIs.

---
 arch/arm64/kvm/sys_regs.c | 34 ++++++++++++++++++++++++++++++++++
 1 file changed, 34 insertions(+)

arch/arm64/kvm/sys_regs.c +34 -0

index 39e7c7f74717..f07ee7c89822 100644
@@ -3948,6 +3948,14 @@ void kvm_init_sysreg(struct kvm_vcpu *vcpu)
 
 	mutex_lock(&kvm->arch.config_lock);
 
+	/*
+	 * In the absence of FGT, we cannot independently trap TLBI
+	 * Range instructions. This isn't great, but trapping all
+	 * TLBIs would be far worse. Live with it...
+	 */
+	if (!kvm_has_feat(kvm, ID_AA64ISAR0_EL1, TLB, OS))
+		vcpu->arch.hcr_el2 |= HCR_TTLBOS;
+
 	if (test_bit(KVM_ARCH_FLAG_FGU_INITIALIZED, &kvm->arch.flags))
 		goto out;

@@ -3960,6 +3968,32 @@ void kvm_init_sysreg(struct kvm_vcpu *vcpu)
 				       HFGxTR_EL2_nSMPRI_EL1_MASK	|
 				       HFGxTR_EL2_nTPIDR2_EL0_MASK);
 
+	if (!kvm_has_feat(kvm, ID_AA64ISAR0_EL1, TLB, OS))
+		kvm->arch.fgu[HFGITR_GROUP] |= (HFGITR_EL2_TLBIRVAALE1OS|
+						HFGITR_EL2_TLBIRVALE1OS	|
+						HFGITR_EL2_TLBIRVAAE1OS	|
+						HFGITR_EL2_TLBIRVAE1OS	|
+						HFGITR_EL2_TLBIVAALE1OS	|
+						HFGITR_EL2_TLBIVALE1OS	|
+						HFGITR_EL2_TLBIVAAE1OS	|
+						HFGITR_EL2_TLBIASIDE1OS	|
+						HFGITR_EL2_TLBIVAE1OS	|
+						HFGITR_EL2_TLBIVMALLE1OS);
+
+	if (!kvm_has_feat(kvm, ID_AA64ISAR0_EL1, TLB, RANGE))
+		kvm->arch.fgu[HFGITR_GROUP] |= (HFGITR_EL2_TLBIRVAALE1	|
+						HFGITR_EL2_TLBIRVALE1	|
+						HFGITR_EL2_TLBIRVAAE1	|
+						HFGITR_EL2_TLBIRVAE1	|
+						HFGITR_EL2_TLBIRVAALE1IS|
+						HFGITR_EL2_TLBIRVALE1IS	|
+						HFGITR_EL2_TLBIRVAAE1IS	|
+						HFGITR_EL2_TLBIRVAE1IS	|
+						HFGITR_EL2_TLBIRVAALE1OS|
+						HFGITR_EL2_TLBIRVALE1OS	|
+						HFGITR_EL2_TLBIRVAAE1OS	|
+						HFGITR_EL2_TLBIRVAE1OS);
+
 	set_bit(KVM_ARCH_FLAG_FGU_INITIALIZED, &kvm->arch.flags);
 out:
 	mutex_unlock(&kvm->arch.config_lock);

Signature · 1 line

2.39.2

Marc Zyngier

author maintainer

2024-02-14 13:18 UTC #23 lore raw

PATCH v4 22/26 KVM: arm64: Make PIR{,E0}_EL1 UNDEF if S1PIE is not advertised to the guest

As part of the ongoing effort to honor the guest configuration, add the necessary checks to make PIR_EL1 and co UNDEF if not advertised to the guest, and avoid context switching them.

---
 arch/arm64/kvm/hyp/include/hyp/sysreg-sr.h | 24 +++++++++++++++++++---
 arch/arm64/kvm/sys_regs.c                  |  4 ++++
 2 files changed, 25 insertions(+), 3 deletions(-)

arch/arm64/kvm/hyp/include/hyp/sysreg-sr.h +21 -3

index bb6b571ec627..4be6a7fa0070 100644
@@ -27,16 +27,34 @@ static inline void __sysreg_save_user_state(struct kvm_cpu_context *ctxt)
 	ctxt_sys_reg(ctxt, TPIDRRO_EL0)	= read_sysreg(tpidrro_el0);
 }
 
-static inline bool ctxt_has_mte(struct kvm_cpu_context *ctxt)
+static inline struct kvm_vcpu *ctxt_to_vcpu(struct kvm_cpu_context *ctxt)
 {
 	struct kvm_vcpu *vcpu = ctxt->__hyp_running_vcpu;
 
 	if (!vcpu)
 		vcpu = container_of(ctxt, struct kvm_vcpu, arch.ctxt);
 
+	return vcpu;
+}
+
+static inline bool ctxt_has_mte(struct kvm_cpu_context *ctxt)
+{
+	struct kvm_vcpu *vcpu = ctxt_to_vcpu(ctxt);
+
 	return kvm_has_mte(kern_hyp_va(vcpu->kvm));
 }
 
+static inline bool ctxt_has_s1pie(struct kvm_cpu_context *ctxt)
+{
+	struct kvm_vcpu *vcpu;
+
+	if (!cpus_have_final_cap(ARM64_HAS_S1PIE))
+		return false;
+
+	vcpu = ctxt_to_vcpu(ctxt);
+	return kvm_has_feat(kern_hyp_va(vcpu->kvm), ID_AA64MMFR3_EL1, S1PIE, IMP);
+}
+
 static inline void __sysreg_save_el1_state(struct kvm_cpu_context *ctxt)
 {
 	ctxt_sys_reg(ctxt, SCTLR_EL1)	= read_sysreg_el1(SYS_SCTLR);

@@ -55,7 +73,7 @@ static inline void __sysreg_save_el1_state(struct kvm_cpu_context *ctxt)
 	ctxt_sys_reg(ctxt, CONTEXTIDR_EL1) = read_sysreg_el1(SYS_CONTEXTIDR);
 	ctxt_sys_reg(ctxt, AMAIR_EL1)	= read_sysreg_el1(SYS_AMAIR);
 	ctxt_sys_reg(ctxt, CNTKCTL_EL1)	= read_sysreg_el1(SYS_CNTKCTL);
-	if (cpus_have_final_cap(ARM64_HAS_S1PIE)) {
+	if (ctxt_has_s1pie(ctxt)) {
 		ctxt_sys_reg(ctxt, PIR_EL1)	= read_sysreg_el1(SYS_PIR);
 		ctxt_sys_reg(ctxt, PIRE0_EL1)	= read_sysreg_el1(SYS_PIRE0);
 	}

@@ -131,7 +149,7 @@ static inline void __sysreg_restore_el1_state(struct kvm_cpu_context *ctxt)
 	write_sysreg_el1(ctxt_sys_reg(ctxt, CONTEXTIDR_EL1), SYS_CONTEXTIDR);
 	write_sysreg_el1(ctxt_sys_reg(ctxt, AMAIR_EL1),	SYS_AMAIR);
 	write_sysreg_el1(ctxt_sys_reg(ctxt, CNTKCTL_EL1), SYS_CNTKCTL);
-	if (cpus_have_final_cap(ARM64_HAS_S1PIE)) {
+	if (ctxt_has_s1pie(ctxt)) {
 		write_sysreg_el1(ctxt_sys_reg(ctxt, PIR_EL1),	SYS_PIR);
 		write_sysreg_el1(ctxt_sys_reg(ctxt, PIRE0_EL1),	SYS_PIRE0);
 	}

arch/arm64/kvm/sys_regs.c +4 -0

index f07ee7c89822..da9db99c77e7 100644
@@ -3994,6 +3994,10 @@ void kvm_init_sysreg(struct kvm_vcpu *vcpu)
 						HFGITR_EL2_TLBIRVAAE1OS	|
 						HFGITR_EL2_TLBIRVAE1OS);
 
+	if (!kvm_has_feat(kvm, ID_AA64MMFR3_EL1, S1PIE, IMP))
+		kvm->arch.fgu[HFGxTR_GROUP] |= (HFGxTR_EL2_nPIRE0_EL1 |
+						HFGxTR_EL2_nPIR_EL1);
+
 	set_bit(KVM_ARCH_FLAG_FGU_INITIALIZED, &kvm->arch.flags);
 out:
 	mutex_unlock(&kvm->arch.config_lock);

Signature · 1 line

2.39.2

Marc Zyngier

author maintainer

2024-02-14 13:18 UTC #24 lore raw

PATCH v4 23/26 KVM: arm64: Make AMU sysreg UNDEF if FEAT_AMU is not advertised to the guest

No AMU? No AMU! IF we see an AMU-related trap, let's turn it into an UNDEF!

---
 arch/arm64/kvm/sys_regs.c | 4 ++++
 1 file changed, 4 insertions(+)

arch/arm64/kvm/sys_regs.c +4 -0

index da9db99c77e7..38ed47bd29db 100644
@@ -3998,6 +3998,10 @@ void kvm_init_sysreg(struct kvm_vcpu *vcpu)
 		kvm->arch.fgu[HFGxTR_GROUP] |= (HFGxTR_EL2_nPIRE0_EL1 |
 						HFGxTR_EL2_nPIR_EL1);
 
+	if (!kvm_has_feat(kvm, ID_AA64PFR0_EL1, AMU, IMP))
+		kvm->arch.fgu[HAFGRTR_GROUP] |= ~(HAFGRTR_EL2_RES0 |
+						  HAFGRTR_EL2_RES1);
+
 	set_bit(KVM_ARCH_FLAG_FGU_INITIALIZED, &kvm->arch.flags);
 out:
 	mutex_unlock(&kvm->arch.config_lock);

Signature · 1 line

2.39.2

Marc Zyngier

author maintainer

2024-02-14 13:18 UTC #25 lore raw

PATCH v4 24/26 KVM: arm64: Make FEAT_MOPS UNDEF if not advertised to the guest

We unconditionally enable FEAT_MOPS, which is obviously wrong.

So let's only do that when it is advertised to the guest. Which means we need to rely on a per-vcpu HCRX_EL2 shadow register.

---
 arch/arm64/include/asm/kvm_arm.h        | 4 +---
 arch/arm64/include/asm/kvm_host.h       | 1 +
 arch/arm64/kvm/hyp/include/hyp/switch.h | 2 +-
 arch/arm64/kvm/sys_regs.c               | 7 +++++++
 4 files changed, 10 insertions(+), 4 deletions(-)

arch/arm64/include/asm/kvm_arm.h +1 -3

index 3c6f8ba1e479..a1769e415d72 100644
@@ -102,9 +102,7 @@
 #define HCR_HOST_NVHE_PROTECTED_FLAGS (HCR_HOST_NVHE_FLAGS | HCR_TSC)
 #define HCR_HOST_VHE_FLAGS (HCR_RW | HCR_TGE | HCR_E2H)
 
-#define HCRX_GUEST_FLAGS \
-	(HCRX_EL2_SMPME | HCRX_EL2_TCR2En | \
-	 (cpus_have_final_cap(ARM64_HAS_MOPS) ? (HCRX_EL2_MSCEn | HCRX_EL2_MCE2) : 0))
+#define HCRX_GUEST_FLAGS (HCRX_EL2_SMPME | HCRX_EL2_TCR2En)
 #define HCRX_HOST_FLAGS (HCRX_EL2_MSCEn | HCRX_EL2_TCR2En)
 
 /* TCR_EL2 Registers bits */

arch/arm64/include/asm/kvm_host.h +1 -0

index 968a997b3f02..3feabde9c926 100644
@@ -584,6 +584,7 @@ struct kvm_vcpu_arch {
 
 	/* Values of trap registers for the guest. */
 	u64 hcr_el2;
+	u64 hcrx_el2;
 	u64 mdcr_el2;
 	u64 cptr_el2;

arch/arm64/kvm/hyp/include/hyp/switch.h +1 -1

index 2d5891518006..e3fcf8c4d5b4 100644
@@ -236,7 +236,7 @@ static inline void __activate_traps_common(struct kvm_vcpu *vcpu)
 	write_sysreg(vcpu->arch.mdcr_el2, mdcr_el2);
 
 	if (cpus_have_final_cap(ARM64_HAS_HCX)) {
-		u64 hcrx = HCRX_GUEST_FLAGS;
+		u64 hcrx = vcpu->arch.hcrx_el2;
 		if (vcpu_has_nv(vcpu) && !is_hyp_ctxt(vcpu)) {
 			u64 clr = 0, set = 0;

arch/arm64/kvm/sys_regs.c +7 -0

index 38ed47bd29db..2cb69efac1dc 100644
@@ -3956,6 +3956,13 @@ void kvm_init_sysreg(struct kvm_vcpu *vcpu)
 	if (!kvm_has_feat(kvm, ID_AA64ISAR0_EL1, TLB, OS))
 		vcpu->arch.hcr_el2 |= HCR_TTLBOS;
 
+	if (cpus_have_final_cap(ARM64_HAS_HCX)) {
+		vcpu->arch.hcrx_el2 = HCRX_GUEST_FLAGS;
+
+		if (kvm_has_feat(kvm, ID_AA64ISAR2_EL1, MOPS, IMP))
+			vcpu->arch.hcrx_el2 |= (HCRX_EL2_MSCEn | HCRX_EL2_MCE2);
+	}
+
 	if (test_bit(KVM_ARCH_FLAG_FGU_INITIALIZED, &kvm->arch.flags))
 		goto out;

Signature · 1 line

2.39.2

Marc Zyngier

author maintainer

2024-02-14 13:18 UTC #26 lore raw

PATCH v4 25/26 KVM: arm64: Snapshot all non-zero RES0/RES1 sysreg fields for later checking

As KVM now strongly relies on accurately handling the RES0/RES1 bits on a number of paths, add a compile-time checker that will blow in the face of the innocent bystander, should they try to sneak in an update that changes any of these RES0/RES1 fields.

It is expected that such an update will come with the relevant KVM update if needed.

---
 arch/arm64/kvm/check-res-bits.h | 121 ++++++++++++++++++++++++++++++++
 arch/arm64/kvm/sys_regs.c       |   3 +
 2 files changed, 124 insertions(+)
 create mode 100644 arch/arm64/kvm/check-res-bits.h

arch/arm64/kvm/check-res-bits.h new file +121 -0

new file mode 100644
index 000000000000..967b5d171d53
@@ -0,0 +1,121 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2024 - Google LLC
+ * Author: Marc Zyngier <[email protected]>
+ */
+
+#include <asm/sysreg-defs.h>
+
+/*
+ * WARNING WARNING WARNING WARNING WARNING WARNING WARNING WARNING
+ *
+ * If any of these BUILD_BUG_ON() fails, that's because some bits that
+ * were reserved have gained some other meaning, and KVM needs to know
+ * about those.
+ *
+ * In such case, do *NOT* blindly change the assertion so that it
+ * passes, but also teach the rest of the code about the actual
+ * change.
+ *
+ * WARNING WARNING WARNING WARNING WARNING WARNING WARNING WARNING
+ */
+static inline void check_res_bits(void)
+{
+	BUILD_BUG_ON(OSDTRRX_EL1_RES0		!= (GENMASK_ULL(63, 32)));
+	BUILD_BUG_ON(MDCCINT_EL1_RES0		!= (GENMASK_ULL(63, 31) | GENMASK_ULL(28, 0)));
+	BUILD_BUG_ON(MDSCR_EL1_RES0		!= (GENMASK_ULL(63, 36) | GENMASK_ULL(28, 28) | GENMASK_ULL(25, 24) | GENMASK_ULL(20, 20) | GENMASK_ULL(18, 16) | GENMASK_ULL(11, 7) | GENMASK_ULL(5, 1)));
+	BUILD_BUG_ON(OSDTRTX_EL1_RES0		!= (GENMASK_ULL(63, 32)));
+	BUILD_BUG_ON(OSECCR_EL1_RES0		!= (GENMASK_ULL(63, 32)));
+	BUILD_BUG_ON(OSLAR_EL1_RES0		!= (GENMASK_ULL(63, 1)));
+	BUILD_BUG_ON(ID_PFR0_EL1_RES0		!= (GENMASK_ULL(63, 32)));
+	BUILD_BUG_ON(ID_PFR1_EL1_RES0		!= (GENMASK_ULL(63, 32)));
+	BUILD_BUG_ON(ID_DFR0_EL1_RES0		!= (GENMASK_ULL(63, 32)));
+	BUILD_BUG_ON(ID_AFR0_EL1_RES0		!= (GENMASK_ULL(63, 16)));
+	BUILD_BUG_ON(ID_MMFR0_EL1_RES0		!= (GENMASK_ULL(63, 32)));
+	BUILD_BUG_ON(ID_MMFR1_EL1_RES0		!= (GENMASK_ULL(63, 32)));
+	BUILD_BUG_ON(ID_MMFR2_EL1_RES0		!= (GENMASK_ULL(63, 32)));
+	BUILD_BUG_ON(ID_MMFR3_EL1_RES0		!= (GENMASK_ULL(63, 32)));
+	BUILD_BUG_ON(ID_ISAR0_EL1_RES0		!= (GENMASK_ULL(63, 28)));
+	BUILD_BUG_ON(ID_ISAR1_EL1_RES0		!= (GENMASK_ULL(63, 32)));
+	BUILD_BUG_ON(ID_ISAR2_EL1_RES0		!= (GENMASK_ULL(63, 32)));
+	BUILD_BUG_ON(ID_ISAR3_EL1_RES0		!= (GENMASK_ULL(63, 32)));
+	BUILD_BUG_ON(ID_ISAR4_EL1_RES0		!= (GENMASK_ULL(63, 32)));
+	BUILD_BUG_ON(ID_ISAR5_EL1_RES0		!= (GENMASK_ULL(63, 32) | GENMASK_ULL(23, 20)));
+	BUILD_BUG_ON(ID_ISAR6_EL1_RES0		!= (GENMASK_ULL(63, 28)));
+	BUILD_BUG_ON(ID_MMFR4_EL1_RES0		!= (GENMASK_ULL(63, 32)));
+	BUILD_BUG_ON(MVFR0_EL1_RES0		!= (GENMASK_ULL(63, 32)));
+	BUILD_BUG_ON(MVFR1_EL1_RES0		!= (GENMASK_ULL(63, 32)));
+	BUILD_BUG_ON(MVFR2_EL1_RES0		!= (GENMASK_ULL(63, 8)));
+	BUILD_BUG_ON(ID_PFR2_EL1_RES0		!= (GENMASK_ULL(63, 12)));
+	BUILD_BUG_ON(ID_DFR1_EL1_RES0		!= (GENMASK_ULL(63, 8)));
+	BUILD_BUG_ON(ID_MMFR5_EL1_RES0		!= (GENMASK_ULL(63, 8)));
+	BUILD_BUG_ON(ID_AA64PFR1_EL1_RES0	!= (GENMASK_ULL(23, 20)));
+	BUILD_BUG_ON(ID_AA64PFR2_EL1_RES0	!= (GENMASK_ULL(63, 36) | GENMASK_ULL(31, 12)));
+	BUILD_BUG_ON(ID_AA64ZFR0_EL1_RES0	!= (GENMASK_ULL(63, 60) | GENMASK_ULL(51, 48) | GENMASK_ULL(39, 36) | GENMASK_ULL(31, 28) | GENMASK_ULL(15, 8)));
+	BUILD_BUG_ON(ID_AA64SMFR0_EL1_RES0	!= (GENMASK_ULL(62, 61) | GENMASK_ULL(51, 49) | GENMASK_ULL(31, 31) | GENMASK_ULL(27, 0)));
+	BUILD_BUG_ON(ID_AA64FPFR0_EL1_RES0	!= (GENMASK_ULL(63, 32) | GENMASK_ULL(27, 2)));
+	BUILD_BUG_ON(ID_AA64DFR0_EL1_RES0	!= (GENMASK_ULL(27, 24) | GENMASK_ULL(19, 16)));
+	BUILD_BUG_ON(ID_AA64DFR1_EL1_RES0	!= (GENMASK_ULL(63, 0)));
+	BUILD_BUG_ON(ID_AA64AFR0_EL1_RES0	!= (GENMASK_ULL(63, 32)));
+	BUILD_BUG_ON(ID_AA64AFR1_EL1_RES0	!= (GENMASK_ULL(63, 0)));
+	BUILD_BUG_ON(ID_AA64ISAR0_EL1_RES0	!= (GENMASK_ULL(3, 0)));
+	BUILD_BUG_ON(ID_AA64ISAR2_EL1_RES0	!= (GENMASK_ULL(47, 44)));
+	BUILD_BUG_ON(ID_AA64ISAR3_EL1_RES0	!= (GENMASK_ULL(63, 16)));
+	BUILD_BUG_ON(ID_AA64MMFR0_EL1_RES0	!= (GENMASK_ULL(55, 48)));
+	BUILD_BUG_ON(ID_AA64MMFR2_EL1_RES0	!= (GENMASK_ULL(47, 44)));
+	BUILD_BUG_ON(ID_AA64MMFR3_EL1_RES0	!= (GENMASK_ULL(51, 48)));
+	BUILD_BUG_ON(ID_AA64MMFR4_EL1_RES0	!= (GENMASK_ULL(63, 40) | GENMASK_ULL(35, 28) | GENMASK_ULL(3, 0)));
+	BUILD_BUG_ON(SCTLR_EL1_RES0		!= (GENMASK_ULL(17, 17)));
+	BUILD_BUG_ON(CPACR_ELx_RES0		!= (GENMASK_ULL(63, 30) | GENMASK_ULL(27, 26) | GENMASK_ULL(23, 22) | GENMASK_ULL(19, 18) | GENMASK_ULL(15, 0)));
+	BUILD_BUG_ON(SMPRI_EL1_RES0		!= (GENMASK_ULL(63, 4)));
+	BUILD_BUG_ON(ZCR_ELx_RES0		!= (GENMASK_ULL(63, 9)));
+	BUILD_BUG_ON(SMCR_ELx_RES0		!= (GENMASK_ULL(63, 32) | GENMASK_ULL(29, 9)));
+	BUILD_BUG_ON(GCSCR_ELx_RES0		!= (GENMASK_ULL(63, 10) | GENMASK_ULL(7, 7) | GENMASK_ULL(4, 1)));
+	BUILD_BUG_ON(GCSPR_ELx_RES0		!= (GENMASK_ULL(2, 0)));
+	BUILD_BUG_ON(GCSCRE0_EL1_RES0		!= (GENMASK_ULL(63, 11) | GENMASK_ULL(7, 6) | GENMASK_ULL(4, 1)));
+	BUILD_BUG_ON(ALLINT_RES0		!= (GENMASK_ULL(63, 14) | GENMASK_ULL(12, 0)));
+	BUILD_BUG_ON(PMSCR_EL1_RES0		!= (GENMASK_ULL(63, 8) | GENMASK_ULL(2, 2)));
+	BUILD_BUG_ON(PMSICR_EL1_RES0		!= (GENMASK_ULL(55, 32)));
+	BUILD_BUG_ON(PMSIRR_EL1_RES0		!= (GENMASK_ULL(63, 32) | GENMASK_ULL(7, 1)));
+	BUILD_BUG_ON(PMSFCR_EL1_RES0		!= (GENMASK_ULL(63, 19) | GENMASK_ULL(15, 4)));
+	BUILD_BUG_ON(PMSLATFR_EL1_RES0		!= (GENMASK_ULL(63, 16)));
+	BUILD_BUG_ON(PMSIDR_EL1_RES0		!= (GENMASK_ULL(63, 25) | GENMASK_ULL(7, 7)));
+	BUILD_BUG_ON(PMBLIMITR_EL1_RES0		!= (GENMASK_ULL(11, 6) | GENMASK_ULL(4, 3)));
+	BUILD_BUG_ON(PMBSR_EL1_RES0		!= (GENMASK_ULL(63, 32) | GENMASK_ULL(25, 20)));
+	BUILD_BUG_ON(PMBIDR_EL1_RES0		!= (GENMASK_ULL(63, 12) | GENMASK_ULL(7, 6)));
+	BUILD_BUG_ON(CONTEXTIDR_ELx_RES0	!= (GENMASK_ULL(63, 32)));
+	BUILD_BUG_ON(CCSIDR_EL1_RES0		!= (GENMASK_ULL(63, 32)));
+	BUILD_BUG_ON(CLIDR_EL1_RES0		!= (GENMASK_ULL(63, 47)));
+	BUILD_BUG_ON(CCSIDR2_EL1_RES0		!= (GENMASK_ULL(63, 24)));
+	BUILD_BUG_ON(GMID_EL1_RES0		!= (GENMASK_ULL(63, 4)));
+	BUILD_BUG_ON(SMIDR_EL1_RES0		!= (GENMASK_ULL(63, 32) | GENMASK_ULL(14, 12)));
+	BUILD_BUG_ON(CSSELR_EL1_RES0		!= (GENMASK_ULL(63, 5)));
+	BUILD_BUG_ON(CTR_EL0_RES0		!= (GENMASK_ULL(63, 38) | GENMASK_ULL(30, 30) | GENMASK_ULL(13, 4)));
+	BUILD_BUG_ON(CTR_EL0_RES1       	!= (GENMASK_ULL(31, 31)));
+	BUILD_BUG_ON(DCZID_EL0_RES0		!= (GENMASK_ULL(63, 5)));
+	BUILD_BUG_ON(SVCR_RES0			!= (GENMASK_ULL(63, 2)));
+	BUILD_BUG_ON(FPMR_RES0			!= (GENMASK_ULL(63, 38) | GENMASK_ULL(23, 23) | GENMASK_ULL(13, 9)));
+	BUILD_BUG_ON(HFGxTR_EL2_RES0		!= (GENMASK_ULL(51, 51)));
+	BUILD_BUG_ON(HFGITR_EL2_RES0		!= (GENMASK_ULL(63, 63) | GENMASK_ULL(61, 61)));
+	BUILD_BUG_ON(HDFGRTR_EL2_RES0		!= (GENMASK_ULL(49, 49) | GENMASK_ULL(42, 42) | GENMASK_ULL(39, 38) | GENMASK_ULL(21, 20) | GENMASK_ULL(8, 8)));
+	BUILD_BUG_ON(HDFGWTR_EL2_RES0		!= (GENMASK_ULL(63, 63) | GENMASK_ULL(59, 58) | GENMASK_ULL(51, 51) | GENMASK_ULL(47, 47) | GENMASK_ULL(43, 43) | GENMASK_ULL(40, 38) | GENMASK_ULL(34, 34) | GENMASK_ULL(30, 30) | GENMASK_ULL(22, 22) | GENMASK_ULL(9, 9) | GENMASK_ULL(6, 6)));
+	BUILD_BUG_ON(HAFGRTR_EL2_RES0		!= (GENMASK_ULL(63, 50) | GENMASK_ULL(16, 5)));
+	BUILD_BUG_ON(HCRX_EL2_RES0		!= (GENMASK_ULL(63, 25) | GENMASK_ULL(13, 12)));
+	BUILD_BUG_ON(DACR32_EL2_RES0		!= (GENMASK_ULL(63, 32)));
+	BUILD_BUG_ON(PMSCR_EL2_RES0		!= (GENMASK_ULL(63, 8) | GENMASK_ULL(2, 2)));
+	BUILD_BUG_ON(TCR2_EL1x_RES0		!= (GENMASK_ULL(63, 16) | GENMASK_ULL(13, 12) | GENMASK_ULL(9, 6)));
+	BUILD_BUG_ON(TCR2_EL2_RES0		!= (GENMASK_ULL(63, 16)));
+	BUILD_BUG_ON(LORSA_EL1_RES0		!= (GENMASK_ULL(63, 52) | GENMASK_ULL(15, 1)));
+	BUILD_BUG_ON(LOREA_EL1_RES0		!= (GENMASK_ULL(63, 52) | GENMASK_ULL(15, 0)));
+	BUILD_BUG_ON(LORN_EL1_RES0		!= (GENMASK_ULL(63, 8)));
+	BUILD_BUG_ON(LORC_EL1_RES0		!= (GENMASK_ULL(63, 10) | GENMASK_ULL(1, 1)));
+	BUILD_BUG_ON(LORID_EL1_RES0		!= (GENMASK_ULL(63, 24) | GENMASK_ULL(15, 8)));
+	BUILD_BUG_ON(ISR_EL1_RES0		!= (GENMASK_ULL(63, 11) | GENMASK_ULL(5, 0)));
+	BUILD_BUG_ON(ICC_NMIAR1_EL1_RES0	!= (GENMASK_ULL(63, 24)));
+	BUILD_BUG_ON(TRBLIMITR_EL1_RES0		!= (GENMASK_ULL(11, 7)));
+	BUILD_BUG_ON(TRBBASER_EL1_RES0		!= (GENMASK_ULL(11, 0)));
+	BUILD_BUG_ON(TRBSR_EL1_RES0		!= (GENMASK_ULL(63, 56) | GENMASK_ULL(25, 24) | GENMASK_ULL(19, 19) | GENMASK_ULL(16, 16)));
+	BUILD_BUG_ON(TRBMAR_EL1_RES0		!= (GENMASK_ULL(63, 12)));
+	BUILD_BUG_ON(TRBTRG_EL1_RES0		!= (GENMASK_ULL(63, 32)));
+	BUILD_BUG_ON(TRBIDR_EL1_RES0		!= (GENMASK_ULL(63, 12) | GENMASK_ULL(7, 6)));
+}

arch/arm64/kvm/sys_regs.c +3 -0

index 2cb69efac1dc..b5335e5a6e6e 100644
@@ -31,6 +31,7 @@
 
 #include <trace/events/kvm.h>
 
+#include "check-res-bits.h"
 #include "sys_regs.h"
 
 #include "trace.h"

@@ -4021,6 +4022,8 @@ int __init kvm_sys_reg_table_init(void)
 	unsigned int i;
 	int ret = 0;
 
+	check_res_bits();
+
 	/* Make sure tables are unique and in order. */
 	valid &= check_sysreg_table(sys_reg_descs, ARRAY_SIZE(sys_reg_descs), false);
 	valid &= check_sysreg_table(cp14_regs, ARRAY_SIZE(cp14_regs), true);

Signature · 1 line

2.39.2

Marc Zyngier

author maintainer

2024-02-14 13:18 UTC #27 lore raw

PATCH v4 26/26 KVM: arm64: Add debugfs file for guest's ID registers

Debugging ID register setup can be a complicated affair. Give the kernel hacker a way to dump that state in an easy to parse way.

---
 arch/arm64/include/asm/kvm_host.h |  3 ++
 arch/arm64/kvm/sys_regs.c         | 81 +++++++++++++++++++++++++++++++
 2 files changed, 84 insertions(+)

arch/arm64/include/asm/kvm_host.h +3 -0

index 3feabde9c926..181fef12e8e8 100644
@@ -319,6 +319,9 @@ struct kvm_arch {
 	/* PMCR_EL0.N value for the guest */
 	u8 pmcr_n;
 
+	/* Iterator for idreg debugfs */
+	u8	idreg_debugfs_iter;
+
 	/* Hypercall features firmware registers' descriptor */
 	struct kvm_smccc_features smccc_feat;
 	struct maple_tree smccc_filter;

arch/arm64/kvm/sys_regs.c +81 -0

99 lines not on this page · raw message

Signature · 1 line

2.39.2

Oliver Upton

2024-02-15 21:03 UTC #28 lore raw

Quoted 3 lines · Marc Zyngier

This is the fourth version of this configurationm enforcement series after additional reviewing from Suzuki and Oliver. Many thanks to both.

I'm leaning towards applying the whole series, this is looking good. I'm going to take it for a spin on a few machines, especially AmpereOne to make sure that hack still works :)

Signature · 2 lines

Thanks,
Oliver

Oliver Upton

Applied

2024-02-19 17:34 UTC #29 lore raw