Merge branch 'kvm-arm64/pmuv3-asahi' into kvmarm/next

* kvm-arm64/pmuv3-asahi:
  : Support PMUv3 for KVM guests on Apple silicon
  :
  : Take advantage of some IMPLEMENTATION DEFINED traps available on Apple
  : parts to trap-and-emulate the PMUv3 registers on behalf of a KVM guest.
  : Constrain the vPMU to a cycle counter and single event counter, as the
  : Apple PMU has events that cannot be counted on every counter.
  :
  : There is a small new interface between the ARM PMU driver and KVM, where
  : the PMU driver owns the PMUv3 -> hardware event mappings.
  arm64: Enable IMP DEF PMUv3 traps on Apple M*
  KVM: arm64: Provide 1 event counter on IMPDEF hardware
  drivers/perf: apple_m1: Provide helper for mapping PMUv3 events
  KVM: arm64: Remap PMUv3 events onto hardware
  KVM: arm64: Advertise PMUv3 if IMPDEF traps are present
  KVM: arm64: Compute synthetic sysreg ESR for Apple PMUv3 traps
  KVM: arm64: Move PMUVer filtering into KVM code
  KVM: arm64: Use guard() to cleanup usage of arm_pmus_lock
  KVM: arm64: Drop kvm_arm_pmu_available static key
  KVM: arm64: Use a cpucap to determine if system supports FEAT_PMUv3
  KVM: arm64: Always support SW_INCR PMU event
  KVM: arm64: Compute PMCEID from arm_pmu's event bitmaps
  drivers/perf: apple_m1: Support host/guest event filtering
  drivers/perf: apple_m1: Refactor event select/filter configuration

Signed-off-by: Oliver Upton <oliver.upton@linux.dev>

arch/arm64/include/asm/apple_m1_pmu.h

@@ -37,6 +37,7 @@
 #define PMCR0_PMI_ENABLE_8_9	GENMASK(45, 44)
 
 #define SYS_IMP_APL_PMCR1_EL1	sys_reg(3, 1, 15, 1, 0)
+#define SYS_IMP_APL_PMCR1_EL12	sys_reg(3, 1, 15, 7, 2)
 #define PMCR1_COUNT_A64_EL0_0_7	GENMASK(15, 8)
 #define PMCR1_COUNT_A64_EL1_0_7	GENMASK(23, 16)
 #define PMCR1_COUNT_A64_EL0_8_9	GENMASK(41, 40)

arch/arm64/include/asm/cpucaps.h

@@ -71,6 +71,8 @@ cpucap_is_possible(const unsigned int cap)
 		 * KVM MPAM support doesn't rely on the host kernel supporting MPAM.
 		*/
 		return true;
+	case ARM64_HAS_PMUV3:
+		return IS_ENABLED(CONFIG_HW_PERF_EVENTS);
 	}
 
 	return true;

arch/arm64/include/asm/cpufeature.h

@@ -525,29 +525,6 @@ cpuid_feature_extract_unsigned_field(u64 features, int field)
 	return cpuid_feature_extract_unsigned_field_width(features, field, 4);
 }
 
-/*
- * Fields that identify the version of the Performance Monitors Extension do
- * not follow the standard ID scheme. See ARM DDI 0487E.a page D13-2825,
- * "Alternative ID scheme used for the Performance Monitors Extension version".
- */
-static inline u64 __attribute_const__
-cpuid_feature_cap_perfmon_field(u64 features, int field, u64 cap)
-{
-	u64 val = cpuid_feature_extract_unsigned_field(features, field);
-	u64 mask = GENMASK_ULL(field + 3, field);
-
-	/* Treat IMPLEMENTATION DEFINED functionality as unimplemented */
-	if (val == ID_AA64DFR0_EL1_PMUVer_IMP_DEF)
-		val = 0;
-
-	if (val > cap) {
-		features &= ~mask;
-		features |= (cap << field) & mask;
-	}
-
-	return features;
-}
-
 static inline u64 arm64_ftr_mask(const struct arm64_ftr_bits *ftrp)
 {
 	return (u64)GENMASK(ftrp->shift + ftrp->width - 1, ftrp->shift);
@@ -866,6 +843,11 @@ static __always_inline bool system_supports_mpam_hcr(void)
 	return alternative_has_cap_unlikely(ARM64_MPAM_HCR);
 }
 
+static inline bool system_supports_pmuv3(void)
+{
+	return cpus_have_final_cap(ARM64_HAS_PMUV3);
+}
+
 int do_emulate_mrs(struct pt_regs *regs, u32 sys_reg, u32 rt);
 bool try_emulate_mrs(struct pt_regs *regs, u32 isn);
 

arch/arm64/kernel/cpu_errata.c

@@ -247,6 +247,43 @@ has_neoverse_n1_erratum_1542419(const struct arm64_cpu_capabilities *entry,
 	return is_midr_in_range(&range) && has_dic;
 }
 
+static const struct midr_range impdef_pmuv3_cpus[] = {
+	MIDR_ALL_VERSIONS(MIDR_APPLE_M1_ICESTORM),
+	MIDR_ALL_VERSIONS(MIDR_APPLE_M1_FIRESTORM),
+	MIDR_ALL_VERSIONS(MIDR_APPLE_M1_ICESTORM_PRO),
+	MIDR_ALL_VERSIONS(MIDR_APPLE_M1_FIRESTORM_PRO),
+	MIDR_ALL_VERSIONS(MIDR_APPLE_M1_ICESTORM_MAX),
+	MIDR_ALL_VERSIONS(MIDR_APPLE_M1_FIRESTORM_MAX),
+	MIDR_ALL_VERSIONS(MIDR_APPLE_M2_BLIZZARD),
+	MIDR_ALL_VERSIONS(MIDR_APPLE_M2_AVALANCHE),
+	MIDR_ALL_VERSIONS(MIDR_APPLE_M2_BLIZZARD_PRO),
+	MIDR_ALL_VERSIONS(MIDR_APPLE_M2_AVALANCHE_PRO),
+	MIDR_ALL_VERSIONS(MIDR_APPLE_M2_BLIZZARD_MAX),
+	MIDR_ALL_VERSIONS(MIDR_APPLE_M2_AVALANCHE_MAX),
+	{},
+};
+
+static bool has_impdef_pmuv3(const struct arm64_cpu_capabilities *entry, int scope)
+{
+	u64 dfr0 = read_sanitised_ftr_reg(SYS_ID_AA64DFR0_EL1);
+	unsigned int pmuver;
+
+	if (!is_kernel_in_hyp_mode())
+		return false;
+
+	pmuver = cpuid_feature_extract_unsigned_field(dfr0,
+						      ID_AA64DFR0_EL1_PMUVer_SHIFT);
+	if (pmuver != ID_AA64DFR0_EL1_PMUVer_IMP_DEF)
+		return false;
+
+	return is_midr_in_range_list(impdef_pmuv3_cpus);
+}
+
+static void cpu_enable_impdef_pmuv3_traps(const struct arm64_cpu_capabilities *__unused)
+{
+	sysreg_clear_set_s(SYS_HACR_EL2, 0, BIT(56));
+}
+
 #ifdef CONFIG_ARM64_WORKAROUND_REPEAT_TLBI
 static const struct arm64_cpu_capabilities arm64_repeat_tlbi_list[] = {
 #ifdef CONFIG_QCOM_FALKOR_ERRATUM_1009
@@ -847,6 +884,13 @@ const struct arm64_cpu_capabilities arm64_errata[] = {
 					{}
 				})),
 	},
+	{
+		.desc = "Apple IMPDEF PMUv3 Traps",
+		.capability = ARM64_WORKAROUND_PMUV3_IMPDEF_TRAPS,
+		.type = ARM64_CPUCAP_LOCAL_CPU_ERRATUM,
+		.matches = has_impdef_pmuv3,
+		.cpu_enable = cpu_enable_impdef_pmuv3_traps,
+	},
 	{
 	}
 };

arch/arm64/kernel/cpufeature.c

@@ -1900,6 +1900,28 @@ static bool has_lpa2(const struct arm64_cpu_capabilities *entry, int scope)
 }
 #endif
 
+#ifdef CONFIG_HW_PERF_EVENTS
+static bool has_pmuv3(const struct arm64_cpu_capabilities *entry, int scope)
+{
+	u64 dfr0 = read_sanitised_ftr_reg(SYS_ID_AA64DFR0_EL1);
+	unsigned int pmuver;
+
+	/*
+	 * PMUVer follows the standard ID scheme for an unsigned field with the
+	 * exception of 0xF (IMP_DEF) which is treated specially and implies
+	 * FEAT_PMUv3 is not implemented.
+	 *
+	 * See DDI0487L.a D24.1.3.2 for more details.
+	 */
+	pmuver = cpuid_feature_extract_unsigned_field(dfr0,
+						      ID_AA64DFR0_EL1_PMUVer_SHIFT);
+	if (pmuver == ID_AA64DFR0_EL1_PMUVer_IMP_DEF)
+		return false;
+
+	return pmuver >= ID_AA64DFR0_EL1_PMUVer_IMP;
+}
+#endif
+
 #ifdef CONFIG_UNMAP_KERNEL_AT_EL0
 #define KPTI_NG_TEMP_VA		(-(1UL << PMD_SHIFT))
 
@@ -3010,6 +3032,14 @@ static const struct arm64_cpu_capabilities arm64_features[] = {
 		.matches = has_cpuid_feature,
 		ARM64_CPUID_FIELDS(ID_AA64PFR1_EL1, GCS, IMP)
 	},
+#endif
+#ifdef CONFIG_HW_PERF_EVENTS
+	{
+		.desc = "PMUv3",
+		.capability = ARM64_HAS_PMUV3,
+		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
+		.matches = has_pmuv3,
+	},
 #endif
 	{},
 };

arch/arm64/kernel/image-vars.h

@@ -113,11 +113,6 @@ KVM_NVHE_ALIAS(broken_cntvoff_key);
 KVM_NVHE_ALIAS(__start___kvm_ex_table);
 KVM_NVHE_ALIAS(__stop___kvm_ex_table);
 
-/* PMU available static key */
-#ifdef CONFIG_HW_PERF_EVENTS
-KVM_NVHE_ALIAS(kvm_arm_pmu_available);
-#endif
-
 /* Position-independent library routines */
 KVM_NVHE_ALIAS_HYP(clear_page, __pi_clear_page);
 KVM_NVHE_ALIAS_HYP(copy_page, __pi_copy_page);

arch/arm64/kvm/arm.c

@@ -366,7 +366,7 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext)
 		r = get_num_wrps();
 		break;
 	case KVM_CAP_ARM_PMU_V3:
-		r = kvm_arm_support_pmu_v3();
+		r = kvm_supports_guest_pmuv3();
 		break;
 	case KVM_CAP_ARM_INJECT_SERROR_ESR:
 		r = cpus_have_final_cap(ARM64_HAS_RAS_EXTN);
@@ -1400,7 +1400,7 @@ static unsigned long system_supported_vcpu_features(void)
 	if (!cpus_have_final_cap(ARM64_HAS_32BIT_EL1))
 		clear_bit(KVM_ARM_VCPU_EL1_32BIT, &features);
 
-	if (!kvm_arm_support_pmu_v3())
+	if (!kvm_supports_guest_pmuv3())
 		clear_bit(KVM_ARM_VCPU_PMU_V3, &features);
 
 	if (!system_supports_sve())

arch/arm64/kvm/hyp/include/hyp/switch.h

@@ -244,7 +244,7 @@ static inline void __activate_traps_common(struct kvm_vcpu *vcpu)
 	 * counter, which could make a PMXEVCNTR_EL0 access UNDEF at
 	 * EL1 instead of being trapped to EL2.
 	 */
-	if (kvm_arm_support_pmu_v3()) {
+	if (system_supports_pmuv3()) {
 		struct kvm_cpu_context *hctxt;
 
 		write_sysreg(0, pmselr_el0);
@@ -281,7 +281,7 @@ static inline void __deactivate_traps_common(struct kvm_vcpu *vcpu)
 	write_sysreg(*host_data_ptr(host_debug_state.mdcr_el2), mdcr_el2);
 
 	write_sysreg(0, hstr_el2);
-	if (kvm_arm_support_pmu_v3()) {
+	if (system_supports_pmuv3()) {
 		struct kvm_cpu_context *hctxt;
 
 		hctxt = host_data_ptr(host_ctxt);

arch/arm64/kvm/hyp/vhe/switch.c

@@ -527,6 +527,25 @@ static bool kvm_hyp_handle_sysreg_vhe(struct kvm_vcpu *vcpu, u64 *exit_code)
 	return kvm_hyp_handle_sysreg(vcpu, exit_code);
 }
 
+static bool kvm_hyp_handle_impdef(struct kvm_vcpu *vcpu, u64 *exit_code)
+{
+	u64 iss;
+
+	if (!cpus_have_final_cap(ARM64_WORKAROUND_PMUV3_IMPDEF_TRAPS))
+		return false;
+
+	/*
+	 * Compute a synthetic ESR for a sysreg trap. Conveniently, AFSR1_EL2
+	 * is populated with a correct ISS for a sysreg trap. These fruity
+	 * parts are 64bit only, so unconditionally set IL.
+	 */
+	iss = ESR_ELx_ISS(read_sysreg_s(SYS_AFSR1_EL2));
+	vcpu->arch.fault.esr_el2 = FIELD_PREP(ESR_ELx_EC_MASK, ESR_ELx_EC_SYS64) |
+				   FIELD_PREP(ESR_ELx_ISS_MASK, iss) |
+				   ESR_ELx_IL;
+	return false;
+}
+
 static const exit_handler_fn hyp_exit_handlers[] = {
 	[0 ... ESR_ELx_EC_MAX]		= NULL,
 	[ESR_ELx_EC_CP15_32]		= kvm_hyp_handle_cp15_32,
@@ -538,6 +557,9 @@ static const exit_handler_fn hyp_exit_handlers[] = {
 	[ESR_ELx_EC_WATCHPT_LOW]	= kvm_hyp_handle_watchpt_low,
 	[ESR_ELx_EC_ERET]		= kvm_hyp_handle_eret,
 	[ESR_ELx_EC_MOPS]		= kvm_hyp_handle_mops,
+
+	/* Apple shenanigans */
+	[0x3F]				= kvm_hyp_handle_impdef,
 };
 
 static inline bool fixup_guest_exit(struct kvm_vcpu *vcpu, u64 *exit_code)