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KVM: arm64: Rip out the vestiges of the 'old' ID register scheme

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There's no longer a need for the baggage of the old scheme for handling
configurable ID register fields. Rip it all out in favor of the
generalized infrastructure.

Link: https://lore.kernel.org/r/20230609190054.1542113-12-oliver.upton@linux.dev
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
This commit is contained in:
Oliver Upton 2023-06-09 19:00:54 +00:00
parent 6db7af0d5b
commit 686672407e
4 changed files with 10 additions and 117 deletions
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4
arch/arm64/include/asm/kvm_host.h
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@ -241,10 +241,6 @@ struct kvm_arch {
cpumask_var_t supported_cpus; cpumask_var_t supported_cpus;
u8 pfr0_csv2;
u8 pfr0_csv3;
u8 dfr0_pmuver;
/* Hypercall features firmware registers' descriptor */ /* Hypercall features firmware registers' descriptor */
struct kvm_smccc_features smccc_feat; struct kvm_smccc_features smccc_feat;
struct maple_tree smccc_filter; struct maple_tree smccc_filter;

23
arch/arm64/kvm/arm.c
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@ -102,22 +102,6 @@ static int kvm_arm_default_max_vcpus(void)
return vgic_present ? kvm_vgic_get_max_vcpus() : KVM_MAX_VCPUS; return vgic_present ? kvm_vgic_get_max_vcpus() : KVM_MAX_VCPUS;
} }
static void set_default_spectre(struct kvm *kvm)
{
/*
* The default is to expose CSV2 == 1 if the HW isn't affected.
* Although this is a per-CPU feature, we make it global because
* asymmetric systems are just a nuisance.
*
* Userspace can override this as long as it doesn't promise
* the impossible.
*/
if (arm64_get_spectre_v2_state() == SPECTRE_UNAFFECTED)
kvm->arch.pfr0_csv2 = 1;
if (arm64_get_meltdown_state() == SPECTRE_UNAFFECTED)
kvm->arch.pfr0_csv3 = 1;
}
/** /**
* kvm_arch_init_vm - initializes a VM data structure * kvm_arch_init_vm - initializes a VM data structure
* @kvm: pointer to the KVM struct * @kvm: pointer to the KVM struct
@ -161,15 +145,8 @@ int kvm_arch_init_vm(struct kvm *kvm, unsigned long type)
/* The maximum number of VCPUs is limited by the host's GIC model */ /* The maximum number of VCPUs is limited by the host's GIC model */
kvm->max_vcpus = kvm_arm_default_max_vcpus(); kvm->max_vcpus = kvm_arm_default_max_vcpus();
set_default_spectre(kvm);
kvm_arm_init_hypercalls(kvm); kvm_arm_init_hypercalls(kvm);
/*
* Initialise the default PMUver before there is a chance to
* create an actual PMU.
*/
kvm->arch.dfr0_pmuver = kvm_arm_pmu_get_pmuver_limit();
bitmap_zero(kvm->arch.vcpu_features, KVM_VCPU_MAX_FEATURES); bitmap_zero(kvm->arch.vcpu_features, KVM_VCPU_MAX_FEATURES);
return 0; return 0;

92
arch/arm64/kvm/sys_regs.c
View File

@ -1195,14 +1195,6 @@ static bool access_arch_timer(struct kvm_vcpu *vcpu,
return true; return true;
} }
static u8 vcpu_pmuver(const struct kvm_vcpu *vcpu)
{
if (kvm_vcpu_has_pmu(vcpu))
return vcpu->kvm->arch.dfr0_pmuver;
return 0;
}
static s64 kvm_arm64_ftr_safe_value(u32 id, const struct arm64_ftr_bits *ftrp, static s64 kvm_arm64_ftr_safe_value(u32 id, const struct arm64_ftr_bits *ftrp,
s64 new, s64 cur) s64 new, s64 cur)
{ {
@ -1288,19 +1280,6 @@ static int arm64_check_features(struct kvm_vcpu *vcpu,
return 0; return 0;
} }
static u8 perfmon_to_pmuver(u8 perfmon)
{
switch (perfmon) {
case ID_DFR0_EL1_PerfMon_PMUv3:
return ID_AA64DFR0_EL1_PMUVer_IMP;
case ID_DFR0_EL1_PerfMon_IMPDEF:
return ID_AA64DFR0_EL1_PMUVer_IMP_DEF;
default:
/* Anything ARMv8.1+ and NI have the same value. For now. */
return perfmon;
}
}
static u8 pmuver_to_perfmon(u8 pmuver) static u8 pmuver_to_perfmon(u8 pmuver)
{ {
switch (pmuver) { switch (pmuver) {
@ -1327,19 +1306,6 @@ static u64 __kvm_read_sanitised_id_reg(const struct kvm_vcpu *vcpu,
val = read_sanitised_ftr_reg(id); val = read_sanitised_ftr_reg(id);
switch (id) { switch (id) {
case SYS_ID_AA64PFR0_EL1:
if (!vcpu_has_sve(vcpu))
val &= ~ARM64_FEATURE_MASK(ID_AA64PFR0_EL1_SVE);
val &= ~ARM64_FEATURE_MASK(ID_AA64PFR0_EL1_AMU);
val &= ~ARM64_FEATURE_MASK(ID_AA64PFR0_EL1_CSV2);
val |= FIELD_PREP(ARM64_FEATURE_MASK(ID_AA64PFR0_EL1_CSV2), (u64)vcpu->kvm->arch.pfr0_csv2);
val &= ~ARM64_FEATURE_MASK(ID_AA64PFR0_EL1_CSV3);
val |= FIELD_PREP(ARM64_FEATURE_MASK(ID_AA64PFR0_EL1_CSV3), (u64)vcpu->kvm->arch.pfr0_csv3);
if (kvm_vgic_global_state.type == VGIC_V3) {
val &= ~ARM64_FEATURE_MASK(ID_AA64PFR0_EL1_GIC);
val |= FIELD_PREP(ARM64_FEATURE_MASK(ID_AA64PFR0_EL1_GIC), 1);
}
break;
case SYS_ID_AA64PFR1_EL1: case SYS_ID_AA64PFR1_EL1:
if (!kvm_has_mte(vcpu->kvm)) if (!kvm_has_mte(vcpu->kvm))
val &= ~ARM64_FEATURE_MASK(ID_AA64PFR1_EL1_MTE); val &= ~ARM64_FEATURE_MASK(ID_AA64PFR1_EL1_MTE);
@ -1360,22 +1326,6 @@ static u64 __kvm_read_sanitised_id_reg(const struct kvm_vcpu *vcpu,
if (!cpus_have_final_cap(ARM64_HAS_WFXT)) if (!cpus_have_final_cap(ARM64_HAS_WFXT))
val &= ~ARM64_FEATURE_MASK(ID_AA64ISAR2_EL1_WFxT); val &= ~ARM64_FEATURE_MASK(ID_AA64ISAR2_EL1_WFxT);
break; break;
case SYS_ID_AA64DFR0_EL1:
/* Limit debug to ARMv8.0 */
val &= ~ARM64_FEATURE_MASK(ID_AA64DFR0_EL1_DebugVer);
val |= FIELD_PREP(ARM64_FEATURE_MASK(ID_AA64DFR0_EL1_DebugVer), 6);
/* Set PMUver to the required version */
val &= ~ARM64_FEATURE_MASK(ID_AA64DFR0_EL1_PMUVer);
val |= FIELD_PREP(ARM64_FEATURE_MASK(ID_AA64DFR0_EL1_PMUVer),
vcpu_pmuver(vcpu));
/* Hide SPE from guests */
val &= ~ARM64_FEATURE_MASK(ID_AA64DFR0_EL1_PMSVer);
break;
case SYS_ID_DFR0_EL1:
val &= ~ARM64_FEATURE_MASK(ID_DFR0_EL1_PerfMon);
val |= FIELD_PREP(ARM64_FEATURE_MASK(ID_DFR0_EL1_PerfMon),
pmuver_to_perfmon(vcpu_pmuver(vcpu)));
break;
case SYS_ID_AA64MMFR2_EL1: case SYS_ID_AA64MMFR2_EL1:
val &= ~ID_AA64MMFR2_EL1_CCIDX_MASK; val &= ~ID_AA64MMFR2_EL1_CCIDX_MASK;
break; break;
@ -1505,26 +1455,6 @@ static u64 read_sanitised_id_aa64pfr0_el1(struct kvm_vcpu *vcpu,
return val; return val;
} }
static int set_id_aa64pfr0_el1(struct kvm_vcpu *vcpu,
const struct sys_reg_desc *rd,
u64 val)
{
u8 csv2, csv3;
int r;
csv2 = cpuid_feature_extract_unsigned_field(val, ID_AA64PFR0_EL1_CSV2_SHIFT);
csv3 = cpuid_feature_extract_unsigned_field(val, ID_AA64PFR0_EL1_CSV3_SHIFT);
r = set_id_reg(vcpu, rd, val);
if (r)
return r;
vcpu->kvm->arch.pfr0_csv2 = csv2;
vcpu->kvm->arch.pfr0_csv3 = csv3;
return 0;
}
static u64 read_sanitised_id_aa64dfr0_el1(struct kvm_vcpu *vcpu, static u64 read_sanitised_id_aa64dfr0_el1(struct kvm_vcpu *vcpu,
const struct sys_reg_desc *rd) const struct sys_reg_desc *rd)
{ {
@ -1553,7 +1483,6 @@ static int set_id_aa64dfr0_el1(struct kvm_vcpu *vcpu,
u64 val) u64 val)
{ {
u8 pmuver = SYS_FIELD_GET(ID_AA64DFR0_EL1, PMUVer, val); u8 pmuver = SYS_FIELD_GET(ID_AA64DFR0_EL1, PMUVer, val);
int r;
/* /*
* Prior to commit 3d0dba5764b9 ("KVM: arm64: PMU: Move the * Prior to commit 3d0dba5764b9 ("KVM: arm64: PMU: Move the
@ -1569,17 +1498,10 @@ static int set_id_aa64dfr0_el1(struct kvm_vcpu *vcpu,
* surprising than an ill-guided PMU driver poking at impdef system * surprising than an ill-guided PMU driver poking at impdef system
* registers that end in an UNDEF... * registers that end in an UNDEF...
*/ */
if (pmuver == ID_AA64DFR0_EL1_PMUVer_IMP_DEF) { if (pmuver == ID_AA64DFR0_EL1_PMUVer_IMP_DEF)
val &= ~ID_AA64DFR0_EL1_PMUVer_MASK; val &= ~ID_AA64DFR0_EL1_PMUVer_MASK;
pmuver = 0;
}
r = set_id_reg(vcpu, rd, val); return set_id_reg(vcpu, rd, val);
if (r)
return r;
vcpu->kvm->arch.dfr0_pmuver = pmuver;
return 0;
} }
static u64 read_sanitised_id_dfr0_el1(struct kvm_vcpu *vcpu, static u64 read_sanitised_id_dfr0_el1(struct kvm_vcpu *vcpu,
@ -1600,7 +1522,6 @@ static int set_id_dfr0_el1(struct kvm_vcpu *vcpu,
u64 val) u64 val)
{ {
u8 perfmon = SYS_FIELD_GET(ID_DFR0_EL1, PerfMon, val); u8 perfmon = SYS_FIELD_GET(ID_DFR0_EL1, PerfMon, val);
int r;
if (perfmon == ID_DFR0_EL1_PerfMon_IMPDEF) { if (perfmon == ID_DFR0_EL1_PerfMon_IMPDEF) {
val &= ~ID_DFR0_EL1_PerfMon_MASK; val &= ~ID_DFR0_EL1_PerfMon_MASK;
@ -1616,12 +1537,7 @@ static int set_id_dfr0_el1(struct kvm_vcpu *vcpu,
if (perfmon != 0 && perfmon < ID_DFR0_EL1_PerfMon_PMUv3) if (perfmon != 0 && perfmon < ID_DFR0_EL1_PerfMon_PMUv3)
return -EINVAL; return -EINVAL;
r = set_id_reg(vcpu, rd, val); return set_id_reg(vcpu, rd, val);
if (r)
return r;
vcpu->kvm->arch.dfr0_pmuver = perfmon_to_pmuver(perfmon);
return 0;
} }
/* /*
@ -2076,7 +1992,7 @@ static const struct sys_reg_desc sys_reg_descs[] = {
{ SYS_DESC(SYS_ID_AA64PFR0_EL1), { SYS_DESC(SYS_ID_AA64PFR0_EL1),
.access = access_id_reg, .access = access_id_reg,
.get_user = get_id_reg, .get_user = get_id_reg,
.set_user = set_id_aa64pfr0_el1, .set_user = set_id_reg,
.reset = read_sanitised_id_aa64pfr0_el1, .reset = read_sanitised_id_aa64pfr0_el1,
.val = ID_AA64PFR0_EL1_CSV2_MASK | ID_AA64PFR0_EL1_CSV3_MASK, }, .val = ID_AA64PFR0_EL1_CSV2_MASK | ID_AA64PFR0_EL1_CSV3_MASK, },
ID_SANITISED(ID_AA64PFR1_EL1), ID_SANITISED(ID_AA64PFR1_EL1),

8
include/kvm/arm_pmu.h
View File

@ -92,8 +92,12 @@ void kvm_vcpu_pmu_restore_host(struct kvm_vcpu *vcpu);
/* /*
* Evaluates as true when emulating PMUv3p5, and false otherwise. * Evaluates as true when emulating PMUv3p5, and false otherwise.
*/ */
#define kvm_pmu_is_3p5(vcpu) \ #define kvm_pmu_is_3p5(vcpu) ({ \
(vcpu->kvm->arch.dfr0_pmuver >= ID_AA64DFR0_EL1_PMUVer_V3P5) 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); u8 kvm_arm_pmu_get_pmuver_limit(void);