[PATCH v12 11/11] KVM: arm64: Rip out the vestiges of the 'old' ID register scheme
Oliver Upton
oliver.upton at linux.dev
Fri Jun 9 12:00:54 PDT 2023
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.
Signed-off-by: Oliver Upton <oliver.upton at linux.dev>
---
arch/arm64/include/asm/kvm_host.h | 4 --
arch/arm64/kvm/arm.c | 23 --------
arch/arm64/kvm/sys_regs.c | 92 ++-----------------------------
include/kvm/arm_pmu.h | 8 ++-
4 files changed, 10 insertions(+), 117 deletions(-)
diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
index 39270bc29a3f..e2e9552f2808 100644
--- a/arch/arm64/include/asm/kvm_host.h
+++ b/arch/arm64/include/asm/kvm_host.h
@@ -241,10 +241,6 @@ struct kvm_arch {
cpumask_var_t supported_cpus;
- u8 pfr0_csv2;
- u8 pfr0_csv3;
- u8 dfr0_pmuver;
-
/* Hypercall features firmware registers' descriptor */
struct kvm_smccc_features smccc_feat;
struct maple_tree smccc_filter;
diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c
index 695239e01618..80ca7ec269dc 100644
--- a/arch/arm64/kvm/arm.c
+++ b/arch/arm64/kvm/arm.c
@@ -102,22 +102,6 @@ static int kvm_arm_default_max_vcpus(void)
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: 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 */
kvm->max_vcpus = kvm_arm_default_max_vcpus();
- set_default_spectre(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);
return 0;
diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c
index e5b71ede7928..e9f331772392 100644
--- a/arch/arm64/kvm/sys_regs.c
+++ b/arch/arm64/kvm/sys_regs.c
@@ -1195,14 +1195,6 @@ static bool access_arch_timer(struct kvm_vcpu *vcpu,
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,
s64 new, s64 cur)
{
@@ -1288,19 +1280,6 @@ static int arm64_check_features(struct kvm_vcpu *vcpu,
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)
{
switch (pmuver) {
@@ -1327,19 +1306,6 @@ static u64 __kvm_read_sanitised_id_reg(const struct kvm_vcpu *vcpu,
val = read_sanitised_ftr_reg(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:
if (!kvm_has_mte(vcpu->kvm))
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))
val &= ~ARM64_FEATURE_MASK(ID_AA64ISAR2_EL1_WFxT);
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:
val &= ~ID_AA64MMFR2_EL1_CCIDX_MASK;
break;
@@ -1505,26 +1455,6 @@ static u64 read_sanitised_id_aa64pfr0_el1(struct kvm_vcpu *vcpu,
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,
const struct sys_reg_desc *rd)
{
@@ -1553,7 +1483,6 @@ static int set_id_aa64dfr0_el1(struct kvm_vcpu *vcpu,
u64 val)
{
u8 pmuver = SYS_FIELD_GET(ID_AA64DFR0_EL1, PMUVer, val);
- int r;
/*
* 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
* 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;
- pmuver = 0;
- }
- r = set_id_reg(vcpu, rd, val);
- if (r)
- return r;
-
- vcpu->kvm->arch.dfr0_pmuver = pmuver;
- return 0;
+ return set_id_reg(vcpu, rd, val);
}
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)
{
u8 perfmon = SYS_FIELD_GET(ID_DFR0_EL1, PerfMon, val);
- int r;
if (perfmon == ID_DFR0_EL1_PerfMon_IMPDEF) {
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)
return -EINVAL;
- r = set_id_reg(vcpu, rd, val);
- if (r)
- return r;
-
- vcpu->kvm->arch.dfr0_pmuver = perfmon_to_pmuver(perfmon);
- return 0;
+ return set_id_reg(vcpu, rd, val);
}
/*
@@ -2066,7 +1982,7 @@ static const struct sys_reg_desc sys_reg_descs[] = {
{ SYS_DESC(SYS_ID_AA64PFR0_EL1),
.access = access_id_reg,
.get_user = get_id_reg,
- .set_user = set_id_aa64pfr0_el1,
+ .set_user = set_id_reg,
.reset = read_sanitised_id_aa64pfr0_el1,
.val = ID_AA64PFR0_EL1_CSV2_MASK | ID_AA64PFR0_EL1_CSV3_MASK, },
ID_SANITISED(ID_AA64PFR1_EL1),
diff --git a/include/kvm/arm_pmu.h b/include/kvm/arm_pmu.h
index 0be60d5eebd7..847da6fc2713 100644
--- a/include/kvm/arm_pmu.h
+++ b/include/kvm/arm_pmu.h
@@ -92,8 +92,12 @@ void kvm_vcpu_pmu_restore_host(struct kvm_vcpu *vcpu);
/*
* Evaluates as true when emulating PMUv3p5, and false otherwise.
*/
-#define kvm_pmu_is_3p5(vcpu) \
- (vcpu->kvm->arch.dfr0_pmuver >= ID_AA64DFR0_EL1_PMUVer_V3P5)
+#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);
--
2.41.0.162.gfafddb0af9-goog
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