KVM: arm64: Make ID_AA64PFR1_EL1.RAS_frac writable
Allow userspace to write to RAS_frac, under the condition that
the host supports RASv1p1 with RAS_frac==1. Other configurations
will result in RAS_frac being exposed as 0, and therefore implicitly
not writable.
To avoid the clutter, the ID_AA64PFR1_EL1 sanitisation is moved to
its own function.
Signed-off-by: Marc Zyngier <maz@kernel.org>
diff --git a/arch/arm64/kvm/nested.c b/arch/arm64/kvm/nested.c
index 153b3e11b..1b0aeda 100644
--- a/arch/arm64/kvm/nested.c
+++ b/arch/arm64/kvm/nested.c
@@ -1458,9 +1458,10 @@ u64 limit_nv_id_reg(struct kvm *kvm, u32 reg, u64 val)
break;
case SYS_ID_AA64PFR1_EL1:
- /* Only support BTI, SSBS, CSV2_frac */
+ /* Only support BTI, SSBS, RAS_frac, CSV2_frac */
val &= (ID_AA64PFR1_EL1_BT |
ID_AA64PFR1_EL1_SSBS |
+ ID_AA64PFR1_EL1_RAS_frac|
ID_AA64PFR1_EL1_CSV2_frac);
break;
diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c
index 3306fef..e149786 100644
--- a/arch/arm64/kvm/sys_regs.c
+++ b/arch/arm64/kvm/sys_regs.c
@@ -1584,6 +1584,7 @@ static u8 pmuver_to_perfmon(u8 pmuver)
}
static u64 sanitise_id_aa64pfr0_el1(const struct kvm_vcpu *vcpu, u64 val);
+static u64 sanitise_id_aa64pfr1_el1(const struct kvm_vcpu *vcpu, u64 val);
static u64 sanitise_id_aa64dfr0_el1(const struct kvm_vcpu *vcpu, u64 val);
/* Read a sanitised cpufeature ID register by sys_reg_desc */
@@ -1606,19 +1607,7 @@ static u64 __kvm_read_sanitised_id_reg(const struct kvm_vcpu *vcpu,
val = sanitise_id_aa64pfr0_el1(vcpu, val);
break;
case SYS_ID_AA64PFR1_EL1:
- if (!kvm_has_mte(vcpu->kvm)) {
- val &= ~ARM64_FEATURE_MASK(ID_AA64PFR1_EL1_MTE);
- val &= ~ARM64_FEATURE_MASK(ID_AA64PFR1_EL1_MTE_frac);
- }
-
- val &= ~ARM64_FEATURE_MASK(ID_AA64PFR1_EL1_SME);
- val &= ~ARM64_FEATURE_MASK(ID_AA64PFR1_EL1_RNDR_trap);
- val &= ~ARM64_FEATURE_MASK(ID_AA64PFR1_EL1_NMI);
- val &= ~ARM64_FEATURE_MASK(ID_AA64PFR1_EL1_GCS);
- val &= ~ARM64_FEATURE_MASK(ID_AA64PFR1_EL1_THE);
- val &= ~ARM64_FEATURE_MASK(ID_AA64PFR1_EL1_MTEX);
- val &= ~ARM64_FEATURE_MASK(ID_AA64PFR1_EL1_PFAR);
- val &= ~ARM64_FEATURE_MASK(ID_AA64PFR1_EL1_MPAM_frac);
+ val = sanitise_id_aa64pfr1_el1(vcpu, val);
break;
case SYS_ID_AA64PFR2_EL1:
val &= ID_AA64PFR2_EL1_FPMR |
@@ -1836,6 +1825,31 @@ static u64 sanitise_id_aa64pfr0_el1(const struct kvm_vcpu *vcpu, u64 val)
return val;
}
+static u64 sanitise_id_aa64pfr1_el1(const struct kvm_vcpu *vcpu, u64 val)
+{
+ u64 pfr0 = read_sanitised_ftr_reg(SYS_ID_AA64PFR0_EL1);
+
+ if (!kvm_has_mte(vcpu->kvm)) {
+ val &= ~ARM64_FEATURE_MASK(ID_AA64PFR1_EL1_MTE);
+ val &= ~ARM64_FEATURE_MASK(ID_AA64PFR1_EL1_MTE_frac);
+ }
+
+ if (!(cpus_have_final_cap(ARM64_HAS_RASV1P1_EXTN) &&
+ SYS_FIELD_GET(ID_AA64PFR0_EL1, RAS, pfr0) == ID_AA64PFR0_EL1_RAS_IMP))
+ val &= ~ARM64_FEATURE_MASK(ID_AA64PFR1_EL1_RAS_frac);
+
+ val &= ~ARM64_FEATURE_MASK(ID_AA64PFR1_EL1_SME);
+ val &= ~ARM64_FEATURE_MASK(ID_AA64PFR1_EL1_RNDR_trap);
+ val &= ~ARM64_FEATURE_MASK(ID_AA64PFR1_EL1_NMI);
+ val &= ~ARM64_FEATURE_MASK(ID_AA64PFR1_EL1_GCS);
+ val &= ~ARM64_FEATURE_MASK(ID_AA64PFR1_EL1_THE);
+ val &= ~ARM64_FEATURE_MASK(ID_AA64PFR1_EL1_MTEX);
+ val &= ~ARM64_FEATURE_MASK(ID_AA64PFR1_EL1_PFAR);
+ val &= ~ARM64_FEATURE_MASK(ID_AA64PFR1_EL1_MPAM_frac);
+
+ return val;
+}
+
static u64 sanitise_id_aa64dfr0_el1(const struct kvm_vcpu *vcpu, u64 val)
{
val = ID_REG_LIMIT_FIELD_ENUM(val, ID_AA64DFR0_EL1, DebugVer, V8P8);
@@ -2954,7 +2968,6 @@ static const struct sys_reg_desc sys_reg_descs[] = {
ID_AA64PFR1_EL1_SME |
ID_AA64PFR1_EL1_RES0 |
ID_AA64PFR1_EL1_MPAM_frac |
- ID_AA64PFR1_EL1_RAS_frac |
ID_AA64PFR1_EL1_MTE)),
ID_WRITABLE(ID_AA64PFR2_EL1,
ID_AA64PFR2_EL1_FPMR |
