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| author |   Marc Zyngier <maz@kernel.org> | 2025-08-17 21:21:57 +0100 |
|---|---|---|
| committer |   Oliver Upton <oliver.upton@linux.dev> | 2025-08-21 16:31:56 -0700 |
| commit | 7a765aa88e345782d3e4ed4c82e49f1ea82fd29c (patch) | |
| tree | ba695831be9fcac3f181f0adef05f7a471ee5ed5 | |
| parent | KVM: arm64: Make ID_AA64PFR0_EL1.RAS writable (diff) | |
| download | wireguard-linux-7a765aa88e345782d3e4ed4c82e49f1ea82fd29c.tar.xz wireguard-linux-7a765aa88e345782d3e4ed4c82e49f1ea82fd29c.zip | |
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>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Link: https://lore.kernel.org/r/20250817202158.395078-6-maz@kernel.org
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
| -rw-r--r-- | arch/arm64/kvm/sys_regs.c | 41 |
1 files changed, 27 insertions, 14 deletions
diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c index bf160693963c..5abe4db6c008 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: /* We only expose FPMR */ @@ -1834,6 +1823,31 @@ 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); @@ -2952,7 +2966,6 @@ 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), ID_UNALLOCATED(4,3), |