diff options
| -rw-r--r-- | arch/arm64/kvm/sys_regs.c | 28 |
1 files changed, 26 insertions, 2 deletions
diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c index 005ad28f73068..ee30c94c0aceb 100644 --- a/arch/arm64/kvm/sys_regs.c +++ b/arch/arm64/kvm/sys_regs.c @@ -1600,13 +1600,14 @@ 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)) + 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_MTE_frac); val &= ~ARM64_FEATURE_MASK(ID_AA64PFR1_EL1_GCS); val &= ~ARM64_FEATURE_MASK(ID_AA64PFR1_EL1_THE); val &= ~ARM64_FEATURE_MASK(ID_AA64PFR1_EL1_MTEX); @@ -1953,11 +1954,34 @@ static int set_id_aa64pfr1_el1(struct kvm_vcpu *vcpu, { u64 hw_val = read_sanitised_ftr_reg(SYS_ID_AA64PFR1_EL1); u64 mpam_mask = ID_AA64PFR1_EL1_MPAM_frac_MASK; + u8 mte = SYS_FIELD_GET(ID_AA64PFR1_EL1, MTE, hw_val); + u8 user_mte_frac = SYS_FIELD_GET(ID_AA64PFR1_EL1, MTE_frac, user_val); + u8 hw_mte_frac = SYS_FIELD_GET(ID_AA64PFR1_EL1, MTE_frac, hw_val); /* See set_id_aa64pfr0_el1 for comment about MPAM */ if ((hw_val & mpam_mask) == (user_val & mpam_mask)) user_val &= ~ID_AA64PFR1_EL1_MPAM_frac_MASK; + /* + * Previously MTE_frac was hidden from guest. However, if the + * hardware supports MTE2 but not MTE_ASYM_FAULT then a value + * of 0 for this field indicates that the hardware supports + * MTE_ASYNC. Whereas, 0xf indicates MTE_ASYNC is not supported. + * + * As KVM must accept values from KVM provided by user-space, + * when ID_AA64PFR1_EL1.MTE is 2 allow user-space to set + * ID_AA64PFR1_EL1.MTE_frac to 0. However, ignore it to avoid + * incorrectly claiming hardware support for MTE_ASYNC in the + * guest. + */ + + if (mte == ID_AA64PFR1_EL1_MTE_MTE2 && + hw_mte_frac == ID_AA64PFR1_EL1_MTE_frac_NI && + user_mte_frac == ID_AA64PFR1_EL1_MTE_frac_ASYNC) { + user_val &= ~ID_AA64PFR1_EL1_MTE_frac_MASK; + user_val |= hw_val & ID_AA64PFR1_EL1_MTE_frac_MASK; + } + return set_id_reg(vcpu, rd, user_val); } |