diff options
Diffstat (limited to 'arch/arm64/kvm/sys_regs.c')
| -rw-r--r-- | arch/arm64/kvm/sys_regs.c | 27 |
1 files changed, 25 insertions, 2 deletions
diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c index b29f72478a50..caf80c324b35 100644 --- a/arch/arm64/kvm/sys_regs.c +++ b/arch/arm64/kvm/sys_regs.c @@ -1997,6 +1997,26 @@ static u64 sanitise_id_aa64dfr0_el1(const struct kvm_vcpu *vcpu, u64 val) return val; } +/* + * Older versions of KVM erroneously claim support for FEAT_DoubleLock with + * NV-enabled VMs on unsupporting hardware. Silently ignore the incorrect + * value if it is consistent with the bug. + */ +static bool ignore_feat_doublelock(struct kvm_vcpu *vcpu, u64 val) +{ + u8 host, user; + + if (!vcpu_has_nv(vcpu)) + return false; + + host = SYS_FIELD_GET(ID_AA64DFR0_EL1, DoubleLock, + read_sanitised_ftr_reg(SYS_ID_AA64DFR0_EL1)); + user = SYS_FIELD_GET(ID_AA64DFR0_EL1, DoubleLock, val); + + return host == ID_AA64DFR0_EL1_DoubleLock_NI && + user == ID_AA64DFR0_EL1_DoubleLock_IMP; +} + static int set_id_aa64dfr0_el1(struct kvm_vcpu *vcpu, const struct sys_reg_desc *rd, u64 val) @@ -2028,6 +2048,11 @@ static int set_id_aa64dfr0_el1(struct kvm_vcpu *vcpu, if (debugver < ID_AA64DFR0_EL1_DebugVer_IMP) return -EINVAL; + if (ignore_feat_doublelock(vcpu, val)) { + val &= ~ID_AA64DFR0_EL1_DoubleLock; + val |= SYS_FIELD_PREP_ENUM(ID_AA64DFR0_EL1, DoubleLock, NI); + } + return set_id_reg(vcpu, rd, val); } @@ -3152,8 +3177,6 @@ static const struct sys_reg_desc sys_reg_descs[] = { ~(ID_AA64MMFR0_EL1_RES0 | ID_AA64MMFR0_EL1_ASIDBITS)), ID_WRITABLE(ID_AA64MMFR1_EL1, ~(ID_AA64MMFR1_EL1_RES0 | - ID_AA64MMFR1_EL1_HCX | - ID_AA64MMFR1_EL1_TWED | ID_AA64MMFR1_EL1_XNX | ID_AA64MMFR1_EL1_VH | ID_AA64MMFR1_EL1_VMIDBits)), |