| Message ID | 20220520173638.94324-8-juew@google.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | KVM: x86: Add CMCI and UCNA emulation | expand |
On Fri, May 20, 2022 at 10:37 AM Jue Wang <juew@google.com> wrote: > > Make KVM support the CMCI capability by default by adding MCG_CMCI_P to > kvm_mce_cap_supported. A vCPU can request for this capability via > KVM_X86_SETUP_MCE. Uncorrectable Error No Action required (UCNA) injection > reuses the MCE injection ioctl KVM_X86_SET_MCE. > > Neither of the CMCI and UCNA emulations depends on hardware. > > Signed-off-by: Jue Wang <juew@google.com> > --- > arch/x86/kvm/vmx/vmx.c | 1 + > arch/x86/kvm/x86.c | 50 ++++++++++++++++++++++++++++++++++++++++++ > 2 files changed, 51 insertions(+) > > diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c > index 610355b9ccce..1aed964ee4ee 100644 > --- a/arch/x86/kvm/vmx/vmx.c > +++ b/arch/x86/kvm/vmx/vmx.c > @@ -8037,6 +8037,7 @@ static __init int hardware_setup(void) > } > > kvm_mce_cap_supported |= MCG_LMCE_P; > + kvm_mce_cap_supported |= MCG_CMCI_P; > > if (pt_mode != PT_MODE_SYSTEM && pt_mode != PT_MODE_HOST_GUEST) > return -EINVAL; > diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c > index f8ab592f519b..d0b1bb6e5e4a 100644 > --- a/arch/x86/kvm/x86.c > +++ b/arch/x86/kvm/x86.c > @@ -4826,6 +4826,52 @@ static int kvm_vcpu_ioctl_x86_setup_mce(struct kvm_vcpu *vcpu, > return r; > } > > +/* > + * Validate this is an UCNA error by checking the MCG_STATUS and MCi_STATUS > + * registers that none of the bits for Machine Check Exceptions are set and > + * both the VAL (valid) and UC (uncorrectable) bits are set. > + * UCNA - UnCorrectable No Action required > + * SRAR - Software Recoverable Action Required > + * MCI_STATUS_PCC - Processor Context Corrupted > + * MCI_STATUS_S - Signaled as a Machine Check Exception > + * MCI_STATUS_AR - This MCE is "software recoverable action required" > + */ > +static bool is_ucna(struct kvm_x86_mce *mce) > +{ > + return !mce->mcg_status && > + !(mce->status & (MCI_STATUS_PCC | MCI_STATUS_S | MCI_STATUS_AR)) && > + (mce->status & MCI_STATUS_VAL) && > + (mce->status & MCI_STATUS_UC); > +} > + > +static int kvm_vcpu_x86_set_ucna(struct kvm_vcpu *vcpu, struct kvm_x86_mce *mce) > +{ > + u64 mcg_cap = vcpu->arch.mcg_cap; > + unsigned int bank_num = mcg_cap & 0xff; > + u64 *banks = vcpu->arch.mce_banks; > + > + if (mce->bank >= bank_num) > + return -EINVAL; Drop this check. The caller already checks it. > + > + if (!is_ucna(mce)) > + return -EINVAL; Drop this check. The only caller of this function already checks is_ucna(). > + > + banks += 4 * mce->bank; The caller also computes banks. Perhaps just pass that in rather that re-calculating it here? Also, calculating banks should probably use array_index_nospec() since the index is untrusted (coming from userspace). > + banks[1] = mce->status; > + banks[2] = mce->addr; > + banks[3] = mce->misc; > + vcpu->arch.mcg_status = mce->mcg_status; > + > + if (!(mcg_cap & MCG_CMCI_P) || > + !(vcpu->arch.mci_ctl2_banks[mce->bank] & MCI_CTL2_CMCI_EN)) > + return 0; > + > + if (lapic_in_kernel(vcpu)) > + kvm_apic_local_deliver(vcpu->arch.apic, APIC_LVTCMCI); > + > + return 0; > +} > + > static int kvm_vcpu_ioctl_x86_set_mce(struct kvm_vcpu *vcpu, > struct kvm_x86_mce *mce) > { > @@ -4835,6 +4881,10 @@ static int kvm_vcpu_ioctl_x86_set_mce(struct kvm_vcpu *vcpu, > > if (mce->bank >= bank_num || !(mce->status & MCI_STATUS_VAL)) > return -EINVAL; > + > + if (is_ucna(mce)) > + return kvm_vcpu_x86_set_ucna(vcpu, mce); > + > /* > * if IA32_MCG_CTL is not all 1s, the uncorrected error > * reporting is disabled > -- > 2.36.1.124.g0e6072fb45-goog >
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c index 610355b9ccce..1aed964ee4ee 100644 --- a/arch/x86/kvm/vmx/vmx.c +++ b/arch/x86/kvm/vmx/vmx.c @@ -8037,6 +8037,7 @@ static __init int hardware_setup(void) } kvm_mce_cap_supported |= MCG_LMCE_P; + kvm_mce_cap_supported |= MCG_CMCI_P; if (pt_mode != PT_MODE_SYSTEM && pt_mode != PT_MODE_HOST_GUEST) return -EINVAL; diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index f8ab592f519b..d0b1bb6e5e4a 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -4826,6 +4826,52 @@ static int kvm_vcpu_ioctl_x86_setup_mce(struct kvm_vcpu *vcpu, return r; } +/* + * Validate this is an UCNA error by checking the MCG_STATUS and MCi_STATUS + * registers that none of the bits for Machine Check Exceptions are set and + * both the VAL (valid) and UC (uncorrectable) bits are set. + * UCNA - UnCorrectable No Action required + * SRAR - Software Recoverable Action Required + * MCI_STATUS_PCC - Processor Context Corrupted + * MCI_STATUS_S - Signaled as a Machine Check Exception + * MCI_STATUS_AR - This MCE is "software recoverable action required" + */ +static bool is_ucna(struct kvm_x86_mce *mce) +{ + return !mce->mcg_status && + !(mce->status & (MCI_STATUS_PCC | MCI_STATUS_S | MCI_STATUS_AR)) && + (mce->status & MCI_STATUS_VAL) && + (mce->status & MCI_STATUS_UC); +} + +static int kvm_vcpu_x86_set_ucna(struct kvm_vcpu *vcpu, struct kvm_x86_mce *mce) +{ + u64 mcg_cap = vcpu->arch.mcg_cap; + unsigned int bank_num = mcg_cap & 0xff; + u64 *banks = vcpu->arch.mce_banks; + + if (mce->bank >= bank_num) + return -EINVAL; + + if (!is_ucna(mce)) + return -EINVAL; + + banks += 4 * mce->bank; + banks[1] = mce->status; + banks[2] = mce->addr; + banks[3] = mce->misc; + vcpu->arch.mcg_status = mce->mcg_status; + + if (!(mcg_cap & MCG_CMCI_P) || + !(vcpu->arch.mci_ctl2_banks[mce->bank] & MCI_CTL2_CMCI_EN)) + return 0; + + if (lapic_in_kernel(vcpu)) + kvm_apic_local_deliver(vcpu->arch.apic, APIC_LVTCMCI); + + return 0; +} + static int kvm_vcpu_ioctl_x86_set_mce(struct kvm_vcpu *vcpu, struct kvm_x86_mce *mce) { @@ -4835,6 +4881,10 @@ static int kvm_vcpu_ioctl_x86_set_mce(struct kvm_vcpu *vcpu, if (mce->bank >= bank_num || !(mce->status & MCI_STATUS_VAL)) return -EINVAL; + + if (is_ucna(mce)) + return kvm_vcpu_x86_set_ucna(vcpu, mce); + /* * if IA32_MCG_CTL is not all 1s, the uncorrected error * reporting is disabled
Make KVM support the CMCI capability by default by adding MCG_CMCI_P to kvm_mce_cap_supported. A vCPU can request for this capability via KVM_X86_SETUP_MCE. Uncorrectable Error No Action required (UCNA) injection reuses the MCE injection ioctl KVM_X86_SET_MCE. Neither of the CMCI and UCNA emulations depends on hardware. Signed-off-by: Jue Wang <juew@google.com> --- arch/x86/kvm/vmx/vmx.c | 1 + arch/x86/kvm/x86.c | 50 ++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 51 insertions(+)