KVM: x86: Enable CMCI capability by default and handle injected UCNA errors
This patch enables MCG_CMCI_P by default in kvm_mce_cap_supported. It
reuses ioctl KVM_X86_SET_MCE to implement injection of UnCorrectable
No Action required (UCNA) errors, signaled via Corrected Machine
Check Interrupt (CMCI).
Neither of the CMCI and UCNA emulations depends on hardware.
Signed-off-by: Jue Wang <juew@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20220610171134.772566-8-juew@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index f743e4e..031678e 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -4901,6 +4901,42 @@ static int kvm_vcpu_ioctl_x86_setup_mce(struct kvm_vcpu *vcpu,
return r;
}
+/*
+ * Validate this is an UCNA (uncorrectable no action) error by checking the
+ * MCG_STATUS and MCi_STATUS registers:
+ * - none of the bits for Machine Check Exceptions are set
+ * - both the VAL (valid) and UC (uncorrectable) bits are set
+ * MCI_STATUS_PCC - Processor Context Corrupted
+ * MCI_STATUS_S - Signaled as a Machine Check Exception
+ * MCI_STATUS_AR - 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* banks)
+{
+ u64 mcg_cap = vcpu->arch.mcg_cap;
+
+ 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)
{
@@ -4910,6 +4946,12 @@ static int kvm_vcpu_ioctl_x86_set_mce(struct kvm_vcpu *vcpu,
if (mce->bank >= bank_num || !(mce->status & MCI_STATUS_VAL))
return -EINVAL;
+
+ banks += array_index_nospec(4 * mce->bank, 4 * bank_num);
+
+ if (is_ucna(mce))
+ return kvm_vcpu_x86_set_ucna(vcpu, mce, banks);
+
/*
* if IA32_MCG_CTL is not all 1s, the uncorrected error
* reporting is disabled
@@ -4917,7 +4959,6 @@ static int kvm_vcpu_ioctl_x86_set_mce(struct kvm_vcpu *vcpu,
if ((mce->status & MCI_STATUS_UC) && (mcg_cap & MCG_CTL_P) &&
vcpu->arch.mcg_ctl != ~(u64)0)
return 0;
- banks += 4 * mce->bank;
/*
* if IA32_MCi_CTL is not all 1s, the uncorrected error
* reporting is disabled for the bank
