i386: Add support for overflow recovery
Add cpuid bit definition for overflow recovery. This is needed in the case
where a deferred error has been sent to the guest, a guest process accesses the
poisoned memory, but the machine_check_poll function has not yet handled the
original deferred error. If overflow recovery is not set in this case, when we
handle the uncorrected error from the poisoned memory access, the overflow bit
will be set and will result in the guest being shut down.
By the time the MCE reaches the guest, the overflow has been handled
by the host and has not caused a shutdown, so include the bit unconditionally.
Signed-off-by: John Allen <john.allen@amd.com>
Message-ID: <20240603193622.47156-4-john.allen@amd.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
diff --git a/target/i386/cpu.c b/target/i386/cpu.c
index c5a532a..7466217 100644
--- a/target/i386/cpu.c
+++ b/target/i386/cpu.c
@@ -1183,7 +1183,7 @@
[FEAT_8000_0007_EBX] = {
.type = CPUID_FEATURE_WORD,
.feat_names = {
- NULL, "succor", NULL, NULL,
+ "overflow-recov", "succor", NULL, NULL,
NULL, NULL, NULL, NULL,
NULL, NULL, NULL, NULL,
NULL, NULL, NULL, NULL,
diff --git a/target/i386/cpu.h b/target/i386/cpu.h
index 6786055..8fe28b6 100644
--- a/target/i386/cpu.h
+++ b/target/i386/cpu.h
@@ -984,6 +984,7 @@
#define CPUID_14_0_ECX_LIP (1U << 31)
/* RAS Features */
+#define CPUID_8000_0007_EBX_OVERFLOW_RECOV (1U << 0)
#define CPUID_8000_0007_EBX_SUCCOR (1U << 1)
/* CLZERO instruction */
diff --git a/target/i386/kvm/kvm.c b/target/i386/kvm/kvm.c
index 56d8e2a..912f5d5 100644
--- a/target/i386/kvm/kvm.c
+++ b/target/i386/kvm/kvm.c
@@ -533,7 +533,7 @@
cpuid_1_edx = kvm_arch_get_supported_cpuid(s, 1, 0, R_EDX);
ret |= cpuid_1_edx & CPUID_EXT2_AMD_ALIASES;
} else if (function == 0x80000007 && reg == R_EBX) {
- ret |= CPUID_8000_0007_EBX_SUCCOR;
+ ret |= CPUID_8000_0007_EBX_OVERFLOW_RECOV | CPUID_8000_0007_EBX_SUCCOR;
} else if (function == KVM_CPUID_FEATURES && reg == R_EAX) {
/* kvm_pv_unhalt is reported by GET_SUPPORTED_CPUID, but it can't
* be enabled without the in-kernel irqchip
