From 1ea1432199cdddbb4e7f98cee71cabf50a9516f2 Mon Sep 17 00:00:00 2001 From: John Allen Date: Mon, 3 Jun 2024 19:36:22 +0000 Subject: [PATCH] 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 Message-ID: <20240603193622.47156-4-john.allen@amd.com> Signed-off-by: Paolo Bonzini --- target/i386/cpu.c | 2 +- target/i386/cpu.h | 1 + target/i386/kvm/kvm.c | 2 +- 3 files changed, 3 insertions(+), 2 deletions(-) diff --git a/target/i386/cpu.c b/target/i386/cpu.c index c5a532a254..7466217d5e 100644 --- a/target/i386/cpu.c +++ b/target/i386/cpu.c @@ -1183,7 +1183,7 @@ FeatureWordInfo feature_word_info[FEATURE_WORDS] = { [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 6786055ec6..8fe28b67e0 100644 --- a/target/i386/cpu.h +++ b/target/i386/cpu.h @@ -984,6 +984,7 @@ uint64_t x86_cpu_get_supported_feature_word(FeatureWord w, #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 56d8e2a89e..912f5d5a6b 100644 --- a/target/i386/kvm/kvm.c +++ b/target/i386/kvm/kvm.c @@ -533,7 +533,7 @@ uint32_t kvm_arch_get_supported_cpuid(KVMState *s, uint32_t function, 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