diff mbox series

[PULL,40/42] i386: Add support for overflow recovery

Message ID 20240608083415.2769160-41-pbonzini@redhat.com
State New
Headers show
Series [PULL,01/42] target/i386: fix pushed value of EFLAGS.RF | expand

Commit Message

Paolo Bonzini June 8, 2024, 8:34 a.m. UTC 
From: John Allen <john.allen@amd.com>

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>
---
 target/i386/cpu.h     | 1 +
 target/i386/cpu.c     | 2 +-
 target/i386/kvm/kvm.c | 2 +-
 3 files changed, 3 insertions(+), 2 deletions(-)
diff mbox series

Patch

diff --git a/target/i386/cpu.h b/target/i386/cpu.h
index 6786055ec6b..8fe28b67e0f 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/cpu.c b/target/i386/cpu.c
index c5a532a254e..7466217d5ea 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/kvm/kvm.c b/target/i386/kvm/kvm.c
index 56d8e2a89ec..912f5d5a6be 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