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[PATCH] target/i386: check for availability of MSR_IA32_UCODE_REV as an
From: |
Paolo Bonzini |
Subject: |
[PATCH] target/i386: check for availability of MSR_IA32_UCODE_REV as an emulated MSR |
Date: |
Tue, 11 Feb 2020 18:55:16 +0100 |
Even though MSR_IA32_UCODE_REV has been available long before Linux 5.6,
which added it to the emulated MSR list, a bug caused the microcode
version to revert to 0x100000000 on INIT. As a result, processors other
than the bootstrap processor would not see the host microcode revision;
some Windows version complain loudly about this and crash with a
fairly explicit MICROCODE REVISION MISMATCH error.
[If running 5.6 prereleases, the kernel fix "KVM: x86: do not reset
microcode version on INIT or RESET" should also be applied.]
Reported-by: Alex Williamson <address@hidden>
Signed-off-by: Paolo Bonzini <address@hidden>
---
target/i386/kvm.c | 7 +++++--
1 file changed, 5 insertions(+), 2 deletions(-)
diff --git a/target/i386/kvm.c b/target/i386/kvm.c
index 6ef291d580..69eb43d796 100644
--- a/target/i386/kvm.c
+++ b/target/i386/kvm.c
@@ -105,6 +105,7 @@ static bool has_msr_smi_count;
static bool has_msr_arch_capabs;
static bool has_msr_core_capabs;
static bool has_msr_vmx_vmfunc;
+static bool has_msr_ucode_rev;
static uint32_t has_architectural_pmu_version;
static uint32_t num_architectural_pmu_gp_counters;
@@ -2056,6 +2057,9 @@ static int kvm_get_supported_msrs(KVMState *s)
case MSR_IA32_VMX_VMFUNC:
has_msr_vmx_vmfunc = true;
break;
+ case MSR_IA32_UCODE_REV:
+ has_msr_ucode_rev = true;
+ break;
}
}
}
@@ -2696,8 +2700,7 @@ static void kvm_init_msrs(X86CPU *cpu)
env->features[FEAT_CORE_CAPABILITY]);
}
- if (kvm_arch_get_supported_msr_feature(kvm_state,
- MSR_IA32_UCODE_REV)) {
+ if (has_msr_ucode_rev) {
kvm_msr_entry_add(cpu, MSR_IA32_UCODE_REV, cpu->ucode_rev);
}
--
2.21.0
- [PATCH] target/i386: check for availability of MSR_IA32_UCODE_REV as an emulated MSR,
Paolo Bonzini <=