On Thu, 23 Jan 2020 14:50:10 +0100
Paolo Bonzini <pbonz...@redhat.com> wrote:
> KVM can return the host microcode revision as a feature MSR.
> Use it as the default value for -cpu host.
>
> Signed-off-by: Paolo Bonzini <pbonz...@redhat.com>
> Message-Id: <1579544504-3616-4-git-send-email-pbonz...@redhat.com>
> Signed-off-by: Paolo Bonzini <pbonz...@redhat.com>
> ---
> target/i386/cpu.c | 4 ++++
> target/i386/kvm.c | 5 +++++
> 2 files changed, 9 insertions(+)
Hey Paolo,
My Windows 10 VM boot loops with this :-\ It seems to be related to
the CPU model. Now fails (host-passthrough):
-cpu
host,hv-time,hv-relaxed,hv-vapic,hv-spinlocks=0x1fff,hv-vendor-id=KeenlyKVM,kvm=off
Works (host-model):
-cpu
IvyBridge-IBRS,ss=on,vmx=on,pcid=on,hypervisor=on,arat=on,tsc-adjust=on,umip=on,md-clear=on,stibp=on,arch-capabilities=on,ssbd=on,xsaveopt=on,skip-l1dfl-vmentry=on,hv-time,hv-relaxed,hv-vapic,hv-spinlocks=0x1fff,hv-vendor-id=KeenlyKVM,kvm=off
Thanks,
Alex
> diff --git a/target/i386/cpu.c b/target/i386/cpu.c
> index 790254e..ffe5de0 100644
> --- a/target/i386/cpu.c
> +++ b/target/i386/cpu.c
> @@ -6416,6 +6416,10 @@ static void x86_cpu_realizefn(DeviceState *dev, Error
> **errp)
> &cpu->mwait.ecx, &cpu->mwait.edx);
> env->features[FEAT_1_ECX] |= CPUID_EXT_MONITOR;
> }
> + if (kvm_enabled() && cpu->ucode_rev == 0) {
> + cpu->ucode_rev = kvm_arch_get_supported_msr_feature(kvm_state,
> +
> MSR_IA32_UCODE_REV);
> + }
> }
>
> if (cpu->ucode_rev == 0) {
> diff --git a/target/i386/kvm.c b/target/i386/kvm.c
> index f6dd6b7..1b67090 100644
> --- a/target/i386/kvm.c
> +++ b/target/i386/kvm.c
> @@ -2696,6 +2696,11 @@ 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)) {
> + kvm_msr_entry_add(cpu, MSR_IA32_UCODE_REV, cpu->ucode_rev);
> + }
> +
> /*
> * Older kernels do not include VMX MSRs in KVM_GET_MSR_INDEX_LIST, but
> * all kernels with MSR features should have them.
