> >> >diff --git a/arch/x86/kvm/vmx/vmx.h b/arch/x86/kvm/vmx/vmx.h index
> >> >f8c02bd37069..328a3447f064 100644
> >> >--- a/arch/x86/kvm/vmx/vmx.h
> >> >+++ b/arch/x86/kvm/vmx/vmx.h
> >> >@@ -276,6 +276,8 @@ struct vcpu_vmx {
> >> > #ifdef CONFIG_X86_64
> >> > u64 msr_host_kerne
>> >diff --git a/arch/x86/kvm/vmx/vmx.h b/arch/x86/kvm/vmx/vmx.h index
>> >f8c02bd37069..328a3447f064 100644
>> >--- a/arch/x86/kvm/vmx/vmx.h
>> >+++ b/arch/x86/kvm/vmx/vmx.h
>> >@@ -276,6 +276,8 @@ struct vcpu_vmx {
>> > #ifdef CONFIG_X86_64
>> >u64 msr_host_kernel_gs_base;
>
> >+if (cpu_feature_enabled(X86_FEATURE_FRED) &&
> >+guest_cpuid_has(&vmx->vcpu, X86_FEATURE_FRED)) {
>
> IIUC, vmx_prepare_switch_to_host() is called from IRQ-disabled context. using
> guest_cpuid_has() in this context is not desired, see
> lockdep_assert_irqs_enabled() in cpuid_entry
On Wed, Nov 08, 2023 at 10:29:49AM -0800, Xin Li wrote:
>Switch MSR_IA32_FRED_RSP0 between host and guest in
>vmx_prepare_switch_to_{host,guest}().
>
>MSR_IA32_FRED_RSP0 is used during ring 3 event delivery only, thus
>KVM, running on ring 0, can run safely with guest FRED RSP0, i.e.,
>no need to s
