Re: [PATCH v1 09/23] KVM: VMX: Switch FRED RSP0 between host and guest

Chao Gao
2023-11-14T07:48:08Z

>> >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;
>> > u64 msr_guest_kernel_gs_base;
>> >+ u64 msr_host_fred_rsp0;
>> >+ u64 msr_guest_fred_rsp0;
>>
>> resetting guest fred rsp0 to 0 during vcpu reset is missing.
>
>hmm, I assume it gets the same treatment as guest_kernel_gs_base.
>
>It seems we don't reset guest_kernel_gs_base. No?

Yes. But for fred MSRs, FRED spec clearly says their RESET values
are 0s. for kernel_gs_base MSR, looks there is no such description
in SDM.