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

From: Li, Xin3
Date: Tue Nov 14 2023 - 22:04:20 EST


> >> >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.

Right, maybe better to set both to 0s.