Re: [PATCH v9 09/22] KVM: VMX: Save/restore guest FRED RSP0

[Chao Gao]

On Sun, Oct 26, 2025 at 01:18:57PM -0700, Xin Li (Intel) wrote:
>From: Xin Li <xin3.li@xxxxxxxxx>
>
>Save guest FRED RSP0 in vmx_prepare_switch_to_host() and restore it
>in vmx_prepare_switch_to_guest() because MSR_IA32_FRED_RSP0 is passed
>through to the guest, thus is volatile/unknown.
>
>Note, host FRED RSP0 is restored in arch_exit_to_user_mode_prepare(),
>regardless of whether it is modified in KVM.
>
>Signed-off-by: Xin Li <xin3.li@xxxxxxxxx>
>Signed-off-by: Xin Li (Intel) <xin@xxxxxxxxx>
>Tested-by: Shan Kang <shan.kang@xxxxxxxxx>
>Tested-by: Xuelian Guo <xuelian.guo@xxxxxxxxx>

Reviewed-by: Chao Gao <chao.gao@xxxxxxxxx>