Re: [PATCH v2] KVM: VMX: add MSR_IA32_TSX_CTRL into msrs_to_save

[Jim Mattson]

On Thu, May 4, 2023 at 11:18 AM Mingwei Zhang <mizhang@xxxxxxxxxx> wrote:
>
> Add MSR_IA32_TSX_CTRL into msrs_to_save[] to explicitly tell userspace to
> save/restore the register value during migration. Missing this may cause
> userspace that relies on KVM ioctl(KVM_GET_MSR_INDEX_LIST) fail to port the
> value to the target VM.
>
> In addition, there is no need to add MSR_IA32_TSX_CTRL when
> ARCH_CAP_TSX_CTRL_MSR is not supported in guest. So add the checking in
> kvm_probe_msr_to_save().
>
> Fixes: b07a5c53d42a ("KVM: vmx: use MSR_IA32_TSX_CTRL to hard-disable TSX on guest that lack it")
> Reported-by: Jim Mattson <jmattson@xxxxxxxxxx>
> Signed-off-by: Mingwei Zhang <mizhang@xxxxxxxxxx>
Reviewed-by: Jim Mattson <jmattson@xxxxxxxxxx>