On Thu, Oct 13, 2022 at 04:43:15PM +0200, Jan Beulich wrote:
> On 13.10.2022 16:06, Roger Pau Monné wrote:
> > On Wed, Oct 12, 2022 at 10:36:57AM +0200, Jan Beulich wrote:
> >> On 11.10.2022 18:02, Roger Pau Monne wrote:
> >>> --- a/xen/arch/x86/cpu/amd.c
> >>> +++ b/xen/arch/x86/cpu/amd.c
> >>> @@
On 13.10.2022 16:06, Roger Pau Monné wrote:
> On Wed, Oct 12, 2022 at 10:36:57AM +0200, Jan Beulich wrote:
>> On 11.10.2022 18:02, Roger Pau Monne wrote:
>>> --- a/xen/arch/x86/cpu/amd.c
>>> +++ b/xen/arch/x86/cpu/amd.c
>>> @@ -814,7 +814,9 @@ void amd_set_ssbd(bool enable)
>>> wrmsr(MS
On Wed, Oct 12, 2022 at 10:36:57AM +0200, Jan Beulich wrote:
> On 11.10.2022 18:02, Roger Pau Monne wrote:
> > --- a/xen/arch/x86/cpu/amd.c
> > +++ b/xen/arch/x86/cpu/amd.c
> > @@ -814,7 +814,9 @@ void amd_set_ssbd(bool enable)
> > wrmsr(MSR_VIRT_SPEC_CTRL, enable ? SPEC_CTRL_SSBD : 0,
On 11.10.2022 18:02, Roger Pau Monne wrote:
> --- a/xen/arch/x86/cpu/amd.c
> +++ b/xen/arch/x86/cpu/amd.c
> @@ -814,7 +814,9 @@ void amd_set_ssbd(bool enable)
> wrmsr(MSR_VIRT_SPEC_CTRL, enable ? SPEC_CTRL_SSBD : 0, 0);
> else if ( amd_legacy_ssbd )
> core_set_lega
Hardware that exposes SSB_NO can implement the setting of SSBD as a
no-op because it's not affected by SSB.
Take advantage of that and allow exposing VIRT_SPEC_CTRL.SSBD to guest
running on hadrware that has SSB_NO. Only set VIRT_SSBD on the max
policy though, as the feature is only intended to b
