On Wed, Dec 12, 2018 at 05:01:10PM +0000, Daniel P. Berrangé wrote: > On Wed, Dec 12, 2018 at 04:57:42PM +0000, Lendacky, Thomas wrote: > > On 12/11/2018 02:53 PM, Eduardo Habkost wrote: > > > The STIBP flag may be supported by the host KVM module, so QEMU > > > can allow it to be configured manually, and it can be exposed to > > > guests when using "-cpu host". > > > > > > No additional migration code is required because the whole > > > contents of spec_ctrl is already migrated in the "cpu/spec_ctrl" > > > section. > > > > > > Corresponding KVM patch was submitted at: > > > https://lore.kernel.org/lkml/20181205191956.31480-1-ehabkost@xxxxxxxxxx/ > > > > > > Signed-off-by: Eduardo Habkost <ehabkost@xxxxxxxxxx> > > > Message-Id: <20181210180250.31299-1-ehabkost@xxxxxxxxxx> > > > Signed-off-by: Eduardo Habkost <ehabkost@xxxxxxxxxx> > > > --- > > > target/i386/cpu.c | 2 +- > > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > > > diff --git a/target/i386/cpu.c b/target/i386/cpu.c > > > index 86a934d450..12f559b6af 100644 > > > --- a/target/i386/cpu.c > > > +++ b/target/i386/cpu.c > > > @@ -1042,7 +1042,7 @@ static FeatureWordInfo feature_word_info[FEATURE_WORDS] = { > > > NULL, NULL, NULL, NULL, > > > NULL, NULL, "pconfig", NULL, > > > NULL, NULL, NULL, NULL, > > > - NULL, NULL, "spec-ctrl", NULL, > > > + NULL, NULL, "spec-ctrl", "stibp", > > > > I guess I missed this earlier. Is there a corresponding patch for the AMD > > STIBP bit (CPUID 0x80000008_EBX[15]) that is in KVM? > > This Intel STIBP patch is one that many distros have carried downstream > since the flaw came to light. > > I've not seen any equiv patch for AMD STIBP bit, in either QMEU or libvirt, > so guess that's a gap that needs filling. I can submit a "amd-stibp" patch for completeness, although I doubt many people will actually use the flag. -- Eduardo
