Re: [Xen-devel] [PATCH v2 for-4.7/4.8] x86: Fix "x86: further CPUID handling adjustments"

2018-05-18 Thread Andrew Cooper
On 18/05/18 13:37, Jan Beulich wrote: On 18.05.18 at 14:21, wrote: >> On 17/05/18 13:23, Jan Beulich wrote: >> On 16.05.18 at 19:27, wrote: c/s 62b187969 "x86: further CPUID handling adjustments" make some adjustments.

Re: [Xen-devel] [PATCH v2 for-4.7/4.8] x86: Fix "x86: further CPUID handling adjustments"

2018-05-18 Thread Jan Beulich
>>> On 18.05.18 at 14:21, wrote: > On 17/05/18 13:23, Jan Beulich wrote: > On 16.05.18 at 19:27, wrote: >>> c/s 62b187969 "x86: further CPUID handling adjustments" make some >>> adjustments. >>> However, it breaks levelling of guests,

Re: [Xen-devel] [PATCH v2 for-4.7/4.8] x86: Fix "x86: further CPUID handling adjustments"

2018-05-18 Thread Andrew Cooper
On 17/05/18 13:23, Jan Beulich wrote: On 16.05.18 at 19:27, wrote: >> c/s 62b187969 "x86: further CPUID handling adjustments" make some >> adjustments. >> However, it breaks levelling of guests, making it impossible for the >> toolstack >> to hide STIBP or IBPB

Re: [Xen-devel] [PATCH v2 for-4.7/4.8] x86: Fix "x86: further CPUID handling adjustments"

2018-05-17 Thread Jan Beulich
>>> On 16.05.18 at 19:27, wrote: > c/s 62b187969 "x86: further CPUID handling adjustments" make some adjustments. > However, it breaks levelling of guests, making it impossible for the toolstack > to hide STIBP or IBPB from guests on hardware with up-to-date microcode.

Re: [Xen-devel] [PATCH v2 for-4.7/4.8] x86: Fix "x86: further CPUID handling adjustments"

2018-05-17 Thread Jan Beulich
>>> On 16.05.18 at 19:27, wrote: > c/s f9616884e (a backport of c/s 0d703a701 "x86/feature: Definitions for > Indirect Branch Controls") missed a CPUID adjustment when calculating the raw > featureset. This impacts host administrator diagnostics. > > Signed-off-by: