Re: [PATCH v3 2/8] KVM:CPUID: Define CET CPUID bits and CR4.CET master enable bit.

From: Xiaoyao Li
Date: Thu Feb 28 2019 - 21:15:32 EST


On Tue, 2019-02-26 at 15:57 +0800, Yang Weijiang wrote:
> On Tue, Feb 26, 2019 at 11:48:59AM -0800, Jim Mattson wrote:
> > On Mon, Feb 25, 2019 at 10:32 PM Yang Weijiang <weijiang.yang@xxxxxxxxx>
> > wrote:
> > >
> > > Guest queries CET SHSTK and IBT support by CPUID.(EAX=0x7,ECX=0),
> > > in return, ECX[bit 7] corresponds to SHSTK feature, and EDX[bit 20]
> > > corresponds to IBT feature.
> > > CR4.CET[bit 23] is CET master enable bit, it controls CET feature
> > > availability in guest OS.
> > >
> > > Note: Although SHSTK or IBT can be enabled independently,
> > > either of the features is controlled by CR4.CET.
> > >
> > > Signed-off-by: Zhang Yi Z <yi.z.zhang@xxxxxxxxxxxxxxx>
> > > Signed-off-by: Yang Weijiang <weijiang.yang@xxxxxxxxx>
> >
> > Am I missing something? X86_CR4_CET and X86_FEATURE_SHSTK and
> > X86_FEATURE_IBT don't appear to be defined in Linus' tree.
>
> The patch-set has dependency on this CET Kernel patch-set:
> https://lkml.org/lkml/2018/11/20/203
> I reused some definitions from the kernel patches.

Right, the definitions should be defined by the kernel patches.
However, I have checked the latest kernel patches and found it didn't define
the related CPUID feature bits.