On 1/26/21 1:30 AM, Kai Huang wrote: > From: Sean Christopherson <seanjc@xxxxxxxxxx> > > Add SGX1 and SGX2 feature flags, via CPUID.0x12.0x0.EAX, as scattered > features, since adding a new leaf for only two bits would be wasteful. > As part of virtualizing SGX, KVM will expose the SGX CPUID leafs to its > guest, and to do so correctly needs to query hardware and kernel support > for SGX1 and SGX2. It's also not _just_ exposing the CPUID leaves. There are some checks here when KVM is emulating some SGX instructions too, right? > diff --git a/arch/x86/include/asm/cpufeatures.h b/arch/x86/include/asm/cpufeatures.h > index 84b887825f12..18b2d0c8bbbe 100644 > --- a/arch/x86/include/asm/cpufeatures.h > +++ b/arch/x86/include/asm/cpufeatures.h > @@ -292,6 +292,8 @@ > #define X86_FEATURE_FENCE_SWAPGS_KERNEL (11*32+ 5) /* "" LFENCE in kernel entry SWAPGS path */ > #define X86_FEATURE_SPLIT_LOCK_DETECT (11*32+ 6) /* #AC for split lock */ > #define X86_FEATURE_PER_THREAD_MBA (11*32+ 7) /* "" Per-thread Memory Bandwidth Allocation */ > +#define X86_FEATURE_SGX1 (11*32+ 8) /* Software Guard Extensions sub-feature SGX1 */ > +#define X86_FEATURE_SGX2 (11*32+ 9) /* Software Guard Extensions sub-feature SGX2 */ FWIW, I'm not sure how valuable it is to spell the SGX acronym out three times. Can't we use those bytes to put something more useful in that comment?
