On Thu, 2020-07-23 at 09:10 -0700, Sean Christopherson wrote: > On Wed, Apr 29, 2020 at 03:07:09PM -0700, Yu-cheng Yu wrote: > > diff --git a/arch/x86/include/asm/msr-index.h b/arch/x86/include/asm/msr-index.h > > index 12c9684d59ba..47f603729543 100644 > > --- a/arch/x86/include/asm/msr-index.h > > +++ b/arch/x86/include/asm/msr-index.h > > @@ -885,4 +885,22 @@ > > #define MSR_VM_IGNNE 0xc0010115 > > #define MSR_VM_HSAVE_PA 0xc0010117 > > > > +/* Control-flow Enforcement Technology MSRs */ > > +#define MSR_IA32_U_CET 0x6a0 /* user mode cet setting */ > > +#define MSR_IA32_S_CET 0x6a2 /* kernel mode cet setting */ > > +#define MSR_IA32_PL0_SSP 0x6a4 /* kernel shstk pointer */ > > +#define MSR_IA32_PL1_SSP 0x6a5 /* ring-1 shstk pointer */ > > +#define MSR_IA32_PL2_SSP 0x6a6 /* ring-2 shstk pointer */ > > +#define MSR_IA32_PL3_SSP 0x6a7 /* user shstk pointer */ > > +#define MSR_IA32_INT_SSP_TAB 0x6a8 /* exception shstk table */ > > + > > +/* MSR_IA32_U_CET and MSR_IA32_S_CET bits */ > > +#define MSR_IA32_CET_SHSTK_EN 0x0000000000000001ULL > > Can we drop the MSR_IA32 prefix for the individual bits? Mostly to yield > shorter line lengths, but also because it's more or less redundant info, > and in some ways unhelpful as it's hard to quickly differentiate between > "this is an MSR index" and "this is a bit/mask for an MSR". Agree! > > My vote would also be to use BIT() or BIT_ULL(). The SDM defines the flags > by their (decimal) bit number. Manually converting the bits to masks makes > it difficult to check for correctness. > > E.g. > > #define CET_SHSTK_EN BIT(0) > #define CET_WRSS_EN BIT(1) > #define CET_ENDBR_EN BIT(2) > #define CET_LEG_IW_EN BIT(3) > #define CET_NO_TRACK_EN BIT(4) > #define CET_WAIT_ENDBR BIT(5) I will change them. > > > +#define MSR_IA32_CET_WRSS_EN 0x0000000000000002ULL > > +#define MSR_IA32_CET_ENDBR_EN 0x0000000000000004ULL > > +#define MSR_IA32_CET_LEG_IW_EN 0x0000000000000008ULL > > +#define MSR_IA32_CET_NO_TRACK_EN 0x0000000000000010ULL > > +#define MSR_IA32_CET_WAIT_ENDBR 0x00000000000000800UL > > +#define MSR_IA32_CET_BITMAP_MASK 0xfffffffffffff000ULL > > This particular define, the so called BITMAP_MASK, is no longer used in the > IBT series. IMO it'd be better off dropping this mask as it's not clear > from the name that this is really nothing more than a mask for a virtual > address, e.g. at first glance (for someone without CET knowledge) it looks > like bits 63:12 hold a bitmap as opposed to holding a pointer to a bitmap. I will remove this. Thanks, Yu-cheng
