On Thu, Jan 18, 2018 at 07:31:16PM +0100, Borislav Petkov wrote: > On Thu, Jan 18, 2018 at 02:48:29PM +0100, Peter Zijlstra wrote: > > From: Thomas Gleixner <t...@linutronix.de> > > <--- Add commit message here. > > > Signed-off-by: Thomas Gleixner <t...@linutronix.de> > > Signed-off-by: Peter Zijlstra (Intel) <pet...@infradead.org> > > --- > > arch/x86/include/asm/cpufeatures.h | 4 +++- > > arch/x86/include/asm/msr-index.h | 3 +++ > > arch/x86/include/asm/nospec-branch.h | 9 +++++++++ > > arch/x86/kernel/cpu/bugs.c | 2 ++ > > arch/x86/kernel/cpu/specctrl.c | 9 +++++++++ > > 5 files changed, 26 insertions(+), 1 deletion(-) > > > > --- a/arch/x86/include/asm/cpufeatures.h > > +++ b/arch/x86/include/asm/cpufeatures.h > > @@ -212,8 +212,9 @@ > > > > #define X86_FEATURE_MBA ( 7*32+18) /* Memory Bandwidth > > Allocation */ > > #define X86_FEATURE_RSB_CTXSW ( 7*32+19) /* Fill RSB on > > context switches */ > > -#define X86_FEATURE_SPEC_CTRL ( 7*32+20) /* Speculation > > Control */ > > +#define X86_FEATURE_SPEC_CTRL ( 7*32+20) /* Speculation > > Control - Intel only */ > > #define X86_FEATURE_IBRS ( 7*32+21) /* Indirect Branch > > Restricted Speculation */ > > +#define X86_FEATURE_IBPB ( 7*32+22) /* Indirect Branch > > Prediction Barrier */ > > > > /* Virtualization flags: Linux defined, word 8 */ > > #define X86_FEATURE_TPR_SHADOW ( 8*32+ 0) /* Intel TPR Shadow > > */ > > @@ -273,6 +274,7 @@ > > #define X86_FEATURE_CLZERO (13*32+ 0) /* CLZERO instruction */ > > #define X86_FEATURE_IRPERF (13*32+ 1) /* Instructions Retired > > Count */ > > #define X86_FEATURE_XSAVEERPTR (13*32+ 2) /* Always > > save/restore FP error pointers */ > > +#define X86_FEATURE_AMD_IBPB (13*32+12) /* Indirect Branch > > Prediction Barrier support */ > > I guess you could make that > > #define X86_FEATURE_AMD_IBPB (13*32+12) /* "" Indirect Branch > Prediction Barrier support */ > > (note the "" in the comment) > > so that it doesn't appear in /proc/cpuinfo as those two flags denote the > same thing.
Maybe I missed the memo, why do we need both X86_FEATURE_IBPB and X86_FEATURE_AMD_IBPB? -- Josh
