On 05/05/2017 20:17, Ricardo Neri wrote: > User-Mode Instruction Prevention is a security feature present in new > Intel processors that, when set, prevents the execution of a subset of > instructions if such instructions are executed in user mode (CPL > 0). > Attempting to execute such instructions causes a general protection > exception. > > The subset of instructions comprises: > > * SGDT - Store Global Descriptor Table > * SIDT - Store Interrupt Descriptor Table > * SLDT - Store Local Descriptor Table > * SMSW - Store Machine Status Word > * STR - Store Task Register > > This feature is also added to the list of disabled-features to allow > a cleaner handling of build-time configuration. > > Cc: Andy Lutomirski <luto@xxxxxxxxxx> > Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> > Cc: H. Peter Anvin <hpa@xxxxxxxxx> > Cc: Borislav Petkov <bp@xxxxxxx> > Cc: Brian Gerst <brgerst@xxxxxxxxx> > Cc: Chen Yucong <slaoub@xxxxxxxxx> > Cc: Chris Metcalf <cmetcalf@xxxxxxxxxxxx> > Cc: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx> > Cc: Fenghua Yu <fenghua.yu@xxxxxxxxx> > Cc: Huang Rui <ray.huang@xxxxxxx> > Cc: Jiri Slaby <jslaby@xxxxxxx> > Cc: Jonathan Corbet <corbet@xxxxxxx> > Cc: Michael S. Tsirkin <mst@xxxxxxxxxx> > Cc: Paul Gortmaker <paul.gortmaker@xxxxxxxxxxxxx> > Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx> > Cc: Ravi V. Shankar <ravi.v.shankar@xxxxxxxxx> > Cc: Shuah Khan <shuah@xxxxxxxxxx> > Cc: Vlastimil Babka <vbabka@xxxxxxx> > Cc: Tony Luck <tony.luck@xxxxxxxxx> > Cc: Paolo Bonzini <pbonzini@xxxxxxxxxx> > Cc: Liang Z. Li <liang.z.li@xxxxxxxxx> > Cc: Alexandre Julliard <julliard@xxxxxxxxxx> > Cc: Stas Sergeev <stsp@xxxxxxx> > Cc: x86@xxxxxxxxxx > Cc: linux-msdos@xxxxxxxxxxxxxxx > > Signed-off-by: Ricardo Neri <ricardo.neri-calderon@xxxxxxxxxxxxxxx> Would it be possible to have this patch in a topic branch for KVM's consumption? Thanks, Paolo > --- > arch/x86/include/asm/cpufeatures.h | 1 + > arch/x86/include/asm/disabled-features.h | 8 +++++++- > arch/x86/include/uapi/asm/processor-flags.h | 2 ++ > 3 files changed, 10 insertions(+), 1 deletion(-) > > diff --git a/arch/x86/include/asm/cpufeatures.h b/arch/x86/include/asm/cpufeatures.h > index 2701e5f..f1d61d2 100644 > --- a/arch/x86/include/asm/cpufeatures.h > +++ b/arch/x86/include/asm/cpufeatures.h > @@ -289,6 +289,7 @@ > > /* Intel-defined CPU features, CPUID level 0x00000007:0 (ecx), word 16 */ > #define X86_FEATURE_AVX512VBMI (16*32+ 1) /* AVX512 Vector Bit Manipulation instructions*/ > +#define X86_FEATURE_UMIP (16*32+ 2) /* User Mode Instruction Protection */ > #define X86_FEATURE_PKU (16*32+ 3) /* Protection Keys for Userspace */ > #define X86_FEATURE_OSPKE (16*32+ 4) /* OS Protection Keys Enable */ > #define X86_FEATURE_AVX512_VPOPCNTDQ (16*32+14) /* POPCNT for vectors of DW/QW */ > diff --git a/arch/x86/include/asm/disabled-features.h b/arch/x86/include/asm/disabled-features.h > index 5dff775..7adaef7 100644 > --- a/arch/x86/include/asm/disabled-features.h > +++ b/arch/x86/include/asm/disabled-features.h > @@ -16,6 +16,12 @@ > # define DISABLE_MPX (1<<(X86_FEATURE_MPX & 31)) > #endif > > +#ifdef CONFIG_X86_INTEL_UMIP > +# define DISABLE_UMIP 0 > +#else > +# define DISABLE_UMIP (1<<(X86_FEATURE_UMIP & 31)) > +#endif > + > #ifdef CONFIG_X86_64 > # define DISABLE_VME (1<<(X86_FEATURE_VME & 31)) > # define DISABLE_K6_MTRR (1<<(X86_FEATURE_K6_MTRR & 31)) > @@ -61,7 +67,7 @@ > #define DISABLED_MASK13 0 > #define DISABLED_MASK14 0 > #define DISABLED_MASK15 0 > -#define DISABLED_MASK16 (DISABLE_PKU|DISABLE_OSPKE|DISABLE_LA57) > +#define DISABLED_MASK16 (DISABLE_PKU|DISABLE_OSPKE|DISABLE_LA57|DISABLE_UMIP) > #define DISABLED_MASK17 0 > #define DISABLED_MASK_CHECK BUILD_BUG_ON_ZERO(NCAPINTS != 18) > > diff --git a/arch/x86/include/uapi/asm/processor-flags.h b/arch/x86/include/uapi/asm/processor-flags.h > index 567de50..d2c2af8 100644 > --- a/arch/x86/include/uapi/asm/processor-flags.h > +++ b/arch/x86/include/uapi/asm/processor-flags.h > @@ -104,6 +104,8 @@ > #define X86_CR4_OSFXSR _BITUL(X86_CR4_OSFXSR_BIT) > #define X86_CR4_OSXMMEXCPT_BIT 10 /* enable unmasked SSE exceptions */ > #define X86_CR4_OSXMMEXCPT _BITUL(X86_CR4_OSXMMEXCPT_BIT) > +#define X86_CR4_UMIP_BIT 11 /* enable UMIP support */ > +#define X86_CR4_UMIP _BITUL(X86_CR4_UMIP_BIT) > #define X86_CR4_VMXE_BIT 13 /* enable VMX virtualization */ > #define X86_CR4_VMXE _BITUL(X86_CR4_VMXE_BIT) > #define X86_CR4_SMXE_BIT 14 /* enable safer mode (TXT) */ > -- To unsubscribe from this list: send the line "unsubscribe linux-msdos" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
