[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] Re: [Xen-devel] [PATCH] x86/vmx: correct the SMEP logic for HVM_CR0_GUEST_RESERVED_BITS
On 23/04/14 15:32, Feng Wu wrote: > When checking the SMEP feature for HVM guests, we should check the > VCPU instead of the host CPU. > > Signed-off-by: Feng Wu <feng.wu@xxxxxxxxx> > --- > xen/include/asm-x86/hvm/hvm.h | 11 ++++++++++- > 1 file changed, 10 insertions(+), 1 deletion(-) > > diff --git a/xen/include/asm-x86/hvm/hvm.h b/xen/include/asm-x86/hvm/hvm.h > index dcc3483..74a09ef 100644 > --- a/xen/include/asm-x86/hvm/hvm.h > +++ b/xen/include/asm-x86/hvm/hvm.h > @@ -351,6 +351,15 @@ static inline int hvm_event_pending(struct vcpu *v) > return hvm_funcs.event_pending(v); > } > > +static inline bool_t hvm_vcpu_has_smep(void) > +{ > + unsigned int ebx = 0, leaf = 0x7; You need to check hvm_cpuid.0.eax for max leaf. ~Andrew > + > + hvm_cpuid(leaf, NULL, &ebx, NULL, NULL); > + > + return !!(ebx & cpufeat_mask(X86_FEATURE_SMEP)); > +} > + > /* These reserved bits in lower 32 remain 0 after any load of CR0 */ > #define HVM_CR0_GUEST_RESERVED_BITS \ > (~((unsigned long) \ > @@ -370,7 +379,7 @@ static inline int hvm_event_pending(struct vcpu *v) > X86_CR4_DE | X86_CR4_PSE | X86_CR4_PAE | \ > X86_CR4_MCE | X86_CR4_PGE | X86_CR4_PCE | \ > X86_CR4_OSFXSR | X86_CR4_OSXMMEXCPT | \ > - (cpu_has_smep ? X86_CR4_SMEP : 0) | \ > + (hvm_vcpu_has_smep() ? X86_CR4_SMEP : 0) | \ > (cpu_has_fsgsbase ? X86_CR4_FSGSBASE : 0) | \ > ((nestedhvm_enabled((_v)->domain) && cpu_has_vmx)\ > ? X86_CR4_VMXE : 0) | \ _______________________________________________ Xen-devel mailing list Xen-devel@xxxxxxxxxxxxx http://lists.xen.org/xen-devel
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