From 1c23b1bfba9ebeb444bbf73382e5edb16042da46 Mon Sep 17 00:00:00 2001 From: Feng Wu Date: Mon, 12 May 2014 17:41:42 +0200 Subject: [PATCH] x86/HVM: correct the SMEP logic for HVM_CR0_GUEST_RESERVED_BITS When checking the SMEP feature for HVM guests, we should check the VCPU instead of the host CPU. Signed-off-by: Feng Wu Reviewed-by: Andrew Cooper master commit: 31ee951a3bee6e7cc21f94f900fe989e3701a79a master date: 2014-04-28 12:47:24 +0200 --- xen/include/asm-x86/hvm/hvm.h | 15 ++++++++++++++- 1 file changed, 14 insertions(+), 1 deletion(-) diff --git a/xen/include/asm-x86/hvm/hvm.h b/xen/include/asm-x86/hvm/hvm.h index f9ea093ddc..902f224859 100644 --- a/xen/include/asm-x86/hvm/hvm.h +++ b/xen/include/asm-x86/hvm/hvm.h @@ -339,6 +339,19 @@ static inline int hvm_do_pmu_interrupt(struct cpu_user_regs *regs) return hvm_funcs.do_pmu_interrupt(regs); } +static inline bool_t hvm_vcpu_has_smep(void) +{ + unsigned int eax, ebx, ecx = 0, dummy; + + hvm_cpuid(0, &eax, &dummy, &dummy, &dummy); + + if ( eax < 7 ) + return 0; + + hvm_cpuid(7, &dummy, &ebx, &ecx, &dummy); + 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) \ @@ -358,7 +371,7 @@ static inline int hvm_do_pmu_interrupt(struct cpu_user_regs *regs) 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) | \ -- 2.39.5