From ceee7df749da03fa17ab5dc7d06dffb4980a32db Mon Sep 17 00:00:00 2001 From: Xiao Guangrong Date: Thu, 7 May 2015 16:20:15 +0800 Subject: KVM: MMU: fix smap permission check Current permission check assumes that RSVD bit in PFEC is always zero, however, it is not true since MMIO #PF will use it to quickly identify MMIO access Fix it by clearing the bit if walking guest page table is needed Signed-off-by: Xiao Guangrong Signed-off-by: Paolo Bonzini --- arch/x86/kvm/mmu.h | 2 ++ 1 file changed, 2 insertions(+) (limited to 'arch/x86/kvm/mmu.h') diff --git a/arch/x86/kvm/mmu.h b/arch/x86/kvm/mmu.h index c7d65637c851..06eb2fc1bab8 100644 --- a/arch/x86/kvm/mmu.h +++ b/arch/x86/kvm/mmu.h @@ -166,6 +166,8 @@ static inline bool permission_fault(struct kvm_vcpu *vcpu, struct kvm_mmu *mmu, int index = (pfec >> 1) + (smap >> (X86_EFLAGS_AC_BIT - PFERR_RSVD_BIT + 1)); + WARN_ON(pfec & PFERR_RSVD_MASK); + return (mmu->permissions[index] >> pte_access) & 1; } -- cgit v1.2.3