From: Sean Christopherson Date: Tue, 22 Jun 2021 17:57:38 +0000 (-0700) Subject: KVM: x86/mmu: Get CR4.SMEP from MMU, not vCPU, in shadow page fault X-Git-Tag: microblaze-v5.15~167^2~7 X-Git-Url: http://git.monstr.eu/?p=linux-2.6-microblaze.git;a=commitdiff_plain;h=9a65d0b70fa06ae46b9f8ab7dc8e6b3c6f4661ba KVM: x86/mmu: Get CR4.SMEP from MMU, not vCPU, in shadow page fault Use the current MMU instead of vCPU state to query CR4.SMEP when handling a page fault. In the nested NPT case, the current CR4.SMEP reflects L2, whereas the page fault is shadowing L1's NPT, which uses L1's hCR4. Practically speaking, this is a nop a NPT walks are always user faults, i.e. this code will never be reached, but fix it up for consistency. Signed-off-by: Sean Christopherson Message-Id: <20210622175739.3610207-54-seanjc@google.com> Signed-off-by: Paolo Bonzini --- diff --git a/arch/x86/kvm/mmu/paging_tmpl.h b/arch/x86/kvm/mmu/paging_tmpl.h index 2f5a0e8d05ed..490a028ddabe 100644 --- a/arch/x86/kvm/mmu/paging_tmpl.h +++ b/arch/x86/kvm/mmu/paging_tmpl.h @@ -903,7 +903,7 @@ static int FNAME(page_fault)(struct kvm_vcpu *vcpu, gpa_t addr, u32 error_code, * then we should prevent the kernel from executing it * if SMEP is enabled. */ - if (kvm_read_cr4_bits(vcpu, X86_CR4_SMEP)) + if (is_cr4_smep(vcpu->arch.mmu)) walker.pte_access &= ~ACC_EXEC_MASK; }