From c4409905cd6eb42cfd06126e9226b0150e05a715 Mon Sep 17 00:00:00 2001 From: Sean Christopherson Date: Thu, 23 Aug 2018 13:56:46 -0700 Subject: [PATCH] KVM: VMX: Do not allow reexecute_instruction() when skipping MMIO instr MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Re-execution after an emulation decode failure is only intended to handle a case where two or vCPUs race to write a shadowed page, i.e. we should never re-execute an instruction as part of MMIO emulation. As handle_ept_misconfig() is only used for MMIO emulation, it should pass EMULTYPE_NO_REEXECUTE when using the emulator to skip an instr in the fast-MMIO case where VM_EXIT_INSTRUCTION_LEN is invalid. And because the cr2 value passed to x86_emulate_instruction() is only destined for use when retrying or reexecuting, we can simply call emulate_instruction(). Fixes: d391f1207067 ("x86/kvm/vmx: do not use vm-exit instruction length for fast MMIO when running nested") Cc: Vitaly Kuznetsov Signed-off-by: Sean Christopherson Cc: stable@vger.kernel.org Signed-off-by: Radim Krčmář --- arch/x86/kvm/vmx.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index 92f027745842..b345ad91809c 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -7704,8 +7704,8 @@ static int handle_ept_misconfig(struct kvm_vcpu *vcpu) if (!static_cpu_has(X86_FEATURE_HYPERVISOR)) return kvm_skip_emulated_instruction(vcpu); else - return x86_emulate_instruction(vcpu, gpa, EMULTYPE_SKIP, - NULL, 0) == EMULATE_DONE; + return emulate_instruction(vcpu, EMULTYPE_SKIP) == + EMULATE_DONE; } return kvm_mmu_page_fault(vcpu, gpa, PFERR_RSVD_MASK, NULL, 0); -- GitLab