| From | Greg Kroah-Hartman <> | Subject | [PATCH 4.9 050/102] KVM: VMX: Do not allow reexecute_instruction() when skipping MMIO instr | Date | Wed, 1 Apr 2020 18:17:53 +0200 |
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From: Sean Christopherson <sean.j.christopherson@intel.com>
[ Upstream commit c4409905cd6eb42cfd06126e9226b0150e05a715 ]
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 <vkuznets@redhat.com> Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Cc: stable@vger.kernel.org Signed-off-by: Radim Krčmář <rkrcmar@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org> --- 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 8bd336651de52..1fa4545c55e35 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -6564,8 +6564,8 @@ static int handle_ept_misconfig(struct kvm_vcpu *vcpu) return 1; } else - return x86_emulate_instruction(vcpu, gpa, EMULTYPE_SKIP, - NULL, 0) == EMULATE_DONE; + return emulate_instruction(vcpu, EMULTYPE_SKIP) == + EMULATE_DONE; } ret = kvm_mmu_page_fault(vcpu, gpa, PFERR_RSVD_MASK, NULL, 0); -- 2.20.1
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