4.18-stable review patch. If anyone has any objections, please let me know.
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From: Sean Christopherson sean.j.christopherson@intel.com
commit c4409905cd6eb42cfd06126e9226b0150e05a715 upstream.
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: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- arch/x86/kvm/vmx.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
--- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -7539,8 +7539,8 @@ static int handle_ept_misconfig(struct k 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);