3.16.55-rc1 review patch. If anyone has any objections, please let me know.
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From: Liran Alon liran.alon@oracle.com
commit 61cb57c9ed631c95b54f8e9090c89d18b3695b3c upstream.
Instruction emulation after trapping a #UD exception can result in an MMIO access, for example when emulating a MOVBE on a processor that doesn't support the instruction. In this case, the #UD vmexit handler must exit to user mode, but there wasn't any code to do so. Add it for both VMX and SVM.
Signed-off-by: Liran Alon liran.alon@oracle.com Reviewed-by: Nikita Leshenko nikita.leshchenko@oracle.com Reviewed-by: Konrad Rzeszutek Wilk konrad.wilk@oracle.com Signed-off-by: Konrad Rzeszutek Wilk konrad.wilk@oracle.com Reviewed-by: Wanpeng Li wanpeng.li@hotmail.com Reviewed-by: Paolo Bonzini pbonzini@redhat.com Signed-off-by: Radim Krčmář rkrcmar@redhat.com Signed-off-by: Ben Hutchings ben@decadent.org.uk --- arch/x86/kvm/svm.c | 2 ++ arch/x86/kvm/vmx.c | 2 ++ 2 files changed, 4 insertions(+)
--- a/arch/x86/kvm/svm.c +++ b/arch/x86/kvm/svm.c @@ -1776,6 +1776,8 @@ static int ud_interception(struct vcpu_s int er;
er = emulate_instruction(&svm->vcpu, EMULTYPE_TRAP_UD); + if (er == EMULATE_USER_EXIT) + return 0; if (er != EMULATE_DONE) kvm_queue_exception(&svm->vcpu, UD_VECTOR); return 1; --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -4853,6 +4853,8 @@ static int handle_exception(struct kvm_v
if (is_invalid_opcode(intr_info)) { er = emulate_instruction(vcpu, EMULTYPE_TRAP_UD); + if (er == EMULATE_USER_EXIT) + return 0; if (er != EMULATE_DONE) kvm_queue_exception(vcpu, UD_VECTOR); return 1;