Commit ccabc053 authored Nov 05, 2017 by Liran Alon Committed by Greg Kroah-Hartman Dec 05, 2017

KVM: x86: Exit to user-mode on #UD intercept when emulator requires



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: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

parent ab1f0096

arch/x86/kvm/svm.c

+2 −0

Original line number	Diff line number	Diff line
		@@ -1785,6 +1785,8 @@ static int ud_interception(struct vcpu_svm *svm)
		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;

arch/x86/kvm/vmx.c

+2 −0

Original line number	Diff line number	Diff line
		@@ -4899,6 +4899,8 @@ static int handle_exception(struct kvm_vcpu *vcpu)

		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;