Commit 7dffecaf authored by Maxim Levitsky's avatar Maxim Levitsky Committed by Paolo Bonzini
Browse files

KVM: x86: report negative values from wrmsr emulation to userspace 



This will allow the KVM to report such errors (e.g -ENOMEM)
to the userspace.

Signed-off-by: default avatarMaxim Levitsky <mlevitsk@redhat.com>
Message-Id: <20201001112954.6258-3-mlevitsk@redhat.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent 36385ccc

arch/x86/kvm/emulate.c

+2 −2
Original line number Diff line number Diff line
@@ -3712,10 +3712,10 @@ static int em_wrmsr(struct x86_emulate_ctxt *ctxt) 
	if (r == X86EMUL_IO_NEEDED)

		return r;



	if (r)

	if (r > 0)

		return emulate_gp(ctxt, 0);



	return X86EMUL_CONTINUE;

	return r < 0 ? X86EMUL_UNHANDLEABLE : X86EMUL_CONTINUE;

}



static int em_rdmsr(struct x86_emulate_ctxt *ctxt)

arch/x86/kvm/x86.c

+6 −3
Original line number Diff line number Diff line
@@ -1737,13 +1737,16 @@ int kvm_emulate_wrmsr(struct kvm_vcpu *vcpu) 
	r = kvm_set_msr(vcpu, ecx, data);



	/* MSR write failed? See if we should ask user space */

	if (r && kvm_set_msr_user_space(vcpu, ecx, data, r)) {

	if (r && kvm_set_msr_user_space(vcpu, ecx, data, r))

		/* Bounce to user space */

		return 0;

	}



	/* Signal all other negative errors to userspace */

	if (r < 0)

		return r;



	/* MSR write failed? Inject a #GP */

	if (r) {

	if (r > 0) {

		trace_kvm_msr_write_ex(ecx, data);

		kvm_inject_gp(vcpu, 0);

		return 1;