Commit a2b5c3c0 authored Mar 29, 2016 by Paolo Bonzini

KVM: Hyper-V: do not do hypercall userspace exits if SynIC is disabled



If SynIC is disabled, there is nothing that userspace can do to
handle these exits; on the other hand, userspace probably will
not know about KVM_EXIT_HYPERV_HCALL and complain about it or
even exit.  Just prevent anything bad from happening by handling
the hypercall in KVM and returning an "invalid hypercall" code.

Fixes: 83326e43
Cc: Andrey Smetanin <irqlevel@gmail.com>
Reviewed-by: Roman Kagan <rkagan@virtuozzo.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

parent 321c5658

arch/x86/kvm/hyperv.c

+5 −0

Original line number	Diff line number	Diff line
		@@ -1116,6 +1116,11 @@ int kvm_hv_hypercall(struct kvm_vcpu *vcpu)
		break;
		case HVCALL_POST_MESSAGE:
		case HVCALL_SIGNAL_EVENT:
		/* don't bother userspace if it has no way to handle it */
		if (!vcpu_to_synic(vcpu)->active) {
		res = HV_STATUS_INVALID_HYPERCALL_CODE;
		break;
		}
		vcpu->run->exit_reason = KVM_EXIT_HYPERV;
		vcpu->run->hyperv.type = KVM_EXIT_HYPERV_HCALL;
		vcpu->run->hyperv.u.hcall.input = param;