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: 83326e43f27e9a8a501427a0060f8af519a39bb2 Cc: Andrey Smetanin <[email protected]> Signed-off-by: Paolo Bonzini <[email protected]> --- arch/x86/kvm/hyperv.c | 17 ++++++++++------- 1 file changed, 10 insertions(+), 7 deletions(-) diff --git a/arch/x86/kvm/hyperv.c b/arch/x86/kvm/hyperv.c index b960d9ea171f..9e2becd20a59 100644 --- a/arch/x86/kvm/hyperv.c +++ b/arch/x86/kvm/hyperv.c @@ -1237,14 +1237,17 @@ int kvm_hv_hypercall(struct kvm_vcpu *vcpu) break; case HVCALL_POST_MESSAGE: case HVCALL_SIGNAL_EVENT: - vcpu->run->exit_reason = KVM_EXIT_HYPERV; - vcpu->run->hyperv.type = KVM_EXIT_HYPERV_HCALL; - vcpu->run->hyperv.u.hcall.input = param; - vcpu->run->hyperv.u.hcall.params[0] = ingpa; - vcpu->run->hyperv.u.hcall.params[1] = outgpa; - vcpu->arch.complete_userspace_io = + if (vcpu_to_synic(vcpu)->active) { + vcpu->run->exit_reason = KVM_EXIT_HYPERV; + vcpu->run->hyperv.type = KVM_EXIT_HYPERV_HCALL; + vcpu->run->hyperv.u.hcall.input = param; + vcpu->run->hyperv.u.hcall.params[0] = ingpa; + vcpu->run->hyperv.u.hcall.params[1] = outgpa; + vcpu->arch.complete_userspace_io = kvm_hv_hypercall_complete_userspace; - return 0; + return 0; + } + /* fall through */ default: res = HV_STATUS_INVALID_HYPERCALL_CODE; break; -- 1.8.3.1
