s390x: adapter routes error handling

If the kernel irqchip has been disabled, we don't want the
{add,release}_adapter_routes routines to call any kvm_irqchip_*
interfaces, as they may rely on an irqchip actually having been
created. Just take a quick exit in that case instead. If you are
trying to use irqfd without a kernel irqchip, we will fail with
an error.

Also initialize routes->gsi[] with -1 in the virtio-ccw handling,
to make sure we don't trip over other errors, either. (Nobody
else uses the gsi array in that structure.)

Fixes: d426d9fba8ea ("s390x/virtio-ccw: wire up irq routing and irqfds")
Reviewed-by: Thomas Huth <thuth@redhat.com>
Acked-by: Christian Borntraeger <borntraeger@de.ibm.com>
Message-Id: <20200117111147.5006-1-cohuck@redhat.com>
Signed-off-by: Cornelia Huck <cohuck@redhat.com>

1 files changed, 8 insertions, 0 deletions

diff --git a/hw/intc/s390_flic_kvm.c b/hw/intc/s390_flic_kvm.c
index 2e1e70c61d..a306b26faa 100644
--- a/hw/intc/s390_flic_kvm.c
+++ b/hw/intc/s390_flic_kvm.c
@@ -331,6 +331,10 @@ static int kvm_s390_add_adapter_routes(S390FLICState *fs,
     int ret, i;
     uint64_t ind_offset = routes->adapter.ind_offset;
 
+    if (!kvm_gsi_routing_enabled()) {
+        return -ENOSYS;
+    }
+
     for (i = 0; i < routes->num_routes; i++) {
         ret = kvm_irqchip_add_adapter_route(kvm_state, &routes->adapter);
         if (ret < 0) {
@@ -358,6 +362,10 @@ static void kvm_s390_release_adapter_routes(S390FLICState *fs,
 {
     int i;
 
+    if (!kvm_gsi_routing_enabled()) {
+        return;
+    }
+
     for (i = 0; i < routes->num_routes; i++) {
         if (routes->gsi[i] >= 0) {
             kvm_irqchip_release_virq(kvm_state, routes->gsi[i]);