vfio: refactor out IRQ signalling setup

This makes for a slightly more readable vfio_msix_vector_do_use()
implementation, and we will rely on this shortly.

Signed-off-by: John Levon <john.levon@nutanix.com>
Reviewed-by: Cédric Le Goater <clg@redhat.com>
Link: https://lore.kernel.org/qemu-devel/20250520150419.2172078-5-john.levon@nutanix.com
Signed-off-by: Cédric Le Goater <clg@redhat.com>

diff --git a/hw/vfio/pci.c b/hw/vfio/pci.c
index a873f82aeb355cfef68033e43b4829f64145d606..b1250d85bf0124a22e3ba3859a47d2b176ade648 100644 (file)
--- a/hw/vfio/pci.c
+++ b/hw/vfio/pci.c
@@ -511,6 +511,25 @@ static void vfio_update_kvm_msi_virq(VFIOMSIVector *vector, MSIMessage msg,
     kvm_irqchip_commit_routes(kvm_state);
 }
 
+static void set_irq_signalling(VFIODevice *vbasedev, VFIOMSIVector *vector,
+                               unsigned int nr)
+{
+    Error *err = NULL;
+    int32_t fd;
+
+    if (vector->virq >= 0) {
+        fd = event_notifier_get_fd(&vector->kvm_interrupt);
+    } else {
+        fd = event_notifier_get_fd(&vector->interrupt);
+    }
+
+    if (!vfio_device_irq_set_signaling(vbasedev, VFIO_PCI_MSIX_IRQ_INDEX, nr,
+                                       VFIO_IRQ_SET_ACTION_TRIGGER,
+                                       fd, &err)) {
+        error_reportf_err(err, VFIO_MSG_PREFIX, vbasedev->name);
+    }
+}
+
 static int vfio_msix_vector_do_use(PCIDevice *pdev, unsigned int nr,
                                    MSIMessage *msg, IOHandler *handler)
 {
@@ -583,21 +602,7 @@ static int vfio_msix_vector_do_use(PCIDevice *pdev, unsigned int nr,
                              strerror(-ret));
             }
         } else {
-            Error *err = NULL;
-            int32_t fd;
-
-            if (vector->virq >= 0) {
-                fd = event_notifier_get_fd(&vector->kvm_interrupt);
-            } else {
-                fd = event_notifier_get_fd(&vector->interrupt);
-            }
-
-            if (!vfio_device_irq_set_signaling(&vdev->vbasedev,
-                                        VFIO_PCI_MSIX_IRQ_INDEX, nr,
-                                        VFIO_IRQ_SET_ACTION_TRIGGER, fd,
-                                        &err)) {
-                error_reportf_err(err, VFIO_MSG_PREFIX, vdev->vbasedev.name);
-            }
+            set_irq_signalling(&vdev->vbasedev, vector, nr);
         }
     }