vfio: add vfio_device_get_irq_info() helper

Add a helper similar to vfio_device_get_region_info() and use it
everywhere.

Replace a couple of needless allocations with stack variables.

As a side-effect, this fixes a minor error reporting issue in the call
from vfio_msix_early_setup().

Reviewed-by: Cédric Le Goater <clg@redhat.com>
Signed-off-by: John Levon <john.levon@nutanix.com>
Link: https://lore.kernel.org/qemu-devel/20250507152020.1254632-5-john.levon@nutanix.com
Signed-off-by: Cédric Le Goater <clg@redhat.com>

1 files changed, 10 insertions, 9 deletions

diff --git a/hw/vfio/ap.c b/hw/vfio/ap.c
index 1207c08d8d..785c0a0197 100644
--- a/hw/vfio/ap.c
+++ b/hw/vfio/ap.c
@@ -74,10 +74,10 @@ static bool vfio_ap_register_irq_notifier(VFIOAPDevice *vapdev,
                                           unsigned int irq, Error **errp)
 {
     int fd;
-    size_t argsz;
+    int ret;
     IOHandler *fd_read;
     EventNotifier *notifier;
-    g_autofree struct vfio_irq_info *irq_info = NULL;
+    struct vfio_irq_info irq_info;
     VFIODevice *vdev = &vapdev->vdev;
 
     switch (irq) {
@@ -96,14 +96,15 @@ static bool vfio_ap_register_irq_notifier(VFIOAPDevice *vapdev,
         return false;
     }
 
-    argsz = sizeof(*irq_info);
-    irq_info = g_malloc0(argsz);
-    irq_info->index = irq;
-    irq_info->argsz = argsz;
+    ret = vfio_device_get_irq_info(vdev, irq, &irq_info);
+
+    if (ret < 0) {
+        error_setg_errno(errp, -ret, "vfio: Error getting irq info");
+        return false;
+    }
 
-    if (ioctl(vdev->fd, VFIO_DEVICE_GET_IRQ_INFO,
-              irq_info) < 0 || irq_info->count < 1) {
-        error_setg_errno(errp, errno, "vfio: Error getting irq info");
+    if (irq_info.count < 1) {
+        error_setg(errp, "vfio: Error getting irq info, count=0");
         return false;
     }