Re: [PATCH 04/27] vfio: move config space read into vfio_pci_config_setup()

[Cédric Le Goater]

On 5/15/25 17:43, John Levon wrote:

Small cleanup that reduces duplicate code for vfio-user.

It also reduces vfio_realize(). It's time to rename it to
vfio_pci_realize() too.

Reviewed-by: Cédric Le Goater <c...@redhat.com>

Thanks,

C.

Signed-off-by: John Levon <john.le...@nutanix.com>
---
  hw/vfio/pci.c | 27 ++++++++++++++-------------
  1 file changed, 14 insertions(+), 13 deletions(-)

diff --git a/hw/vfio/pci.c b/hw/vfio/pci.c
index d96b55f80c..7912c17dd2 100644
--- a/hw/vfio/pci.c
+++ b/hw/vfio/pci.c
@@ -3017,6 +3017,19 @@ static bool vfio_pci_config_setup(VFIOPCIDevice *vdev, 
Error **errp)
  {
      PCIDevice *pdev = &vdev->pdev;
      VFIODevice *vbasedev = &vdev->vbasedev;
+    uint32_t config_space_size;
+    int ret;
+
+    config_space_size = MIN(pci_config_size(&vdev->pdev), vdev->config_size);
+
+    /* Get a copy of config space */
+    ret = vfio_pci_config_space_read(vdev, 0, config_space_size,
+                                     vdev->pdev.config);
+    if (ret < (int)config_space_size) {
+        ret = ret < 0 ? -ret : EFAULT;
+        error_setg_errno(errp, ret, "failed to read device config space");
+        return false;
+    }

/* vfio emulates a lot for us, but some bits need extra love */

      vdev->emulated_config_bits = g_malloc0(vdev->config_size);
@@ -3143,10 +3156,9 @@ static void vfio_realize(PCIDevice *pdev, Error **errp)
      ERRP_GUARD();
      VFIOPCIDevice *vdev = VFIO_PCI_BASE(pdev);
      VFIODevice *vbasedev = &vdev->vbasedev;
-    int i, ret;
+    int i;
      char uuid[UUID_STR_LEN];
      g_autofree char *name = NULL;
-    uint32_t config_space_size;

if (vbasedev->fd < 0 && !vbasedev->sysfsdev) {

          if (!(~vdev->host.domain || ~vdev->host.bus ||
@@ -3201,17 +3213,6 @@ static void vfio_realize(PCIDevice *pdev, Error **errp)
          goto error;
      }

- config_space_size = MIN(pci_config_size(&vdev->pdev), vdev->config_size);

-
-    /* Get a copy of config space */
-    ret = vfio_pci_config_space_read(vdev, 0, config_space_size,
-                                     vdev->pdev.config);
-    if (ret < (int)config_space_size) {
-        ret = ret < 0 ? -ret : EFAULT;
-        error_setg_errno(errp, ret, "failed to read device config space");
-        goto error;
-    }
-
      if (!vfio_pci_config_setup(vdev, errp)) {
          goto error;
      }