vfio: add read/write to device IO ops vector

Now we have the region info cache, add ->region_read/write device I/O
operations instead of explicit pread()/pwrite() system calls.

Signed-off-by: John Levon <john.levon@nutanix.com>
Link: https://lore.kernel.org/qemu-devel/20250507152020.1254632-13-john.levon@nutanix.com
Signed-off-by: Cédric Le Goater <clg@redhat.com>

1 files changed, 14 insertions, 14 deletions

diff --git a/hw/vfio/pci.c b/hw/vfio/pci.c
index 9136cf52c8..1236de315d 100644
--- a/hw/vfio/pci.c
+++ b/hw/vfio/pci.c
@@ -918,18 +918,22 @@ static void vfio_pci_load_rom(VFIOPCIDevice *vdev)
     memset(vdev->rom, 0xff, size);
 
     while (size) {
-        bytes = pread(vbasedev->fd, vdev->rom + off,
-                      size, vdev->rom_offset + off);
+        bytes = vbasedev->io_ops->region_read(vbasedev,
+                                              VFIO_PCI_ROM_REGION_INDEX,
+                                              off, size, vdev->rom + off);
+
         if (bytes == 0) {
             break;
         } else if (bytes > 0) {
             off += bytes;
             size -= bytes;
         } else {
-            if (errno == EINTR || errno == EAGAIN) {
+            if (bytes == -EINTR || bytes == -EAGAIN) {
                 continue;
             }
-            error_report("vfio: Error reading device ROM: %m");
+            error_report("vfio: Error reading device ROM: %s",
+                         strreaderror(bytes));
+
             break;
         }
     }
@@ -969,22 +973,18 @@ static void vfio_pci_load_rom(VFIOPCIDevice *vdev)
 static int vfio_pci_config_space_read(VFIOPCIDevice *vdev, off_t offset,
                                       uint32_t size, void *data)
 {
-    ssize_t ret;
-
-    ret = pread(vdev->vbasedev.fd, data, size, vdev->config_offset + offset);
-
-    return ret < 0 ? -errno : (int)ret;
+    return vdev->vbasedev.io_ops->region_read(&vdev->vbasedev,
+                                              VFIO_PCI_CONFIG_REGION_INDEX,
+                                              offset, size, data);
 }
 
 /* "Raw" write of underlying config space. */
 static int vfio_pci_config_space_write(VFIOPCIDevice *vdev, off_t offset,
                                        uint32_t size, void *data)
 {
-    ssize_t ret;
-
-    ret = pwrite(vdev->vbasedev.fd, data, size, vdev->config_offset + offset);
-
-    return ret < 0 ? -errno : (int)ret;
+    return vdev->vbasedev.io_ops->region_write(&vdev->vbasedev,
+                                               VFIO_PCI_CONFIG_REGION_INDEX,
+                                               offset, size, data);
 }
 
 static uint64_t vfio_rom_read(void *opaque, hwaddr addr, unsigned size)