vfio: Use g_autofree in all call site of vfio_get_region_info()

There are some exceptions when pointer to vfio_region_info is reused.
In that case, the pointed memory is freed manually.

Suggested-by: Cédric Le Goater <clg@redhat.com>
Signed-off-by: Zhenzhong Duan <zhenzhong.duan@intel.com>
Reviewed-by: Cédric Le Goater <clg@redhat.com>
Signed-off-by: Cédric Le Goater <clg@redhat.com>

hw/vfio/helpers.c

@@ -343,7 +343,7 @@ static int vfio_setup_region_sparse_mmaps(VFIORegion *region,
 int vfio_region_setup(Object *obj, VFIODevice *vbasedev, VFIORegion *region,
                       int index, const char *name)
 {
-    struct vfio_region_info *info;
+    g_autofree struct vfio_region_info *info = NULL;
     int ret;
 
     ret = vfio_get_region_info(vbasedev, index, &info);
@@ -376,8 +376,6 @@ int vfio_region_setup(Object *obj, VFIODevice *vbasedev, VFIORegion *region,
         }
     }
 
-    g_free(info);
-
     trace_vfio_region_setup(vbasedev->name, index, name,
                             region->flags, region->fd_offset, region->size);
     return 0;
@@ -594,14 +592,13 @@ int vfio_get_dev_region_info(VFIODevice *vbasedev, uint32_t type,
 
 bool vfio_has_region_cap(VFIODevice *vbasedev, int region, uint16_t cap_type)
 {
-    struct vfio_region_info *info = NULL;
+    g_autofree struct vfio_region_info *info = NULL;
     bool ret = false;
 
     if (!vfio_get_region_info(vbasedev, region, &info)) {
         if (vfio_get_region_info_cap(info, cap_type)) {
             ret = true;
         }
-        g_free(info);
     }
 
     return ret;

hw/vfio/igd.c

@@ -367,8 +367,8 @@ static const MemoryRegionOps vfio_igd_index_quirk = {
 
 void vfio_probe_igd_bar4_quirk(VFIOPCIDevice *vdev, int nr)
 {
-    struct vfio_region_info *rom = NULL, *opregion = NULL,
-                            *host = NULL, *lpc = NULL;
+    g_autofree struct vfio_region_info *rom = NULL;
+    struct vfio_region_info *opregion = NULL, *host = NULL, *lpc = NULL;
     VFIOQuirk *quirk;
     VFIOIGDQuirk *igd;
     PCIDevice *lpc_bridge;
@@ -609,7 +609,6 @@ void vfio_probe_igd_bar4_quirk(VFIOPCIDevice *vdev, int nr)
     trace_vfio_pci_igd_bdsm_enabled(vdev->vbasedev.name, ggms_mb + gms_mb);
 
 out:
-    g_free(rom);
     g_free(opregion);
     g_free(host);
     g_free(lpc);

hw/vfio/pci.c

@@ -879,7 +879,7 @@ static void vfio_update_msi(VFIOPCIDevice *vdev)
 
 static void vfio_pci_load_rom(VFIOPCIDevice *vdev)
 {
-    struct vfio_region_info *reg_info;
+    g_autofree struct vfio_region_info *reg_info = NULL;
     uint64_t size;
     off_t off = 0;
     ssize_t bytes;
@@ -897,8 +897,6 @@ static void vfio_pci_load_rom(VFIOPCIDevice *vdev)
     vdev->rom_size = size = reg_info->size;
     vdev->rom_offset = reg_info->offset;
 
-    g_free(reg_info);
-
     if (!vdev->rom_size) {
         vdev->rom_read_failed = true;
         error_report("vfio-pci: Cannot read device rom at "
@@ -2668,7 +2666,7 @@ static VFIODeviceOps vfio_pci_ops = {
 bool vfio_populate_vga(VFIOPCIDevice *vdev, Error **errp)
 {
     VFIODevice *vbasedev = &vdev->vbasedev;
-    struct vfio_region_info *reg_info;
+    g_autofree struct vfio_region_info *reg_info = NULL;
     int ret;
 
     ret = vfio_get_region_info(vbasedev, VFIO_PCI_VGA_REGION_INDEX, &reg_info);
@@ -2685,7 +2683,6 @@ bool vfio_populate_vga(VFIOPCIDevice *vdev, Error **errp)
         error_setg(errp, "unexpected VGA info, flags 0x%lx, size 0x%lx",
                    (unsigned long)reg_info->flags,
                    (unsigned long)reg_info->size);
-        g_free(reg_info);
         return false;
     }
 
@@ -2694,8 +2691,6 @@ bool vfio_populate_vga(VFIOPCIDevice *vdev, Error **errp)
     vdev->vga->fd_offset = reg_info->offset;
     vdev->vga->fd = vdev->vbasedev.fd;
 
-    g_free(reg_info);
-
     vdev->vga->region[QEMU_PCI_VGA_MEM].offset = QEMU_PCI_VGA_MEM_BASE;
     vdev->vga->region[QEMU_PCI_VGA_MEM].nr = QEMU_PCI_VGA_MEM;
     QLIST_INIT(&vdev->vga->region[QEMU_PCI_VGA_MEM].quirks);
@@ -2736,7 +2731,7 @@ bool vfio_populate_vga(VFIOPCIDevice *vdev, Error **errp)
 static bool vfio_populate_device(VFIOPCIDevice *vdev, Error **errp)
 {
     VFIODevice *vbasedev = &vdev->vbasedev;
-    struct vfio_region_info *reg_info;
+    g_autofree struct vfio_region_info *reg_info = NULL;
     struct vfio_irq_info irq_info = { .argsz = sizeof(irq_info) };
     int i, ret = -1;
 
@@ -2790,8 +2785,6 @@ static bool vfio_populate_device(VFIOPCIDevice *vdev, Error **errp)
     }
     vdev->config_offset = reg_info->offset;
 
-    g_free(reg_info);
-
     if (vdev->features & VFIO_FEATURE_ENABLE_VGA) {
         if (!vfio_populate_vga(vdev, errp)) {
             error_append_hint(errp, "device does not support "