vfio: Create device specific region info helper

Given a device specific region type and sub-type, find it.  Also
cleanup return point on error in vfio_get_region_info() so that we
always return 0 with a valid pointer or -errno and NULL.

Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Reviewed-by: Gerd Hoffmann <kraxel@redhat.com>
Tested-by: Gerd Hoffmann <kraxel@redhat.com>

hw/vfio/common.c

@@ -1145,6 +1145,7 @@ int vfio_get_region_info(VFIODevice *vbasedev, int index,
 
     if (ioctl(vbasedev->fd, VFIO_DEVICE_GET_REGION_INFO, *info)) {
         g_free(*info);
+        *info = NULL;
         return -errno;
     }
 
@@ -1158,6 +1159,41 @@ int vfio_get_region_info(VFIODevice *vbasedev, int index,
     return 0;
 }
 
+int vfio_get_dev_region_info(VFIODevice *vbasedev, uint32_t type,
+                             uint32_t subtype, struct vfio_region_info **info)
+{
+    int i;
+
+    for (i = 0; i < vbasedev->num_regions; i++) {
+        struct vfio_info_cap_header *hdr;
+        struct vfio_region_info_cap_type *cap_type;
+
+        if (vfio_get_region_info(vbasedev, i, info)) {
+            continue;
+        }
+
+        hdr = vfio_get_region_info_cap(*info, VFIO_REGION_INFO_CAP_TYPE);
+        if (!hdr) {
+            g_free(*info);
+            continue;
+        }
+
+        cap_type = container_of(hdr, struct vfio_region_info_cap_type, header);
+
+        trace_vfio_get_dev_region(vbasedev->name, i,
+                                  cap_type->type, cap_type->subtype);
+
+        if (cap_type->type == type && cap_type->subtype == subtype) {
+            return 0;
+        }
+
+        g_free(*info);
+    }
+
+    *info = NULL;
+    return -ENODEV;
+}
+
 /*
  * Interfaces for IBM EEH (Enhanced Error Handling)
  */

include/hw/vfio/vfio-common.h

@@ -154,5 +154,7 @@ extern QLIST_HEAD(vfio_as_head, VFIOAddressSpace) vfio_address_spaces;
 #ifdef CONFIG_LINUX
 int vfio_get_region_info(VFIODevice *vbasedev, int index,
                          struct vfio_region_info **info);
+int vfio_get_dev_region_info(VFIODevice *vbasedev, uint32_t type,
+                             uint32_t subtype, struct vfio_region_info **info);
 #endif
 #endif /* !HW_VFIO_VFIO_COMMON_H */

trace-events

@@ -1714,8 +1714,7 @@ vfio_quirk_ati_bonaire_reset_timeout(const char *name) "%s"
 vfio_quirk_ati_bonaire_reset_done(const char *name) "%s"
 vfio_quirk_ati_bonaire_reset(const char *name) "%s"
 
-
-# hw/vfio/vfio-common.c
+# hw/vfio/common.c
 vfio_region_write(const char *name, int index, uint64_t addr, uint64_t data, unsigned size) " (%s:region%d+0x%"PRIx64", 0x%"PRIx64 ", %d)"
 vfio_region_read(char *name, int index, uint64_t addr, unsigned size, uint64_t data) " (%s:region%d+0x%"PRIx64", %d) = 0x%"PRIx64
 vfio_iommu_map_notify(uint64_t iova_start, uint64_t iova_end) "iommu map @ %"PRIx64" - %"PRIx64
@@ -1736,6 +1735,7 @@ vfio_region_finalize(const char *name, int index) "Device %s, region %d"
 vfio_region_mmaps_set_enabled(const char *name, bool enabled) "Region %s mmaps enabled: %d"
 vfio_region_sparse_mmap_header(const char *name, int index, int nr_areas) "Device %s region %d: %d sparse mmap entries"
 vfio_region_sparse_mmap_entry(int i, unsigned long start, unsigned long end) "sparse entry %d [0x%lx - 0x%lx]"
+vfio_get_dev_region(const char *name, int index, uint32_t type, uint32_t subtype) "%s index %d, %08x/%0x8"
 
 # hw/vfio/platform.c
 vfio_platform_base_device_init(char *name, int groupid) "%s belongs to group #%d"