[Qemu-devel] [RFC 09/24] qed: add qed_bdrv_get_mapping()

[Devin Nakamura <devin122@gmail.com>]

Fuction to get drive mapping from qed images

Signed-off-by: Devin Nakamura <devin122@gmail.com>
---
 block/qed.c |   32 ++++++++++++++++++++++++++++++++
 1 files changed, 32 insertions(+), 0 deletions(-)

diff --git a/block/qed.c b/block/qed.c
index 00cf895..dadb7f8 100644
--- a/block/qed.c
+++ b/block/qed.c
@@ -1451,6 +1451,37 @@ static int bdrv_qed_check(BlockDriverState *bs, BdrvCheckResult *result)
     return qed_check(s, result, false);
 }
 
+static int bdrv_qed_get_mapping(BlockDriverState *bs, uint64_t *guest_offset,
+                                uint64_t *host_offset,
+                                uint64_t *contiguous_bytes)
+{
+    BDRVQEDState *s = bs->opaque;
+    size_t l2_size = s->header.cluster_size * s->table_nelems;
+    uint64_t pos = *guest_offset + *contiguous_bytes;
+    uint64_t offset = pos;
+    size_t len = 0;
+    QEDRequest req = {.l2_table = NULL};
+    int ret;
+
+    if (pos >= s->header.image_size) {
+        *contiguous_bytes = 0;
+        return 0;
+    }
+
+    do {
+        pos += len;
+        ret = qed_find_cluster_sync(s, &req, pos, l2_size, &offset, &len);
+    } while (ret != QED_CLUSTER_FOUND && pos < s->header.image_size);
+    *guest_offset = pos;
+    *host_offset = offset;
+    if (pos >= s->header.image_size) {
+        *contiguous_bytes = 0;
+    } else {
+        *contiguous_bytes = len;
+    }
+    return 0;
+}
+
 static QEMUOptionParameter qed_create_options[] = {
     {
         .name = BLOCK_OPT_SIZE,
@@ -1497,6 +1528,7 @@ static BlockDriver bdrv_qed = {
     .bdrv_get_info            = bdrv_qed_get_info,
     .bdrv_change_backing_file = bdrv_qed_change_backing_file,
     .bdrv_check               = bdrv_qed_check,
+    .bdrv_get_mapping         = bdrv_qed_get_mapping,
 };
 
 static void bdrv_qed_init(void)
-- 
1.7.6.rc1