BlockConf: Call backend functions to detect geometry and blocksizes

geometry: hd_geometry_guess function autodetects the drive geometry.
This patch adds a block backend call, that probes the backing device
geometry. If the inner driver method is implemented and succeeds
(currently only for DASDs), the blkconf_geometry will pass-through
the backing device geometry. Otherwise will fallback to old logic.

blocksize: This patch initializes blocksize properties to 0.
In order to set the property a blkconf_blocksizes was introduced.
If user didn't set physical or logical blocksize, it will
retrieve its value from a driver (only succeeds for DASD), otherwise
it will set default 512 value.

The blkconf_blocksizes call was added to all users of BlkConf.

Signed-off-by: Ekaterina Tumanova <tumanova@linux.vnet.ibm.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-id: 1424087278-49393-6-git-send-email-tumanova@linux.vnet.ibm.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

1 files changed, 24 insertions, 0 deletions

diff --git a/hw/block/block.c b/hw/block/block.c
index a625773d44..f7243e5b94 100644
--- a/hw/block/block.c
+++ b/hw/block/block.c
@@ -25,6 +25,30 @@ void blkconf_serial(BlockConf *conf, char **serial)
     }
 }
 
+void blkconf_blocksizes(BlockConf *conf)
+{
+    BlockBackend *blk = conf->blk;
+    BlockSizes blocksizes;
+    int backend_ret;
+
+    backend_ret = blk_probe_blocksizes(blk, &blocksizes);
+    /* fill in detected values if they are not defined via qemu command line */
+    if (!conf->physical_block_size) {
+        if (!backend_ret) {
+           conf->physical_block_size = blocksizes.phys;
+        } else {
+            conf->physical_block_size = BDRV_SECTOR_SIZE;
+        }
+    }
+    if (!conf->logical_block_size) {
+        if (!backend_ret) {
+            conf->logical_block_size = blocksizes.log;
+        } else {
+            conf->logical_block_size = BDRV_SECTOR_SIZE;
+        }
+    }
+}
+
 void blkconf_geometry(BlockConf *conf, int *ptrans,
                       unsigned cyls_max, unsigned heads_max, unsigned secs_max,
                       Error **errp)