virtio-blk: move config size params to virtio-blk-common
This way we can reuse it for other virtio-blk devices, e.g
vhost-user-blk, which currently does not control its config space size
dynamically.
Signed-off-by: Daniil Tatianin <d-tatianin@yandex-team.ru>
Reviewed-by: Raphael Norwitz <raphael.norwitz@nutanix.com>
Message-Id: <20220906073111.353245-3-d-tatianin@yandex-team.ru>
Reviewed-by: Raphael Norwitz <raphael.norwitz@nutanix.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
diff --git a/hw/block/virtio-blk-common.c b/hw/block/virtio-blk-common.c
new file mode 100644
index 0000000..ac52d7c
--- /dev/null
+++ b/hw/block/virtio-blk-common.c
@@ -0,0 +1,39 @@
+/*
+ * Virtio Block Device common helpers
+ *
+ * Copyright IBM, Corp. 2007
+ *
+ * Authors:
+ * Anthony Liguori <aliguori@us.ibm.com>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2. See
+ * the COPYING file in the top-level directory.
+ */
+
+#include "qemu/osdep.h"
+
+#include "standard-headers/linux/virtio_blk.h"
+#include "hw/virtio/virtio.h"
+#include "hw/virtio/virtio-blk-common.h"
+
+/* Config size before the discard support (hide associated config fields) */
+#define VIRTIO_BLK_CFG_SIZE offsetof(struct virtio_blk_config, \
+ max_discard_sectors)
+
+/*
+ * Starting from the discard feature, we can use this array to properly
+ * set the config size depending on the features enabled.
+ */
+static const VirtIOFeature feature_sizes[] = {
+ {.flags = 1ULL << VIRTIO_BLK_F_DISCARD,
+ .end = endof(struct virtio_blk_config, discard_sector_alignment)},
+ {.flags = 1ULL << VIRTIO_BLK_F_WRITE_ZEROES,
+ .end = endof(struct virtio_blk_config, write_zeroes_may_unmap)},
+ {}
+};
+
+const VirtIOConfigSizeParams virtio_blk_cfg_size_params = {
+ .min_size = VIRTIO_BLK_CFG_SIZE,
+ .max_size = sizeof(struct virtio_blk_config),
+ .feature_sizes = feature_sizes
+};
