[PATCH v1 2/5] virtio-blk: move config space sizing code to virtio-blk-common

[Daniil Tatianin]

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>
---
 MAINTAINERS                           |  4 +++
 hw/block/meson.build                  |  4 +--
 hw/block/virtio-blk-common.c          | 42 +++++++++++++++++++++++++++
 hw/block/virtio-blk.c                 | 24 +--------------
 include/hw/virtio/virtio-blk-common.h | 21 ++++++++++++++
 5 files changed, 70 insertions(+), 25 deletions(-)
 create mode 100644 hw/block/virtio-blk-common.c
 create mode 100644 include/hw/virtio/virtio-blk-common.h

diff --git a/MAINTAINERS b/MAINTAINERS
index 5ce4227ff6..a7d3914735 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -2030,8 +2030,10 @@ virtio-blk
 M: Stefan Hajnoczi <stefanha@redhat.com>
 L: qemu-block@nongnu.org
 S: Supported
+F: hw/block/virtio-blk-common.c
 F: hw/block/virtio-blk.c
 F: hw/block/dataplane/*
+F: include/hw/virtio/virtio-blk-common.h
 F: tests/qtest/virtio-blk-test.c
 T: git https://github.com/stefanha/qemu.git block
 
@@ -2271,11 +2273,13 @@ S: Maintained
 F: contrib/vhost-user-blk/
 F: contrib/vhost-user-scsi/
 F: hw/block/vhost-user-blk.c
+F: hw/block/virtio-blk-common.c
 F: hw/scsi/vhost-user-scsi.c
 F: hw/virtio/vhost-user-blk-pci.c
 F: hw/virtio/vhost-user-scsi-pci.c
 F: include/hw/virtio/vhost-user-blk.h
 F: include/hw/virtio/vhost-user-scsi.h
+F: include/hw/virtio/virtio-blk-common.h
 
 vhost-user-gpu
 M: Marc-André Lureau <marcandre.lureau@redhat.com>
diff --git a/hw/block/meson.build b/hw/block/meson.build
index 2389326112..1908abd45c 100644
--- a/hw/block/meson.build
+++ b/hw/block/meson.build
@@ -16,7 +16,7 @@ softmmu_ss.add(when: 'CONFIG_SWIM', if_true: files('swim.c'))
 softmmu_ss.add(when: 'CONFIG_XEN', if_true: files('xen-block.c'))
 softmmu_ss.add(when: 'CONFIG_TC58128', if_true: files('tc58128.c'))
 
-specific_ss.add(when: 'CONFIG_VIRTIO_BLK', if_true: files('virtio-blk.c'))
-specific_ss.add(when: 'CONFIG_VHOST_USER_BLK', if_true: 
files('vhost-user-blk.c'))
+specific_ss.add(when: 'CONFIG_VIRTIO_BLK', if_true: files('virtio-blk.c', 
'virtio-blk-common.c'))
+specific_ss.add(when: 'CONFIG_VHOST_USER_BLK', if_true: 
files('vhost-user-blk.c', 'virtio-blk-common.c'))
 
 subdir('dataplane')
diff --git a/hw/block/virtio-blk-common.c b/hw/block/virtio-blk-common.c
new file mode 100644
index 0000000000..ac54568eb6
--- /dev/null
+++ b/hw/block/virtio-blk-common.c
@@ -0,0 +1,42 @@
+/*
+ * 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 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)},
+    {}
+};
+
+size_t virtio_blk_common_get_config_size(uint64_t host_features)
+{
+    size_t config_size = MAX(VIRTIO_BLK_CFG_SIZE,
+        virtio_feature_get_config_size(feature_sizes, host_features));
+
+    assert(config_size <= sizeof(struct virtio_blk_config));
+    return config_size;
+}
diff --git a/hw/block/virtio-blk.c b/hw/block/virtio-blk.c
index a4162dbbf2..4ca6d0f211 100644
--- a/hw/block/virtio-blk.c
+++ b/hw/block/virtio-blk.c
@@ -32,31 +32,9 @@
 #include "hw/virtio/virtio-bus.h"
 #include "migration/qemu-file-types.h"
 #include "hw/virtio/virtio-access.h"
+#include "hw/virtio/virtio-blk-common.h"
 #include "qemu/coroutine.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)},
-    {}
-};
-
-static size_t virtio_blk_common_get_config_size(uint64_t host_features)
-{
-    size_t config_size = MAX(VIRTIO_BLK_CFG_SIZE,
-        virtio_feature_get_config_size(feature_sizes, host_features));
-
-    assert(config_size <= sizeof(struct virtio_blk_config));
-    return config_size;
-}
 
 static void virtio_blk_init_request(VirtIOBlock *s, VirtQueue *vq,
                                     VirtIOBlockReq *req)
diff --git a/include/hw/virtio/virtio-blk-common.h 
b/include/hw/virtio/virtio-blk-common.h
new file mode 100644
index 0000000000..08e9f1ab48
--- /dev/null
+++ b/include/hw/virtio/virtio-blk-common.h
@@ -0,0 +1,21 @@
+/*
+ * 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.
+ */
+
+#ifndef VIRTIO_BLK_COMMON_H
+#define VIRTIO_BLK_COMMON_H
+
+#include <stddef.h>
+#include <stdint.h>
+
+size_t virtio_blk_common_get_config_size(uint64_t host_features);
+
+#endif
-- 
2.25.1