[Qemu-devel] [RFC PATCH v5 6/6] virtio-blk : Refactor virtio-blk.

[fred.konrad@greensocs.com]

From: KONRAD Frederic <fred.konrad@greensocs.com>

Create virtio-blk which extends virtio-device, so it can be connected on
virtio-bus.

Signed-off-by: KONRAD Frederic <fred.konrad@greensocs.com>
---
 hw/virtio-blk.c | 170 ++++++++++++++++++++++++++++++++++++++++++++++++--------
 hw/virtio-blk.h |   4 ++
 2 files changed, 150 insertions(+), 24 deletions(-)

diff --git a/hw/virtio-blk.c b/hw/virtio-blk.c
index e25cc96..ee1ea8b 100644
--- a/hw/virtio-blk.c
+++ b/hw/virtio-blk.c
@@ -21,24 +21,42 @@
 #ifdef __linux__
 # include <scsi/sg.h>
 #endif
+#include "virtio-bus.h"
 
+/* Take this structure as our device structure. */
 typedef struct VirtIOBlock
 {
+    /*
+     * Adding parent_obj breaks to_virtio_blk cast function,
+     * and virtio_blk_init.
+     */
+    DeviceState parent_obj;
+    /*
+     * We don't need that anymore, as we'll use QOM cast to get the
+     * VirtIODevice. Just temporary keep it, for not breaking functionality.
+     */
     VirtIODevice vdev;
     BlockDriverState *bs;
     VirtQueue *vq;
     void *rq;
     QEMUBH *bh;
     BlockConf *conf;
-    VirtIOBlkConf *blk;
+    /*
+     * We can't use pointer with properties.
+     */
+    VirtIOBlkConf blk;
     unsigned short sector_mask;
     DeviceState *qdev;
 } VirtIOBlock;
 
-static VirtIOBlock *to_virtio_blk(VirtIODevice *vdev)
-{
-    return (VirtIOBlock *)vdev;
-}
+/*
+ * Use the QOM cast, so we don't need that anymore.
+ *
+ * static VirtIOBlock *to_virtio_blk(VirtIODevice *vdev)
+ * {
+ *     return (VirtIOBlock *)vdev;
+ * }
+ */
 
 typedef struct VirtIOBlockReq
 {
@@ -55,18 +73,20 @@ typedef struct VirtIOBlockReq
 static void virtio_blk_req_complete(VirtIOBlockReq *req, int status)
 {
     VirtIOBlock *s = req->dev;
+    VirtIODevice *vdev = VIRTIO_DEVICE(s);
 
     trace_virtio_blk_req_complete(req, status);
 
     stb_p(&req->in->status, status);
     virtqueue_push(s->vq, &req->elem, req->qiov.size + sizeof(*req->in));
-    virtio_notify(&s->vdev, s->vq);
+    virtio_notify(vdev, s->vq);
 }
 
 static int virtio_blk_handle_rw_error(VirtIOBlockReq *req, int error,
     bool is_read)
 {
-    BlockErrorAction action = bdrv_get_error_action(req->dev->bs, is_read, error);
+    BlockErrorAction action = bdrv_get_error_action(req->dev->bs, is_read,
+                                                    error);
     VirtIOBlock *s = req->dev;
 
     if (action == BDRV_ACTION_STOP) {
@@ -164,7 +184,7 @@ static void virtio_blk_handle_scsi(VirtIOBlockReq *req)
      */
     req->scsi = (void *)req->elem.in_sg[req->elem.in_num - 2].iov_base;
 
-    if (!req->dev->blk->scsi) {
+    if (!req->dev->blk.scsi) {
         status = VIRTIO_BLK_S_UNSUPP;
         goto fail;
     }
@@ -384,7 +404,7 @@ static void virtio_blk_handle_request(VirtIOBlockReq *req,
          * terminated by '\0' only when shorter than buffer.
          */
         strncpy(req->elem.in_sg[0].iov_base,
-                s->blk->serial ? s->blk->serial : "",
+                s->blk.serial ? s->blk.serial : "",
                 MIN(req->elem.in_sg[0].iov_len, VIRTIO_BLK_ID_BYTES));
         virtio_blk_req_complete(req, VIRTIO_BLK_S_OK);
         g_free(req);
@@ -401,7 +421,7 @@ static void virtio_blk_handle_request(VirtIOBlockReq *req,
 
 static void virtio_blk_handle_output(VirtIODevice *vdev, VirtQueue *vq)
 {
-    VirtIOBlock *s = to_virtio_blk(vdev);
+    VirtIOBlock *s = VIRTIO_BLK(vdev);
     VirtIOBlockReq *req;
     MultiReqBuffer mrb = {
         .num_writes = 0,
@@ -422,7 +442,7 @@ static void virtio_blk_handle_output(VirtIODevice *vdev, VirtQueue *vq)
 
 static void virtio_blk_dma_restart_bh(void *opaque)
 {
-    VirtIOBlock *s = opaque;
+    VirtIOBlock *s = VIRTIO_BLK(opaque);
     VirtIOBlockReq *req = s->rq;
     MultiReqBuffer mrb = {
         .num_writes = 0,
@@ -444,7 +464,7 @@ static void virtio_blk_dma_restart_bh(void *opaque)
 static void virtio_blk_dma_restart_cb(void *opaque, int running,
                                       RunState state)
 {
-    VirtIOBlock *s = opaque;
+    VirtIOBlock *s = VIRTIO_BLK(opaque);
 
     if (!running)
         return;
@@ -468,7 +488,7 @@ static void virtio_blk_reset(VirtIODevice *vdev)
  */
 static void virtio_blk_update_config(VirtIODevice *vdev, uint8_t *config)
 {
-    VirtIOBlock *s = to_virtio_blk(vdev);
+    VirtIOBlock *s = VIRTIO_BLK(vdev);
     struct virtio_blk_config blkcfg;
     uint64_t capacity;
     int blk_size = s->conf->logical_block_size;
@@ -507,7 +527,7 @@ static void virtio_blk_update_config(VirtIODevice *vdev, uint8_t *config)
 
 static void virtio_blk_set_config(VirtIODevice *vdev, const uint8_t *config)
 {
-    VirtIOBlock *s = to_virtio_blk(vdev);
+    VirtIOBlock *s = VIRTIO_BLK(vdev);
     struct virtio_blk_config blkcfg;
 
     memcpy(&blkcfg, config, sizeof(blkcfg));
@@ -516,7 +536,7 @@ static void virtio_blk_set_config(VirtIODevice *vdev, const uint8_t *config)
 
 static uint32_t virtio_blk_get_features(VirtIODevice *vdev, uint32_t features)
 {
-    VirtIOBlock *s = to_virtio_blk(vdev);
+    VirtIOBlock *s = VIRTIO_BLK(vdev);
 
     features |= (1 << VIRTIO_BLK_F_SEG_MAX);
     features |= (1 << VIRTIO_BLK_F_GEOMETRY);
@@ -535,7 +555,7 @@ static uint32_t virtio_blk_get_features(VirtIODevice *vdev, uint32_t features)
 
 static void virtio_blk_set_status(VirtIODevice *vdev, uint8_t status)
 {
-    VirtIOBlock *s = to_virtio_blk(vdev);
+    VirtIOBlock *s = VIRTIO_BLK(vdev);
     uint32_t features;
 
     if (!(status & VIRTIO_CONFIG_S_DRIVER_OK)) {
@@ -548,10 +568,11 @@ static void virtio_blk_set_status(VirtIODevice *vdev, uint8_t status)
 
 static void virtio_blk_save(QEMUFile *f, void *opaque)
 {
-    VirtIOBlock *s = opaque;
+    VirtIOBlock *s = VIRTIO_BLK(opaque);
+    VirtIODevice *vdev = VIRTIO_DEVICE(opaque);
     VirtIOBlockReq *req = s->rq;
 
-    virtio_save(&s->vdev, f);
+    virtio_save(vdev, f);
     
     while (req) {
         qemu_put_sbyte(f, 1);
@@ -563,13 +584,14 @@ static void virtio_blk_save(QEMUFile *f, void *opaque)
 
 static int virtio_blk_load(QEMUFile *f, void *opaque, int version_id)
 {
-    VirtIOBlock *s = opaque;
+    VirtIOBlock *s = VIRTIO_BLK(opaque);
+    VirtIODevice *vdev = VIRTIO_DEVICE(opaque);
     int ret;
 
     if (version_id != 2)
         return -EINVAL;
 
-    ret = virtio_load(&s->vdev, f);
+    ret = virtio_load(vdev, f);
     if (ret) {
         return ret;
     }
@@ -591,9 +613,9 @@ static int virtio_blk_load(QEMUFile *f, void *opaque, int version_id)
 
 static void virtio_blk_resize(void *opaque)
 {
-    VirtIOBlock *s = opaque;
+    VirtIODevice *vdev = VIRTIO_DEVICE(opaque);
 
-    virtio_notify_config(&s->vdev);
+    virtio_notify_config(vdev);
 }
 
 static const BlockDevOps virtio_block_ops = {
@@ -630,7 +652,7 @@ VirtIODevice *virtio_blk_init(DeviceState *dev, VirtIOBlkConf *blk)
     s->vdev.reset = virtio_blk_reset;
     s->bs = blk->conf.bs;
     s->conf = &blk->conf;
-    s->blk = blk;
+    memcpy(&(s->blk), blk, sizeof(struct VirtIOBlkConf));
     s->rq = NULL;
     s->sector_mask = (s->conf->logical_block_size / BDRV_SECTOR_SIZE) - 1;
 
@@ -651,8 +673,108 @@ VirtIODevice *virtio_blk_init(DeviceState *dev, VirtIOBlkConf *blk)
 
 void virtio_blk_exit(VirtIODevice *vdev)
 {
-    VirtIOBlock *s = to_virtio_blk(vdev);
+    VirtIOBlock *s = VIRTIO_BLK(vdev);
     unregister_savevm(s->qdev, "virtio-blk", s);
     blockdev_mark_auto_del(s->bs);
     virtio_cleanup(vdev);
 }
+
+static int virtio_device_init(DeviceState *qdev)
+{
+    VirtIODevice *vdev = VIRTIO_DEVICE(qdev);
+    VirtIOBlock *s = VIRTIO_BLK(qdev);
+
+    VirtIOBlkConf *blk = &(s->blk);
+    static int virtio_blk_id;
+
+    if (!blk->conf.bs) {
+        error_report("drive property not set");
+        return -1;
+    }
+    if (!bdrv_is_inserted(blk->conf.bs)) {
+        error_report("Device needs media, but drive is empty");
+        return -1;
+    }
+
+    blkconf_serial(&blk->conf, &blk->serial);
+    if (blkconf_geometry(&blk->conf, NULL, 65535, 255, 255) < 0) {
+        return -1;
+    }
+
+    virtio_common_init_(vdev, "virtio-blk", VIRTIO_ID_BLOCK,
+                                          sizeof(struct virtio_blk_config),
+                                          sizeof(VirtIOBlock));
+
+    vdev->get_config = virtio_blk_update_config;
+    vdev->set_config = virtio_blk_set_config;
+    vdev->get_features = virtio_blk_get_features;
+    vdev->set_status = virtio_blk_set_status;
+    vdev->reset = virtio_blk_reset;
+    s->bs = blk->conf.bs;
+    s->conf = &blk->conf;
+    memcpy(&(s->blk), blk, sizeof(struct VirtIOBlkConf));
+    s->rq = NULL;
+    s->sector_mask = (s->conf->logical_block_size / BDRV_SECTOR_SIZE) - 1;
+
+    s->vq = virtio_add_queue(vdev, 128, virtio_blk_handle_output);
+
+    qemu_add_vm_change_state_handler(virtio_blk_dma_restart_cb, s);
+    s->qdev = qdev;
+    register_savevm(qdev, "virtio-blk", virtio_blk_id++, 2,
+                    virtio_blk_save, virtio_blk_load, s);
+    bdrv_set_dev_ops(s->bs, &virtio_block_ops, s);
+    bdrv_set_buffer_alignment(s->bs, s->conf->logical_block_size);
+
+    bdrv_iostatus_enable(s->bs);
+    add_boot_device_path(s->conf->bootindex, qdev, "/disk@0,0");
+
+    virtio_bus_plug_device(vdev);
+
+    return 0;
+}
+
+static int virtio_device_exit(DeviceState *dev)
+{
+    VirtIODevice *vdev = VIRTIO_DEVICE(dev);
+    virtio_blk_exit(vdev);
+    return 0;
+}
+
+static Property virtio_blk_properties[] = {
+    DEFINE_BLOCK_PROPERTIES(VirtIOBlock, blk.conf),
+    DEFINE_BLOCK_CHS_PROPERTIES(VirtIOBlock, blk.conf),
+    DEFINE_PROP_STRING("serial", VirtIOBlock, blk.serial),
+#ifdef __linux__
+    DEFINE_PROP_BIT("scsi", VirtIOBlock, blk.scsi, 0, true),
+#endif
+    DEFINE_PROP_BIT("config-wce", VirtIOBlock, blk.config_wce, 0, true),
+    DEFINE_PROP_END_OF_LIST(),
+};
+
+static void virtio_blk_class_init(ObjectClass *klass, void *data)
+{
+    DeviceClass *dc = DEVICE_CLASS(klass);
+    VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass);
+    dc->init = virtio_device_init;
+    dc->exit = virtio_device_exit;
+    dc->props = virtio_blk_properties;
+    vdc->get_config = virtio_blk_update_config;
+    vdc->set_config = virtio_blk_set_config;
+    vdc->get_features = virtio_blk_get_features;
+    vdc->set_status = virtio_blk_set_status;
+    vdc->reset = virtio_blk_reset;
+}
+
+static const TypeInfo virtio_device_info = {
+    .name = TYPE_VIRTIO_BLK,
+    .parent = TYPE_VIRTIO_DEVICE,
+    .instance_size = sizeof(VirtIOBlock),
+    .class_init = virtio_blk_class_init,
+};
+
+static void virtio_register_types(void)
+{
+    type_register_static(&virtio_device_info);
+}
+
+type_init(virtio_register_types)
diff --git a/hw/virtio-blk.h b/hw/virtio-blk.h
index f0740d0..a33336e 100644
--- a/hw/virtio-blk.h
+++ b/hw/virtio-blk.h
@@ -111,4 +111,8 @@ struct VirtIOBlkConf
         DEFINE_VIRTIO_COMMON_FEATURES(_state, _field), \
         DEFINE_PROP_BIT("config-wce", _state, _field, VIRTIO_BLK_F_CONFIG_WCE, true)
 
+#define TYPE_VIRTIO_BLK "virtio-blk"
+#define VIRTIO_BLK(obj) \
+        OBJECT_CHECK(VirtIOBlock, (obj), TYPE_VIRTIO_BLK)
+
 #endif
-- 
1.7.11.7