This commit introduces a new vhost-user device for block, it uses a
chardev to connect with the backend, same with Qemu virito-blk device,
Guest OS still uses the virtio-blk frontend driver.
To use it, start QEMU with command line like this:
qemu-system-x86_64 \
-chardev socket,id=char0,path=/path/vhost.socket \
-device vhost-user-blk-pci,chardev=char0,num-queues=2, \
bootindex=2... \
Users can use different parameters for `num-queues` and `bootindex`.
Different with exist Qemu virtio-blk host device, it makes more easy
for users to implement their own I/O processing logic, such as all
user space I/O stack against hardware block device. It uses the new
vhost messages(VHOST_USER_GET_CONFIG) to get block virtio config
information from backend process.
Signed-off-by: Changpeng Liu
---
default-configs/pci.mak| 1 +
hw/block/Makefile.objs | 3 +
hw/block/vhost-user-blk.c | 357 +
hw/virtio/virtio-pci.c | 55 ++
hw/virtio/virtio-pci.h | 18 ++
include/hw/virtio/vhost-user-blk.h | 41 +
6 files changed, 475 insertions(+)
create mode 100644 hw/block/vhost-user-blk.c
create mode 100644 include/hw/virtio/vhost-user-blk.h
diff --git a/default-configs/pci.mak b/default-configs/pci.mak
index e514bde..49a0f28 100644
--- a/default-configs/pci.mak
+++ b/default-configs/pci.mak
@@ -43,3 +43,4 @@ CONFIG_VGA_PCI=y
CONFIG_IVSHMEM_DEVICE=$(CONFIG_IVSHMEM)
CONFIG_ROCKER=y
CONFIG_VHOST_USER_SCSI=$(call land,$(CONFIG_VHOST_USER),$(CONFIG_LINUX))
+CONFIG_VHOST_USER_BLK=$(call land,$(CONFIG_VHOST_USER),$(CONFIG_LINUX))
diff --git a/hw/block/Makefile.objs b/hw/block/Makefile.objs
index e0ed980..4c19a58 100644
--- a/hw/block/Makefile.objs
+++ b/hw/block/Makefile.objs
@@ -13,3 +13,6 @@ obj-$(CONFIG_SH4) += tc58128.o
obj-$(CONFIG_VIRTIO) += virtio-blk.o
obj-$(CONFIG_VIRTIO) += dataplane/
+ifeq ($(CONFIG_VIRTIO),y)
+obj-$(CONFIG_VHOST_USER_BLK) += vhost-user-blk.o
+endif
diff --git a/hw/block/vhost-user-blk.c b/hw/block/vhost-user-blk.c
new file mode 100644
index 000..c46d139
--- /dev/null
+++ b/hw/block/vhost-user-blk.c
@@ -0,0 +1,357 @@
+/*
+ * vhost-user-blk host device
+ *
+ * Copyright(C) 2017 Intel Corporation.
+ *
+ * Authors:
+ * Changpeng Liu
+ *
+ * Largely based on the "vhost-user-scsi.c" and "vhost-scsi.c" implemented by:
+ * Felipe Franciosi
+ * Stefan Hajnoczi
+ * Nicholas Bellinger
+ *
+ * This work is licensed under the terms of the GNU LGPL, version 2 or later.
+ * See the COPYING.LIB file in the top-level directory.
+ *
+ */
+
+#include "qemu/osdep.h"
+#include "qapi/error.h"
+#include "qemu/error-report.h"
+#include "qemu/typedefs.h"
+#include "qemu/cutils.h"
+#include "qom/object.h"
+#include "hw/qdev-core.h"
+#include "hw/virtio/vhost.h"
+#include "hw/virtio/vhost-user-blk.h"
+#include "hw/virtio/virtio.h"
+#include "hw/virtio/virtio-bus.h"
+#include "hw/virtio/virtio-access.h"
+
+static const int user_feature_bits[] = {
+VIRTIO_BLK_F_SIZE_MAX,
+VIRTIO_BLK_F_SEG_MAX,
+VIRTIO_BLK_F_GEOMETRY,
+VIRTIO_BLK_F_BLK_SIZE,
+VIRTIO_BLK_F_TOPOLOGY,
+VIRTIO_BLK_F_MQ,
+VIRTIO_BLK_F_RO,
+VIRTIO_BLK_F_FLUSH,
+VIRTIO_BLK_F_CONFIG_WCE,
+VIRTIO_F_VERSION_1,
+VIRTIO_RING_F_INDIRECT_DESC,
+VIRTIO_RING_F_EVENT_IDX,
+VIRTIO_F_NOTIFY_ON_EMPTY,
+VHOST_INVALID_FEATURE_BIT
+};
+
+static void vhost_user_blk_update_config(VirtIODevice *vdev, uint8_t *config)
+{
+VHostUserBlk *s = VHOST_USER_BLK(vdev);
+
+memcpy(config, &s->blkcfg, sizeof(struct virtio_blk_config));
+}
+
+static void vhost_user_blk_set_config(VirtIODevice *vdev, const uint8_t
*config)
+{
+VHostUserBlk *s = VHOST_USER_BLK(vdev);
+struct virtio_blk_config *blkcfg = (struct virtio_blk_config *)config;
+int ret;
+
+if (blkcfg->wce == s->blkcfg.wce) {
+return;
+}
+
+ret = vhost_dev_set_config(&s->dev, config,
+ offsetof(struct virtio_blk_config, wce),
+ sizeof(blkcfg->wce),
+ VHOST_SET_CONFIG_TYPE_MASTER);
+if (ret) {
+error_report("set device config space failed");
+return;
+}
+
+s->blkcfg.wce = blkcfg->wce;
+}
+
+static void vhost_user_blk_handle_config_change(struct vhost_dev *dev)
+{
+int ret;
+struct virtio_blk_config blkcfg;
+VHostUserBlk *s = VHOST_USER_BLK(dev->vdev);
+
+ret = vhost_dev_get_config(dev, (uint8_t *)&blkcfg,
+ sizeof(struct virtio_blk_config));
+if (ret < 0) {
+error_report("get config space failed");
+return;
+}
+
+/* valid for resize only */
+if (blkcfg.capacity != s->blkcfg.capacity) {
+s->blkcfg.capacity = blkcfg.capacity;
+memcpy(dev->vdev->config, &s->blkcfg, sizeof(struct
virtio_blk_config));
+virtio_notify_config(dev->vdev);
+}
+}
+
+const VhostDevConfigOps blk_ops = {
+.vhost_dev_c
