examples/vhost_blk: introduce vhost storage sample
authorJin Yu <jin.yu@intel.com>
Mon, 4 Nov 2019 16:36:26 +0000 (00:36 +0800)
committerFerruh Yigit <ferruh.yigit@intel.com>
Mon, 11 Nov 2019 13:23:02 +0000 (14:23 +0100)
A Vhost-blk example that support inflight feature. It uses the
new APIs that introduced in the first patch, so it can show how these
APIs work to support inflight feature.

Signed-off-by: Jin Yu <jin.yu@intel.com>
Reviewed-by: Maxime Coquelin <maxime.coquelin@redhat.com>
12 files changed:
MAINTAINERS
doc/guides/sample_app_ug/index.rst
doc/guides/sample_app_ug/vhost_blk.rst [new file with mode: 0644]
examples/Makefile
examples/meson.build
examples/vhost_blk/Makefile [new file with mode: 0644]
examples/vhost_blk/blk.c [new file with mode: 0644]
examples/vhost_blk/blk_spec.h [new file with mode: 0644]
examples/vhost_blk/meson.build [new file with mode: 0644]
examples/vhost_blk/vhost_blk.c [new file with mode: 0644]
examples/vhost_blk/vhost_blk.h [new file with mode: 0644]
examples/vhost_blk/vhost_blk_compat.c [new file with mode: 0644]

index e8d79ea..ab83986 100644 (file)
@@ -839,6 +839,8 @@ F: lib/librte_vhost/
 F: doc/guides/prog_guide/vhost_lib.rst
 F: examples/vhost/
 F: doc/guides/sample_app_ug/vhost.rst
+F: examples/vhost_blk/
+F: doc/guides/sample_app_ug/vhost_blk.rst
 F: examples/vhost_crypto/
 F: examples/vdpa/
 F: doc/guides/sample_app_ug/vdpa.rst
index 16ddabe..ac34451 100644 (file)
@@ -41,6 +41,7 @@ Sample Applications User Guides
     packet_ordering
     vmdq_dcb_forwarding
     vhost
+    vhost_blk
     vhost_crypto
     vdpa
     ip_pipeline
diff --git a/doc/guides/sample_app_ug/vhost_blk.rst b/doc/guides/sample_app_ug/vhost_blk.rst
new file mode 100644 (file)
index 0000000..39096e2
--- /dev/null
@@ -0,0 +1,63 @@
+..  SPDX-License-Identifier: BSD-3-Clause
+    Copyright(c) 2010-2017 Intel Corporation.
+
+Vhost_blk Sample Application
+=============================
+
+The vhost_blk sample application implemented a simple block device,
+which used as the  backend of Qemu vhost-user-blk device. Users can extend
+the exist example to use other type of block device(e.g. AIO) besides
+memory based block device. Similar with vhost-user-net device, the sample
+application used domain socket to communicate with Qemu, and the virtio
+ring (split or packed format) was processed by vhost_blk sample application.
+
+The sample application reuse lots codes from SPDK(Storage Performance
+Development Kit, https://github.com/spdk/spdk) vhost-user-blk target,
+for DPDK vhost library used in storage area, user can take SPDK as
+reference as well.
+
+Testing steps
+-------------
+
+This section shows the steps how to start a VM with the block device as
+fast data path for critical application.
+
+Compiling the Application
+-------------------------
+
+To compile the sample application see :doc:`compiling`.
+
+The application is located in the ``examples`` sub-directory.
+
+You will also need to build DPDK both on the host and inside the guest
+
+Start the vhost_blk example
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+.. code-block:: console
+
+        ./vhost_blk -m 1024
+
+.. _vhost_blk_app_run_vm:
+
+Start the VM
+~~~~~~~~~~~~
+
+.. code-block:: console
+
+    qemu-system-x86_64 -machine accel=kvm \
+        -m $mem -object memory-backend-file,id=mem,size=$mem,\
+        mem-path=/dev/hugepages,share=on -numa node,memdev=mem \
+        -drive file=os.img,if=none,id=disk \
+        -device ide-hd,drive=disk,bootindex=0 \
+        -chardev socket,id=char0,reconnect=1,path=/tmp/vhost.socket \
+        -device vhost-user-blk-pci,ring_packed=1,chardev=char0,num-queues=1 \
+        ...
+
+.. note::
+    You must check whether your Qemu can support "vhost-user-blk" or not,
+    Qemu v4.0 or newer version is required.
+    reconnect=1 means live recovery support that qemu can reconnect vhost_blk
+    after we restart vhost_blk example.
+    ring_packed=1 means the device support packed ring but need the guest kernel
+    version >= 5.0
index c4d1343..feff797 100644 (file)
@@ -68,7 +68,7 @@ ifeq ($(CONFIG_RTE_LIBRTE_HASH),y)
 DIRS-$(CONFIG_RTE_LIBRTE_VHOST) += tep_termination
 endif
 DIRS-$(CONFIG_RTE_LIBRTE_TIMER) += timer
-DIRS-$(CONFIG_RTE_LIBRTE_VHOST) += vhost vdpa
+DIRS-$(CONFIG_RTE_LIBRTE_VHOST) += vhost vdpa vhost_blk
 ifeq ($(CONFIG_RTE_LIBRTE_CRYPTODEV),y)
 DIRS-$(CONFIG_RTE_LIBRTE_VHOST) += vhost_crypto
 endif
index 9d46870..1f2b6f5 100644 (file)
@@ -42,7 +42,7 @@ all_examples = [
        'skeleton', 'tep_termination',
        'timer', 'vdpa',
        'vhost', 'vhost_crypto',
-       'vm_power_manager',
+       'vhost_blk', 'vm_power_manager',
        'vm_power_manager/guest_cli',
        'vmdq', 'vmdq_dcb',
 ]
diff --git a/examples/vhost_blk/Makefile b/examples/vhost_blk/Makefile
new file mode 100644 (file)
index 0000000..a10a900
--- /dev/null
@@ -0,0 +1,68 @@
+# SPDX-License-Identifier: BSD-3-Clause
+# Copyright(c) 2010-2014 Intel Corporation
+
+# binary name
+APP = vhost-blk
+
+# all source are stored in SRCS-y
+SRCS-y := blk.c vhost_blk.c vhost_blk_compat.c
+
+# Build using pkg-config variables if possible
+$(shell pkg-config --exists libdpdk)
+ifeq ($(.SHELLSTATUS),0)
+
+all: shared
+.PHONY: shared static
+shared: build/$(APP)-shared
+       ln -sf $(APP)-shared build/$(APP)
+static: build/$(APP)-static
+       ln -sf $(APP)-static build/$(APP)
+
+LDFLAGS += -pthread
+
+PC_FILE := $(shell pkg-config --path libdpdk)
+CFLAGS += -O3 $(shell pkg-config --cflags libdpdk)
+LDFLAGS_SHARED = $(shell pkg-config --libs libdpdk)
+LDFLAGS_STATIC = -Wl,-Bstatic $(shell pkg-config --static --libs libdpdk)
+
+CFLAGS += -DALLOW_EXPERIMENTAL_API
+
+build/$(APP)-shared: $(SRCS-y) Makefile $(PC_FILE) | build
+       $(CC) $(CFLAGS) $(SRCS-y) -o $@ $(LDFLAGS) $(LDFLAGS_SHARED)
+
+build/$(APP)-static: $(SRCS-y) Makefile $(PC_FILE) | build
+       $(CC) $(CFLAGS) $(SRCS-y) -o $@ $(LDFLAGS) $(LDFLAGS_STATIC)
+
+build:
+       @mkdir -p $@
+
+.PHONY: clean
+clean:
+       rm -f build/$(APP) build/$(APP)-static build/$(APP)-shared
+       test -d build && rmdir -p build || true
+
+else # Build using legacy build system
+
+ifeq ($(RTE_SDK),)
+$(error "Please define RTE_SDK environment variable")
+endif
+
+# Default target, detect a build directory, by looking for a path with a .config
+RTE_TARGET ?= $(notdir $(abspath $(dir $(firstword $(wildcard $(RTE_SDK)/*/.config)))))
+
+include $(RTE_SDK)/mk/rte.vars.mk
+
+ifneq ($(CONFIG_RTE_EXEC_ENV_LINUX),y)
+$(info This application can only operate in a linux environment, \
+please change the definition of the RTE_TARGET environment variable)
+all:
+else
+
+CFLAGS += -DALLOW_EXPERIMENTAL_API
+CFLAGS += -O2 -D_FILE_OFFSET_BITS=64
+CFLAGS += $(WERROR_FLAGS)
+
+include $(RTE_SDK)/mk/rte.extapp.mk
+
+endif
+endif
diff --git a/examples/vhost_blk/blk.c b/examples/vhost_blk/blk.c
new file mode 100644 (file)
index 0000000..1b0b764
--- /dev/null
@@ -0,0 +1,126 @@
+/* SPDX-License-Identifier: BSD-3-Clause
+ * Copyright(c) 2010-2019 Intel Corporation
+ */
+
+/**
+ * This work is largely based on the "vhost-user-blk" implementation by
+ * SPDK(https://github.com/spdk/spdk).
+ */
+
+#include <stdio.h>
+#include <stdint.h>
+#include <unistd.h>
+#include <assert.h>
+#include <ctype.h>
+#include <string.h>
+#include <stddef.h>
+
+#include <rte_atomic.h>
+#include <rte_cycles.h>
+#include <rte_log.h>
+#include <rte_malloc.h>
+#include <rte_byteorder.h>
+#include <rte_string_fns.h>
+
+#include "vhost_blk.h"
+#include "blk_spec.h"
+
+static void
+vhost_strcpy_pad(void *dst, const char *src, size_t size, int pad)
+{
+       size_t len;
+
+       len = strlen(src);
+       if (len < size) {
+               memcpy(dst, src, len);
+               memset((char *)dst + len, pad, size - len);
+       } else {
+               memcpy(dst, src, size);
+       }
+}
+
+static int
+vhost_bdev_blk_readwrite(struct vhost_block_dev *bdev,
+                         struct vhost_blk_task *task,
+                         uint64_t lba_512, __rte_unused uint32_t xfer_len)
+{
+       uint32_t i;
+       uint64_t offset;
+       uint32_t nbytes = 0;
+
+       offset = lba_512 * 512;
+
+       for (i = 0; i < task->iovs_cnt; i++) {
+               if (task->dxfer_dir == BLK_DIR_TO_DEV)
+                       memcpy(bdev->data + offset, task->iovs[i].iov_base,
+                              task->iovs[i].iov_len);
+               else
+                       memcpy(task->iovs[i].iov_base, bdev->data + offset,
+                              task->iovs[i].iov_len);
+               offset += task->iovs[i].iov_len;
+               nbytes += task->iovs[i].iov_len;
+       }
+
+       return nbytes;
+}
+
+int
+vhost_bdev_process_blk_commands(struct vhost_block_dev *bdev,
+                                struct vhost_blk_task *task)
+{
+       int used_len;
+
+       if (unlikely(task->data_len > (bdev->blockcnt * bdev->blocklen))) {
+               fprintf(stderr, "read or write beyond capacity\n");
+               return VIRTIO_BLK_S_UNSUPP;
+       }
+
+       switch (task->req->type) {
+       case VIRTIO_BLK_T_IN:
+               if (unlikely(task->data_len == 0 ||
+                       (task->data_len & (512 - 1)) != 0)) {
+                       fprintf(stderr,
+                               "%s - passed IO buffer is not multiple of 512b"
+                               "(req_idx = %"PRIu16").\n",
+                               task->req->type ? "WRITE" : "READ",
+                               task->head_idx);
+                       return VIRTIO_BLK_S_UNSUPP;
+               }
+
+               task->dxfer_dir = BLK_DIR_FROM_DEV;
+               vhost_bdev_blk_readwrite(bdev, task,
+                                        task->req->sector, task->data_len);
+               break;
+       case VIRTIO_BLK_T_OUT:
+               if (unlikely(task->data_len == 0 ||
+                       (task->data_len & (512 - 1)) != 0)) {
+                       fprintf(stderr,
+                               "%s - passed IO buffer is not multiple of 512b"
+                               "(req_idx = %"PRIu16").\n",
+                               task->req->type ? "WRITE" : "READ",
+                               task->head_idx);
+                       return VIRTIO_BLK_S_UNSUPP;
+               }
+
+               if (task->readtype) {
+                       fprintf(stderr, "type isn't right\n");
+                       return VIRTIO_BLK_S_IOERR;
+               }
+               task->dxfer_dir = BLK_DIR_TO_DEV;
+               vhost_bdev_blk_readwrite(bdev, task,
+                                        task->req->sector, task->data_len);
+               break;
+       case VIRTIO_BLK_T_GET_ID:
+               if (!task->iovs_cnt || task->data_len)
+                       return VIRTIO_BLK_S_UNSUPP;
+               used_len = min(VIRTIO_BLK_ID_BYTES, task->data_len);
+               vhost_strcpy_pad(task->iovs[0].iov_base,
+                                bdev->product_name, used_len, ' ');
+               break;
+       default:
+               fprintf(stderr, "unsupported cmd\n");
+               return VIRTIO_BLK_S_UNSUPP;
+       }
+
+       return VIRTIO_BLK_S_OK;
+}
diff --git a/examples/vhost_blk/blk_spec.h b/examples/vhost_blk/blk_spec.h
new file mode 100644 (file)
index 0000000..5875e2f
--- /dev/null
@@ -0,0 +1,95 @@
+/* SPDX-License-Identifier: BSD-3-Clause
+ * Copyright(c) 2019 Intel Corporation
+ */
+
+#ifndef _BLK_SPEC_H
+#define _BLK_SPEC_H
+
+#include <stdint.h>
+
+#ifndef VHOST_USER_MEMORY_MAX_NREGIONS
+#define VHOST_USER_MEMORY_MAX_NREGIONS         8
+#endif
+
+#ifndef VHOST_USER_MAX_CONFIG_SIZE
+#define VHOST_USER_MAX_CONFIG_SIZE             256
+#endif
+
+#ifndef VHOST_USER_PROTOCOL_F_CONFIG
+#define VHOST_USER_PROTOCOL_F_CONFIG           9
+#endif
+
+#ifndef VHOST_USER_PROTOCOL_F_INFLIGHT_SHMFD
+#define VHOST_USER_PROTOCOL_F_INFLIGHT_SHMFD   12
+#endif
+
+#define VIRTIO_BLK_ID_BYTES    20      /* ID string length */
+
+#define VIRTIO_BLK_T_IN                        0
+#define VIRTIO_BLK_T_OUT               1
+#define VIRTIO_BLK_T_FLUSH             4
+#define VIRTIO_BLK_T_GET_ID            8
+#define VIRTIO_BLK_T_DISCARD           11
+#define VIRTIO_BLK_T_WRITE_ZEROES      13
+
+#define VIRTIO_BLK_S_OK                        0
+#define VIRTIO_BLK_S_IOERR             1
+#define VIRTIO_BLK_S_UNSUPP            2
+
+enum vhost_user_request {
+       VHOST_USER_NONE = 0,
+       VHOST_USER_GET_FEATURES = 1,
+       VHOST_USER_SET_FEATURES = 2,
+       VHOST_USER_SET_OWNER = 3,
+       VHOST_USER_RESET_OWNER = 4,
+       VHOST_USER_SET_MEM_TABLE = 5,
+       VHOST_USER_SET_LOG_BASE = 6,
+       VHOST_USER_SET_LOG_FD = 7,
+       VHOST_USER_SET_VRING_NUM = 8,
+       VHOST_USER_SET_VRING_ADDR = 9,
+       VHOST_USER_SET_VRING_BASE = 10,
+       VHOST_USER_GET_VRING_BASE = 11,
+       VHOST_USER_SET_VRING_KICK = 12,
+       VHOST_USER_SET_VRING_CALL = 13,
+       VHOST_USER_SET_VRING_ERR = 14,
+       VHOST_USER_GET_PROTOCOL_FEATURES = 15,
+       VHOST_USER_SET_PROTOCOL_FEATURES = 16,
+       VHOST_USER_GET_QUEUE_NUM = 17,
+       VHOST_USER_SET_VRING_ENABLE = 18,
+       VHOST_USER_MAX
+};
+
+/** Get/set config msg payload */
+struct vhost_user_config {
+       uint32_t offset;
+       uint32_t size;
+       uint32_t flags;
+       uint8_t region[VHOST_USER_MAX_CONFIG_SIZE];
+};
+
+/** Fixed-size vhost_memory struct */
+struct vhost_memory_padded {
+       uint32_t nregions;
+       uint32_t padding;
+       struct vhost_memory_region regions[VHOST_USER_MEMORY_MAX_NREGIONS];
+};
+
+struct vhost_user_msg {
+       enum vhost_user_request request;
+
+#define VHOST_USER_VERSION_MASK     0x3
+#define VHOST_USER_REPLY_MASK       (0x1 << 2)
+       uint32_t flags;
+       uint32_t size; /**< the following payload size */
+       union {
+#define VHOST_USER_VRING_IDX_MASK   0xff
+#define VHOST_USER_VRING_NOFD_MASK  (0x1 << 8)
+               uint64_t u64;
+               struct vhost_vring_state state;
+               struct vhost_vring_addr addr;
+               struct vhost_memory_padded memory;
+               struct vhost_user_config cfg;
+       } payload;
+} __attribute((packed));
+
+#endif
diff --git a/examples/vhost_blk/meson.build b/examples/vhost_blk/meson.build
new file mode 100644 (file)
index 0000000..8573671
--- /dev/null
@@ -0,0 +1,21 @@
+# SPDX-License-Identifier: BSD-3-Clause
+# Copyright(c) 2017 Intel Corporation
+
+# meson file, for building this example as part of a main DPDK build.
+#
+# To build this example as a standalone application with an already-installed
+# DPDK instance, use 'make'
+
+if not is_linux
+       build = false
+endif
+
+if not cc.has_header('linux/virtio_blk.h')
+       build = false
+endif
+
+deps += 'vhost'
+allow_experimental_apis = true
+sources = files(
+       'blk.c', 'vhost_blk.c', 'vhost_blk_compat.c'
+)
diff --git a/examples/vhost_blk/vhost_blk.c b/examples/vhost_blk/vhost_blk.c
new file mode 100644 (file)
index 0000000..8c57013
--- /dev/null
@@ -0,0 +1,1095 @@
+/* SPDX-License-Identifier: BSD-3-Clause
+ * Copyright(c) 2010-2019 Intel Corporation
+ */
+
+#include <stdint.h>
+#include <unistd.h>
+#include <stdbool.h>
+#include <signal.h>
+#include <assert.h>
+#include <semaphore.h>
+#include <linux/virtio_blk.h>
+#include <linux/virtio_ring.h>
+
+#include <rte_atomic.h>
+#include <rte_cycles.h>
+#include <rte_log.h>
+#include <rte_malloc.h>
+#include <rte_vhost.h>
+
+#include "vhost_blk.h"
+#include "blk_spec.h"
+
+#define VIRTQ_DESC_F_NEXT      1
+#define VIRTQ_DESC_F_AVAIL     (1 << 7)
+#define VIRTQ_DESC_F_USED      (1 << 15)
+
+#define MAX_TASK               12
+
+#define VHOST_BLK_FEATURES ((1ULL << VIRTIO_F_RING_PACKED) | \
+                           (1ULL << VIRTIO_F_VERSION_1) |\
+                           (1ULL << VIRTIO_F_NOTIFY_ON_EMPTY) | \
+                           (1ULL << VHOST_USER_F_PROTOCOL_FEATURES))
+
+/* Path to folder where character device will be created. Can be set by user. */
+static char dev_pathname[PATH_MAX] = "";
+static sem_t exit_sem;
+static int g_should_stop = -1;
+
+struct vhost_blk_ctrlr *
+vhost_blk_ctrlr_find(const char *ctrlr_name)
+{
+       if (ctrlr_name == NULL)
+               return NULL;
+
+       /* currently we only support 1 socket file fd */
+       return g_vhost_ctrlr;
+}
+
+static uint64_t gpa_to_vva(int vid, uint64_t gpa, uint64_t *len)
+{
+       char path[PATH_MAX];
+       struct vhost_blk_ctrlr *ctrlr;
+       int ret = 0;
+
+       ret = rte_vhost_get_ifname(vid, path, PATH_MAX);
+       if (ret) {
+               fprintf(stderr, "Cannot get socket name\n");
+               assert(ret != 0);
+       }
+
+       ctrlr = vhost_blk_ctrlr_find(path);
+       if (!ctrlr) {
+               fprintf(stderr, "Controller is not ready\n");
+               assert(ctrlr != NULL);
+       }
+
+       assert(ctrlr->mem != NULL);
+
+       return rte_vhost_va_from_guest_pa(ctrlr->mem, gpa, len);
+}
+
+static struct vring_packed_desc *
+descriptor_get_next_packed(struct rte_vhost_vring *vq,
+                            uint16_t *idx)
+{
+       if (vq->desc_packed[*idx % vq->size].flags & VIRTQ_DESC_F_NEXT) {
+               *idx += 1;
+               return &vq->desc_packed[*idx % vq->size];
+       }
+
+       return NULL;
+}
+
+static bool
+descriptor_has_next_packed(struct vring_packed_desc *cur_desc)
+{
+       return !!(cur_desc->flags & VRING_DESC_F_NEXT);
+}
+
+static bool
+descriptor_is_wr_packed(struct vring_packed_desc *cur_desc)
+{
+       return !!(cur_desc->flags & VRING_DESC_F_WRITE);
+}
+
+static struct rte_vhost_inflight_desc_packed *
+inflight_desc_get_next(struct rte_vhost_inflight_info_packed *inflight_packed,
+                              struct rte_vhost_inflight_desc_packed *cur_desc)
+{
+       if (!!(cur_desc->flags & VIRTQ_DESC_F_NEXT))
+               return &inflight_packed->desc[cur_desc->next];
+
+       return NULL;
+}
+
+static bool
+inflight_desc_has_next(struct rte_vhost_inflight_desc_packed *cur_desc)
+{
+       return !!(cur_desc->flags & VRING_DESC_F_NEXT);
+}
+
+static bool
+inflight_desc_is_wr(struct rte_vhost_inflight_desc_packed *cur_desc)
+{
+       return !!(cur_desc->flags & VRING_DESC_F_WRITE);
+}
+
+static void
+inflight_process_payload_chain_packed(struct inflight_blk_task *task)
+{
+       void *data;
+       uint64_t chunck_len;
+       struct vhost_blk_task *blk_task;
+       struct rte_vhost_inflight_desc_packed *desc;
+
+       blk_task = &task->blk_task;
+       blk_task->iovs_cnt = 0;
+
+       do {
+               desc = task->inflight_desc;
+               chunck_len = desc->len;
+               data = (void *)(uintptr_t)gpa_to_vva(blk_task->bdev->vid,
+                                                    desc->addr,
+                                                    &chunck_len);
+               if (!data || chunck_len != desc->len) {
+                       fprintf(stderr, "failed to translate desc address.\n");
+                       return;
+               }
+
+               blk_task->iovs[blk_task->iovs_cnt].iov_base = data;
+               blk_task->iovs[blk_task->iovs_cnt].iov_len = desc->len;
+               blk_task->data_len += desc->len;
+               blk_task->iovs_cnt++;
+               task->inflight_desc = inflight_desc_get_next(
+                                       task->inflight_packed, desc);
+       } while (inflight_desc_has_next(task->inflight_desc));
+
+       chunck_len = task->inflight_desc->len;
+       blk_task->status = (void *)(uintptr_t)gpa_to_vva(
+               blk_task->bdev->vid, task->inflight_desc->addr, &chunck_len);
+       if (!blk_task->status || chunck_len != task->inflight_desc->len)
+               fprintf(stderr, "failed to translate desc address.\n");
+}
+
+static void
+inflight_submit_completion_packed(struct inflight_blk_task *task,
+                                             uint32_t q_idx, uint16_t *used_id,
+                                             bool *used_wrap_counter)
+{
+       struct vhost_blk_ctrlr *ctrlr;
+       struct rte_vhost_vring *vq;
+       struct vring_packed_desc *desc;
+       int ret;
+
+       ctrlr = vhost_blk_ctrlr_find(dev_pathname);
+       vq = task->blk_task.vq;
+
+       ret = rte_vhost_set_last_inflight_io_packed(ctrlr->bdev->vid, q_idx,
+                                                   task->blk_task.head_idx);
+       if (ret != 0)
+               fprintf(stderr, "failed to set last inflight io\n");
+
+       desc = &vq->desc_packed[*used_id];
+       desc->id = task->blk_task.buffer_id;
+       rte_smp_mb();
+       if (*used_wrap_counter)
+               desc->flags |= VIRTQ_DESC_F_AVAIL | VIRTQ_DESC_F_USED;
+       else
+               desc->flags &= ~(VIRTQ_DESC_F_AVAIL | VIRTQ_DESC_F_USED);
+       rte_smp_mb();
+
+       *used_id += task->blk_task.iovs_cnt + 2;
+       if (*used_id >= vq->size) {
+               *used_id -= vq->size;
+               *used_wrap_counter = !(*used_wrap_counter);
+       }
+
+       ret = rte_vhost_clr_inflight_desc_packed(ctrlr->bdev->vid, q_idx,
+                                                task->blk_task.head_idx);
+       if (ret != 0)
+               fprintf(stderr, "failed to clear inflight io\n");
+
+       /* Send an interrupt back to the guest VM so that it knows
+        * a completion is ready to be processed.
+        */
+       rte_vhost_vring_call(task->blk_task.bdev->vid, q_idx);
+}
+
+static void
+submit_completion_packed(struct vhost_blk_task *task, uint32_t q_idx,
+                                 uint16_t *used_id, bool *used_wrap_counter)
+{
+       struct vhost_blk_ctrlr *ctrlr;
+       struct rte_vhost_vring *vq;
+       struct vring_packed_desc *desc;
+       int ret;
+
+       ctrlr = vhost_blk_ctrlr_find(dev_pathname);
+       vq = task->vq;
+
+       ret = rte_vhost_set_last_inflight_io_packed(ctrlr->bdev->vid, q_idx,
+                                                   task->inflight_idx);
+       if (ret != 0)
+               fprintf(stderr, "failed to set last inflight io\n");
+
+       desc = &vq->desc_packed[*used_id];
+       desc->id = task->buffer_id;
+       rte_smp_mb();
+       if (*used_wrap_counter)
+               desc->flags |= VIRTQ_DESC_F_AVAIL | VIRTQ_DESC_F_USED;
+       else
+               desc->flags &= ~(VIRTQ_DESC_F_AVAIL | VIRTQ_DESC_F_USED);
+       rte_smp_mb();
+
+       *used_id += task->iovs_cnt + 2;
+       if (*used_id >= vq->size) {
+               *used_id -= vq->size;
+               *used_wrap_counter = !(*used_wrap_counter);
+       }
+
+       ret = rte_vhost_clr_inflight_desc_packed(ctrlr->bdev->vid, q_idx,
+                                                task->inflight_idx);
+       if (ret != 0)
+               fprintf(stderr, "failed to clear inflight io\n");
+
+       /* Send an interrupt back to the guest VM so that it knows
+        * a completion is ready to be processed.
+        */
+       rte_vhost_vring_call(task->bdev->vid, q_idx);
+}
+
+static void
+vhost_process_payload_chain_packed(struct vhost_blk_task *task,
+       uint16_t *idx)
+{
+       void *data;
+       uint64_t chunck_len;
+
+       task->iovs_cnt = 0;
+
+       do {
+               chunck_len = task->desc_packed->len;
+               data = (void *)(uintptr_t)gpa_to_vva(task->bdev->vid,
+                                                    task->desc_packed->addr,
+                                                        &chunck_len);
+               if (!data || chunck_len != task->desc_packed->len) {
+                       fprintf(stderr, "failed to translate desc address.\n");
+                       return;
+               }
+
+               task->iovs[task->iovs_cnt].iov_base = data;
+               task->iovs[task->iovs_cnt].iov_len = task->desc_packed->len;
+               task->data_len += task->desc_packed->len;
+               task->iovs_cnt++;
+               task->desc_packed = descriptor_get_next_packed(task->vq, idx);
+       } while (descriptor_has_next_packed(task->desc_packed));
+
+       task->last_idx = *idx % task->vq->size;
+       chunck_len = task->desc_packed->len;
+       task->status = (void *)(uintptr_t)gpa_to_vva(task->bdev->vid,
+                                                  task->desc_packed->addr,
+                                                  &chunck_len);
+       if (!task->status || chunck_len != task->desc_packed->len)
+               fprintf(stderr, "failed to translate desc address.\n");
+}
+
+
+static int
+descriptor_is_available(struct rte_vhost_vring *vring, uint16_t idx,
+                                       bool avail_wrap_counter)
+{
+       uint16_t flags = vring->desc_packed[idx].flags;
+
+       return ((!!(flags & VIRTQ_DESC_F_AVAIL) == avail_wrap_counter) &&
+               (!!(flags & VIRTQ_DESC_F_USED) != avail_wrap_counter));
+}
+
+static void
+process_requestq_packed(struct vhost_blk_ctrlr *ctrlr, uint32_t q_idx)
+{
+       bool avail_wrap_counter, used_wrap_counter;
+       uint16_t avail_idx, used_idx;
+       int ret;
+       uint64_t chunck_len;
+       struct vhost_blk_queue *blk_vq;
+       struct rte_vhost_vring *vq;
+       struct vhost_blk_task *task;
+
+       blk_vq = &ctrlr->bdev->queues[q_idx];
+       vq = &blk_vq->vq;
+
+       avail_idx = blk_vq->last_avail_idx;
+       avail_wrap_counter = blk_vq->avail_wrap_counter;
+       used_idx = blk_vq->last_used_idx;
+       used_wrap_counter = blk_vq->used_wrap_counter;
+
+       task = rte_zmalloc(NULL, sizeof(*task), 0);
+       assert(task != NULL);
+       task->vq = vq;
+       task->bdev = ctrlr->bdev;
+
+       while (descriptor_is_available(vq, avail_idx, avail_wrap_counter)) {
+               task->head_idx = avail_idx;
+               task->desc_packed = &task->vq->desc_packed[task->head_idx];
+               task->iovs_cnt = 0;
+               task->data_len = 0;
+               task->req = NULL;
+               task->status = NULL;
+
+               /* does not support indirect descriptors */
+               assert((task->desc_packed->flags & VRING_DESC_F_INDIRECT) == 0);
+
+               chunck_len = task->desc_packed->len;
+               task->req = (void *)(uintptr_t)gpa_to_vva(task->bdev->vid,
+                       task->desc_packed->addr, &chunck_len);
+               if (!task->req || chunck_len != task->desc_packed->len) {
+                       fprintf(stderr, "failed to translate desc address.\n");
+                       rte_free(task);
+                       return;
+               }
+
+               task->desc_packed = descriptor_get_next_packed(task->vq,
+                                                               &avail_idx);
+               assert(task->desc_packed != NULL);
+               if (!descriptor_has_next_packed(task->desc_packed)) {
+                       task->dxfer_dir = BLK_DIR_NONE;
+                       task->last_idx = avail_idx % vq->size;
+                       chunck_len = task->desc_packed->len;
+                       task->status = (void *)(uintptr_t)
+                                             gpa_to_vva(task->bdev->vid,
+                                                       task->desc_packed->addr,
+                                                       &chunck_len);
+                       if (!task->status ||
+                               chunck_len != task->desc_packed->len) {
+                               fprintf(stderr,
+                                       "failed to translate desc address.\n");
+                               rte_free(task);
+                               return;
+                       }
+               } else {
+                       task->readtype = descriptor_is_wr_packed(
+                                                       task->desc_packed);
+                       vhost_process_payload_chain_packed(task, &avail_idx);
+               }
+               task->buffer_id = vq->desc_packed[task->last_idx].id;
+               rte_vhost_set_inflight_desc_packed(ctrlr->bdev->vid, q_idx,
+                                                  task->head_idx,
+                                                  task->last_idx,
+                                                  &task->inflight_idx);
+
+               if (++avail_idx >= vq->size) {
+                       avail_idx -= vq->size;
+                       avail_wrap_counter = !avail_wrap_counter;
+               }
+               blk_vq->last_avail_idx = avail_idx;
+               blk_vq->avail_wrap_counter = avail_wrap_counter;
+
+               ret = vhost_bdev_process_blk_commands(ctrlr->bdev, task);
+               if (ret) {
+                       /* invalid response */
+                       *task->status = VIRTIO_BLK_S_IOERR;
+               } else {
+                       /* successfully */
+                       *task->status = VIRTIO_BLK_S_OK;
+               }
+
+               submit_completion_packed(task, q_idx, &used_idx,
+                                               &used_wrap_counter);
+               blk_vq->last_used_idx = used_idx;
+               blk_vq->used_wrap_counter = used_wrap_counter;
+       }
+
+       rte_free(task);
+}
+
+static void
+submit_inflight_vq_packed(struct vhost_blk_ctrlr *ctrlr,
+       uint16_t q_idx)
+{
+       bool used_wrap_counter;
+       int req_idx, ret;
+       uint16_t used_idx;
+       uint64_t chunck_len;
+       struct vhost_blk_queue *blk_vq;
+       struct rte_vhost_ring_inflight *inflight_vq;
+       struct rte_vhost_resubmit_info *resubmit_info;
+       struct rte_vhost_vring *vq;
+       struct inflight_blk_task *task;
+       struct vhost_blk_task *blk_task;
+       struct rte_vhost_inflight_info_packed *inflight_info;
+
+       blk_vq = &ctrlr->bdev->queues[q_idx];
+       vq = &blk_vq->vq;
+       inflight_vq = &blk_vq->inflight_vq;
+       resubmit_info = inflight_vq->resubmit_inflight;
+       inflight_info = inflight_vq->inflight_packed;
+       used_idx = blk_vq->last_used_idx;
+       used_wrap_counter = blk_vq->used_wrap_counter;
+
+       task = rte_malloc(NULL, sizeof(*task), 0);
+       if (!task) {
+               fprintf(stderr, "failed to allocate memory\n");
+               return;
+       }
+       blk_task = &task->blk_task;
+       blk_task->vq = vq;
+       blk_task->bdev = ctrlr->bdev;
+       task->inflight_packed = inflight_vq->inflight_packed;
+
+       while (resubmit_info->resubmit_num-- > 0) {
+               req_idx = resubmit_info->resubmit_num;
+               blk_task->head_idx =
+                       resubmit_info->resubmit_list[req_idx].index;
+               task->inflight_desc =
+                       &inflight_info->desc[blk_task->head_idx];
+               task->blk_task.iovs_cnt = 0;
+               task->blk_task.data_len = 0;
+               task->blk_task.req = NULL;
+               task->blk_task.status = NULL;
+
+               /* update the avail idx too
+                * as it's initial value equals to used idx
+                */
+               blk_vq->last_avail_idx += task->inflight_desc->num;
+               if (blk_vq->last_avail_idx >= vq->size) {
+                       blk_vq->last_avail_idx -= vq->size;
+                       blk_vq->avail_wrap_counter =
+                               !blk_vq->avail_wrap_counter;
+               }
+
+               /* does not support indirect descriptors */
+               assert(task->inflight_desc != NULL);
+               assert((task->inflight_desc->flags &
+                       VRING_DESC_F_INDIRECT) == 0);
+
+               chunck_len = task->inflight_desc->len;
+               blk_task->req = (void *)(uintptr_t)
+                                    gpa_to_vva(blk_task->bdev->vid,
+                                               task->inflight_desc->addr,
+                                               &chunck_len);
+               if (!blk_task->req ||
+                       chunck_len != task->inflight_desc->len) {
+                       fprintf(stderr, "failed to translate desc address.\n");
+                       rte_free(task);
+                       return;
+               }
+
+               task->inflight_desc = inflight_desc_get_next(
+                       task->inflight_packed, task->inflight_desc);
+               assert(task->inflight_desc != NULL);
+               if (!inflight_desc_has_next(task->inflight_desc)) {
+                       blk_task->dxfer_dir = BLK_DIR_NONE;
+                       chunck_len = task->inflight_desc->len;
+                       blk_task->status = (void *)(uintptr_t)
+                               gpa_to_vva(blk_task->bdev->vid,
+                                               task->inflight_desc->addr,
+                                               &chunck_len);
+                       if (!blk_task->status ||
+                           chunck_len != task->inflight_desc->len) {
+                               fprintf(stderr,
+                                       "failed to translate desc address.\n");
+                               rte_free(task);
+                               return;
+                       }
+               } else {
+                       blk_task->readtype =
+                       inflight_desc_is_wr(task->inflight_desc);
+                       inflight_process_payload_chain_packed(task);
+               }
+
+               blk_task->buffer_id = task->inflight_desc->id;
+
+               ret = vhost_bdev_process_blk_commands(ctrlr->bdev, blk_task);
+               if (ret)
+                       /* invalid response */
+                       *blk_task->status = VIRTIO_BLK_S_IOERR;
+               else
+                       /* successfully */
+                       *blk_task->status = VIRTIO_BLK_S_OK;
+
+               inflight_submit_completion_packed(task, q_idx, &used_idx,
+                                                 &used_wrap_counter);
+
+               blk_vq->last_used_idx = used_idx;
+               blk_vq->used_wrap_counter = used_wrap_counter;
+       }
+
+       rte_free(task);
+}
+
+static struct vring_desc *
+descriptor_get_next_split(struct vring_desc *vq_desc,
+                                  struct vring_desc *cur_desc)
+{
+       return &vq_desc[cur_desc->next];
+}
+
+static bool
+descriptor_has_next_split(struct vring_desc *cur_desc)
+{
+       return !!(cur_desc->flags & VRING_DESC_F_NEXT);
+}
+
+static bool
+descriptor_is_wr_split(struct vring_desc *cur_desc)
+{
+       return !!(cur_desc->flags & VRING_DESC_F_WRITE);
+}
+
+static void
+vhost_process_payload_chain_split(struct vhost_blk_task *task)
+{
+       void *data;
+       uint64_t chunck_len;
+
+       task->iovs_cnt = 0;
+
+       do {
+               chunck_len = task->desc_split->len;
+               data = (void *)(uintptr_t)gpa_to_vva(task->bdev->vid,
+                                                    task->desc_split->addr,
+                                                    &chunck_len);
+               if (!data || chunck_len != task->desc_split->len) {
+                       fprintf(stderr, "failed to translate desc address.\n");
+                       return;
+               }
+
+               task->iovs[task->iovs_cnt].iov_base = data;
+               task->iovs[task->iovs_cnt].iov_len = task->desc_split->len;
+               task->data_len += task->desc_split->len;
+               task->iovs_cnt++;
+               task->desc_split =
+               descriptor_get_next_split(task->vq->desc, task->desc_split);
+       } while (descriptor_has_next_split(task->desc_split));
+
+       chunck_len = task->desc_split->len;
+       task->status = (void *)(uintptr_t)gpa_to_vva(task->bdev->vid,
+                                                    task->desc_split->addr,
+                                                    &chunck_len);
+       if (!task->status || chunck_len != task->desc_split->len)
+               fprintf(stderr, "failed to translate desc address.\n");
+}
+
+static void
+submit_completion_split(struct vhost_blk_task *task, uint32_t vid,
+       uint32_t q_idx)
+{
+       struct rte_vhost_vring *vq;
+       struct vring_used *used;
+
+       vq = task->vq;
+       used = vq->used;
+
+       rte_vhost_set_last_inflight_io_split(vid, q_idx, task->req_idx);
+
+       /* Fill out the next entry in the "used" ring.  id = the
+        * index of the descriptor that contained the blk request.
+        * len = the total amount of data transferred for the blk
+        * request. We must report the correct len, for variable
+        * length blk CDBs, where we may return less data than
+        * allocated by the guest VM.
+        */
+       used->ring[used->idx & (vq->size - 1)].id = task->req_idx;
+       used->ring[used->idx & (vq->size - 1)].len = task->data_len;
+       rte_smp_mb();
+       used->idx++;
+       rte_smp_mb();
+
+       rte_vhost_clr_inflight_desc_split(vid, q_idx, used->idx, task->req_idx);
+
+       /* Send an interrupt back to the guest VM so that it knows
+        * a completion is ready to be processed.
+        */
+       rte_vhost_vring_call(task->bdev->vid, q_idx);
+}
+
+static void
+submit_inflight_vq_split(struct vhost_blk_ctrlr *ctrlr,
+       uint32_t q_idx)
+{
+       struct vhost_blk_queue *blk_vq;
+       struct rte_vhost_ring_inflight *inflight_vq;
+       struct rte_vhost_resubmit_info *resubmit_inflight;
+       struct rte_vhost_resubmit_desc *resubmit_list;
+       struct vhost_blk_task *task;
+       int req_idx;
+       uint64_t chunck_len;
+       int ret;
+
+       blk_vq = &ctrlr->bdev->queues[q_idx];
+       inflight_vq = &blk_vq->inflight_vq;
+       resubmit_inflight = inflight_vq->resubmit_inflight;
+       resubmit_list = resubmit_inflight->resubmit_list;
+
+       task = rte_zmalloc(NULL, sizeof(*task), 0);
+       assert(task != NULL);
+
+       task->ctrlr = ctrlr;
+       task->bdev = ctrlr->bdev;
+       task->vq = &blk_vq->vq;
+
+       while (resubmit_inflight->resubmit_num-- > 0) {
+               req_idx = resubmit_list[resubmit_inflight->resubmit_num].index;
+               task->req_idx = req_idx;
+               task->desc_split = &task->vq->desc[task->req_idx];
+               task->iovs_cnt = 0;
+               task->data_len = 0;
+               task->req = NULL;
+               task->status = NULL;
+
+               /* does not support indirect descriptors */
+               assert(task->desc_split != NULL);
+               assert((task->desc_split->flags & VRING_DESC_F_INDIRECT) == 0);
+
+               chunck_len = task->desc_split->len;
+               task->req = (void *)(uintptr_t)gpa_to_vva(task->bdev->vid,
+                               task->desc_split->addr, &chunck_len);
+               if (!task->req || chunck_len != task->desc_split->len) {
+                       fprintf(stderr, "failed to translate desc address.\n");
+                       rte_free(task);
+                       return;
+               }
+
+               task->desc_split = descriptor_get_next_split(task->vq->desc,
+                                                            task->desc_split);
+               if (!descriptor_has_next_split(task->desc_split)) {
+                       task->dxfer_dir = BLK_DIR_NONE;
+                       chunck_len = task->desc_split->len;
+                       task->status = (void *)(uintptr_t)
+                                      gpa_to_vva(task->bdev->vid,
+                                                 task->desc_split->addr,
+                                                 &chunck_len);
+                       if (!task->status ||
+                               chunck_len != task->desc_split->len) {
+                               fprintf(stderr,
+                                       "failed to translate desc address.\n");
+                               rte_free(task);
+                               return;
+                       }
+               } else {
+                       task->readtype =
+                               descriptor_is_wr_split(task->desc_split);
+                       vhost_process_payload_chain_split(task);
+               }
+
+               ret = vhost_bdev_process_blk_commands(ctrlr->bdev, task);
+               if (ret) {
+                       /* invalid response */
+                       *task->status = VIRTIO_BLK_S_IOERR;
+               } else {
+                       /* successfully */
+                       *task->status = VIRTIO_BLK_S_OK;
+               }
+               submit_completion_split(task, ctrlr->bdev->vid, q_idx);
+       }
+
+       rte_free(task);
+}
+
+static void
+process_requestq_split(struct vhost_blk_ctrlr *ctrlr, uint32_t q_idx)
+{
+       int ret;
+       int req_idx;
+       uint16_t last_idx;
+       uint64_t chunck_len;
+       struct vhost_blk_queue *blk_vq;
+       struct rte_vhost_vring *vq;
+       struct vhost_blk_task *task;
+
+       blk_vq = &ctrlr->bdev->queues[q_idx];
+       vq = &blk_vq->vq;
+
+       task = rte_zmalloc(NULL, sizeof(*task), 0);
+       assert(task != NULL);
+       task->ctrlr = ctrlr;
+       task->bdev = ctrlr->bdev;
+       task->vq = vq;
+
+       while (vq->avail->idx != blk_vq->last_avail_idx) {
+               last_idx = blk_vq->last_avail_idx & (vq->size - 1);
+               req_idx = vq->avail->ring[last_idx];
+               task->req_idx = req_idx;
+               task->desc_split = &task->vq->desc[task->req_idx];
+               task->iovs_cnt = 0;
+               task->data_len = 0;
+               task->req = NULL;
+               task->status = NULL;
+
+               rte_vhost_set_inflight_desc_split(ctrlr->bdev->vid, q_idx,
+                                                       task->req_idx);
+
+               /* does not support indirect descriptors */
+               assert((task->desc_split->flags & VRING_DESC_F_INDIRECT) == 0);
+
+               chunck_len = task->desc_split->len;
+               task->req = (void *)(uintptr_t)gpa_to_vva(task->bdev->vid,
+                               task->desc_split->addr, &chunck_len);
+               if (!task->req || chunck_len != task->desc_split->len) {
+                       fprintf(stderr, "failed to translate desc address.\n");
+                       rte_free(task);
+                       return;
+               }
+
+               task->desc_split = descriptor_get_next_split(task->vq->desc,
+                                                            task->desc_split);
+               if (!descriptor_has_next_split(task->desc_split)) {
+                       task->dxfer_dir = BLK_DIR_NONE;
+                       chunck_len = task->desc_split->len;
+                       task->status = (void *)(uintptr_t)
+                                             gpa_to_vva(task->bdev->vid,
+                                                        task->desc_split->addr,
+                                                        &chunck_len);
+                       if (!task->status ||
+                               chunck_len != task->desc_split->len) {
+                               fprintf(stderr,
+                                       "failed to translate desc address.\n");
+                               rte_free(task);
+                               return;
+                       }
+               } else {
+                       task->readtype =
+                               descriptor_is_wr_split(task->desc_split);
+                       vhost_process_payload_chain_split(task);
+               }
+               blk_vq->last_avail_idx++;
+
+               ret = vhost_bdev_process_blk_commands(ctrlr->bdev, task);
+               if (ret) {
+                       /* invalid response */
+                       *task->status = VIRTIO_BLK_S_IOERR;
+               } else {
+                       /* successfully */
+                       *task->status = VIRTIO_BLK_S_OK;
+               }
+
+               submit_completion_split(task, ctrlr->bdev->vid, q_idx);
+       }
+
+       rte_free(task);
+}
+
+static void *
+ctrlr_worker(void *arg)
+{
+       struct vhost_blk_ctrlr *ctrlr = (struct vhost_blk_ctrlr *)arg;
+       struct vhost_blk_queue *blk_vq;
+       struct rte_vhost_ring_inflight *inflight_vq;
+       cpu_set_t cpuset;
+       pthread_t thread;
+       int i;
+
+       fprintf(stdout, "Ctrlr Worker Thread start\n");
+
+       if (ctrlr == NULL || ctrlr->bdev == NULL) {
+               fprintf(stderr,
+                       "%s: Error, invalid argument passed to worker thread\n",
+                       __func__);
+               exit(0);
+       }
+
+       thread = pthread_self();
+       CPU_ZERO(&cpuset);
+       CPU_SET(0, &cpuset);
+       pthread_setaffinity_np(thread, sizeof(cpu_set_t), &cpuset);
+
+       for (i = 0; i < NUM_OF_BLK_QUEUES; i++) {
+               blk_vq = &ctrlr->bdev->queues[i];
+               inflight_vq = &blk_vq->inflight_vq;
+               if (inflight_vq->resubmit_inflight != NULL &&
+                   inflight_vq->resubmit_inflight->resubmit_num != 0) {
+                       if (ctrlr->packed_ring)
+                               submit_inflight_vq_packed(ctrlr, i);
+                       else
+                               submit_inflight_vq_split(ctrlr, i);
+               }
+       }
+
+       while (!g_should_stop && ctrlr->bdev != NULL) {
+               for (i = 0; i < NUM_OF_BLK_QUEUES; i++) {
+                       if (ctrlr->packed_ring)
+                               process_requestq_packed(ctrlr, i);
+                       else
+                               process_requestq_split(ctrlr, i);
+               }
+       }
+
+       g_should_stop = 2;
+       fprintf(stdout, "Ctrlr Worker Thread Exiting\n");
+       sem_post(&exit_sem);
+       return NULL;
+}
+
+static int
+new_device(int vid)
+{
+       struct vhost_blk_ctrlr *ctrlr;
+       struct vhost_blk_queue *blk_vq;
+       struct rte_vhost_vring *vq;
+       uint64_t features;
+       pthread_t tid;
+       int i, ret;
+
+       ctrlr = vhost_blk_ctrlr_find(dev_pathname);
+       if (!ctrlr) {
+               fprintf(stderr, "Controller is not ready\n");
+               return -1;
+       }
+
+       if (ctrlr->started)
+               return 0;
+
+       ctrlr->bdev->vid = vid;
+       ret = rte_vhost_get_negotiated_features(vid, &features);
+       if (ret) {
+               fprintf(stderr, "failed to get the negotiated features\n");
+               return -1;
+       }
+       ctrlr->packed_ring = !!(features & (1ULL << VIRTIO_F_RING_PACKED));
+
+       ret = rte_vhost_get_mem_table(vid, &ctrlr->mem);
+       if (ret)
+               fprintf(stderr, "Get Controller memory region failed\n");
+       assert(ctrlr->mem != NULL);
+
+       /* Disable Notifications and init last idx */
+       for (i = 0; i < NUM_OF_BLK_QUEUES; i++) {
+               blk_vq = &ctrlr->bdev->queues[i];
+               vq = &blk_vq->vq;
+
+               ret = rte_vhost_get_vhost_vring(ctrlr->bdev->vid, i, vq);
+               assert(ret == 0);
+
+               ret = rte_vhost_get_vring_base(ctrlr->bdev->vid, i,
+                                              &blk_vq->last_avail_idx,
+                                              &blk_vq->last_used_idx);
+               assert(ret == 0);
+
+               ret = rte_vhost_get_vhost_ring_inflight(ctrlr->bdev->vid, i,
+                                                       &blk_vq->inflight_vq);
+               assert(ret == 0);
+
+               if (ctrlr->packed_ring) {
+                       /* for the reconnection */
+                       ret = rte_vhost_get_vring_base_from_inflight(
+                               ctrlr->bdev->vid, i,
+                               &blk_vq->last_avail_idx,
+                               &blk_vq->last_used_idx);
+
+                       blk_vq->avail_wrap_counter = blk_vq->last_avail_idx &
+                               (1 << 15);
+                       blk_vq->last_avail_idx = blk_vq->last_avail_idx &
+                               0x7fff;
+                       blk_vq->used_wrap_counter = blk_vq->last_used_idx &
+                               (1 << 15);
+                       blk_vq->last_used_idx = blk_vq->last_used_idx &
+                               0x7fff;
+               }
+
+               rte_vhost_enable_guest_notification(vid, i, 0);
+       }
+
+       /* start polling vring */
+       g_should_stop = 0;
+       fprintf(stdout, "New Device %s, Device ID %d\n", dev_pathname, vid);
+       if (pthread_create(&tid, NULL, &ctrlr_worker, ctrlr) < 0) {
+               fprintf(stderr, "Worker Thread Started Failed\n");
+               return -1;
+       }
+
+       /* device has been started */
+       ctrlr->started = 1;
+       pthread_detach(tid);
+       return 0;
+}
+
+static void
+destroy_device(int vid)
+{
+       char path[PATH_MAX];
+       struct vhost_blk_ctrlr *ctrlr;
+       struct vhost_blk_queue *blk_vq;
+       int i, ret;
+
+       ret = rte_vhost_get_ifname(vid, path, PATH_MAX);
+       if (ret) {
+               fprintf(stderr, "Destroy Ctrlr Failed\n");
+               return;
+       }
+
+       fprintf(stdout, "Destroy %s Device ID %d\n", path, vid);
+       ctrlr = vhost_blk_ctrlr_find(path);
+       if (!ctrlr) {
+               fprintf(stderr, "Destroy Ctrlr Failed\n");
+               return;
+       }
+
+       if (!ctrlr->started)
+               return;
+
+       g_should_stop = 1;
+       while (g_should_stop != 2)
+               ;
+
+       for (i = 0; i < NUM_OF_BLK_QUEUES; i++) {
+               blk_vq = &ctrlr->bdev->queues[i];
+               if (ctrlr->packed_ring) {
+                       blk_vq->last_avail_idx |= (blk_vq->avail_wrap_counter <<
+                               15);
+                       blk_vq->last_used_idx |= (blk_vq->used_wrap_counter <<
+                               15);
+               }
+               rte_vhost_set_vring_base(ctrlr->bdev->vid, i,
+                                        blk_vq->last_avail_idx,
+                                        blk_vq->last_used_idx);
+       }
+
+       free(ctrlr->mem);
+
+       ctrlr->started = 0;
+       sem_wait(&exit_sem);
+}
+
+static int
+new_connection(int vid)
+{
+       /* extend the proper features for block device */
+       vhost_session_install_rte_compat_hooks(vid);
+
+       return 0;
+}
+
+struct vhost_device_ops vhost_blk_device_ops = {
+       .new_device =  new_device,
+       .destroy_device = destroy_device,
+       .new_connection = new_connection,
+};
+
+static struct vhost_block_dev *
+vhost_blk_bdev_construct(const char *bdev_name,
+       const char *bdev_serial, uint32_t blk_size, uint64_t blk_cnt,
+       bool wce_enable)
+{
+       struct vhost_block_dev *bdev;
+
+       bdev = rte_zmalloc(NULL, sizeof(*bdev), RTE_CACHE_LINE_SIZE);
+       if (!bdev)
+               return NULL;
+
+       strncpy(bdev->name, bdev_name, sizeof(bdev->name));
+       strncpy(bdev->product_name, bdev_serial, sizeof(bdev->product_name));
+       bdev->blocklen = blk_size;
+       bdev->blockcnt = blk_cnt;
+       bdev->write_cache = wce_enable;
+
+       fprintf(stdout, "blocklen=%d, blockcnt=%"PRIx64"\n", bdev->blocklen,
+               bdev->blockcnt);
+
+       /* use memory as disk storage space */
+       bdev->data = rte_zmalloc(NULL, blk_cnt * blk_size, 0);
+       if (!bdev->data) {
+               fprintf(stderr, "no enough reserved huge memory for disk\n");
+               free(bdev);
+               return NULL;
+       }
+
+       return bdev;
+}
+
+static struct vhost_blk_ctrlr *
+vhost_blk_ctrlr_construct(const char *ctrlr_name)
+{
+       int ret;
+       struct vhost_blk_ctrlr *ctrlr;
+       char *path;
+       char cwd[PATH_MAX];
+
+       /* always use current directory */
+       path = getcwd(cwd, PATH_MAX);
+       if (!path) {
+               fprintf(stderr, "Cannot get current working directory\n");
+               return NULL;
+       }
+       snprintf(dev_pathname, sizeof(dev_pathname), "%s/%s", path, ctrlr_name);
+
+       if (access(dev_pathname, F_OK) != -1) {
+               if (unlink(dev_pathname) != 0)
+                       rte_exit(EXIT_FAILURE, "Cannot remove %s.\n",
+                                dev_pathname);
+       }
+
+       if (rte_vhost_driver_register(dev_pathname, 0) != 0) {
+               fprintf(stderr, "socket %s already exists\n", dev_pathname);
+               return NULL;
+       }
+
+       ret = rte_vhost_driver_set_features(dev_pathname, VHOST_BLK_FEATURES);
+       if (ret != 0) {
+               fprintf(stderr, "Set vhost driver features failed\n");
+               rte_vhost_driver_unregister(dev_pathname);
+               return NULL;
+       }
+
+       /* set proper features */
+       vhost_dev_install_rte_compat_hooks(dev_pathname);
+
+       ctrlr = rte_zmalloc(NULL, sizeof(*ctrlr), RTE_CACHE_LINE_SIZE);
+       if (!ctrlr) {
+               rte_vhost_driver_unregister(dev_pathname);
+               return NULL;
+       }
+
+       /* hardcoded block device information with 128MiB */
+       ctrlr->bdev = vhost_blk_bdev_construct("malloc0", "vhost_blk_malloc0",
+                                               4096, 32768, 0);
+       if (!ctrlr->bdev) {
+               rte_free(ctrlr);
+               rte_vhost_driver_unregister(dev_pathname);
+               return NULL;
+       }
+
+       rte_vhost_driver_callback_register(dev_pathname,
+                                          &vhost_blk_device_ops);
+
+       return ctrlr;
+}
+
+static void
+signal_handler(__rte_unused int signum)
+{
+       struct vhost_blk_ctrlr *ctrlr;
+
+       if (access(dev_pathname, F_OK) == 0)
+               unlink(dev_pathname);
+
+       if (g_should_stop != -1) {
+               g_should_stop = 1;
+               while (g_should_stop != 2)
+                       ;
+       }
+
+       ctrlr = vhost_blk_ctrlr_find(dev_pathname);
+       if (ctrlr != NULL) {
+               if (ctrlr->bdev != NULL) {
+                       rte_free(ctrlr->bdev->data);
+                       rte_free(ctrlr->bdev);
+               }
+               rte_free(ctrlr);
+       }
+
+       rte_vhost_driver_unregister(dev_pathname);
+       exit(0);
+}
+
+int main(int argc, char *argv[])
+{
+       int ret;
+
+       signal(SIGINT, signal_handler);
+
+       /* init EAL */
+       ret = rte_eal_init(argc, argv);
+       if (ret < 0)
+               rte_exit(EXIT_FAILURE, "Error with EAL initialization\n");
+
+       g_vhost_ctrlr = vhost_blk_ctrlr_construct("vhost.socket");
+       if (g_vhost_ctrlr == NULL) {
+               fprintf(stderr, "Construct vhost blk controller failed\n");
+               return 0;
+       }
+
+       if (sem_init(&exit_sem, 0, 0) < 0) {
+               fprintf(stderr, "Error init exit_sem\n");
+               return -1;
+       }
+
+       rte_vhost_driver_start(dev_pathname);
+
+       /* loop for exit the application */
+       while (1)
+               sleep(1);
+
+       return 0;
+}
+
diff --git a/examples/vhost_blk/vhost_blk.h b/examples/vhost_blk/vhost_blk.h
new file mode 100644 (file)
index 0000000..933e2b7
--- /dev/null
@@ -0,0 +1,127 @@
+/* SPDX-License-Identifier: BSD-3-Clause
+ * Copyright(c) 2010-2017 Intel Corporation
+ */
+
+#ifndef _VHOST_BLK_H_
+#define _VHOST_BLK_H_
+
+#include <stdio.h>
+#include <sys/uio.h>
+#include <stdint.h>
+#include <stdbool.h>
+#include <linux/virtio_blk.h>
+#include <linux/virtio_ring.h>
+
+#include <rte_vhost.h>
+
+#ifndef VIRTIO_F_RING_PACKED
+#define VIRTIO_F_RING_PACKED 34
+
+struct vring_packed_desc {
+       /* Buffer Address. */
+       __le64 addr;
+       /* Buffer Length. */
+       __le32 len;
+       /* Buffer ID. */
+       __le16 id;
+       /* The flags depending on descriptor type. */
+       __le16 flags;
+};
+#endif
+
+struct vhost_blk_queue {
+       struct rte_vhost_vring vq;
+       struct rte_vhost_ring_inflight inflight_vq;
+       uint16_t last_avail_idx;
+       uint16_t last_used_idx;
+       bool avail_wrap_counter;
+       bool used_wrap_counter;
+};
+
+#define NUM_OF_BLK_QUEUES 1
+
+#define min(a, b) (((a) < (b)) ? (a) : (b))
+
+struct vhost_block_dev {
+       /** ID for vhost library. */
+       int vid;
+       /** Queues for the block device */
+       struct vhost_blk_queue queues[NUM_OF_BLK_QUEUES];
+       /** Unique name for this block device. */
+       char name[64];
+
+       /** Unique product name for this kind of block device. */
+       char product_name[256];
+
+       /** Size in bytes of a logical block for the backend */
+       uint32_t blocklen;
+
+       /** Number of blocks */
+       uint64_t blockcnt;
+
+       /** write cache enabled, not used at the moment */
+       int write_cache;
+
+       /** use memory as disk storage space */
+       uint8_t *data;
+};
+
+struct vhost_blk_ctrlr {
+       uint8_t started;
+       uint8_t packed_ring;
+       uint8_t need_restart;
+       /** Only support 1 LUN for the example */
+       struct vhost_block_dev *bdev;
+       /** VM memory region */
+       struct rte_vhost_memory *mem;
+} __rte_cache_aligned;
+
+#define VHOST_BLK_MAX_IOVS 128
+
+enum blk_data_dir {
+       BLK_DIR_NONE = 0,
+       BLK_DIR_TO_DEV = 1,
+       BLK_DIR_FROM_DEV = 2,
+};
+
+struct vhost_blk_task {
+       uint8_t readtype;
+       uint8_t req_idx;
+       uint16_t head_idx;
+       uint16_t last_idx;
+       uint16_t inflight_idx;
+       uint16_t buffer_id;
+       uint32_t dxfer_dir;
+       uint32_t data_len;
+       struct virtio_blk_outhdr *req;
+
+       volatile uint8_t *status;
+
+       struct iovec iovs[VHOST_BLK_MAX_IOVS];
+       uint32_t iovs_cnt;
+       struct vring_packed_desc *desc_packed;
+       struct vring_desc *desc_split;
+       struct rte_vhost_vring *vq;
+       struct vhost_block_dev *bdev;
+       struct vhost_blk_ctrlr *ctrlr;
+};
+
+struct inflight_blk_task {
+       struct vhost_blk_task blk_task;
+       struct rte_vhost_inflight_desc_packed *inflight_desc;
+       struct rte_vhost_inflight_info_packed *inflight_packed;
+};
+
+struct vhost_blk_ctrlr *g_vhost_ctrlr;
+struct vhost_device_ops vhost_blk_device_ops;
+
+int vhost_bdev_process_blk_commands(struct vhost_block_dev *bdev,
+                                    struct vhost_blk_task *task);
+
+void vhost_session_install_rte_compat_hooks(uint32_t vid);
+
+void vhost_dev_install_rte_compat_hooks(const char *path);
+
+struct vhost_blk_ctrlr *vhost_blk_ctrlr_find(const char *ctrlr_name);
+
+#endif /* _VHOST_blk_H_ */
diff --git a/examples/vhost_blk/vhost_blk_compat.c b/examples/vhost_blk/vhost_blk_compat.c
new file mode 100644 (file)
index 0000000..51a1be6
--- /dev/null
@@ -0,0 +1,174 @@
+/* SPDX-License-Identifier: BSD-3-Clause
+ * Copyright(c) 2010-2019 Intel Corporation
+ */
+
+#ifndef _VHOST_BLK_COMPAT_H_
+#define _VHOST_BLK_COMPAT_H_
+
+#include <sys/uio.h>
+#include <stdint.h>
+#include <linux/virtio_blk.h>
+#include <linux/virtio_ring.h>
+
+#include <rte_vhost.h>
+#include "vhost_blk.h"
+#include "blk_spec.h"
+
+#define VHOST_MAX_VQUEUES      256
+#define SPDK_VHOST_MAX_VQ_SIZE 1024
+
+#define VHOST_USER_GET_CONFIG  24
+#define VHOST_USER_SET_CONFIG  25
+
+static int
+vhost_blk_get_config(struct vhost_block_dev *bdev, uint8_t *config,
+                         uint32_t len)
+{
+       struct virtio_blk_config blkcfg;
+       uint32_t blk_size;
+       uint64_t blkcnt;
+
+       if (bdev == NULL) {
+               /* We can't just return -1 here as this GET_CONFIG message might
+                * be caused by a QEMU VM reboot. Returning -1 will indicate an
+                * error to QEMU, who might then decide to terminate itself.
+                * We don't want that. A simple reboot shouldn't break the
+                * system.
+                *
+                * Presenting a block device with block size 0 and block count 0
+                * doesn't cause any problems on QEMU side and the virtio-pci
+                * device is even still available inside the VM, but there will
+                * be no block device created for it - the kernel drivers will
+                * silently reject it.
+                */
+               blk_size = 0;
+               blkcnt = 0;
+       } else {
+               blk_size = bdev->blocklen;
+               blkcnt = bdev->blockcnt;
+       }
+
+       memset(&blkcfg, 0, sizeof(blkcfg));
+       blkcfg.blk_size = blk_size;
+       /* minimum I/O size in blocks */
+       blkcfg.min_io_size = 1;
+       /* expressed in 512 Bytes sectors */
+       blkcfg.capacity = (blkcnt * blk_size) / 512;
+       /* QEMU can overwrite this value when started */
+       blkcfg.num_queues = VHOST_MAX_VQUEUES;
+
+       fprintf(stdout, "block device:blk_size = %d, blkcnt = %"PRIx64"\n",
+               blk_size, blkcnt);
+
+       memcpy(config, &blkcfg, min(len, sizeof(blkcfg)));
+
+       return 0;
+}
+
+static enum rte_vhost_msg_result
+extern_vhost_pre_msg_handler(int vid, void *_msg)
+{
+       char path[PATH_MAX];
+       struct vhost_blk_ctrlr *ctrlr;
+       struct vhost_user_msg *msg = _msg;
+       int ret;
+
+       ret = rte_vhost_get_ifname(vid, path, PATH_MAX);
+       if (ret) {
+               fprintf(stderr, "Cannot get socket name\n");
+               return -1;
+       }
+
+       ctrlr = vhost_blk_ctrlr_find(path);
+       if (!ctrlr) {
+               fprintf(stderr, "Controller is not ready\n");
+               return -1;
+       }
+
+       switch ((int)msg->request) {
+       case VHOST_USER_GET_VRING_BASE:
+       case VHOST_USER_SET_VRING_BASE:
+       case VHOST_USER_SET_VRING_ADDR:
+       case VHOST_USER_SET_VRING_NUM:
+       case VHOST_USER_SET_VRING_KICK:
+       case VHOST_USER_SET_VRING_CALL:
+       case VHOST_USER_SET_MEM_TABLE:
+               break;
+       case VHOST_USER_GET_CONFIG: {
+               int rc = 0;
+
+               rc = vhost_blk_get_config(ctrlr->bdev,
+                                         msg->payload.cfg.region,
+                                         msg->payload.cfg.size);
+               if (rc != 0)
+                       msg->size = 0;
+
+               return RTE_VHOST_MSG_RESULT_REPLY;
+       }
+       case VHOST_USER_SET_CONFIG:
+       default:
+               break;
+       }
+
+       return RTE_VHOST_MSG_RESULT_NOT_HANDLED;
+}
+
+static enum rte_vhost_msg_result
+extern_vhost_post_msg_handler(int vid, void *_msg)
+{
+       char path[PATH_MAX];
+       struct vhost_blk_ctrlr *ctrlr;
+       struct vhost_user_msg *msg = _msg;
+       int ret;
+
+       ret = rte_vhost_get_ifname(vid, path, PATH_MAX);
+       if (ret) {
+               fprintf(stderr, "Cannot get socket name\n");
+               return -1;
+       }
+
+       ctrlr = vhost_blk_ctrlr_find(path);
+       if (!ctrlr) {
+               fprintf(stderr, "Controller is not ready\n");
+               return -1;
+       }
+
+       switch (msg->request) {
+       case VHOST_USER_SET_FEATURES:
+       case VHOST_USER_SET_VRING_KICK:
+       default:
+               break;
+       }
+
+       return RTE_VHOST_MSG_RESULT_NOT_HANDLED;
+}
+
+struct rte_vhost_user_extern_ops g_extern_vhost_ops = {
+       .pre_msg_handle = extern_vhost_pre_msg_handler,
+       .post_msg_handle = extern_vhost_post_msg_handler,
+};
+
+void
+vhost_session_install_rte_compat_hooks(uint32_t vid)
+{
+       int rc;
+
+       rc = rte_vhost_extern_callback_register(vid, &g_extern_vhost_ops, NULL);
+       if (rc != 0)
+               fprintf(stderr,
+                       "rte_vhost_extern_callback_register() failed for vid = %d\n",
+                       vid);
+}
+
+void
+vhost_dev_install_rte_compat_hooks(const char *path)
+{
+       uint64_t protocol_features = 0;
+
+       rte_vhost_driver_get_protocol_features(path, &protocol_features);
+       protocol_features |= (1ULL << VHOST_USER_PROTOCOL_F_CONFIG);
+       protocol_features |= (1ULL << VHOST_USER_PROTOCOL_F_INFLIGHT_SHMFD);
+       rte_vhost_driver_set_protocol_features(path, protocol_features);
+}
+
+#endif