add subtree-ish sources for 12.0.3

[ceph.git] / ceph / src / spdk / lib / vhost / rte_vhost / vhost_user.c

/*-
 *   BSD LICENSE
 *
 *   Copyright(c) 2010-2016 Intel Corporation. All rights reserved.
 *   All rights reserved.
 *
 *   Redistribution and use in source and binary forms, with or without
 *   modification, are permitted provided that the following conditions
 *   are met:
 *
 *     * Redistributions of source code must retain the above copyright
 *       notice, this list of conditions and the following disclaimer.
 *     * Redistributions in binary form must reproduce the above copyright
 *       notice, this list of conditions and the following disclaimer in
 *       the documentation and/or other materials provided with the
 *       distribution.
 *     * Neither the name of Intel Corporation nor the names of its
 *       contributors may be used to endorse or promote products derived
 *       from this software without specific prior written permission.
 *
 *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 *   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 *   A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 *   OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 *   SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 *   LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 *   DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 *   THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 *   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <sys/mman.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <assert.h>
#ifdef RTE_LIBRTE_VHOST_NUMA
#include <numaif.h>
#endif

#include <rte_common.h>
#include <rte_malloc.h>
#include <rte_log.h>

#include "vhost.h"
#include "vhost_user.h"

static const char *vhost_message_str[VHOST_USER_MAX] = {
        [VHOST_USER_NONE] = "VHOST_USER_NONE",
        [VHOST_USER_GET_FEATURES] = "VHOST_USER_GET_FEATURES",
        [VHOST_USER_SET_FEATURES] = "VHOST_USER_SET_FEATURES",
        [VHOST_USER_SET_OWNER] = "VHOST_USER_SET_OWNER",
        [VHOST_USER_RESET_OWNER] = "VHOST_USER_RESET_OWNER",
        [VHOST_USER_SET_MEM_TABLE] = "VHOST_USER_SET_MEM_TABLE",
        [VHOST_USER_SET_LOG_BASE] = "VHOST_USER_SET_LOG_BASE",
        [VHOST_USER_SET_LOG_FD] = "VHOST_USER_SET_LOG_FD",
        [VHOST_USER_SET_VRING_NUM] = "VHOST_USER_SET_VRING_NUM",
        [VHOST_USER_SET_VRING_ADDR] = "VHOST_USER_SET_VRING_ADDR",
        [VHOST_USER_SET_VRING_BASE] = "VHOST_USER_SET_VRING_BASE",
        [VHOST_USER_GET_VRING_BASE] = "VHOST_USER_GET_VRING_BASE",
        [VHOST_USER_SET_VRING_KICK] = "VHOST_USER_SET_VRING_KICK",
        [VHOST_USER_SET_VRING_CALL] = "VHOST_USER_SET_VRING_CALL",
        [VHOST_USER_SET_VRING_ERR]  = "VHOST_USER_SET_VRING_ERR",
        [VHOST_USER_GET_PROTOCOL_FEATURES]  = "VHOST_USER_GET_PROTOCOL_FEATURES",
        [VHOST_USER_SET_PROTOCOL_FEATURES]  = "VHOST_USER_SET_PROTOCOL_FEATURES",
        [VHOST_USER_GET_QUEUE_NUM]  = "VHOST_USER_GET_QUEUE_NUM",
        [VHOST_USER_SET_VRING_ENABLE]  = "VHOST_USER_SET_VRING_ENABLE",
        [VHOST_USER_SEND_RARP]  = "VHOST_USER_SEND_RARP",
};

static uint64_t
get_blk_size(int fd)
{
        struct stat stat;
        int ret;

        ret = fstat(fd, &stat);
        return ret == -1 ? (uint64_t)-1 : (uint64_t)stat.st_blksize;
}

static void
free_mem_region(struct virtio_net *dev)
{
        uint32_t i;
        struct virtio_memory_region *reg;

        if (!dev || !dev->mem)
                return;

        for (i = 0; i < dev->mem->nregions; i++) {
                reg = &dev->mem->regions[i];
                if (reg->host_user_addr) {
                        munmap(reg->mmap_addr, reg->mmap_size);
                        close(reg->fd);
                }
        }
}

void
vhost_backend_cleanup(struct virtio_net *dev)
{
        if (dev->mem) {
                free_mem_region(dev);
                rte_free(dev->mem);
                dev->mem = NULL;
        }
        if (dev->log_addr) {
                munmap((void *)(uintptr_t)dev->log_addr, dev->log_size);
                dev->log_addr = 0;
        }
}

/*
 * This function just returns success at the moment unless
 * the device hasn't been initialised.
 */
static int
vhost_user_set_owner(void)
{
        return 0;
}

static int
vhost_user_reset_owner(struct virtio_net *dev)
{
        if (dev->flags & VIRTIO_DEV_RUNNING) {
                dev->flags &= ~VIRTIO_DEV_RUNNING;
                notify_ops->destroy_device(dev->vid);
        }

        cleanup_device(dev, 0);
        reset_device(dev);
        return 0;
}

/*
 * The features that we support are requested.
 */
static uint64_t
vhost_user_get_features(void)
{
        return VHOST_FEATURES;
}

/*
 * We receive the negotiated features supported by us and the virtio device.
 */
static int
vhost_user_set_features(struct virtio_net *dev, uint64_t features)
{
        if (features & ~VHOST_FEATURES)
                return -1;

        dev->features = features;
        if (dev->features &
                ((1 << VIRTIO_NET_F_MRG_RXBUF) | (1ULL << VIRTIO_F_VERSION_1))) {
                dev->vhost_hlen = sizeof(struct virtio_net_hdr_mrg_rxbuf);
        } else {
                dev->vhost_hlen = sizeof(struct virtio_net_hdr);
        }
        LOG_DEBUG(VHOST_CONFIG,
                "(%d) mergeable RX buffers %s, virtio 1 %s\n",
                dev->vid,
                (dev->features & (1 << VIRTIO_NET_F_MRG_RXBUF)) ? "on" : "off",
                (dev->features & (1ULL << VIRTIO_F_VERSION_1)) ? "on" : "off");

        return 0;
}

/*
 * The virtio device sends us the size of the descriptor ring.
 */
static int
vhost_user_set_vring_num(struct virtio_net *dev,
                         VhostUserMsg *msg)
{
        struct vhost_virtqueue *vq = dev->virtqueue[msg->payload.state.index];

        vq->size = msg->payload.state.num;

        if (dev->dequeue_zero_copy) {
                vq->nr_zmbuf = 0;
                vq->last_zmbuf_idx = 0;
                vq->zmbuf_size = vq->size;
                vq->zmbufs = rte_zmalloc(NULL, vq->zmbuf_size *
                                         sizeof(struct zcopy_mbuf), 0);
                if (vq->zmbufs == NULL) {
                        RTE_LOG(WARNING, VHOST_CONFIG,
                                "failed to allocate mem for zero copy; "
                                "zero copy is force disabled\n");
                        dev->dequeue_zero_copy = 0;
                }
        }

        vq->shadow_used_ring = rte_malloc(NULL,
                                vq->size * sizeof(struct vring_used_elem),
                                RTE_CACHE_LINE_SIZE);
        if (!vq->shadow_used_ring) {
                RTE_LOG(ERR, VHOST_CONFIG,
                        "failed to allocate memory for shadow used ring.\n");
                return -1;
        }

        return 0;
}

/*
 * Reallocate virtio_dev and vhost_virtqueue data structure to make them on the
 * same numa node as the memory of vring descriptor.
 */
#ifdef RTE_LIBRTE_VHOST_NUMA
static struct virtio_net*
numa_realloc(struct virtio_net *dev, int index)
{
        int oldnode, newnode;
        struct virtio_net *old_dev;
        struct vhost_virtqueue *old_vq, *vq;
        int ret;

        /*
         * vq is allocated on pairs, we should try to do realloc
         * on first queue of one queue pair only.
         */
        if (index % VIRTIO_QNUM != 0)
                return dev;

        old_dev = dev;
        vq = old_vq = dev->virtqueue[index];

        ret = get_mempolicy(&newnode, NULL, 0, old_vq->desc,
                            MPOL_F_NODE | MPOL_F_ADDR);

        /* check if we need to reallocate vq */
        ret |= get_mempolicy(&oldnode, NULL, 0, old_vq,
                             MPOL_F_NODE | MPOL_F_ADDR);
        if (ret) {
                RTE_LOG(ERR, VHOST_CONFIG,
                        "Unable to get vq numa information.\n");
                return dev;
        }
        if (oldnode != newnode) {
                RTE_LOG(INFO, VHOST_CONFIG,
                        "reallocate vq from %d to %d node\n", oldnode, newnode);
                vq = rte_malloc_socket(NULL, sizeof(*vq) * VIRTIO_QNUM, 0,
                                       newnode);
                if (!vq)
                        return dev;

                memcpy(vq, old_vq, sizeof(*vq) * VIRTIO_QNUM);
                rte_free(old_vq);
        }

        /* check if we need to reallocate dev */
        ret = get_mempolicy(&oldnode, NULL, 0, old_dev,
                            MPOL_F_NODE | MPOL_F_ADDR);
        if (ret) {
                RTE_LOG(ERR, VHOST_CONFIG,
                        "Unable to get dev numa information.\n");
                goto out;
        }
        if (oldnode != newnode) {
                RTE_LOG(INFO, VHOST_CONFIG,
                        "reallocate dev from %d to %d node\n",
                        oldnode, newnode);
                dev = rte_malloc_socket(NULL, sizeof(*dev), 0, newnode);
                if (!dev) {
                        dev = old_dev;
                        goto out;
                }

                memcpy(dev, old_dev, sizeof(*dev));
                rte_free(old_dev);
        }

out:
        dev->virtqueue[index] = vq;
        dev->virtqueue[index + 1] = vq + 1;
        vhost_devices[dev->vid] = dev;

        return dev;
}
#else
static struct virtio_net*
numa_realloc(struct virtio_net *dev, int index __rte_unused)
{
        return dev;
}
#endif

/*
 * Converts QEMU virtual address to Vhost virtual address. This function is
 * used to convert the ring addresses to our address space.
 */
static uint64_t
qva_to_vva(struct virtio_net *dev, uint64_t qva)
{
        struct virtio_memory_region *reg;
        uint32_t i;

        /* Find the region where the address lives. */
        for (i = 0; i < dev->mem->nregions; i++) {
                reg = &dev->mem->regions[i];

                if (qva >= reg->guest_user_addr &&
                    qva <  reg->guest_user_addr + reg->size) {
                        return qva - reg->guest_user_addr +
                               reg->host_user_addr;
                }
        }

        return 0;
}

static int vhost_setup_mem_table(struct virtio_net *dev);

/*
 * The virtio device sends us the desc, used and avail ring addresses.
 * This function then converts these to our address space.
 */
static int
vhost_user_set_vring_addr(struct virtio_net *dev, VhostUserMsg *msg)
{
        struct vhost_virtqueue *vq;

        if (dev->has_new_mem_table) {
                vhost_setup_mem_table(dev);
                dev->has_new_mem_table = 0;
        }


        if (dev->mem == NULL)
                return -1;

        /* addr->index refers to the queue index. The txq 1, rxq is 0. */
        vq = dev->virtqueue[msg->payload.addr.index];

        /* The addresses are converted from QEMU virtual to Vhost virtual. */
        vq->desc = (struct vring_desc *)(uintptr_t)qva_to_vva(dev,
                        msg->payload.addr.desc_user_addr);
        if (vq->desc == 0) {
                RTE_LOG(ERR, VHOST_CONFIG,
                        "(%d) failed to find desc ring address.\n",
                        dev->vid);
                return -1;
        }

        dev = numa_realloc(dev, msg->payload.addr.index);
        vq = dev->virtqueue[msg->payload.addr.index];

        vq->avail = (struct vring_avail *)(uintptr_t)qva_to_vva(dev,
                        msg->payload.addr.avail_user_addr);
        if (vq->avail == 0) {
                RTE_LOG(ERR, VHOST_CONFIG,
                        "(%d) failed to find avail ring address.\n",
                        dev->vid);
                return -1;
        }

        vq->used = (struct vring_used *)(uintptr_t)qva_to_vva(dev,
                        msg->payload.addr.used_user_addr);
        if (vq->used == 0) {
                RTE_LOG(ERR, VHOST_CONFIG,
                        "(%d) failed to find used ring address.\n",
                        dev->vid);
                return -1;
        }

        if (vq->last_used_idx != vq->used->idx) {
                RTE_LOG(WARNING, VHOST_CONFIG,
                        "last_used_idx (%u) and vq->used->idx (%u) mismatches; "
                        "some packets maybe resent for Tx and dropped for Rx\n",
                        vq->last_used_idx, vq->used->idx);
                vq->last_used_idx  = vq->used->idx;
                vq->last_avail_idx = vq->used->idx;
        }

        vq->log_guest_addr = msg->payload.addr.log_guest_addr;

        LOG_DEBUG(VHOST_CONFIG, "(%d) mapped address desc: %p\n",
                        dev->vid, vq->desc);
        LOG_DEBUG(VHOST_CONFIG, "(%d) mapped address avail: %p\n",
                        dev->vid, vq->avail);
        LOG_DEBUG(VHOST_CONFIG, "(%d) mapped address used: %p\n",
                        dev->vid, vq->used);
        LOG_DEBUG(VHOST_CONFIG, "(%d) log_guest_addr: %" PRIx64 "\n",
                        dev->vid, vq->log_guest_addr);

        return 0;
}

/*
 * The virtio device sends us the available ring last used index.
 */
static int
vhost_user_set_vring_base(struct virtio_net *dev,
                          VhostUserMsg *msg)
{
        dev->virtqueue[msg->payload.state.index]->last_used_idx  = msg->payload.state.num;
        dev->virtqueue[msg->payload.state.index]->last_avail_idx = msg->payload.state.num;

        return 0;
}

static void
add_one_guest_page(struct virtio_net *dev, uint64_t guest_phys_addr,
                   uint64_t host_phys_addr, uint64_t size)
{
        struct guest_page *page, *last_page;

        if (dev->nr_guest_pages == dev->max_guest_pages &&
            dev->nr_guest_pages > 0) {
                dev->max_guest_pages *= 2;
                dev->guest_pages = realloc(dev->guest_pages,
                                        dev->max_guest_pages * sizeof(*page));
                if (!dev->guest_pages) {
                        RTE_LOG(ERR, VHOST_CONFIG, "cannot realloc guest_pages\n");
                        abort();
                }
        }

        if (dev->nr_guest_pages > 0) {
                last_page = &dev->guest_pages[dev->nr_guest_pages - 1];
                /* merge if the two pages are continuous */
                if (host_phys_addr == last_page->host_phys_addr +
                                      last_page->size) {
                        last_page->size += size;
                        return;
                }
        }

        page = &dev->guest_pages[dev->nr_guest_pages++];
        page->guest_phys_addr = guest_phys_addr;
        page->host_phys_addr  = host_phys_addr;
        page->size = size;
}

static void
add_guest_pages(struct virtio_net *dev, struct virtio_memory_region *reg,
                uint64_t page_size)
{
        uint64_t reg_size = reg->size;
        uint64_t host_user_addr  = reg->host_user_addr;
        uint64_t guest_phys_addr = reg->guest_phys_addr;
        uint64_t host_phys_addr;
        uint64_t size;

        host_phys_addr = rte_mem_virt2phy((void *)(uintptr_t)host_user_addr);
        size = page_size - (guest_phys_addr & (page_size - 1));
        size = RTE_MIN(size, reg_size);

        add_one_guest_page(dev, guest_phys_addr, host_phys_addr, size);
        host_user_addr  += size;
        guest_phys_addr += size;
        reg_size -= size;

        while (reg_size > 0) {
                host_phys_addr = rte_mem_virt2phy((void *)(uintptr_t)
                                                  host_user_addr);
                add_one_guest_page(dev, guest_phys_addr, host_phys_addr,
                                   page_size);

                host_user_addr  += page_size;
                guest_phys_addr += page_size;
                reg_size -= page_size;
        }
}

#ifdef RTE_LIBRTE_VHOST_DEBUG
/* TODO: enable it only in debug mode? */
static void
dump_guest_pages(struct virtio_net *dev)
{
        uint32_t i;
        struct guest_page *page;

        for (i = 0; i < dev->nr_guest_pages; i++) {
                page = &dev->guest_pages[i];

                RTE_LOG(INFO, VHOST_CONFIG,
                        "guest physical page region %u\n"
                        "\t guest_phys_addr: %" PRIx64 "\n"
                        "\t host_phys_addr : %" PRIx64 "\n"
                        "\t size           : %" PRIx64 "\n",
                        i,
                        page->guest_phys_addr,
                        page->host_phys_addr,
                        page->size);
        }
}
#else
#define dump_guest_pages(dev)
#endif

static int
vhost_user_set_mem_table(struct virtio_net *dev, struct VhostUserMsg *pmsg)
{
        uint32_t i;

        if (dev->has_new_mem_table) {
                /*
                 * The previous mem table was not consumed, so close the
                 *  file descriptors from that mem table before copying
                 *  the new one.
                 */
                for (i = 0; i < dev->mem_table.nregions; i++) {
                        close(dev->mem_table_fds[i]);
                }
        }

        memcpy(&dev->mem_table, &pmsg->payload.memory, sizeof(dev->mem_table));
        memcpy(dev->mem_table_fds, pmsg->fds, sizeof(dev->mem_table_fds));
        dev->has_new_mem_table = 1;

        return 0;
}

static int
vhost_setup_mem_table(struct virtio_net *dev)
{
        struct VhostUserMemory memory = dev->mem_table;
        struct virtio_memory_region *reg;
        void *mmap_addr;
        uint64_t mmap_size;
        uint64_t mmap_offset;
        uint64_t alignment;
        uint32_t i;
        int fd;

        if (dev->mem) {
                free_mem_region(dev);
                rte_free(dev->mem);
                dev->mem = NULL;
        }

        dev->nr_guest_pages = 0;
        if (!dev->guest_pages) {
                dev->max_guest_pages = 8;
                dev->guest_pages = malloc(dev->max_guest_pages *
                                                sizeof(struct guest_page));
        }

        dev->mem = rte_zmalloc("vhost-mem-table", sizeof(struct virtio_memory) +
                sizeof(struct virtio_memory_region) * memory.nregions, 0);
        if (dev->mem == NULL) {
                RTE_LOG(ERR, VHOST_CONFIG,
                        "(%d) failed to allocate memory for dev->mem\n",
                        dev->vid);
                return -1;
        }
        dev->mem->nregions = memory.nregions;

        for (i = 0; i < memory.nregions; i++) {
                fd  = dev->mem_table_fds[i];
                reg = &dev->mem->regions[i];

                reg->guest_phys_addr = memory.regions[i].guest_phys_addr;
                reg->guest_user_addr = memory.regions[i].userspace_addr;
                reg->size            = memory.regions[i].memory_size;
                reg->fd              = fd;

                mmap_offset = memory.regions[i].mmap_offset;
                mmap_size   = reg->size + mmap_offset;

                /* mmap() without flag of MAP_ANONYMOUS, should be called
                 * with length argument aligned with hugepagesz at older
                 * longterm version Linux, like 2.6.32 and 3.2.72, or
                 * mmap() will fail with EINVAL.
                 *
                 * to avoid failure, make sure in caller to keep length
                 * aligned.
                 */
                alignment = get_blk_size(fd);
                if (alignment == (uint64_t)-1) {
                        RTE_LOG(ERR, VHOST_CONFIG,
                                "couldn't get hugepage size through fstat\n");
                        goto err_mmap;
                }
                mmap_size = RTE_ALIGN_CEIL(mmap_size, alignment);

                mmap_addr = mmap(NULL, mmap_size, PROT_READ | PROT_WRITE,
                                 MAP_SHARED | MAP_POPULATE, fd, 0);

                if (mmap_addr == MAP_FAILED) {
                        RTE_LOG(ERR, VHOST_CONFIG,
                                "mmap region %u failed.\n", i);
                        goto err_mmap;
                }

                reg->mmap_addr = mmap_addr;
                reg->mmap_size = mmap_size;
                reg->host_user_addr = (uint64_t)(uintptr_t)mmap_addr +
                                      mmap_offset;

                add_guest_pages(dev, reg, alignment);

                RTE_LOG(INFO, VHOST_CONFIG,
                        "guest memory region %u, size: 0x%" PRIx64 "\n"
                        "\t guest physical addr: 0x%" PRIx64 "\n"
                        "\t guest virtual  addr: 0x%" PRIx64 "\n"
                        "\t host  virtual  addr: 0x%" PRIx64 "\n"
                        "\t mmap addr : 0x%" PRIx64 "\n"
                        "\t mmap size : 0x%" PRIx64 "\n"
                        "\t mmap align: 0x%" PRIx64 "\n"
                        "\t mmap off  : 0x%" PRIx64 "\n",
                        i, reg->size,
                        reg->guest_phys_addr,
                        reg->guest_user_addr,
                        reg->host_user_addr,
                        (uint64_t)(uintptr_t)mmap_addr,
                        mmap_size,
                        alignment,
                        mmap_offset);
        }

        dump_guest_pages(dev);

        return 0;

err_mmap:
        free_mem_region(dev);
        rte_free(dev->mem);
        dev->mem = NULL;
        return -1;
}

static int
vq_is_ready(struct vhost_virtqueue *vq)
{
        return vq && vq->desc   &&
               vq->kickfd != VIRTIO_UNINITIALIZED_EVENTFD &&
               vq->callfd != VIRTIO_UNINITIALIZED_EVENTFD;
}

static int
virtio_is_ready(struct virtio_net *dev)
{
        struct vhost_virtqueue *vq;
        uint32_t i;

        for (i = 0; i < dev->num_queues; i++) {
                vq = dev->virtqueue[i];

                if (!vq_is_ready(vq)) {
                        RTE_LOG(INFO, VHOST_CONFIG,
                                "virtio is not ready for processing.\n");
                        return 0;
                }
        }

        RTE_LOG(INFO, VHOST_CONFIG,
                "virtio is now ready for processing.\n");
        return 1;
}

static void
vhost_user_set_vring_call(struct virtio_net *dev, struct VhostUserMsg *pmsg)
{
        struct vhost_vring_file file;
        struct vhost_virtqueue *vq;
        uint32_t cur_qp_idx;

        file.index = pmsg->payload.u64 & VHOST_USER_VRING_IDX_MASK;
        if (pmsg->payload.u64 & VHOST_USER_VRING_NOFD_MASK)
                file.fd = VIRTIO_INVALID_EVENTFD;
        else
                file.fd = pmsg->fds[0];
        RTE_LOG(INFO, VHOST_CONFIG,
                "vring call idx:%d file:%d\n", file.index, file.fd);

        if (file.index + 1 > dev->num_queues) {
                dev->num_queues = file.index + 1;
        }

        /*
         * FIXME: VHOST_SET_VRING_CALL is the first per-vring message
         * we get, so we do vring queue pair allocation here.
         */
        cur_qp_idx = file.index / VIRTIO_QNUM;
        if (cur_qp_idx + 1 > dev->virt_qp_nb) {
                if (alloc_vring_queue_pair(dev, cur_qp_idx) < 0)
                        return;
        }

        vq = dev->virtqueue[file.index];
        assert(vq != NULL);

        if (vq->callfd >= 0)
                close(vq->callfd);

        vq->callfd = file.fd;

        if (virtio_is_ready(dev) && !(dev->flags & VIRTIO_DEV_RUNNING)) {
                notify_ops->new_device(dev->vid);
        }
}

/*
 *  In vhost-user, when we receive kick message, will test whether virtio
 *  device is ready for packet processing.
 */
static void
vhost_user_set_vring_kick(struct virtio_net *dev, struct VhostUserMsg *pmsg)
{
        struct vhost_vring_file file;
        struct vhost_virtqueue *vq;

        file.index = pmsg->payload.u64 & VHOST_USER_VRING_IDX_MASK;
        if (pmsg->payload.u64 & VHOST_USER_VRING_NOFD_MASK)
                file.fd = VIRTIO_INVALID_EVENTFD;
        else
                file.fd = pmsg->fds[0];
        RTE_LOG(INFO, VHOST_CONFIG,
                "vring kick idx:%d file:%d\n", file.index, file.fd);

        vq = dev->virtqueue[file.index];
        if (vq->kickfd >= 0)
                close(vq->kickfd);
        vq->kickfd = file.fd;

        if (virtio_is_ready(dev) && !(dev->flags & VIRTIO_DEV_RUNNING)) {
                if (dev->dequeue_zero_copy) {
                        RTE_LOG(INFO, VHOST_CONFIG,
                                "dequeue zero copy is enabled\n");
                }

                if (notify_ops->new_device(dev->vid) == 0)
                        dev->flags |= VIRTIO_DEV_RUNNING;
        }
}

static void
free_zmbufs(struct vhost_virtqueue *vq)
{
        struct zcopy_mbuf *zmbuf, *next;

        for (zmbuf = TAILQ_FIRST(&vq->zmbuf_list);
             zmbuf != NULL; zmbuf = next) {
                next = TAILQ_NEXT(zmbuf, next);

                rte_pktmbuf_free(zmbuf->mbuf);
                TAILQ_REMOVE(&vq->zmbuf_list, zmbuf, next);
        }

        rte_free(vq->zmbufs);
}

/*
 * when virtio is stopped, qemu will send us the GET_VRING_BASE message.
 */
static int
vhost_user_get_vring_base(struct virtio_net *dev,
                          VhostUserMsg *msg)
{
        struct vhost_virtqueue *vq = dev->virtqueue[msg->payload.state.index];

        /* We have to stop the queue (virtio) if it is running. */
        if (dev->flags & VIRTIO_DEV_RUNNING) {
                dev->flags &= ~VIRTIO_DEV_RUNNING;
                notify_ops->destroy_device(dev->vid);
        }

        /* Here we are safe to get the last used index */
        msg->payload.state.num = vq->last_used_idx;

        RTE_LOG(INFO, VHOST_CONFIG,
                "vring base idx:%d file:%d\n", msg->payload.state.index, msg->payload.state.num);
        /*
         * Based on current qemu vhost-user implementation, this message is
         * sent and only sent in vhost_vring_stop.
         * TODO: cleanup the vring, it isn't usable since here.
         */
        if (vq->kickfd >= 0)
                close(vq->kickfd);

        vq->kickfd = VIRTIO_UNINITIALIZED_EVENTFD;
        vq->callfd = VIRTIO_UNINITIALIZED_EVENTFD;

        if (dev->dequeue_zero_copy)
                free_zmbufs(vq);
        rte_free(vq->shadow_used_ring);
        vq->shadow_used_ring = NULL;

        return 0;
}

/*
 * when virtio queues are ready to work, qemu will send us to
 * enable the virtio queue pair.
 */
static int
vhost_user_set_vring_enable(struct virtio_net *dev,
                            VhostUserMsg *msg)
{
        int enable = (int)msg->payload.state.num;

        RTE_LOG(INFO, VHOST_CONFIG,
                "set queue enable: %d to qp idx: %d\n",
                enable, msg->payload.state.index);

        if (notify_ops->vring_state_changed)
                notify_ops->vring_state_changed(dev->vid, msg->payload.state.index, enable);

        dev->virtqueue[msg->payload.state.index]->enabled = enable;

        return 0;
}

static void
vhost_user_set_protocol_features(struct virtio_net *dev,
                                 uint64_t protocol_features)
{
        if (protocol_features & ~VHOST_USER_PROTOCOL_FEATURES)
                return;

        dev->protocol_features = protocol_features;
}

static int
vhost_user_set_log_base(struct virtio_net *dev, struct VhostUserMsg *msg)
{
        int fd = msg->fds[0];
        uint64_t size, off;
        void *addr;

        if (fd < 0) {
                RTE_LOG(ERR, VHOST_CONFIG, "invalid log fd: %d\n", fd);
                return -1;
        }

        if (msg->size != sizeof(VhostUserLog)) {
                RTE_LOG(ERR, VHOST_CONFIG,
                        "invalid log base msg size: %"PRId32" != %d\n",
                        msg->size, (int)sizeof(VhostUserLog));
                return -1;
        }

        size = msg->payload.log.mmap_size;
        off  = msg->payload.log.mmap_offset;
        RTE_LOG(INFO, VHOST_CONFIG,
                "log mmap size: %"PRId64", offset: %"PRId64"\n",
                size, off);

        /*
         * mmap from 0 to workaround a hugepage mmap bug: mmap will
         * fail when offset is not page size aligned.
         */
        addr = mmap(0, size, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
        close(fd);
        if (addr == MAP_FAILED) {
                RTE_LOG(ERR, VHOST_CONFIG, "mmap log base failed!\n");
                return -1;
        }

        /*
         * Free previously mapped log memory on occasionally
         * multiple VHOST_USER_SET_LOG_BASE.
         */
        if (dev->log_addr) {
                munmap((void *)(uintptr_t)dev->log_addr, dev->log_size);
        }
        dev->log_addr = (uint64_t)(uintptr_t)addr;
        dev->log_base = dev->log_addr + off;
        dev->log_size = size;

        return 0;
}

/*
 * An rarp packet is constructed and broadcasted to notify switches about
 * the new location of the migrated VM, so that packets from outside will
 * not be lost after migration.
 *
 * However, we don't actually "send" a rarp packet here, instead, we set
 * a flag 'broadcast_rarp' to let rte_vhost_dequeue_burst() inject it.
 */
static int
vhost_user_send_rarp(struct virtio_net *dev, struct VhostUserMsg *msg)
{
        uint8_t *mac = (uint8_t *)&msg->payload.u64;

        RTE_LOG(DEBUG, VHOST_CONFIG,
                ":: mac: %02x:%02x:%02x:%02x:%02x:%02x\n",
                mac[0], mac[1], mac[2], mac[3], mac[4], mac[5]);
        memcpy(dev->mac.addr_bytes, mac, 6);

        /*
         * Set the flag to inject a RARP broadcast packet at
         * rte_vhost_dequeue_burst().
         *
         * rte_smp_wmb() is for making sure the mac is copied
         * before the flag is set.
         */
        rte_smp_wmb();
        rte_atomic16_set(&dev->broadcast_rarp, 1);

        return 0;
}

/* return bytes# of read on success or negative val on failure. */
static int
read_vhost_message(int sockfd, struct VhostUserMsg *msg)
{
        int ret;

        ret = read_fd_message(sockfd, (char *)msg, VHOST_USER_HDR_SIZE,
                msg->fds, VHOST_MEMORY_MAX_NREGIONS);
        if (ret <= 0)
                return ret;

        if (msg && msg->size) {
                if (msg->size > sizeof(msg->payload)) {
                        RTE_LOG(ERR, VHOST_CONFIG,
                                "invalid msg size: %d\n", msg->size);
                        return -1;
                }
                ret = read(sockfd, &msg->payload, msg->size);
                if (ret <= 0)
                        return ret;
                if (ret != (int)msg->size) {
                        RTE_LOG(ERR, VHOST_CONFIG,
                                "read control message failed\n");
                        return -1;
                }
        }

        return ret;
}

static int
send_vhost_message(int sockfd, struct VhostUserMsg *msg)
{
        int ret;

        if (!msg)
                return 0;

        msg->flags &= ~VHOST_USER_VERSION_MASK;
        msg->flags |= VHOST_USER_VERSION;
        msg->flags |= VHOST_USER_REPLY_MASK;

        ret = send_fd_message(sockfd, (char *)msg,
                VHOST_USER_HDR_SIZE + msg->size, NULL, 0);

        return ret;
}

int
vhost_user_msg_handler(int vid, int fd)
{
        struct virtio_net *dev;
        struct VhostUserMsg msg;
        int ret;

        dev = get_device(vid);
        if (dev == NULL)
                return -1;

        ret = read_vhost_message(fd, &msg);
        if (ret <= 0 || msg.request >= VHOST_USER_MAX) {
                if (ret < 0)
                        RTE_LOG(ERR, VHOST_CONFIG,
                                "vhost read message failed\n");
                else if (ret == 0)
                        RTE_LOG(INFO, VHOST_CONFIG,
                                "vhost peer closed\n");
                else
                        RTE_LOG(ERR, VHOST_CONFIG,
                                "vhost read incorrect message\n");

                return -1;
        }

        RTE_LOG(INFO, VHOST_CONFIG, "read message %s\n",
                vhost_message_str[msg.request]);
        switch (msg.request) {
        case VHOST_USER_GET_FEATURES:
                msg.payload.u64 = vhost_user_get_features();
                msg.size = sizeof(msg.payload.u64);
                send_vhost_message(fd, &msg);
                break;
        case VHOST_USER_SET_FEATURES:
                vhost_user_set_features(dev, msg.payload.u64);
                break;

        case VHOST_USER_GET_PROTOCOL_FEATURES:
                msg.payload.u64 = VHOST_USER_PROTOCOL_FEATURES;
                msg.size = sizeof(msg.payload.u64);
                send_vhost_message(fd, &msg);
                break;
        case VHOST_USER_SET_PROTOCOL_FEATURES:
                vhost_user_set_protocol_features(dev, msg.payload.u64);
                break;

        case VHOST_USER_SET_OWNER:
                vhost_user_set_owner();
                break;
        case VHOST_USER_RESET_OWNER:
                vhost_user_reset_owner(dev);
                break;

        case VHOST_USER_SET_MEM_TABLE:
                vhost_user_set_mem_table(dev, &msg);
                break;

        case VHOST_USER_SET_LOG_BASE:
                vhost_user_set_log_base(dev, &msg);

                /* it needs a reply */
                msg.size = sizeof(msg.payload.u64);
                send_vhost_message(fd, &msg);
                break;
        case VHOST_USER_SET_LOG_FD:
                close(msg.fds[0]);
                RTE_LOG(INFO, VHOST_CONFIG, "not implemented.\n");
                break;

        case VHOST_USER_SET_VRING_NUM:
                vhost_user_set_vring_num(dev, &msg);
                break;
        case VHOST_USER_SET_VRING_ADDR:
                vhost_user_set_vring_addr(dev, &msg);
                break;
        case VHOST_USER_SET_VRING_BASE:
                vhost_user_set_vring_base(dev, &msg);
                break;

        case VHOST_USER_GET_VRING_BASE:
                vhost_user_get_vring_base(dev, &msg);
                msg.size = sizeof(msg.payload.state);
                send_vhost_message(fd, &msg);
                break;

        case VHOST_USER_SET_VRING_KICK:
                vhost_user_set_vring_kick(dev, &msg);
                break;
        case VHOST_USER_SET_VRING_CALL:
                vhost_user_set_vring_call(dev, &msg);
                break;

        case VHOST_USER_SET_VRING_ERR:
                if (!(msg.payload.u64 & VHOST_USER_VRING_NOFD_MASK))
                        close(msg.fds[0]);
                RTE_LOG(INFO, VHOST_CONFIG, "not implemented\n");
                break;

        case VHOST_USER_GET_QUEUE_NUM:
                msg.payload.u64 = VHOST_MAX_QUEUE_PAIRS;
                msg.size = sizeof(msg.payload.u64);
                send_vhost_message(fd, &msg);
                break;

        case VHOST_USER_SET_VRING_ENABLE:
                vhost_user_set_vring_enable(dev, &msg);
                break;
        case VHOST_USER_SEND_RARP:
                vhost_user_send_rarp(dev, &msg);
                break;

        default:
                break;

        }

        return 0;
}