vhost_xen/vhost_monitor.c

/*-
 *   BSD LICENSE
 *
 *   Copyright(c) 2010-2014 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 <stdlib.h>
#include <stdio.h>
#include <dirent.h>
#include <unistd.h>
#include <sys/eventfd.h>
#include <sys/ioctl.h>
#include <sys/mman.h>
#include <xen/xen-compat.h>
#if __XEN_LATEST_INTERFACE_VERSION__ < 0x00040200
#include <xs.h>
#else
#include <xenstore.h>
#endif
#include <linux/virtio_ring.h>
#include <linux/virtio_pci.h>
#include <linux/virtio_net.h>

#include <rte_ethdev.h>
#include <rte_log.h>
#include <rte_malloc.h>
#include <rte_string_fns.h>

#include "virtio-net.h"
#include "xen_vhost.h"

struct virtio_watch {
    struct xs_handle *xs;
    int watch_fd;
};


/* device ops to add/remove device to/from data core. */
static struct virtio_net_device_ops const *notify_ops;

/* root address of the linked list in the configuration core. */
static struct virtio_net_config_ll *ll_root = NULL;

/* root address of VM. */
static struct xen_guestlist guest_root;

static struct virtio_watch watch;

static void
vq_vring_init(struct vhost_virtqueue *vq, unsigned int num, uint8_t *p,
    unsigned long align)
{
    vq->size = num;
    vq->desc = (struct vring_desc *) p;
    vq->avail = (struct vring_avail *) (p +
        num * sizeof(struct vring_desc));
    vq->used = (void *)
        RTE_ALIGN_CEIL( (uintptr_t)(&vq->avail->ring[num]), align);

}

static int
init_watch(void)
{
    struct xs_handle *xs;
    int ret;
    int fd;

    /* get a connection to the daemon */
    xs = xs_daemon_open();
    if (xs == NULL) {
        RTE_LOG(ERR, XENHOST, "xs_daemon_open failed\n");
        return -1;
    }

    ret = xs_watch(xs, "/local/domain", "mytoken");
    if (ret == 0) {
        RTE_LOG(ERR, XENHOST, "%s: xs_watch failed\n", __func__);
        xs_daemon_close(xs);
        return -1;
    }

    /* We are notified of read availability on the watch via the file descriptor. */
    fd = xs_fileno(xs);
    watch.xs = xs;
    watch.watch_fd = fd;

    TAILQ_INIT(&guest_root);
    return 0;
}

static struct xen_guest *
get_xen_guest(int dom_id)
{
    struct xen_guest *guest = NULL;

    TAILQ_FOREACH(guest, &guest_root, next) {
        if(guest->dom_id == dom_id)
            return guest;
    }

    return NULL;
}


static struct xen_guest *
add_xen_guest(int32_t dom_id)
{
    struct xen_guest *guest = NULL;

    if ((guest = get_xen_guest(dom_id)) != NULL)
        return guest;

    guest = calloc(1, sizeof(struct xen_guest));
    if (guest) {
        RTE_LOG(ERR, XENHOST, "  %s: return newly created guest with %d rings\n", __func__, guest->vring_num);
        TAILQ_INSERT_TAIL(&guest_root, guest, next);
        guest->dom_id = dom_id;
    }

    return guest;
}

static void
cleanup_device(struct virtio_net_config_ll *ll_dev)
{
    if (ll_dev == NULL)
        return;
    if (ll_dev->dev.virtqueue_rx) {
        rte_free(ll_dev->dev.virtqueue_rx);
        ll_dev->dev.virtqueue_rx = NULL;
    }
    if (ll_dev->dev.virtqueue_tx) {
        rte_free(ll_dev->dev.virtqueue_tx);
        ll_dev->dev.virtqueue_tx = NULL;
    }
    free(ll_dev);
}

/*
 * Add entry containing a device to the device configuration linked list.
 */
static void
add_config_ll_entry(struct virtio_net_config_ll *new_ll_dev)
{
    struct virtio_net_config_ll *ll_dev = ll_root;

    /* If ll_dev == NULL then this is the first device so go to else */
    if (ll_dev) {
        /* If the 1st device_id != 0 then we insert our device here. */
        if (ll_dev->dev.device_fh != 0) {
            new_ll_dev->dev.device_fh = 0;
            new_ll_dev->next = ll_dev;
            ll_root = new_ll_dev;
        } else {
            /* increment through the ll until we find un unused device_id,
             * insert the device at that entry
             */
            while ((ll_dev->next != NULL) && (ll_dev->dev.device_fh == (ll_dev->next->dev.device_fh - 1)))
                ll_dev = ll_dev->next;

            new_ll_dev->dev.device_fh = ll_dev->dev.device_fh + 1;
            new_ll_dev->next = ll_dev->next;
            ll_dev->next = new_ll_dev;
        }
    } else {
        ll_root = new_ll_dev;
        ll_root->dev.device_fh = 0;
    }
}


/*
 * Remove an entry from the device configuration linked list.
 */
static struct virtio_net_config_ll *
rm_config_ll_entry(struct virtio_net_config_ll *ll_dev, struct virtio_net_config_ll *ll_dev_last)
{
    /* First remove the device and then clean it up. */
    if (ll_dev == ll_root) {
        ll_root = ll_dev->next;
        cleanup_device(ll_dev);
        return ll_root;
    } else {
        ll_dev_last->next = ll_dev->next;
        cleanup_device(ll_dev);
        return ll_dev_last->next;
    }
}

/*
 * Retrieves an entry from the devices configuration linked list.
 */
static struct virtio_net_config_ll *
get_config_ll_entry(unsigned int virtio_idx, unsigned int dom_id)
{
    struct virtio_net_config_ll *ll_dev = ll_root;

    /* Loop through linked list until the dom_id is found. */
    while (ll_dev != NULL) {
        if (ll_dev->dev.dom_id == dom_id && ll_dev->dev.virtio_idx == virtio_idx)
            return ll_dev;
        ll_dev = ll_dev->next;
    }

    return NULL;
}

/*
 * Initialise all variables in device structure.
 */
static void
init_dev(struct virtio_net *dev)
{
    RTE_SET_USED(dev);
}


static struct
virtio_net_config_ll *new_device(unsigned int virtio_idx, struct xen_guest *guest)
{
    struct virtio_net_config_ll *new_ll_dev;
    struct vhost_virtqueue *virtqueue_rx, *virtqueue_tx;
    size_t size, vq_ring_size, vq_size = VQ_DESC_NUM;
    void *vq_ring_virt_mem;
    uint64_t gpa;
    uint32_t i;

    /* Setup device and virtqueues. */
    new_ll_dev   = calloc(1, sizeof(struct virtio_net_config_ll));
    virtqueue_rx = rte_zmalloc(NULL, sizeof(struct vhost_virtqueue), RTE_CACHE_LINE_SIZE);
    virtqueue_tx = rte_zmalloc(NULL, sizeof(struct vhost_virtqueue), RTE_CACHE_LINE_SIZE);
    if (new_ll_dev == NULL || virtqueue_rx == NULL || virtqueue_tx == NULL)
        goto err;

    new_ll_dev->dev.virtqueue_rx = virtqueue_rx;
    new_ll_dev->dev.virtqueue_tx = virtqueue_tx;
    new_ll_dev->dev.dom_id       = guest->dom_id;
    new_ll_dev->dev.virtio_idx   = virtio_idx;
    /* Initialise device and virtqueues. */
    init_dev(&new_ll_dev->dev);

    size = vring_size(vq_size, VIRTIO_PCI_VRING_ALIGN);
    vq_ring_size = RTE_ALIGN_CEIL(size, VIRTIO_PCI_VRING_ALIGN);
    (void)vq_ring_size;

    vq_ring_virt_mem = guest->vring[virtio_idx].rxvring_addr;
    vq_vring_init(virtqueue_rx, vq_size, vq_ring_virt_mem, VIRTIO_PCI_VRING_ALIGN);
    virtqueue_rx->size = vq_size;
    virtqueue_rx->vhost_hlen = sizeof(struct virtio_net_hdr);

    vq_ring_virt_mem = guest->vring[virtio_idx].txvring_addr;
    vq_vring_init(virtqueue_tx, vq_size, vq_ring_virt_mem, VIRTIO_PCI_VRING_ALIGN);
    virtqueue_tx->size = vq_size;
    memcpy(&new_ll_dev->dev.mac_address, &guest->vring[virtio_idx].addr, sizeof(struct ether_addr));

    /* virtio_memory has to be one per domid */
    new_ll_dev->dev.mem = malloc(sizeof(struct virtio_memory) + sizeof(struct virtio_memory_regions) * MAX_XENVIRT_MEMPOOL);
    new_ll_dev->dev.mem->nregions = guest->pool_num;
    for (i = 0; i < guest->pool_num; i++) {
        gpa = new_ll_dev->dev.mem->regions[i].guest_phys_address =
                (uint64_t)((uintptr_t)guest->mempool[i].gva);
        new_ll_dev->dev.mem->regions[i].guest_phys_address_end =
                gpa + guest->mempool[i].mempfn_num * getpagesize();
        new_ll_dev->dev.mem->regions[i].address_offset =
                (uint64_t)((uintptr_t)guest->mempool[i].hva -
                    (uintptr_t)gpa);
    }

    new_ll_dev->next = NULL;

    /* Add entry to device configuration linked list. */
    add_config_ll_entry(new_ll_dev);
    return new_ll_dev;
err:
    free(new_ll_dev);
    rte_free(virtqueue_rx);
    rte_free(virtqueue_tx);

    return NULL;
}

static void
destroy_guest(struct xen_guest *guest)
{
    uint32_t i;

    for (i = 0; i < guest->vring_num; i++)
        cleanup_vring(&guest->vring[i]);
    /* clean mempool */
    for (i = 0; i < guest->pool_num; i++)
        cleanup_mempool(&guest->mempool[i]);
    free(guest);

    return;
}

/*
 * This function will cleanup the device and remove it from device configuration linked list.
 */
static void
destroy_device(unsigned int virtio_idx, unsigned int dom_id)
{
    struct virtio_net_config_ll *ll_dev_cur_ctx, *ll_dev_last = NULL;
    struct virtio_net_config_ll *ll_dev_cur = ll_root;

    /* clean virtio device */
    struct xen_guest *guest = NULL;
    guest = get_xen_guest(dom_id);
    if (guest == NULL)
        return;

    /* Find the linked list entry for the device to be removed. */
    ll_dev_cur_ctx = get_config_ll_entry(virtio_idx, dom_id);
    while (ll_dev_cur != NULL) {
        /* If the device is found or a device that doesn't exist is found then it is removed. */
        if  (ll_dev_cur == ll_dev_cur_ctx) {
            if ((ll_dev_cur->dev.flags & VIRTIO_DEV_RUNNING))
                notify_ops->destroy_device(&(ll_dev_cur->dev));
            ll_dev_cur = rm_config_ll_entry(ll_dev_cur, ll_dev_last);
        } else {
            ll_dev_last = ll_dev_cur;
            ll_dev_cur = ll_dev_cur->next;
        }
    }
    RTE_LOG(INFO, XENHOST, "  %s guest:%p vring:%p rxvring:%p txvring:%p flag:%p\n",
        __func__, guest, &guest->vring[virtio_idx], guest->vring[virtio_idx].rxvring_addr, guest->vring[virtio_idx].txvring_addr, guest->vring[virtio_idx].flag);
    cleanup_vring(&guest->vring[virtio_idx]);
    guest->vring[virtio_idx].removed = 1;
    guest->vring_num -= 1;
}




static void
watch_unmap_event(void)
{
    int i;
    struct xen_guest *guest  = NULL;
    bool remove_request;

    TAILQ_FOREACH(guest, &guest_root, next) {
        for (i = 0; i < MAX_VIRTIO; i++) {
            if (guest->vring[i].dom_id && guest->vring[i].removed == 0 && *guest->vring[i].flag == 0) {
                RTE_LOG(INFO, XENHOST, "\n\n");
                RTE_LOG(INFO, XENHOST, "  #####%s:  (%d, %d) to be removed\n",
                    __func__,
                    guest->vring[i].dom_id,
                    i);
                destroy_device(i, guest->dom_id);
                RTE_LOG(INFO, XENHOST, "  %s: DOM %u, vring num: %d\n",
                    __func__,
                    guest->dom_id,
                    guest->vring_num);
            }
        }
    }

_find_next_remove:
    guest = NULL;
    remove_request = false;
    TAILQ_FOREACH(guest, &guest_root, next) {
        if (guest->vring_num == 0) {
            remove_request = true;
            break;
        }
    }
    if (remove_request == true) {
        TAILQ_REMOVE(&guest_root, guest, next);
        RTE_LOG(INFO, XENHOST, "  #####%s: destroy guest (%d)\n", __func__, guest->dom_id);
        destroy_guest(guest);
        goto _find_next_remove;
    }
    return;
}

/*
 * OK, if the guest starts first, it is ok.
 * if host starts first, it is ok.
 * if guest starts, and has run for sometime, and host stops and restarts,
 * then last_used_idx  0? how to solve this. */

static void virtio_init(void)
{
    uint32_t len, e_num;
    uint32_t i,j;
    char **dom;
    char *status;
    int dom_id;
    char path[PATH_MAX];
    char node[PATH_MAX];
    xs_transaction_t th;
    struct xen_guest *guest;
    struct virtio_net_config_ll *net_config;
    char *end;
    int val;

    /* init env for watch the node */
    if (init_watch() < 0)
        return;

    dom = xs_directory(watch.xs, XBT_NULL, "/local/domain", &e_num);

    for (i = 0; i < e_num; i++) {
        errno = 0;
        dom_id = strtol(dom[i], &end, 0);
        if (errno != 0 || end == NULL || dom_id == 0)
            continue;

        for (j = 0; j < RTE_MAX_ETHPORTS; j++) {
            snprintf(node, PATH_MAX, "%s%d", VIRTIO_START, j);
            snprintf(path, PATH_MAX, XEN_VM_NODE_FMT,
                    dom_id, node);

            th = xs_transaction_start(watch.xs);
            status = xs_read(watch.xs, th, path, &len);
            xs_transaction_end(watch.xs, th, false);

            if (status == NULL)
                break;

            /* if there's any valid virtio device */
            errno = 0;
            val = strtol(status, &end, 0);
            if (errno != 0 || end == NULL || dom_id == 0)
                val = 0;
            if (val == 1) {
                guest = add_xen_guest(dom_id);
                if (guest == NULL)
                    continue;
                RTE_LOG(INFO, XENHOST, "  there's a new virtio existed, new a virtio device\n\n");

                RTE_LOG(INFO, XENHOST, "  parse_vringnode dom_id %d virtioidx %d\n",dom_id,j);
                if (parse_vringnode(guest, j)) {
                    RTE_LOG(ERR, XENHOST, "  there is invalid information in xenstore\n");
                    TAILQ_REMOVE(&guest_root, guest, next);
                    destroy_guest(guest);

                    continue;
                }

                /*if pool_num > 0, then mempool has already been parsed*/
                if (guest->pool_num == 0 && parse_mempoolnode(guest)) {
                    RTE_LOG(ERR, XENHOST, "  there is error information in xenstore\n");
                    TAILQ_REMOVE(&guest_root, guest, next);
                    destroy_guest(guest);
                    continue;
                }

                net_config = new_device(j, guest);
                /* every thing is ready now, added into data core */
                notify_ops->new_device(&net_config->dev);
            }
        }
    }

    free(dom);
    return;
}

void
virtio_monitor_loop(void)
{
    char **vec;
    xs_transaction_t th;
    char *buf;
    unsigned int len;
    unsigned int dom_id;
    uint32_t virtio_idx;
    struct xen_guest *guest;
    struct virtio_net_config_ll *net_config;
    enum fieldnames {
        FLD_NULL = 0,
        FLD_LOCAL,
        FLD_DOMAIN,
        FLD_ID,
        FLD_CONTROL,
        FLD_DPDK,
        FLD_NODE,
        _NUM_FLD
    };
    char *str_fld[_NUM_FLD];
    char *str;
    char *end;

    virtio_init();
    while (1) {
        watch_unmap_event();

        usleep(50);
        vec = xs_check_watch(watch.xs);

        if (vec == NULL)
            continue;

        th = xs_transaction_start(watch.xs);

        buf = xs_read(watch.xs, th, vec[XS_WATCH_PATH],&len);
        xs_transaction_end(watch.xs, th, false);

        if (buf) {
            /* theres' some node for vhost existed */
            if (rte_strsplit(vec[XS_WATCH_PATH], strnlen(vec[XS_WATCH_PATH], PATH_MAX),
                        str_fld, _NUM_FLD, '/') == _NUM_FLD) {
                if (strstr(str_fld[FLD_NODE], VIRTIO_START)) {
                    errno = 0;
                    str = str_fld[FLD_ID];
                    dom_id = strtoul(str, &end, 0);
                    if (errno != 0 || end == NULL || end == str ) {
                        RTE_LOG(INFO, XENHOST, "invalid domain id\n");
                        continue;
                    }

                    errno = 0;
                    str = str_fld[FLD_NODE] + sizeof(VIRTIO_START) - 1;
                    virtio_idx = strtoul(str, &end, 0);
                    if (errno != 0 || end == NULL || end == str
                            || virtio_idx > MAX_VIRTIO) {
                        RTE_LOG(INFO, XENHOST, "invalid virtio idx\n");
                        continue;
                    }
                    RTE_LOG(INFO, XENHOST, "  #####virtio dev (%d, %d) is started\n", dom_id, virtio_idx);

                    guest = add_xen_guest(dom_id);
                    if (guest == NULL)
                        continue;
                    guest->dom_id = dom_id;
                    if (parse_vringnode(guest, virtio_idx)) {
                        RTE_LOG(ERR, XENHOST, "  there is invalid information in xenstore\n");
                        /*guest newly created? guest existed ?*/
                        TAILQ_REMOVE(&guest_root, guest, next);
                        destroy_guest(guest);
                        continue;
                    }
                    /*if pool_num > 0, then mempool has already been parsed*/
                    if (guest->pool_num == 0 && parse_mempoolnode(guest)) {
                        RTE_LOG(ERR, XENHOST, "  there is error information in xenstore\n");
                        TAILQ_REMOVE(&guest_root, guest, next);
                        destroy_guest(guest);
                        continue;
                    }


                    net_config = new_device(virtio_idx, guest);
                    RTE_LOG(INFO, XENHOST, "  Add to dataplane core\n");
                    notify_ops->new_device(&net_config->dev);

                }
            }
        }

        free(vec);
    }
    return;
}

/*
 * Register ops so that we can add/remove device to data core.
 */
int
init_virtio_xen(struct virtio_net_device_ops const *const ops)
{
    notify_ops = ops;
    if (xenhost_init())
        return -1;
    return 0;
}