Archipelago » qemu

#include "monitor.h"

#include "qlist.h"

#include "qint.h"

#include "qstring.h"

    VirtQueue *ivq, *dvq, *svq;

    uint64_t stats[VIRTIO_BALLOON_S_NR];

    VirtQueueElement stats_vq_elem;

    size_t stats_vq_offset;

    MonitorCompletion *stats_callback;

    void *stats_opaque_callback_data;

/*

 * reset_stats - Mark all items in the stats array as unset

 *

 * This function needs to be called at device intialization and before

 * before updating to a set of newly-generated stats.  This will ensure that no

 * stale values stick around in case the guest reports a subset of the supported

 * statistics.

 */

static inline void reset_stats(VirtIOBalloon *dev)

{

    int i;

    for (i = 0; i < VIRTIO_BALLOON_S_NR; dev->stats[i++] = -1);

}

static void stat_put(QDict *dict, const char *label, uint64_t val)

{

    if (val != -1)

        qdict_put(dict, label, qint_from_int(val));

}

static QObject *get_stats_qobject(VirtIOBalloon *dev)

{

    QDict *dict = qdict_new();

    uint32_t actual = ram_size - (dev->actual << VIRTIO_BALLOON_PFN_SHIFT);

    stat_put(dict, "actual", actual);

    stat_put(dict, "mem_swapped_in", dev->stats[VIRTIO_BALLOON_S_SWAP_IN]);

    stat_put(dict, "mem_swapped_out", dev->stats[VIRTIO_BALLOON_S_SWAP_OUT]);

    stat_put(dict, "major_page_faults", dev->stats[VIRTIO_BALLOON_S_MAJFLT]);

    stat_put(dict, "minor_page_faults", dev->stats[VIRTIO_BALLOON_S_MINFLT]);

    stat_put(dict, "free_mem", dev->stats[VIRTIO_BALLOON_S_MEMFREE]);

    stat_put(dict, "total_mem", dev->stats[VIRTIO_BALLOON_S_MEMTOT]);

    return QOBJECT(dict);

}

static void complete_stats_request(VirtIOBalloon *vb)

{

    QObject *stats;

    if (!vb->stats_opaque_callback_data)

        return;

    stats = get_stats_qobject(vb);

    vb->stats_callback(vb->stats_opaque_callback_data, stats);

    qobject_decref(stats);

    vb->stats_opaque_callback_data = NULL;

    vb->stats_callback = NULL;

}

static void virtio_balloon_receive_stats(VirtIODevice *vdev, VirtQueue *vq)

{

    VirtIOBalloon *s = DO_UPCAST(VirtIOBalloon, vdev, vdev);

    VirtQueueElement *elem = &s->stats_vq_elem;

    VirtIOBalloonStat stat;

    size_t offset = 0;

    if (!virtqueue_pop(vq, elem)) {

        return;

    }

    /* Initialize the stats to get rid of any stale values.  This is only

     * needed to handle the case where a guest supports fewer stats than it

     * used to (ie. it has booted into an old kernel).

     */

    reset_stats(s);

    while (memcpy_from_iovector(&stat, offset, sizeof(stat), elem->out_sg,

                                elem->out_num) == sizeof(stat)) {

        uint16_t tag = tswap16(stat.tag);

        uint64_t val = tswap64(stat.val);

        offset += sizeof(stat);

        if (tag < VIRTIO_BALLOON_S_NR)

            s->stats[tag] = val;

    }

    s->stats_vq_offset = offset;

    complete_stats_request(s);

}

    f |= (1 << VIRTIO_BALLOON_F_STATS_VQ);

static void virtio_balloon_to_target(void *opaque, ram_addr_t target,

                                     MonitorCompletion cb, void *cb_data)

    } else {

        /* For now, only allow one request at a time.  This restriction can be

         * removed later by queueing callback and data pairs.

         */

        if (dev->stats_callback != NULL) {

            return;

        }

        dev->stats_callback = cb;

        dev->stats_opaque_callback_data = cb_data; 

        if (dev->vdev.guest_features & (1 << VIRTIO_BALLOON_F_STATS_VQ)) {

            virtqueue_push(dev->svq, &dev->stats_vq_elem, dev->stats_vq_offset);

            virtio_notify(&dev->vdev, dev->svq);

        } else {

            /* Stats are not supported.  Clear out any stale values that might

             * have been set by a more featureful guest kernel.

             */

            reset_stats(dev);

            complete_stats_request(dev);

        }

    qemu_put_buffer(f, (uint8_t *)&s->stats_vq_elem, sizeof(VirtQueueElement));

    qemu_put_buffer(f, (uint8_t *)&s->stats_vq_offset, sizeof(size_t));

    qemu_put_buffer(f, (uint8_t *)&s->stats_callback, sizeof(MonitorCompletion));

    qemu_put_buffer(f, (uint8_t *)&s->stats_opaque_callback_data, sizeof(void));

    qemu_get_buffer(f, (uint8_t *)&s->stats_vq_elem, sizeof(VirtQueueElement));

    qemu_get_buffer(f, (uint8_t *)&s->stats_vq_offset, sizeof(size_t));

    qemu_get_buffer(f, (uint8_t *)&s->stats_callback, sizeof(MonitorCompletion));

    qemu_get_buffer(f, (uint8_t *)&s->stats_opaque_callback_data, sizeof(void));

    s->svq = virtio_add_queue(&s->vdev, 128, virtio_balloon_receive_stats);

    reset_stats(s);