C++ (Cpp) vring_avail_idx示例

示例#1

文件： virtio.c 项目： iggy/qemu

static int virtqueue_num_heads(VirtQueue *vq, unsigned int idx)
{
    uint16_t num_heads = vring_avail_idx(vq) - idx;

    /* Check it isn't doing very strange things with descriptor numbers. */
    if (num_heads > vq->vring.num) {
        fprintf(stderr, "Guest moved used index from %u to %u",
                idx, vring_avail_idx(vq));
        exit(1);
    }

    return num_heads;
}

示例#2

文件： virtio.c 项目： dsqmoore/qemu-1

void virtio_queue_set_notification(VirtQueue *vq, int enable)
{
    vq->notification = enable;
    if (vq->vdev->guest_features & (1 << VIRTIO_RING_F_EVENT_IDX)) {
        vring_avail_event(vq, vring_avail_idx(vq));
    } else if (enable) {
        vring_used_flags_unset_bit(vq, VRING_USED_F_NO_NOTIFY);
    } else {
        vring_used_flags_set_bit(vq, VRING_USED_F_NO_NOTIFY);
    }
}

示例#3

文件： Hardware.c 项目： asadpanda/kvm-guest-drivers-windows

void virtio_queue_set_notification(VirtQueue *vq, int enable)
{
    vq->notification = enable;
    if (bUsePublishedIndices) {
        vring_avail_event(vq, vring_avail_idx(vq));
    } else if (enable) {
        vring_used_flags_unset_bit(vq, VRING_USED_F_NO_NOTIFY);
    } else {
        vring_used_flags_set_bit(vq, VRING_USED_F_NO_NOTIFY);
    }
}

示例#4

文件： virtio.c 项目： iggy/qemu

void virtio_notify(VirtIODevice *vdev, VirtQueue *vq)
{
    /* Always notify when queue is empty (when feature acknowledge) */
    if ((vring_avail_flags(vq) & VRING_AVAIL_F_NO_INTERRUPT) &&
        (!(vdev->guest_features & (1 << VIRTIO_F_NOTIFY_ON_EMPTY)) ||
         (vq->inuse || vring_avail_idx(vq) != vq->last_avail_idx)))
        return;

    vdev->isr |= 0x01;
    virtio_notify_vector(vdev, vq->vector);
}

示例#5

文件： libvhost-user.c 项目： Marshalzxy/qemu

/* Fetch avail_idx from VQ memory only when we really need to know if
 * guest has added some buffers. */
bool
vu_queue_empty(VuDev *dev, VuVirtq *vq)
{
    if (unlikely(dev->broken) ||
        unlikely(!vq->vring.avail)) {
        return true;
    }

    if (vq->shadow_avail_idx != vq->last_avail_idx) {
        return false;
    }

    return vring_avail_idx(vq) == vq->last_avail_idx;
}

示例#6

文件： virtio.c 项目： chonghw/pemu

void virtio_queue_set_notification(VirtQueue *vq, int enable)
{
    vq->notification = enable;
    if (vq->vdev->guest_features & (1 << VIRTIO_RING_F_EVENT_IDX)) {
        vring_avail_event(vq, vring_avail_idx(vq));
    } else if (enable) {
        vring_used_flags_unset_bit(vq, VRING_USED_F_NO_NOTIFY);
    } else {
        vring_used_flags_set_bit(vq, VRING_USED_F_NO_NOTIFY);
    }
    if (enable) {
        /* Expose avail event/used flags before caller checks the avail idx. */
        smp_mb();
    }
}

示例#7

文件： libvhost-user.c 项目： Marshalzxy/qemu

static int
virtqueue_num_heads(VuDev *dev, VuVirtq *vq, unsigned int idx)
{
    uint16_t num_heads = vring_avail_idx(vq) - idx;

    /* Check it isn't doing very strange things with descriptor numbers. */
    if (num_heads > vq->vring.num) {
        vu_panic(dev, "Guest moved used index from %u to %u",
                 idx, vq->shadow_avail_idx);
        return -1;
    }
    if (num_heads) {
        /* On success, callers read a descriptor at vq->last_avail_idx.
         * Make sure descriptor read does not bypass avail index read. */
        smp_rmb();
    }

    return num_heads;
}

示例#8

文件： Hardware.c 项目： asadpanda/kvm-guest-drivers-windows

static bool vring_notify(PVOID unused, VirtQueue *vq)
{
    uint16_t old, _new;
    bool v;
    /* Always notify when queue is empty (when feature acknowledge) */
    //if (((vdev->guest_features & (1 << VIRTIO_F_NOTIFY_ON_EMPTY)) &&
	if ((bVirtioF_NotifyOnEmpty &&
         !vq->inuse && vring_avail_idx(vq) == vq->last_avail_idx)) {
        return TRUE;
    }

    //if (!(vdev->guest_features & (1 << VIRTIO_RING_F_EVENT_IDX))) {
	if (!bUsePublishedIndices) {
        return !(vring_avail_flags(vq) & VRING_AVAIL_F_NO_INTERRUPT);
    }

    v = vq->signalled_used_valid;
    vq->signalled_used_valid = TRUE;
    old = vq->signalled_used;
    _new = vq->signalled_used = vring_used_idx(vq);
    return !v || vring_need_event(vring_used_event(vq), _new, old);
}

示例#9

文件： virtio.c 项目： chonghw/pemu

int virtio_queue_empty(VirtQueue *vq)
{
    return vring_avail_idx(vq) == vq->last_avail_idx;
}