Commit ab223c95 authored by Cornelia Huck's avatar Cornelia Huck Committed by Michael S. Tsirkin
Browse files

virtio: allow virtio-1 queue layout 



For virtio-1 devices, we allow a more complex queue layout that doesn't
require descriptor table and rings on a physically-contigous memory area:
add virtio_queue_set_rings() to allow transports to set this up.

Signed-off-by: default avatarCornelia Huck <cornelia.huck@de.ibm.com>
Reviewed-by: default avatarMichael S. Tsirkin <mst@redhat.com>
Signed-off-by: default avatarMichael S. Tsirkin <mst@redhat.com>
Reviewed-by: default avatarMichael S. Tsirkin <mst@redhat.com>
parent 3c185597

hw/virtio/virtio-mmio.c

+3 −0
Original line number Diff line number Diff line
@@ -333,8 +333,11 @@ static void virtio_mmio_write(void *opaque, hwaddr offset, uint64_t value, 
    case VIRTIO_MMIO_QUEUENUM:

        DPRINTF("mmio_queue write %d max %d\n", (int)value, VIRTQUEUE_MAX_SIZE);

        virtio_queue_set_num(vdev, vdev->queue_sel, value);

        /* Note: only call this function for legacy devices */

        virtio_queue_update_rings(vdev, vdev->queue_sel);

        break;

    case VIRTIO_MMIO_QUEUEALIGN:

        /* Note: this is only valid for legacy devices */

        virtio_queue_set_align(vdev, vdev->queue_sel, value);

        break;

    case VIRTIO_MMIO_QUEUEPFN:

hw/virtio/virtio.c

+34 −19
Original line number Diff line number Diff line
@@ -69,7 +69,6 @@ typedef struct VRing 
struct VirtQueue

{

    VRing vring;

    hwaddr pa;

    uint16_t last_avail_idx;

    /* Last used index value we have signalled on */

    uint16_t signalled_used;
@@ -93,15 +92,18 @@ struct VirtQueue 
};



/* virt queue functions */

static void virtqueue_init(VirtQueue *vq)

void virtio_queue_update_rings(VirtIODevice *vdev, int n)

{

    hwaddr pa = vq->pa;

    VRing *vring = &vdev->vq[n].vring;



    vq->vring.desc = pa;

    vq->vring.avail = pa + vq->vring.num * sizeof(VRingDesc);

    vq->vring.used = vring_align(vq->vring.avail +

                                 offsetof(VRingAvail, ring[vq->vring.num]),

                                 vq->vring.align);

    if (!vring->desc) {

        /* not yet setup -> nothing to do */

        return;

    }

    vring->avail = vring->desc + vring->num * sizeof(VRingDesc);

    vring->used = vring_align(vring->avail +

                              offsetof(VRingAvail, ring[vring->num]),

                              vring->align);

}



static inline uint64_t vring_desc_addr(VirtIODevice *vdev, hwaddr desc_pa,
@@ -605,7 +607,6 @@ void virtio_reset(void *opaque) 
        vdev->vq[i].vring.avail = 0;

        vdev->vq[i].vring.used = 0;

        vdev->vq[i].last_avail_idx = 0;

        vdev->vq[i].pa = 0;

        virtio_queue_set_vector(vdev, i, VIRTIO_NO_VECTOR);

        vdev->vq[i].signalled_used = 0;

        vdev->vq[i].signalled_used_valid = false;
@@ -708,13 +709,21 @@ void virtio_config_writel(VirtIODevice *vdev, uint32_t addr, uint32_t data) 


void virtio_queue_set_addr(VirtIODevice *vdev, int n, hwaddr addr)

{

    vdev->vq[n].pa = addr;

    virtqueue_init(&vdev->vq[n]);

    vdev->vq[n].vring.desc = addr;

    virtio_queue_update_rings(vdev, n);

}



hwaddr virtio_queue_get_addr(VirtIODevice *vdev, int n)

{

    return vdev->vq[n].pa;

    return vdev->vq[n].vring.desc;

}



void virtio_queue_set_rings(VirtIODevice *vdev, int n, hwaddr desc,

                            hwaddr avail, hwaddr used)

{

    vdev->vq[n].vring.desc = desc;

    vdev->vq[n].vring.avail = avail;

    vdev->vq[n].vring.used = used;

}



void virtio_queue_set_num(VirtIODevice *vdev, int n, int num)
@@ -728,7 +737,6 @@ void virtio_queue_set_num(VirtIODevice *vdev, int n, int num) 
        return;

    }

    vdev->vq[n].vring.num = num;

    virtqueue_init(&vdev->vq[n]);

}



VirtQueue *virtio_vector_first_queue(VirtIODevice *vdev, uint16_t vector)
@@ -771,6 +779,11 @@ void virtio_queue_set_align(VirtIODevice *vdev, int n, int align) 
    BusState *qbus = qdev_get_parent_bus(DEVICE(vdev));

    VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus);



    /* virtio-1 compliant devices cannot change the alignment */

    if (virtio_has_feature(vdev, VIRTIO_F_VERSION_1)) {

        error_report("tried to modify queue alignment for virtio-1 device");

        return;

    }

    /* Check that the transport told us it was going to do this

     * (so a buggy transport will immediately assert rather than

     * silently failing to migrate this state)
@@ -778,7 +791,7 @@ void virtio_queue_set_align(VirtIODevice *vdev, int n, int align) 
    assert(k->has_variable_vring_alignment);



    vdev->vq[n].vring.align = align;

    virtqueue_init(&vdev->vq[n]);

    virtio_queue_update_rings(vdev, n);

}



void virtio_queue_notify_vq(VirtQueue *vq)
@@ -992,7 +1005,8 @@ void virtio_save(VirtIODevice *vdev, QEMUFile *f) 
        if (k->has_variable_vring_alignment) {

            qemu_put_be32(f, vdev->vq[i].vring.align);

        }

        qemu_put_be64(f, vdev->vq[i].pa);

        /* XXX virtio-1 devices */

        qemu_put_be64(f, vdev->vq[i].vring.desc);

        qemu_put_be16s(f, &vdev->vq[i].last_avail_idx);

        if (k->save_queue) {

            k->save_queue(qbus->parent, i, f);
@@ -1076,13 +1090,14 @@ int virtio_load(VirtIODevice *vdev, QEMUFile *f, int version_id) 
        if (k->has_variable_vring_alignment) {

            vdev->vq[i].vring.align = qemu_get_be32(f);

        }

        vdev->vq[i].pa = qemu_get_be64(f);

        vdev->vq[i].vring.desc = qemu_get_be64(f);

        qemu_get_be16s(f, &vdev->vq[i].last_avail_idx);

        vdev->vq[i].signalled_used_valid = false;

        vdev->vq[i].notification = true;



        if (vdev->vq[i].pa) {

            virtqueue_init(&vdev->vq[i]);

        if (vdev->vq[i].vring.desc) {

            /* XXX virtio-1 devices */

            virtio_queue_update_rings(vdev, i);

        } else if (vdev->vq[i].last_avail_idx) {

            error_report("VQ %d address 0x0 "

                         "inconsistent with Host index 0x%x",
@@ -1138,7 +1153,7 @@ int virtio_load(VirtIODevice *vdev, QEMUFile *f, int version_id) 
    }



    for (i = 0; i < num; i++) {

        if (vdev->vq[i].pa) {

        if (vdev->vq[i].vring.desc) {

            uint16_t nheads;

            nheads = vring_avail_idx(&vdev->vq[i]) - vdev->vq[i].last_avail_idx;

            /* Check it isn't doing strange things with descriptor numbers. */

include/hw/virtio/virtio.h

+3 −0
Original line number Diff line number Diff line
@@ -177,6 +177,9 @@ hwaddr virtio_queue_get_addr(VirtIODevice *vdev, int n); 
void virtio_queue_set_num(VirtIODevice *vdev, int n, int num);

int virtio_queue_get_num(VirtIODevice *vdev, int n);

int virtio_get_num_queues(VirtIODevice *vdev);

void virtio_queue_set_rings(VirtIODevice *vdev, int n, hwaddr desc,

                            hwaddr avail, hwaddr used);

void virtio_queue_update_rings(VirtIODevice *vdev, int n);

void virtio_queue_set_align(VirtIODevice *vdev, int n, int align);

void virtio_queue_notify(VirtIODevice *vdev, int n);

uint16_t virtio_queue_vector(VirtIODevice *vdev, int n);