diff options
Diffstat (limited to 'hw/virtio')
| -rw-r--r-- | hw/virtio/virtio.c | 32 |
1 files changed, 29 insertions, 3 deletions
diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c index 01b05f37e1..09f62c6c70 100644 --- a/hw/virtio/virtio.c +++ b/hw/virtio/virtio.c @@ -19,8 +19,11 @@ #include "qemu/atomic.h" #include "hw/virtio/virtio-bus.h" -/* The alignment to use between consumer and producer parts of vring. - * x86 pagesize again. */ +/* + * The alignment to use between consumer and producer parts of vring. + * x86 pagesize again. This is the default, used by transports like PCI + * which don't provide a means for the guest to tell the host the alignment. + */ #define VIRTIO_PCI_VRING_ALIGN 4096 typedef struct VRingDesc @@ -54,6 +57,7 @@ typedef struct VRingUsed typedef struct VRing { unsigned int num; + unsigned int align; hwaddr desc; hwaddr avail; hwaddr used; @@ -93,7 +97,7 @@ static void virtqueue_init(VirtQueue *vq) vq->vring.avail = pa + vq->vring.num * sizeof(VRingDesc); vq->vring.used = vring_align(vq->vring.avail + offsetof(VRingAvail, ring[vq->vring.num]), - VIRTIO_PCI_VRING_ALIGN); + vq->vring.align); } static inline uint64_t vring_desc_addr(hwaddr desc_pa, int i) @@ -687,6 +691,21 @@ int virtio_queue_get_id(VirtQueue *vq) return vq - &vdev->vq[0]; } +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); + + /* 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) + */ + assert(k->has_variable_vring_alignment); + + vdev->vq[n].vring.align = align; + virtqueue_init(&vdev->vq[n]); +} + void virtio_queue_notify_vq(VirtQueue *vq) { if (vq->vring.desc) { @@ -727,6 +746,7 @@ VirtQueue *virtio_add_queue(VirtIODevice *vdev, int queue_size, abort(); vdev->vq[i].vring.num = queue_size; + vdev->vq[i].vring.align = VIRTIO_PCI_VRING_ALIGN; vdev->vq[i].handle_output = handle_output; return &vdev->vq[i]; @@ -833,6 +853,9 @@ void virtio_save(VirtIODevice *vdev, QEMUFile *f) break; qemu_put_be32(f, vdev->vq[i].vring.num); + if (k->has_variable_vring_alignment) { + qemu_put_be32(f, vdev->vq[i].vring.align); + } qemu_put_be64(f, vdev->vq[i].pa); qemu_put_be16s(f, &vdev->vq[i].last_avail_idx); if (k->save_queue) { @@ -889,6 +912,9 @@ int virtio_load(VirtIODevice *vdev, QEMUFile *f) for (i = 0; i < num; i++) { vdev->vq[i].vring.num = qemu_get_be32(f); + if (k->has_variable_vring_alignment) { + vdev->vq[i].vring.align = qemu_get_be32(f); + } vdev->vq[i].pa = qemu_get_be64(f); qemu_get_be16s(f, &vdev->vq[i].last_avail_idx); vdev->vq[i].signalled_used_valid = false; |