diff options
Diffstat (limited to 'hw/virtio.c')
| -rw-r--r-- | hw/virtio.c | 14 |
1 files changed, 12 insertions, 2 deletions
diff --git a/hw/virtio.c b/hw/virtio.c index 22ea8181c0..e759b58ead 100644 --- a/hw/virtio.c +++ b/hw/virtio.c @@ -19,7 +19,9 @@ #include "qemu-barrier.h" /* The alignment to use between consumer and producer parts of vring. - * x86 pagesize again. */ + * 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 @@ -53,6 +55,7 @@ typedef struct VRingUsed typedef struct VRing { unsigned int num; + unsigned int align; target_phys_addr_t desc; target_phys_addr_t avail; target_phys_addr_t used; @@ -90,7 +93,7 @@ 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(target_phys_addr_t desc_pa, int i) @@ -630,6 +633,12 @@ int virtio_queue_get_num(VirtIODevice *vdev, int n) return vdev->vq[n].vring.num; } +void virtio_queue_set_align(VirtIODevice *vdev, int n, int align) +{ + vdev->vq[n].vring.align = align; + virtqueue_init(&vdev->vq[n]); +} + void virtio_queue_notify_vq(VirtQueue *vq) { if (vq->vring.desc) { @@ -670,6 +679,7 @@ 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]; |