diff options
| author | Peter Maydell <peter.maydell@linaro.org> | 2012-01-06 16:44:19 +0000 |
|---|---|---|
| committer | Peter Maydell <peter.maydell@linaro.org> | 2012-03-03 21:48:08 +0000 |
| commit | 9969507eb502b845ab1135d95623f50be093080b (patch) | |
| tree | ec9ab3ac6e0c0a423201141bf60eb513fcfa4731 | |
| parent | 116364bd8e654646aaf79591077ac0c4b9b7c3fa (diff) | |
virtio: Support transports which can specify the vring alignment
Support virtio transports which can specify the vring alignment
(ie where the guest communicates this to the host) by providing
a new virtio_queue_set_align() function. (The default alignment
remains as before.)
FIXME save/load support for this new field!
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
| -rw-r--r-- | hw/virtio.c | 14 | ||||
| -rw-r--r-- | hw/virtio.h | 1 |
2 files changed, 13 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]; diff --git a/hw/virtio.h b/hw/virtio.h index 1f5aa57075..311e7e4e2a 100644 --- a/hw/virtio.h +++ b/hw/virtio.h @@ -180,6 +180,7 @@ void virtio_queue_set_addr(VirtIODevice *vdev, int n, target_phys_addr_t addr); target_phys_addr_t 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); +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); void virtio_queue_set_vector(VirtIODevice *vdev, int n, uint16_t vector); |