On Tue, Oct 27, 2015 at 7:27 PM, Christian Borntraeger
<borntraeger@xxxxxxxxxx> wrote:
> Am 28.10.2015 um 10:17 schrieb Andy Lutomirski:
> @@ -423,27 +522,42 @@ EXPORT_SYMBOL_GPL(virtqueue_kick);
>>
>> static void detach_buf(struct vring_virtqueue *vq, unsigned int head)
>> {
>> - unsigned int i;
>> + unsigned int i, j;
>> + u16 nextflag = cpu_to_virtio16(vq->vq.vdev, VRING_DESC_F_NEXT);
>>
>> /* Clear data ptr. */
>> - vq->data[head] = NULL;
>> + vq->desc_state[head].data = NULL;
>>
>> - /* Put back on free list: find end */
>> + /* Put back on free list: unmap first-level descriptors and find end */
>> i = head;
>>
>> - /* Free the indirect table */
>> - if (vq->vring.desc[i].flags & cpu_to_virtio16(vq->vq.vdev, VRING_DESC_F_INDIRECT))
>> - kfree(phys_to_virt(virtio64_to_cpu(vq->vq.vdev, vq->vring.desc[i].addr)));
>> -
>> - while (vq->vring.desc[i].flags & cpu_to_virtio16(vq->vq.vdev, VRING_DESC_F_NEXT)) {
>> + while (vq->vring.desc[i].flags & nextflag) {
>> + vring_unmap_one(vq, &vq->vring.desc[i]);
>> i = virtio16_to_cpu(vq->vq.vdev, vq->vring.desc[i].next);
>> vq->vq.num_free++;
>> }
>>
>> + vring_unmap_one(vq, &vq->vring.desc[i]);
>> vq->vring.desc[i].next = cpu_to_virtio16(vq->vq.vdev, vq->free_head);
>> vq->free_head = head;
>> +
>> /* Plus final descriptor */
>> vq->vq.num_free++;
>> +
>> + /* Free the indirect table, if any, now that it's unmapped. */
>> + if (vq->desc_state[head].indir_desc) {
>> + struct vring_desc *indir_desc = vq->desc_state[head].indir_desc;
>> + u32 len = vq->vring.desc[head].len;
>> +
>> + BUG_ON(!(vq->vring.desc[head].flags & VRING_DESC_F_INDIRECT));
>> + BUG_ON(len == 0 || len % sizeof(struct vring_desc));
>> +
>> + for (j = 0; j < len / sizeof(struct vring_desc); j++)
>> + vring_unmap_one(vq, &indir_desc[j]);
>> +
>> + kfree(vq->desc_state[head].indir_desc);
>> + vq->desc_state[head].indir_desc = NULL;
>> + }
>> }
>
> something seems to be broken with indirect descriptors with that change
You're big endian, right? I had an endian handling bug, and I'll fix it in v2.
--Andy
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