A virtqueue is a coherent DMA mapping. Use the DMA API for it. This fixes virtio_pci on Xen.
Signed-off-by: Andy Lutomirski <[email protected]> --- drivers/virtio/virtio_pci.c | 25 ++++++++++++++++++------- 1 file changed, 18 insertions(+), 7 deletions(-) diff --git a/drivers/virtio/virtio_pci.c b/drivers/virtio/virtio_pci.c index 3d1463c6b120..19039c5bec24 100644 --- a/drivers/virtio/virtio_pci.c +++ b/drivers/virtio/virtio_pci.c @@ -80,8 +80,9 @@ struct virtio_pci_vq_info /* the number of entries in the queue */ int num; - /* the virtual address of the ring queue */ - void *queue; + /* the ring queue */ + void *queue; /* virtual address */ + dma_addr_t queue_dma_addr; /* bus address */ /* the list node for the virtqueues list */ struct list_head node; @@ -417,15 +418,16 @@ static struct virtqueue *setup_vq(struct virtio_device *vdev, unsigned index, info->num = num; info->msix_vector = msix_vec; - size = PAGE_ALIGN(vring_size(num, VIRTIO_PCI_VRING_ALIGN)); - info->queue = alloc_pages_exact(size, GFP_KERNEL|__GFP_ZERO); + size = vring_size(num, VIRTIO_PCI_VRING_ALIGN); + info->queue = dma_zalloc_coherent(vdev->dev.parent, size, + &info->queue_dma_addr, GFP_KERNEL); if (info->queue == NULL) { err = -ENOMEM; goto out_info; } /* activate the queue */ - iowrite32(virt_to_phys(info->queue) >> VIRTIO_PCI_QUEUE_ADDR_SHIFT, + iowrite32(info->queue_dma_addr >> VIRTIO_PCI_QUEUE_ADDR_SHIFT, vp_dev->ioaddr + VIRTIO_PCI_QUEUE_PFN); /* create the vring */ @@ -462,7 +464,8 @@ out_assign: vring_del_virtqueue(vq); out_activate_queue: iowrite32(0, vp_dev->ioaddr + VIRTIO_PCI_QUEUE_PFN); - free_pages_exact(info->queue, size); + dma_free_coherent(vdev->dev.parent, size, + info->queue, info->queue_dma_addr); out_info: kfree(info); return ERR_PTR(err); @@ -493,7 +496,8 @@ static void vp_del_vq(struct virtqueue *vq) iowrite32(0, vp_dev->ioaddr + VIRTIO_PCI_QUEUE_PFN); size = PAGE_ALIGN(vring_size(info->num, VIRTIO_PCI_VRING_ALIGN)); - free_pages_exact(info->queue, size); + dma_free_coherent(vq->vdev->dev.parent, size, + info->queue, info->queue_dma_addr); kfree(info); } @@ -712,6 +716,13 @@ static int virtio_pci_probe(struct pci_dev *pci_dev, if (err) goto out; + /* + * We support 64-bit DMA. If this fails (e.g. some bridge + * or PV code doesn't or DAC is disabled), then we're okay + * with 32-bit DMA. + */ + dma_set_mask_and_coherent(&pci_dev->dev, DMA_BIT_MASK(64)); + err = pci_request_regions(pci_dev, "virtio-pci"); if (err) goto out_enable_device; -- 1.9.3 _______________________________________________ Virtualization mailing list [email protected] https://lists.linuxfoundation.org/mailman/listinfo/virtualization
