Will Deacon
2021-Dec-01 11:20 UTC
[PATCH] virtio_ring: Fix querying of maximum DMA mapping size for virtio device
virtio_max_dma_size() returns the maximum DMA mapping size of the virtio device by querying dma_max_mapping_size() for the device when the DMA API is in use for the vring. Unfortunately, the device passed is initialised by register_virtio_device() and does not inherit the DMA configuration from its parent, resulting in SWIOTLB errors when bouncing is enabled and the default 256K mapping limit (IO_TLB_SEGSIZE) is not respected: | virtio-pci 0000:00:01.0: swiotlb buffer is full (sz: 294912 bytes), total 1024 (slots), used 725 (slots) Follow the pattern used elsewhere in the virtio_ring code when calling into the DMA layer and pass the parent device to dma_max_mapping_size() instead. Cc: Marc Zyngier <maz at kernel.org> Cc: Quentin Perret <qperret at google.com> Cc: "Michael S. Tsirkin" <mst at redhat.com> Cc: Jason Wang <jasowang at redhat.com> Signed-off-by: Will Deacon <will at kernel.org> --- drivers/virtio/virtio_ring.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c index 6d2614e34470..028b05d44546 100644 --- a/drivers/virtio/virtio_ring.c +++ b/drivers/virtio/virtio_ring.c @@ -268,7 +268,7 @@ size_t virtio_max_dma_size(struct virtio_device *vdev) size_t max_segment_size = SIZE_MAX; if (vring_use_dma_api(vdev)) - max_segment_size = dma_max_mapping_size(&vdev->dev); + max_segment_size = dma_max_mapping_size(vdev->dev.parent); return max_segment_size; } -- 2.34.0.rc2.393.gf8c9666880-goog
Jason Wang
2021-Dec-02 03:12 UTC
[PATCH] virtio_ring: Fix querying of maximum DMA mapping size for virtio device
On Wed, Dec 1, 2021 at 7:20 PM Will Deacon <will at kernel.org> wrote:> > virtio_max_dma_size() returns the maximum DMA mapping size of the virtio > device by querying dma_max_mapping_size() for the device when the DMA > API is in use for the vring. Unfortunately, the device passed is > initialised by register_virtio_device() and does not inherit the DMA > configuration from its parent, resulting in SWIOTLB errors when bouncing > is enabled and the default 256K mapping limit (IO_TLB_SEGSIZE) is not > respected: > > | virtio-pci 0000:00:01.0: swiotlb buffer is full (sz: 294912 bytes), total 1024 (slots), used 725 (slots) > > Follow the pattern used elsewhere in the virtio_ring code when calling > into the DMA layer and pass the parent device to dma_max_mapping_size() > instead. > > Cc: Marc Zyngier <maz at kernel.org> > Cc: Quentin Perret <qperret at google.com> > Cc: "Michael S. Tsirkin" <mst at redhat.com> > Cc: Jason Wang <jasowang at redhat.com> > Signed-off-by: Will Deacon <will at kernel.org>Acked-by: Jason Wang <jasowang at redhat.com>> --- > drivers/virtio/virtio_ring.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c > index 6d2614e34470..028b05d44546 100644 > --- a/drivers/virtio/virtio_ring.c > +++ b/drivers/virtio/virtio_ring.c > @@ -268,7 +268,7 @@ size_t virtio_max_dma_size(struct virtio_device *vdev) > size_t max_segment_size = SIZE_MAX; > > if (vring_use_dma_api(vdev)) > - max_segment_size = dma_max_mapping_size(&vdev->dev); > + max_segment_size = dma_max_mapping_size(vdev->dev.parent); > > return max_segment_size; > } > -- > 2.34.0.rc2.393.gf8c9666880-goog >