diff options
| author | Andy Lutomirski <luto@kernel.org> | 2016-02-02 21:46:36 -0800 |
|---|---|---|
| committer | Alistair Strachan <astrachan@google.com> | 2019-01-16 12:43:19 -0800 |
| commit | 6bb68f96a00a13a71c3fa8c77aa0609a6b31dc2e (patch) | |
| tree | dfafe48ff40cf0918904da4ec66427525e96b57a /tools | |
| parent | dbe5b486ca9a7f537c0dc5bfe9f875948b43e91b (diff) | |
UPSTREAM: virtio_ring: Support DMA APIs
virtio_ring currently sends the device (usually a hypervisor)
physical addresses of its I/O buffers. This is okay when DMA
addresses and physical addresses are the same thing, but this isn't
always the case. For example, this never works on Xen guests, and
it is likely to fail if a physical "virtio" device ever ends up
behind an IOMMU or swiotlb.
The immediate use case for me is to enable virtio on Xen guests.
For that to work, we need vring to support DMA address translation
as well as a corresponding change to virtio_pci or to another
driver.
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
(cherry picked from commit 780bc7903a32edb63be138487fd981694d993610)
Bug: 121166534
Test: Ran cuttlefish with android-4.4 + VSOCKETS, VMWARE_VMCI_VSOCKETS
Signed-off-by: Alistair Strachan <astrachan@google.com>
Change-Id: I0b21ea8a054df791fe114a10701a1120341806ce
Diffstat (limited to 'tools')
| -rw-r--r-- | tools/virtio/linux/dma-mapping.h | 17 |
1 files changed, 17 insertions, 0 deletions
diff --git a/tools/virtio/linux/dma-mapping.h b/tools/virtio/linux/dma-mapping.h new file mode 100644 index 000000000000..4f93af89ae16 --- /dev/null +++ b/tools/virtio/linux/dma-mapping.h @@ -0,0 +1,17 @@ +#ifndef _LINUX_DMA_MAPPING_H +#define _LINUX_DMA_MAPPING_H + +#ifdef CONFIG_HAS_DMA +# error Virtio userspace code does not support CONFIG_HAS_DMA +#endif + +#define PCI_DMA_BUS_IS_PHYS 1 + +enum dma_data_direction { + DMA_BIDIRECTIONAL = 0, + DMA_TO_DEVICE = 1, + DMA_FROM_DEVICE = 2, + DMA_NONE = 3, +}; + +#endif |