This fixes virtio on Xen guests as well as on any other platform
that uses virtio_pci on which physical addresses don't match bus
addresses.
This can be tested with:
virtme-run --xen xen --kimg arch/x86/boot/bzImage --console
using virtme from here:
https://git.kernel.org/cgit/utils/kernel/virtme/virtme.git
Without these patches, the guest hangs forever. With these patches,
everything works.
This should be safe on all platforms that I'm aware of. That
doesn't mean that there isn't anything that I missed.
Patches 4 and 5 are optional cleanups. I strongly encourage the
virtio maintainers to apply patch 4, since it should be a very minor
speedup as well as a cleanup, and patch 4 is critical fix if patch 5
is applied.
Patch 5 is last for ease of reversion in case it causes problems.
It is not necessary for DMA mappings to work, and it does not fix
any bugs that I know of. It's just a cleanup.
Thanks to everyone for putting up with the development of this
series. Hopefully it'll be the end of DMA issues in virtio. :)
Changes from v2:
- Reordered patches.
- Fixed a virtio_net OOPS.
Changes from v1:
- Using the DMA API is optional now. It would be nice to improve the
DMA API to the point that it could be used unconditionally, but s390
proves that we're not there yet.
- Includes patch 4, which fixes DMA debugging warnings from virtio_net.
Andy Lutomirski (5):
virtio_ring: Support DMA APIs if requested
virtio_pci: Use the DMA API for virtqueues
virtio_net: Stop doing DMA from the stack
virtio_net: Don't set the end flag on reusable sg entries
virtio_ring: Remove sg_next indirection
drivers/lguest/lguest_device.c | 3 +-
drivers/misc/mic/card/mic_virtio.c | 2 +-
drivers/net/virtio_net.c | 59 ++++++---
drivers/remoteproc/remoteproc_virtio.c | 4 +-
drivers/s390/kvm/kvm_virtio.c | 2 +-
drivers/s390/kvm/virtio_ccw.c | 4 +-
drivers/virtio/virtio_mmio.c | 5 +-
drivers/virtio/virtio_pci.c | 35 ++++--
drivers/virtio/virtio_ring.c | 219 ++++++++++++++++++++++++++-------
include/linux/virtio_ring.h | 1 +
tools/virtio/linux/virtio.h | 1 +
tools/virtio/virtio_test.c | 2 +-
tools/virtio/vringh_test.c | 3 +-
13 files changed, 256 insertions(+), 84 deletions(-)
--
1.9.3
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