Re: [PATCH v5 0/3] virtio: Use the DMA API when appropriate

[Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>]

On Tue, Sep 16, 2014 at 10:22:25PM -0700, Andy Lutomirski wrote:
> 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.

I can do 'Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>'
but not sure through whom this patch should go through?


> 
> 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.
> 
> Applies to net-next.
> 
> Changes from v4:
>  - Rebased onto net-next.
>  - Dropped the sg end mark changes from virtio_net, as that issue
>    is solved differently in net-next.
>  - virtio_pci does not use the DMA API on powerpc, for reasons that
>    are explained in a detailed comment in virtio_ring.
> 
> Changes from v3:
>  - virtio_pci only asks virtio_ring to use the DMA API if
>    !PCI_DMA_BUS_IS_PHYS.
>  - Reduce tools/virtio breakage.  It's now merely as broken as before
>    instead of being even more broken.
>  - Drop the sg_next changes -- Rusty's version is better.
> 
> 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 (3):
>   virtio_ring: Support DMA APIs if requested
>   virtio_pci: Use the DMA API for virtqueues when possible
>   virtio_net: Stop doing DMA from the stack
> 
>  drivers/lguest/lguest_device.c         |   3 +-
>  drivers/misc/mic/card/mic_virtio.c     |   2 +-
>  drivers/net/virtio_net.c               |  53 ++++++---
>  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            |  91 ++++++++++++++--
>  drivers/virtio/virtio_ring.c           | 194 +++++++++++++++++++++++++++------
>  include/linux/virtio_ring.h            |   1 +
>  tools/virtio/linux/dma-mapping.h       |  17 +++
>  tools/virtio/linux/virtio.h            |   1 +
>  tools/virtio/virtio_test.c             |   2 +-
>  tools/virtio/vringh_test.c             |   3 +-
>  14 files changed, 314 insertions(+), 68 deletions(-)
>  create mode 100644 tools/virtio/linux/dma-mapping.h
> 
> -- 
> 1.9.3
>