Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > linux.kernel > #1257770

Re: [PATCH v3 0/3] virtio DMA API core stuff

Show all headers | View raw

[Multipart message — attachments visible in raw view] - view raw

On Wed, 2015-10-28 at 16:40 +0900, Christian Borntraeger wrote:
> Am 28.10.2015 um 16:17 schrieb Michael S. Tsirkin:
> > On Tue, Oct 27, 2015 at 11:38:57PM -0700, Andy Lutomirski wrote:
> > > This switches virtio to use the DMA API unconditionally.  I'm sure
> > > it breaks things, but it seems to work on x86 using virtio-pci, with
> > > and without Xen, and using both the modern 1.0 variant and the
> > > legacy variant.
> > 
> > I'm very glad to see work on this making progress.
> > 
> > I suspect we'll have to find a way to make this optional though, and
> > keep doing the non-DMA API thing with old devices.  And I've been
> > debating with myself whether a pci specific thing or a feature bit is
> > preferable.
> > 
> 
> We have discussed that at kernel summit. I will try to implement a dummy dma_ops for
> s390 that does 1:1 mapping and Ben will look into doing some quirk to handle "old"
> code in addition to also make it possible to mark devices as iommu bypass (IIRC,
> via device tree, Ben?)

Right. You never eschew the DMA API in the *driver* — you just expect
the DMA API to do the right thing for devices which don't need
translation (with platforms using per-device dma_ops and generally
getting their act together).

We're pushing that on the platforms where it's currently an issue,
including Power, SPARC and S390.

-- 
dwmw2

Back to linux.kernel | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread

Thread

[PATCH v3 0/3] virtio DMA API core stuff Andy Lutomirski <luto@kernel.org> - 2015-10-28 07:40 +0100
  [PATCH v3 2/3] virtio_ring: Support DMA APIs Andy Lutomirski <luto@kernel.org> - 2015-10-28 07:50 +0100
  [PATCH v3 3/3] virtio_pci: Use the DMA API Andy Lutomirski <luto@kernel.org> - 2015-10-28 07:50 +0100
  [PATCH v3 1/3] virtio_net: Stop doing DMA from the stack Andy Lutomirski <luto@kernel.org> - 2015-10-28 07:50 +0100
    Re: [PATCH v3 1/3] virtio_net: Stop doing DMA from the stack "Michael S. Tsirkin" <mst@redhat.com> - 2015-10-28 08:10 +0100
  Re: [PATCH v3 0/3] virtio DMA API core stuff David Woodhouse <dwmw2@infradead.org> - 2015-10-28 08:00 +0100
    Re: [PATCH v3 0/3] virtio DMA API core stuff Andy Lutomirski <luto@amacapital.net> - 2015-10-28 08:20 +0100
  Re: [PATCH v3 0/3] virtio DMA API core stuff "Michael S. Tsirkin" <mst@redhat.com> - 2015-10-28 08:20 +0100
    Re: [PATCH v3 0/3] virtio DMA API core stuff Christian Borntraeger <borntraeger@de.ibm.com> - 2015-10-28 08:50 +0100
      Re: [PATCH v3 0/3] virtio DMA API core stuff David Woodhouse <dwmw2@infradead.org> - 2015-10-28 09:20 +0100
        Re: [PATCH v3 0/3] virtio DMA API core stuff "Michael S. Tsirkin" <mst@redhat.com> - 2015-10-28 12:40 +0100
          Re: [PATCH v3 0/3] virtio DMA API core stuff David Woodhouse <dwmw2@infradead.org> - 2015-10-28 14:40 +0100
            Re: [PATCH v3 0/3] virtio DMA API core stuff "Michael S. Tsirkin" <mst@redhat.com> - 2015-10-28 15:10 +0100
              Re: [PATCH v3 0/3] virtio DMA API core stuff David Woodhouse <dwmw2@infradead.org> - 2015-10-28 15:20 +0100
                Re: [PATCH v3 0/3] virtio DMA API core stuff "Michael S. Tsirkin" <mst@redhat.com> - 2015-10-28 15:30 +0100
                Re: [PATCH v3 0/3] virtio DMA API core stuff David Woodhouse <dwmw2@infradead.org> - 2015-10-28 15:40 +0100
                Re: [PATCH v3 0/3] virtio DMA API core stuff "Michael S. Tsirkin" <mst@redhat.com> - 2015-10-28 17:20 +0100
                Re: [PATCH v3 0/3] virtio DMA API core stuff Andy Lutomirski <luto@amacapital.net> - 2015-10-29 00:00 +0100
                Re: [PATCH v3 0/3] virtio DMA API core stuff "Michael S. Tsirkin" <mst@redhat.com> - 2015-10-29 10:10 +0100
                Re: [PATCH v3 0/3] virtio DMA API core stuff David Woodhouse <dwmw2@infradead.org> - 2015-10-29 17:20 +0100
                Re: [PATCH v3 0/3] virtio DMA API core stuff Joerg Roedel <jroedel@suse.de> - 2015-10-30 16:20 +0100
                Re: [PATCH v3 0/3] virtio DMA API core stuff David Woodhouse <dwmw2@infradead.org> - 2015-10-30 18:00 +0100
      Re: [PATCH v3 0/3] virtio DMA API core stuff Benjamin Herrenschmidt <benh@kernel.crashing.org> - 2015-10-28 09:40 +0100
        Re: [PATCH v3 0/3] virtio DMA API core stuff "Michael S. Tsirkin" <mst@redhat.com> - 2015-10-28 12:30 +0100
          Re: [PATCH v3 0/3] virtio DMA API core stuff David Woodhouse <dwmw2@infradead.org> - 2015-10-28 14:40 +0100
            Re: [PATCH v3 0/3] virtio DMA API core stuff "Michael S. Tsirkin" <mst@redhat.com> - 2015-10-28 15:10 +0100

csiph-web