From: Benjamin Herrenschmidt <benh@kernel.crashing.org>
To: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: "linux-s390@vger.kernel.org" <linux-s390@vger.kernel.org>,
Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>,
"Michael S. Tsirkin" <mst@redhat.com>,
Andy Lutomirski <luto@amacapital.net>,
Paolo Bonzini <pbonzini@redhat.com>,
"linux390@de.ibm.com" <linux390@de.ibm.com>,
Linux Virtualization <virtualization@lists.linux-foundation.org>
Subject: Re: [PATCH v5 2/3] virtio_pci: Use the DMA API for virtqueues when possible
Date: Mon, 06 Oct 2014 21:48:26 +1100 [thread overview]
Message-ID: <1412592506.30859.74.camel@pasglop> (raw)
In-Reply-To: <543267FC.4030900@de.ibm.com>
On Mon, 2014-10-06 at 11:59 +0200, Christian Borntraeger wrote:
> Just as a comment: On s390 we always considered the memory access as
> access to real memory (not device memory) for virtio accesses. I
> prefer to not touch the DMA API on s390 as it is quite s390-PCI
> specific but it is somewhat strange for CCW devices.
>
> We would basically have two kinds of DMA mappings on s390 then, one
> iommu like for the PCI devices and one that maps DMA memory 1:1 to
> real memory. We would also need some buy-in from the s390 arch
> maintainers then.
It's pretty standard to have the dma API go via dma-ops hanging off
struct device, you can then easily make them to the right thing for the
type of device... Provided we have a way to identify "bypass everyting"
virtio vs. virtio going through normal PCI translation.
Cheers,
Ben.
next prev parent reply other threads:[~2014-10-06 10:48 UTC|newest]
Thread overview: 42+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-09-17 5:22 [PATCH v5 0/3] virtio: Use the DMA API when appropriate Andy Lutomirski
2014-09-17 5:22 ` [PATCH v5 1/3] virtio_ring: Support DMA APIs if requested Andy Lutomirski
2014-09-17 5:22 ` [PATCH v5 2/3] virtio_pci: Use the DMA API for virtqueues when possible Andy Lutomirski
2014-09-17 12:02 ` Benjamin Herrenschmidt
2014-09-17 14:16 ` Michael S. Tsirkin
2014-09-17 16:07 ` Andy Lutomirski
2014-09-17 16:49 ` David Woodhouse
2014-09-19 21:28 ` Benjamin Herrenschmidt
2014-09-19 21:33 ` Benjamin Herrenschmidt
2014-09-20 5:59 ` Andy Lutomirski
2014-09-21 5:03 ` Benjamin Herrenschmidt
2014-09-21 5:05 ` Benjamin Herrenschmidt
2014-09-21 5:48 ` Andy Lutomirski
2014-09-21 6:01 ` David Woodhouse
2014-09-24 21:41 ` Andy Lutomirski
2014-09-24 21:50 ` Benjamin Herrenschmidt
2014-09-24 21:59 ` Andy Lutomirski
2014-09-24 22:04 ` Benjamin Herrenschmidt
2014-09-24 22:15 ` Andy Lutomirski
2014-09-24 22:38 ` Benjamin Herrenschmidt
2014-09-24 22:49 ` Andy Lutomirski
2014-09-19 21:31 ` Benjamin Herrenschmidt
2014-09-29 18:55 ` Andy Lutomirski
2014-09-29 20:49 ` Benjamin Herrenschmidt
2014-09-29 20:55 ` Andy Lutomirski
2014-09-29 21:06 ` Benjamin Herrenschmidt
2014-09-30 15:38 ` Michael S. Tsirkin
2014-09-30 15:48 ` Andy Lutomirski
2014-09-30 16:19 ` Andy Lutomirski
2014-09-30 17:53 ` Konrad Rzeszutek Wilk
2014-09-30 18:01 ` Andy Lutomirski
2014-10-02 16:36 ` Konrad Rzeszutek Wilk
2014-10-01 6:42 ` Michael S. Tsirkin
2014-09-30 15:53 ` Paolo Bonzini
2014-10-01 7:36 ` Michael S. Tsirkin
2014-09-30 20:05 ` Andy Lutomirski
2014-10-06 9:59 ` Christian Borntraeger
2014-10-06 10:48 ` Benjamin Herrenschmidt [this message]
2014-09-17 16:09 ` Ira W. Snyder
2014-09-17 16:15 ` Andy Lutomirski
2014-09-17 5:22 ` [PATCH v5 3/3] virtio_net: Stop doing DMA from the stack Andy Lutomirski
2014-09-19 18:25 ` [PATCH v5 0/3] virtio: Use the DMA API when appropriate Konrad Rzeszutek Wilk
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