From: Joerg Roedel <joro@8bytes.org>
To: "Michael S. Tsirkin" <mst@redhat.com>
Cc: David Woodhouse <dwmw2@infradead.org>,
Kevin Wolf <kwolf@redhat.com>, Wei Liu <wei.liu2@citrix.com>,
Andy Lutomirski <luto@kernel.org>,
qemu-block@nongnu.org,
Christian Borntraeger <borntraeger@de.ibm.com>,
Jason Wang <jasowang@redhat.com>,
Stefano Stabellini <stefano.stabellini@eu.citrix.com>,
qemu-devel@nongnu.org, peterx@redhat.com,
linux-kernel@vger.kernel.org, Amit Shah <amit.shah@redhat.com>,
iommu@lists.linux-foundation.org,
Stefan Hajnoczi <stefanha@redhat.com>,
kvm@vger.kernel.org, cornelia.huck@de.ibm.com,
pbonzini@redhat.com, virtualization@lists.linux-foundation.org,
Anthony PERARD <anthony.perard@citrix.com>
Subject: Re: [PATCH V2 RFC] fixup! virtio: convert to use DMA api
Date: Wed, 27 Apr 2016 16:56:32 +0200 [thread overview]
Message-ID: <20160427145632.GI17926@8bytes.org> (raw)
In-Reply-To: <20160427172630-mutt-send-email-mst@redhat.com>
On Wed, Apr 27, 2016 at 05:34:30PM +0300, Michael S. Tsirkin wrote:
> On Wed, Apr 27, 2016 at 04:23:32PM +0200, Joerg Roedel wrote:
> QEMU can choose to bypass IOMMU for one device and not the other.
> IOMMU in QEMU isn't involved when it's bypassed.
And it is QEMU's task to tell the OS, right? And the correct way to do
this is via the firmware ACPI tables.
> Fine but this is beside the point. Almost all virtio devices
> bypass IOMMU and what this patch does is create a way
> to detect devices that don't. This code can maybe go into
> platform.
Again, the way to detect this is in platform code must not be device
specific. This is what the DMAR and IVRS tables on x86 are for.
When there is no way to do this in the firmware (or there is no firmware
at all), we have to do a quirk in the platform code for it.
Joerg
next prev parent reply other threads:[~2016-04-27 14:56 UTC|newest]
Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-04-21 13:43 [PATCH V2 RFC] fixup! virtio: convert to use DMA api Michael S. Tsirkin
2016-04-21 13:54 ` Wei Liu
2016-04-27 12:18 ` David Woodhouse
2016-04-27 13:37 ` Michael S. Tsirkin
2016-04-27 14:23 ` Joerg Roedel
2016-04-27 14:31 ` Andy Lutomirski
2016-04-27 14:38 ` Michael S. Tsirkin
2016-04-27 14:43 ` Andy Lutomirski
2016-04-27 14:54 ` Michael S. Tsirkin
2016-04-27 14:58 ` Joerg Roedel
2016-04-27 15:09 ` Michael S. Tsirkin
2016-04-27 15:10 ` Andy Lutomirski
2016-04-27 14:34 ` Michael S. Tsirkin
2016-04-27 14:56 ` Joerg Roedel [this message]
2016-04-27 15:05 ` Michael S. Tsirkin
2016-04-27 15:15 ` David Woodhouse
2016-04-27 18:17 ` Michael S. Tsirkin
2016-04-27 19:16 ` David Woodhouse
2016-04-28 14:34 ` Michael S. Tsirkin
2016-04-28 15:11 ` David Woodhouse
2016-04-28 15:37 ` Michael S. Tsirkin
2016-04-28 15:48 ` David Woodhouse
2016-05-01 10:37 ` Michael S. Tsirkin
2016-05-09 11:09 ` Paolo Bonzini
2016-04-21 14:56 ` Stefan Hajnoczi
2016-04-21 15:11 ` Michael S. Tsirkin
2016-04-22 9:33 ` Stefan Hajnoczi
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20160427145632.GI17926@8bytes.org \
--to=joro@8bytes.org \
--cc=amit.shah@redhat.com \
--cc=anthony.perard@citrix.com \
--cc=borntraeger@de.ibm.com \
--cc=cornelia.huck@de.ibm.com \
--cc=dwmw2@infradead.org \
--cc=iommu@lists.linux-foundation.org \
--cc=jasowang@redhat.com \
--cc=kvm@vger.kernel.org \
--cc=kwolf@redhat.com \
--cc=linux-kernel@vger.kernel.org \
--cc=luto@kernel.org \
--cc=mst@redhat.com \
--cc=pbonzini@redhat.com \
--cc=peterx@redhat.com \
--cc=qemu-block@nongnu.org \
--cc=qemu-devel@nongnu.org \
--cc=stefanha@redhat.com \
--cc=stefano.stabellini@eu.citrix.com \
--cc=virtualization@lists.linux-foundation.org \
--cc=wei.liu2@citrix.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).