From: "Michael S. Tsirkin" <mst@redhat.com>
To: Paolo Bonzini <pbonzini@redhat.com>
Cc: Jan Kiszka <jan.kiszka@siemens.com>,
Anthony Liguori <aliguori@us.ibm.com>,
Marcel Apfelbaum <marcel.a@redhat.com>,
QEMU Developers <qemu-devel@nongnu.org>,
Peter Maydell <peter.maydell@linaro.org>
Subject: Re: [Qemu-devel] [PATCH RFC v2 2/2] hw/pci: handle unassigned pci addresses
Date: Mon, 9 Sep 2013 22:35:47 +0300 [thread overview]
Message-ID: <20130909193547.GE2674@redhat.com> (raw)
In-Reply-To: <522E0F4D.8090007@redhat.com>
On Mon, Sep 09, 2013 at 08:11:25PM +0200, Paolo Bonzini wrote:
> Il 09/09/2013 20:06, Jan Kiszka ha scritto:
> > archive, was in the context of lock-less MMIO dispatching), and the
> > consensus back then was that device-to-device DMA is generally a bug
> > that is not worth supporting in all its beauty. But if you know a
> > concrete scenario / guest where it matters, that would bring in a new
> > aspect.
>
> Well, one I know is
>
> 10 SCREEN 1
> 20 COLOR 1: CIRCLE (160, 100), 80
> 30 PRINT "Hello QEMU!"
> 40 DEF SEG=&hB800
> 50 BSAVE "FOO.PIC", 16000
> RUN
>
> Not sure if that counts as something that matters, or even if it works
> right now with virtio-blk.
>
> Paolo
I don't think it matters for virtio - it's a PV device and
we can reasonably limit what works and what doesn't work there.
It makes some sense for assigned devices (I think VFIO
supports this to some extent) and we might at some
point start emulating devices that do this.
But mostly it's a driver bug, and all we need to do
is make sure it doesn't cause security issues.
--
MST
next prev parent reply other threads:[~2013-09-09 19:33 UTC|newest]
Thread overview: 71+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-09-09 11:11 [Qemu-devel] [PATCH RFC v2 0/3] pci: complete master abort protocol Marcel Apfelbaum
2013-09-09 11:11 ` [Qemu-devel] [PATCH RFC v2 1/2] memory: allow MemoryRegion's priority field to accept negative values Marcel Apfelbaum
2013-09-09 11:28 ` Peter Maydell
2013-09-09 12:03 ` Marcel Apfelbaum
2013-09-09 11:11 ` [Qemu-devel] [PATCH RFC v2 2/2] hw/pci: handle unassigned pci addresses Marcel Apfelbaum
2013-09-09 11:40 ` Michael S. Tsirkin
2013-09-09 12:11 ` Marcel Apfelbaum
2013-09-09 12:23 ` Michael S. Tsirkin
2013-09-09 12:43 ` Marcel Apfelbaum
2013-09-09 12:52 ` Peter Maydell
2013-09-09 12:59 ` Michael S. Tsirkin
2013-09-09 13:02 ` Peter Maydell
2013-09-09 13:15 ` Marcel Apfelbaum
2013-09-09 13:19 ` Peter Maydell
2013-09-09 13:29 ` Marcel Apfelbaum
2013-09-09 13:39 ` Peter Maydell
2013-09-09 14:04 ` Marcel Apfelbaum
2013-09-09 14:21 ` Peter Maydell
2013-09-09 14:51 ` Marcel Apfelbaum
2013-09-09 14:58 ` Peter Maydell
2013-09-09 16:00 ` Michael S. Tsirkin
2013-09-09 16:02 ` Peter Maydell
2013-09-09 16:34 ` Michael S. Tsirkin
2013-09-09 16:54 ` Jan Kiszka
2013-09-09 16:58 ` Peter Maydell
2013-09-09 17:09 ` Jan Kiszka
2013-09-09 17:14 ` Peter Maydell
2013-09-09 17:27 ` Jan Kiszka
2013-09-09 17:37 ` Michael S. Tsirkin
2013-09-09 17:41 ` Peter Maydell
2013-09-09 18:06 ` Jan Kiszka
2013-09-09 18:11 ` Paolo Bonzini
2013-09-09 19:35 ` Michael S. Tsirkin [this message]
2013-09-09 18:03 ` Paolo Bonzini
2013-09-09 18:49 ` Jan Kiszka
2013-09-09 18:59 ` Peter Maydell
2013-09-09 19:04 ` Jan Kiszka
2013-09-09 19:27 ` Michael S. Tsirkin
2013-09-09 19:31 ` Michael S. Tsirkin
2013-09-09 15:54 ` Michael S. Tsirkin
2013-09-09 14:04 ` Michael S. Tsirkin
2013-09-09 14:16 ` Marcel Apfelbaum
2013-09-09 13:59 ` Michael S. Tsirkin
2013-09-09 13:07 ` Marcel Apfelbaum
2013-09-09 13:16 ` Peter Maydell
2013-09-09 13:44 ` Marcel Apfelbaum
2013-09-10 12:39 ` Michael S. Tsirkin
2013-09-10 12:50 ` Peter Maydell
2013-09-10 13:02 ` Michael S. Tsirkin
2013-09-10 13:12 ` Peter Maydell
2013-09-10 14:11 ` Michael S. Tsirkin
2013-09-15 7:14 ` Michael S. Tsirkin
2013-09-15 10:56 ` Peter Maydell
2013-09-15 11:05 ` Michael S. Tsirkin
2013-09-15 11:23 ` Peter Maydell
2013-09-15 12:17 ` Michael S. Tsirkin
2013-09-15 13:24 ` Peter Maydell
2013-09-15 13:39 ` Michael S. Tsirkin
2013-09-15 13:49 ` Peter Maydell
2013-09-15 14:08 ` Michael S. Tsirkin
2013-09-15 14:08 ` Peter Maydell
2013-09-15 14:20 ` Michael S. Tsirkin
2013-09-15 14:49 ` Peter Maydell
2013-09-15 15:05 ` Michael S. Tsirkin
2013-09-15 15:08 ` Peter Maydell
2013-09-15 15:31 ` Michael S. Tsirkin
2013-09-15 17:12 ` Peter Maydell
2013-09-15 9:29 ` Marcel Apfelbaum
2013-09-09 14:01 ` Michael S. Tsirkin
2013-09-09 13:58 ` Michael S. Tsirkin
2013-09-09 14:10 ` Marcel Apfelbaum
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=20130909193547.GE2674@redhat.com \
--to=mst@redhat.com \
--cc=aliguori@us.ibm.com \
--cc=jan.kiszka@siemens.com \
--cc=marcel.a@redhat.com \
--cc=pbonzini@redhat.com \
--cc=peter.maydell@linaro.org \
--cc=qemu-devel@nongnu.org \
/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).