From: Jan Kiszka <jan.kiszka@siemens.com>
To: Peter Maydell <peter.maydell@linaro.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>,
Anthony Liguori <aliguori@us.ibm.com>,
"Michael S. Tsirkin" <mst@redhat.com>,
QEMU Developers <qemu-devel@nongnu.org>,
Marcel Apfelbaum <marcel.a@redhat.com>
Subject: Re: [Qemu-devel] [PATCH RFC v2 2/2] hw/pci: handle unassigned pci addresses
Date: Mon, 09 Sep 2013 21:04:03 +0200 [thread overview]
Message-ID: <522E1BA3.90906@siemens.com> (raw)
In-Reply-To: <CAFEAcA_wCG1Xr6qbJe1Art=GtgP4OjVDp5MsWkYkT05KWSVFFg@mail.gmail.com>
On 2013-09-09 20:59, Peter Maydell wrote:
> On 9 September 2013 19:49, Jan Kiszka <jan.kiszka@siemens.com> wrote:
>> Well, even if you resolve the locking issues in all the interesting
>> devices (not impossible, just pretty costly in several regards), you
>> cannot reasonably allow device A talking to device B triggering a
>> request on A issuing a command to B... in the general case. If such
>> recursions are programmable, we need to stop them before QEMU's stack
>> explodes.
>
> Typically on real hardware configuring things this way causes
> either (a) a memory transaction abort or (b) a deadlock. I
> think we could reasonably model that by deadlocking our
> device model, though as you say we should avoid actually
> crashing :-)
If the deadlock makes the QEMU process unresponsive for management
software that tries to reset the machine, or emulated hardware watchdogs...
Jan
--
Siemens AG, Corporate Technology, CT RTC ITP SES-DE
Corporate Competence Center Embedded Linux
next prev parent reply other threads:[~2013-09-09 19:04 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
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 [this message]
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
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