From: Avi Kivity <avi@redhat.com>
To: Jan Kiszka <jan.kiszka@siemens.com>
Cc: Anthony Liguori <aliguori@us.ibm.com>,
qemu-devel <qemu-devel@nongnu.org>,
David Gibson <david@gibson.dropbear.id.au>
Subject: Re: [Qemu-devel] [PATCH 1/2] Move graphic-related coalesced MMIO flushes to affected device models
Date: Tue, 18 Oct 2011 18:40:34 +0200 [thread overview]
Message-ID: <4E9DAC02.4040208@redhat.com> (raw)
In-Reply-To: <4E9D8D81.308@redhat.com>
On 10/18/2011 04:30 PM, Avi Kivity wrote:
> This takes a while to reproduce, let me talk to gdb for a bit.
>
a vcpu exit causes kvm_flush_coalesced_mmio_buffer() to run, which does
a bitblt, which is cirrus_do_copy(), which goes to vga_hw_update, which
does vga_update_display(), which calls
qemu_flush_coalesced_mmio_buffer(), which is not reentrant.
It's easy to make qemu_flush_coalesced_mmio_buffer reentrant:
if (s->coalesced_flush_in_progress) {
return;
}
it isn't very pretty and is also a lie. Other ideas?
I'll probably commit this soon to avoid the regression, to be replaced
by a better fix when we find it.
--
error compiling committee.c: too many arguments to function
next prev parent reply other threads:[~2011-10-18 16:40 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-09-30 10:31 [Qemu-devel] [PATCH 1/2] Move graphic-related coalesced MMIO flushes to affected device models Jan Kiszka
2011-10-15 21:35 ` Blue Swirl
2011-10-18 14:00 ` Avi Kivity
2011-10-18 14:05 ` Jan Kiszka
2011-10-18 14:08 ` Avi Kivity
2011-10-18 14:10 ` Jan Kiszka
2011-10-18 14:30 ` Avi Kivity
2011-10-18 16:40 ` Avi Kivity [this message]
2011-10-18 16:49 ` Jan Kiszka
2011-10-18 17:34 ` Avi Kivity
2011-10-18 19:50 ` Jan Kiszka
2011-10-19 9:04 ` Avi Kivity
2011-10-19 11:18 ` Jan Kiszka
2011-10-18 18:06 ` Alon Levy
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