[Top][All Lists]
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [Qemu-devel] memory trace with qemu
From: |
malc |
Subject: |
Re: [Qemu-devel] memory trace with qemu |
Date: |
Mon, 26 Jul 2010 15:16:34 +0400 (MSD) |
User-agent: |
Alpine 2.00 (LNX 1167 2008-08-23) |
On Mon, 26 Jul 2010, Eliot Moss wrote:
> On 7/26/2010 6:20 AM, Llu?s wrote:
> > Eduardo Cruz writes:
> >
> > > Thanks for your awnsers. Stean, after I find the right place to capture
> > > the
> > > reads and writes I'll definitely try your trace tool.
> >
> > > Until now, this is what i found:
> >
> > > I am using the x86-64 target, and I know that, for instance, lots of reads
> > > pass here:
> >
> > > target-i386/translate.c gen_op_ld_T1_A0()
> >
> > Ok, I've seen at least 3 people working on this lately.
> >
> > Some time ago I wrote a message proposing two sets of modifications for
> > qemu, in
> > order to allow the analysis of guest code (like feeding traces to an
> > architecture simulator).
> >
> > What I proposed is based on two different functionalities:
> >
> > 1) backdoor: a mechanism for the guest to communicate with qemu, such that
> > tracing can be started, stopped, etc.
> >
> > My current approach is to decode an instruction that is deemed invalid
> > by the
> > target ISA according to the manual.
> >
> > This is only implemented for x86 right now, but it is trivial to
> > implement on
> > other architectures as long as there are unused opcodes.
> >
> > 2) instrumentation: a set of generic macros that signal events that might be
> > of
> > interest.
>
> Etc.
>
> In the context of another simulator, we developed a different
> technique, which would be quite general and might be of interest
> for QEMU. We communicate with the simulator via a "fake" *device*,
> mapped into user-mode memory using an mmap call. If someone
> devised and coded such a device, then it could be used from any
> guest.
I'v done something similar a while ago:
http://repo.or.cz/w/qemu/malc.git/shortlog/refs/heads/wctpci
--
mailto:address@hidden
- Re: [Qemu-devel] memory trace with qemu, (continued)
- Re: [Qemu-devel] memory trace with qemu, Jun Koi, 2010/07/23
- Re: [Qemu-devel] memory trace with qemu, Stefan Hajnoczi, 2010/07/23
- Re: [Qemu-devel] memory trace with qemu, Yufei Chen, 2010/07/23
- Re: [Qemu-devel] memory trace with qemu, Stefan Hajnoczi, 2010/07/24
- Re: [Qemu-devel] memory trace with qemu, Eduardo Cruz, 2010/07/25
- Re: [Qemu-devel] memory trace with qemu, Yufei Chen, 2010/07/25
- Re: [Qemu-devel] memory trace with qemu, Lluís, 2010/07/26
- Re: [Qemu-devel] memory trace with qemu, Eliot Moss, 2010/07/26
- Re: [Qemu-devel] memory trace with qemu,
malc <=
- Re: [Qemu-devel] memory trace with qemu, Lluís, 2010/07/26
- Re: [Qemu-devel] memory trace with qemu, Jun Koi, 2010/07/26
- Re: [Qemu-devel] memory trace with qemu, malc, 2010/07/27
- Re: [Qemu-devel] memory trace with qemu, Yufei Chen, 2010/07/26
- Re: [Qemu-devel] memory trace with qemu, Eduardo Cruz, 2010/07/26
- Re: [Qemu-devel] memory trace with qemu, Lluís, 2010/07/26
- Re: [Qemu-devel] memory trace with qemu, Eduardo Cruz, 2010/07/26