Re: [Qemu-devel] 64-on-32 TCG broken

[Stefan Weil]

Am 31.10.2012 00:56, schrieb Aurelien Jarno:
> On Tue, Oct 30, 2012 at 11:24:34PM +0100, Stefan Weil wrote:
> > Am 30.10.2012 09:15, schrieb Paolo Bonzini:
> > > Il 29/10/2012 19:29, Aurelien Jarno ha scritto:
> > > > On Mon, Oct 29, 2012 at 06:53:14PM +0100, Paolo Bonzini wrote:
> > > > > > Known-good commit: 8473f377393219390ea6f2d8d450a2b054bb823e
> > > > > > Known-bad commit: d262cb02861dd33375c08fc798930653b14769e9
> > > > > >
> > > > > > i386-softmmu seems to work.  I may try to bisect it tomorrow, but I'd be
> > > > > > glad if somebody else beats me.  It can be reproduced with Wine and
> > > > > > "x86_64-softmmu/qemu-system-x86_64.exe -L ../pc-bios"; it hangs at iPXE.
> > > > Oops, sorry about that. Is it win32 or win64? I'll try to fix it asap,
> > > > but right now I don't have a good network connection enough to either
> > > > setup a mingw build environment or to connect to a remote machine with
> > > > such an environment.
> > > It's win32, and the first bad commit is 9c43b68 (tcg: rework liveness
> > > analysis, 2012-10-09).  But it looks like 64-on-32 emulation is more
> > > generally broken.  I now tried x86_64-linux-user compiled for 32-bit,
> > > and it segfaults on startup.  Even the previous commit cannot run
> > > qemu-x86_64 /bin/ls correctly:
> > I just tested with latest qemu-system-x86_64 on 32 bit Linux.
> >
> > It also hangs during boot (BIOS), so it looks like this
> > is not a MinGW only problem.
> >
> > Your test with x86_64-linux-user indicates that, too.
> >
> > I also get the problem with TCI. Therefore I expect that any
> > 32 bit TCG target will show it.
> It ended up to be a merge issue. The newly added special cases
> for half-dead operations also need to be changed with the liveness
> analysis rework.
>
> The attached patch fixes the issue on a 32-bit linux host. I haven't
> tried win32 yet, maybe someone will beat me.


Tested-by: Stefan Weil <address@hidden>

Your attached patch fixes the problem seen with qemu-system-x86_64
on 32 bit Linux and with 32 bit Windows.

I think you can commit it to git master.

Merci,
Stefan