Re: [Qemu-devel] [PULL 7/7] tcg-i386: Use new return-argument ld/st helpers

[Richard Henderson]

On 05/27/2014 03:37 PM, Stefan Weil wrote:
> Hi Richard,
> 
> this patch has broken the 64 bit version of QEMU for Windows: a Linux
> guest starts booting, but hangs after "Booting the kernel.". I got a bug
> report from a user and did a "git bisect" with a Tiny Core Linux guest /
> cross build with default options / cross test with wine64 and default
> options. Git reported this commit:
> 
> 401c227b0a1134245ec61c6c5a9997cfc963c8e4 is the first bad commit
> commit 401c227b0a1134245ec61c6c5a9997cfc963c8e4
> Author: Richard Henderson <address@hidden>
> Date:   Thu Jul 25 07:16:52 2013 -1000
> 
>     tcg-i386: Use new return-argument ld/st helpers
>    
>     Discontinue the jump-around-jump-to-jump scheme, trading it for a single
>     immediate move instruction.  The two extra jumps always consume 7 bytes,
>     whereas the immediate move is either 5 or 7 bytes depending on where the
>     code_gen_buffer gets located.
>    
>     Signed-off-by: Richard Henderson <address@hidden>
> 
> :040000 040000 dfd9a66c85713cd1886a3342de1e9ac95d7ea43f
> df8673dea69bc89cc2cc979aa24415e3fea4ed53 M    include
> :040000 040000 1f7cd5291f2c69b4126c63bd567c6b106eb332c9
> 87e7ece766168dda860b513dc97fe5af28ec2c4b M    tcg
> 
> 32 bit versions of QEMU for Windows don't show this problem.

I'm having problem booting any iso with wine at the moment:

$ wine64 ./x86_64-softmmu/qemu-system-x86_64.exe -L ./pc-bios \
    -vnc :1 -cdrom ../../../Downloads/TinyCore-current.iso
Assertion failed!

Program: Z:\home\rth\work\qemu\bld-w64\x86_64-softmmu\qemu-system-x86_64.exe
File: /home/rth/work/qemu/qemu/qemu-coroutine-lock.c, Line 91

Expression: qemu_in_coroutine()

abnormal program termination

Naturally, this isn't happening with a native linux boot with the same 
arguments.

But I can boot an alpha rom:

$ wine64 ./alpha-softmmu/qemu-system-alpha.exe -L ./pc-bios/ -nographic
PCI: 00:00:0 class 0300 id 1013:00b8
PCI:   region 0: 10000000
PCI:   region 1: 12000000
PCI: 00:01:0 class 0200 id 8086:100e
PCI:   region 0: 12020000
PCI:   region 1: 0000c000
PCI: 00:02:0 class 0101 id 1095:0646
PCI:   region 0: 0000c040
PCI:   region 1: 0000c048
PCI:   region 3: 0000c04c
>>>

Which says to me that it's rather unlikely that this basic load/store patch
could be the problem.


r~