Re: [Qemu-devel] qemu-fast 0.6.0 hanging... [follow up in case this email got lost...]

[Damien Mascord <tusker@tusker.org>]

Damien Mascord wrote:

> Hi,
> 
> I am trying to get qemu 0.6.0 running on Debian testing, running vanilla 
> 2.4.26 kernel.
> 
> If I use the qemu 0.6.0 binaries from the qemu website, qemu-fast and 
> qemu binaries do in fact load the kernel as expected, though both hang 
> upon shutdown.
> 
> Though, if I compile the 0.6.0 from source on the host itself, I see the 
> following behaviour:
> 
> If I run qemu without the "-fast" affix, then it will load the 
> linux-test image (as provided on the qemu website), though on shutdown, 
> it hangs and uses 99-100% CPU.
> 
> If I run qemu-fast, then it hangs on startup, and uses 99-100% CPU 
> straight away.
> 
> I am using gcc (GCC) 3.3.4 (Debian 1:3.3.4-3), with libc6 2.3.2.
> 
> I am compiling with the following options:
> 
> CFLAGS="-Wall -g -O2" ./configure --target-list="i386-user i386 
> i386-softmmu arm-user sparc-user ppc-user ppc-softmmu" --prefix=/usr 
> --enable-slirp
> Install prefix    /usr
> BIOS directory    /usr/share/qemu
> binary directory  /usr/bin
> Manual directory  /usr/share/man
> ELF interp prefix /usr/gnemul/qemu-%M
> Source path       /home/tusker/qemu-0.6.0
> C compiler        gcc
> make              make
> host CPU          i386
> host big endian   no
> target list       i386-user i386 i386-softmmu arm-user sparc-user 
> ppc-user ppc-softmmu
> gprof enabled     no
> static build      no
> SDL support       yes
> SDL static link   yes
> mingw32 support   no
> 
> If I change the -O2 to -O0, it fails to compile.  If I change to -O1 it 
> compiles correctly, though still behaves like -O2. (ie, hangs on startup 
> for qemu-fast, hangs on shutdown for qemu.)
> 
> The compile error for -O0 is as follows:
> 
> gcc -Wall -g -O0 -fno-strict-aliasing -fomit-frame-pointer -I. 
> -I/home/tusker/qemu-0.6.0/target-i386 -I/home/tusker/qemu-0.6.0 
> -I/home/tusker/qemu-0.6.0/linux-user 
> -I/home/tusker/qemu-0.6.0/linux-user/i386 -D_GNU_SOURCE 
> -I/home/tusker/qemu-0.6.0/slirp -c -o cpu-exec.o 
> /home/tusker/qemu-0.6.0/cpu-exec.c
> /home/tusker/qemu-0.6.0/exec-all.h: In function `testandset':
> /home/tusker/qemu-0.6.0/exec-all.h:413: error: can't find a register in 
> class `GENERAL_REGS' while reloading `asm'
> make[2]: *** [cpu-exec.o] Error 1
> make[2]: Leaving directory `/home/tusker/qemu-0.6.0/i386-user'
> make[1]: *** [all] Error 1
> make[1]: Leaving directory `/home/tusker/qemu-0.6.0'
> make: *** [build-stamp] Error 2
> 
> Is there an easy way to debug what is going wrong here?
> 
> According to the user documention, attaching with gdb, and then issueing 
> a few commands through gdb should help, but I'm not very familiar with 
> gdb... :)
> 
> For interest sake, here is the following when normal qemu is shutting down:
> 
> 1) On the console it says:
> 
> flushing ide devices: hda hdc
> Restarting system.
> 
> 2) gdb 'info reg' shows:
> eax            0x909d   37021
> ecx            0x30001  196609
> edx            0x80     128
> ebx            0x80     128
> esp            0x8ff8   0x8ff8
> ebp            0x0      0x0
> esi            0x9d     157
> edi            0xffe4   65508
> eip            0xff53   0xff53
> eflags         0x86     134
> cs             0xf000   61440
> ss             0x9000   36864
> ds             0x9000   36864
> es             0x9000   36864
> fs             0x9000   36864
> gs             0x9000   36864
> 
> 3) gdb 'x/10i $eip' shows:
> 0xff53: (bad)
> 0xff54: jbe    0xff55
> 0xff56: add    %al,(%eax)
> 0xff58: aad    $0x3
> 0xff5a: outsb  %ds:(%esi),(%dx)
> 0xff5b: call   *%ebp
> 0xff5d: aas
> 0xff5e: aad    $0x3
> 0xff60: push   %eax
> 0xff61: add    %dl,%ah
> 
> For the qemu-fast binary, gdb can't seem to attach to anything, and the 
> following message comes up:
> 
> Interrupted while waiting for the program.
> Give up (and stop debugging it)? (y or n) n
> 
> 
> Is there anything I can do to work out what is going on ?
> 
> Damien
> 


-- 
Damien Mascord (tusker at tusker dot org)
GPG key 2CB181BE / 93B2 EF21 0C7C F022 F467  7966 219E 92B3 2CB1 81BE