Jan Kiszka wrote: > David S. Ahern wrote: >> On 03/03/2010 04:20 PM, Jan Kiszka wrote: >>> David S. Ahern wrote: >>>> >>>> On 03/03/2010 04:08 PM, Jan Kiszka wrote: >>>>> David S. Ahern wrote: >>>>>> With latest qemu-kvm.git I am getting a segfault at start: >>>>>> >>>>>> /tmp/qemu-kvm-test/bin/qemu-system-x86_64 -m 1024 -smp 2 \ >>>>>> -drive file=/images/f12-x86_64.img,if=virtio,cache=none,boot=on >>>>>> >>>>>> kvm_create_vcpu: Invalid argument >>>>>> Segmentation fault (core dumped) >>>>>> >>>>>> >>>>>> git bisect points to: >>>>>> >>>>>> Bisecting: 0 revisions left to test after this (roughly 0 steps) >>>>>> [52b03dd70261934688cb00768c4b1e404716a337] qemu-kvm: Move >>>>>> kvm_set_boot_cpu_id >>>>>> >>>>>> >>>>>> $ git show >>>>>> commit 7811d4e8ec057d25db68f900be1f09a142faca49 >>>>>> Author: Marcelo Tosatti <mtosatti@xxxxxxxxxx> >>>>>> Date: Mon Mar 1 21:36:31 2010 -0300 >>>>>> >>>>>> >>>>>> If I manually back out the patch it will boot fine. >>>>>> >>>>> Problem persists after removing the build directory and doing a fresh >>>>> configure && make? I'm asking before taking the bug (which would be >>>>> mine, likely) as I recently spent some hours "debugging" a volatile >>>>> build system issue. >>>>> >>>>> Jan >>>>> >>>> Before sending the email I pulled a fresh clone in a completely >>>> different directory (/tmp) to determine if it was something I >>>> introduced. I then went back to my usual location, unapplied the patch >>>> and it worked fine. >>> OK, that reason can be excluded. What's your host kernel kvm version? >>> >>> (Of course, the issue does not show up here. But virtio currently does >>> not boot for me - independent of my patch.) >>> >>> Jan >>> >> Fedora Core 12, >> >> Linux daahern-lx 2.6.31.12-174.2.22.fc12.x86_64 #1 SMP Fri Feb 19 >> 18:55:03 UTC 2010 x86_64 x86_64 x86_64 GNU/Linux >> > > Reproduced after switching back to kvm-kmod-2.6.31, will debug. > Subtle memory corruption: qemu_malloc is returning a pointer that happens to become kvm_state twice. I bet my patch just exchanges some of the involved parties and exposes the issue more prominently. Trying to understand malloc's issue now... Jan
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