Hi Chris, Could you please try this patch? http://git.kernel.org/?p=linux/kernel/git/next/linux-next.git;a=commit;h=ccebf448daf7964ee2aff7947c0bbe4c7962d059 On 07/26/2012 05:52 PM, Chris Clayton wrote: > On 07/19/12 19:23, Chris Clayton wrote: >> On 07/19/12 13:17, Avi Kivity wrote: >>> On 07/19/2012 03:14 PM, Chris Clayton wrote: >>> >>>>> Change of diagnostics, unfortunately. qemu-kvm-1.0.1 can, in fact, >>>>> crash >>>>> on 3.5.0-rc6 (and rc7). I didn't get it earlier because it takes many >>>>> times more invocations before the crash occurs with 1.0.1 and I haven't >>>>> used qemu-kvm much in the past few weeks. >>>>> >>>>> I'm now checking whether I can get crashes (with 1.0.1 and/or 1.1.0) on >>>>> linux-3.4.4. I'll report back in a day or two. >>>> >>>> I've started up qemu-kvm on kernel 3.4.4 many times and not see a crash. >>>> That would indicate that the problem is in the kernel. However, I pulled >>>> the latest and greatest from Linus yesterday evening and I now can't get >>>> the crash there either, so whatever it was seems to have been fixed. If >>>> I checkout and build 3.5.0-rc[1..7], I can get the crash pretty quickly, >>>> so it's been fixed in the last few days. >>> >>> There were no kvm changes post-rc7. >>> >> Yes, I'm aware of that, Avi. This thread started because I was getting a >> crash in qemu-kvm, which I thought was only in v1.1.0. Later it turned >> out the the problem was also present in v1.0.1, but much harder to hit. >> However, it only ever happened with 3.5.0 kernels. 3.4.4, with either >> version of qemu-kvm, was stable. So then it seemed that the problem was >> in the kernel, (but not necessarily in the kvm code). >> >> Something that's changed since rc7 has either fixed the problem or made >> it much harder to hit. With rc7 and earlier I can recreate the crash >> quite easily with qemu-kvm-1.1.0 and with enough runs of 1.0.1. With >> rc7+, I haven't been able to get a crash at all. >> > Well, I'm getting the crash again, but this time I've managed to get a backtrace: > > Program received signal SIGSEGV, Segmentation fault. > [Switching to Thread 0xb60ffb40 (LWP 9405)] > 0xb7803d77 in __strcmp_sse4_2 () from /lib/libc.so.6 > (gdb) bt > #0 0xb7803d77 in __strcmp_sse4_2 () from /lib/libc.so.6 > #1 0xb7e65333 in g_str_equal () from /usr/lib/libglib-2.0.so.0 > #2 0xb7e6458d in g_hash_table_lookup () from /usr/lib/libglib-2.0.so.0 > #3 0x8014e2cf in type_table_lookup (name=0x802b0c50 "apic-common") at qom/object.c:94 > #4 type_get_by_name (name=name@entry=0x802b0c50 "apic-common") at qom/object.c:149 > #5 0x8014e933 in object_dynamic_cast (obj=obj@entry=0x80a5d818, typename=typename@entry=0x802b0c50 "apic-common") > at qom/object.c:416 > #6 0x8014e8b9 in object_dynamic_cast_assert (obj=obj@entry=0x80a5d818, > typename=typename@entry=0x802b0c50 "apic-common") at qom/object.c:478 > #7 0x80193462 in cpu_set_apic_tpr (d=0x80a5d818, val=8 '\b') > at /home/chris/rpm/BUILD/qemu-kvm-1.1.1/hw/apic_common.c:60 > #8 0x801d0560 in kvm_arch_post_run (env=env@entry=0x80a55a60, run=run@entry=0xb6239000) > at /home/chris/rpm/BUILD/qemu-kvm-1.1.1/target-i386/kvm.c:1695 > #9 0x801cb05f in kvm_cpu_exec (env=env@entry=0x80a55a60) at /home/chris/rpm/BUILD/qemu-kvm-1.1.1/kvm-all.c:1269 > #10 0x80199d1e in qemu_kvm_cpu_thread_fn (arg=0x80a55a60) at /home/chris/rpm/BUILD/qemu-kvm-1.1.1/cpus.c:752 > #11 0xb7a1fd9e in start_thread () from /lib/libpthread.so.0 > #12 0xb77bbbbe in clone () from /lib/libc.so.6 > > This is with kernel 3.5.0 and qemu-kvm-1.1.1. glibc is 2.16.0 built against 3.4.4 kernel headers. The glibc, the kernel headers and the kernel are vanilla and the only change to the qemu-kvm sources is: > > --- qemu-kvm-1.1.0/configure~ 2012-07-15 22:38:39.000000000 +0100 > +++ qemu-kvm-1.1.0/configure 2012-07-15 22:39:09.000000000 +0100 > @@ -2783,7 +2783,7 @@ int main(int argc, char **argv) > } > EOF > if ! compile_prog "" "" ; then > - CFLAGS+="-march=i486" > + CFLAGS+="-march=i686" > fi > fi > > Please let me know of anything I can do to help track this down. > > Thanks > > Chris > >> I'm not inclined to bisect to find out which patch provided the fix, but >> this mail should at least close the mail thread down tidily. >> >> Chris > > -- > To unsubscribe from this list: send the line "unsubscribe kvm" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html > > > -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
