On 07/11/13 21:16, Daniel Kiper wrote: > On Wed, Nov 06, 2013 at 02:49:37PM +0000, David Vrabel wrote: >> The series (for Xen 4.4) improves the kexec hypercall by making Xen >> responsible for loading and relocating the image. This allows kexec >> to be usable by pv-ops kernels and should allow kexec to be usable >> from a HVM or PVH privileged domain. >> >> I have now tested this with a Linux kernel image using the VGA console >> which was what was causing problems in v9 (this turned out to be a >> kexec-tools bug). >> >> The required patch series for kexec-tools will be posted shortly and >> are available from the xen-v7 branch of: > In general it works. However, quite often I am not able to execute panic > kernel. Machine hangs with following message: > > (XEN) Domain 0 crashed: Executing crash image > > gdb shows: > > (gdb) bt > #0 0xffff82d0801a0092 in do_nmi_crash (regs=<optimized out>) at crash.c:113 > #1 0xffff82d0802281d9 in nmi_crash () at entry.S:666 > #2 0x0000000000000000 in ?? () > (gdb) > > Especially second bt line scares me... ;-))) Why? This is completely normal. If you look in crash.c at that line, it is a for (;;) halt(); loop How are you hooking gdb up? > > I have not been able to identify why NMI was activated because > stack is completely cleared. I tried to record execution in gdb > but it stops with following message: NMIs are used for cpu shootdown of the non-crashing cpus. Again, this is not touched by the series. ~Andrew > > cpumask_clear_cpu (dstp=0xffff82d0802f7f78 <call_data+24>, cpu=0) > at /srv/dev/xen/xen_20130413_20131107.kexec/xen/include/xen/cpumask.h:108 > 108 clear_bit(cpumask_check(cpu), dstp->bits); > Process record: failed to record execution log. > > Do you know how to find out why NMI was activated? > > I am able almost always reproduce this issue doing this: > - boot Xen, > - load panic kernel, > - echo c > /proc/sysrq-trigger, > - reboot from command line, > - boot Xen, > - load panic kernel, > - echo c > /proc/sysrq-trigger. > > Additionally, my compiler fails because it detects unused result > variable in xen/common/kimage.c:kimage_crash_alloc(). > > Daniel > > _______________________________________________ > Xen-devel mailing list > Xen-devel at lists.xen.org > http://lists.xen.org/xen-devel
