Messages in this thread | | | Date | Wed, 03 Apr 2013 20:00:37 +0800 | From | Zhenzhong Duan <> | Subject | Re: [PATCH] xen: Don't call arch_trigger_all_cpu_backtrace in dom0(pvm) |
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On 2013-04-01 20:41, Konrad Rzeszutek Wilk wrote: > On Mon, Apr 01, 2013 at 01:26:34PM +0800, Zhenzhong Duan wrote: >> On 2013-03-29 21:46, Konrad Rzeszutek Wilk wrote: >>> On Fri, Mar 29, 2013 at 03:22:38PM +0800, Zhenzhong Duan wrote: >> The problem is even without overwrite, like xapic system, >> xen_send_IPI_all doesn't work for nmi vector. > Can you tweak the x2apic_mode = 0 in enligthen.c for example? > Or clear the X86_FEATURE_X2APIC in the enlighten.c ? (Similar > to how the other features are cleared) Wouldn't > that stop x2apic_enabled from detecting x2APIC? Hi Konrad, I used the second method. x2apic is totally masked in dom0. Thanks Tamon to do the test.
Testing result:
The server didn't get crashed by "echo l > /proc/sysrq-trigger". On this machine, VT-d is enabled in BIOS. However, no backtrace was shown.
[root@x4470m2-bur09-b ~]# uname -a Linux x4470m2-bur09-b.us.oracle.com 2.6.39-200.1.14.el5uek.bug16372098.test #1 SMP Tue Apr 2 21:09:27 PDT 2013 x86_64 x86_64 x86_64 GNU/Linux [root@x4470m2-bur09-b ~]# cat /proc/cpuinfo | grep x2apic [root@x4470m2-bur09-b ~]# dmesg | grep x2apic [root@x4470m2-bur09-b ~]# cat /proc/cmdline ro root=UUID=486fc42b-3383-462f-aca3-b1340fbd4ad9 console=tty1 console=ttyS0,9600n8 [root@x4470m2-bur09-b ~]# echo l > /proc/sysrq-trigger [root@x4470m2-bur09-b ~]#
/var/log/messages: (snip) Apr 3 14:14:33 x4470m2-bur09-b kernel: SysRq : Show backtrace of all active CPUs Apr 3 14:14:33 x4470m2-bur09-b kernel: sending NMI to all CPUs: (EOF)
On the console, no backtrace either. I did it twice, and got the same results.
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