* 32-bit qemu on current x86-64 kernel segfauls very early
@ 2010-10-31 13:06 Christoph Hellwig
2010-11-02 15:11 ` Christoph Hellwig
0 siblings, 1 reply; 6+ messages in thread
From: Christoph Hellwig @ 2010-10-31 13:06 UTC (permalink / raw)
To: kvm
With Linus' git tree from today I can't boot qemu when using kvm. It
seems to do fine, just glacially slow without -enable-kvm. The command
simplest command line that fails is:
/opt/qemu/bin/qemu-system-x86_64 -enable-kvm
I tried to get a backtrace from gdb, but it looks like:
(gdb) bt
#0 0x0806c491 in ?? ()
#1 0x0806cc38 in ?? ()
#2 0x0811be10 in ?? ()
Backtrace stopped: previous frame inner to this frame (corrupt stack?)
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: 32-bit qemu on current x86-64 kernel segfauls very early
2010-10-31 13:06 32-bit qemu on current x86-64 kernel segfauls very early Christoph Hellwig
@ 2010-11-02 15:11 ` Christoph Hellwig
2010-11-02 15:59 ` Avi Kivity
2010-11-03 12:37 ` Michael S. Tsirkin
0 siblings, 2 replies; 6+ messages in thread
From: Christoph Hellwig @ 2010-11-02 15:11 UTC (permalink / raw)
To: kvm, avi
On Sun, Oct 31, 2010 at 09:06:29AM -0400, Christoph Hellwig wrote:
> With Linus' git tree from today I can't boot qemu when using kvm. It
> seems to do fine, just glacially slow without -enable-kvm. The command
> simplest command line that fails is:
>
> /opt/qemu/bin/qemu-system-x86_64 -enable-kvm
This issue was caused by commit 9581d442b9058d3699b4be568b6e5eae38a41493
"KVM: Fix fs/gs reload oops with invalid ldt"
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: 32-bit qemu on current x86-64 kernel segfauls very early
2010-11-02 15:11 ` Christoph Hellwig
@ 2010-11-02 15:59 ` Avi Kivity
2010-11-02 16:02 ` Christoph Hellwig
2010-11-03 12:37 ` Michael S. Tsirkin
1 sibling, 1 reply; 6+ messages in thread
From: Avi Kivity @ 2010-11-02 15:59 UTC (permalink / raw)
To: Christoph Hellwig; +Cc: kvm
On 11/02/2010 11:11 AM, Christoph Hellwig wrote:
> On Sun, Oct 31, 2010 at 09:06:29AM -0400, Christoph Hellwig wrote:
> > With Linus' git tree from today I can't boot qemu when using kvm. It
> > seems to do fine, just glacially slow without -enable-kvm. The command
> > simplest command line that fails is:
> >
> > /opt/qemu/bin/qemu-system-x86_64 -enable-kvm
>
> This issue was caused by commit 9581d442b9058d3699b4be568b6e5eae38a41493
>
> "KVM: Fix fs/gs reload oops with invalid ldt"
>
Interesting, I guess we corrupt %fs on x86_64.
Intel or AMD?
--
I have a truly marvellous patch that fixes the bug which this
signature is too narrow to contain.
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: 32-bit qemu on current x86-64 kernel segfauls very early
2010-11-02 15:59 ` Avi Kivity
@ 2010-11-02 16:02 ` Christoph Hellwig
2010-11-02 19:10 ` Avi Kivity
0 siblings, 1 reply; 6+ messages in thread
From: Christoph Hellwig @ 2010-11-02 16:02 UTC (permalink / raw)
To: Avi Kivity; +Cc: Christoph Hellwig, kvm
On Tue, Nov 02, 2010 at 11:59:48AM -0400, Avi Kivity wrote:
> > "KVM: Fix fs/gs reload oops with invalid ldt"
> >
>
> Interesting, I guess we corrupt %fs on x86_64.
>
> Intel or AMD?
Intel:
processor : 0
vendor_id : GenuineIntel
cpu family : 6
model : 23
model name : Intel(R) Core(TM)2 Duo CPU T9600 @ 2.80GHz
stepping : 6
cpu MHz : 2133.000
cache size : 6144 KB
physical id : 0
siblings : 2
core id : 0
cpu cores : 2
apicid : 0
initial apicid : 0
fpu : yes
fpu_exception : yes
cpuid level : 10
wp : yes
flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe syscall nx lm constant_tsc arch_perfmon pebs bts rep_good aperfmperf pni dtes64 monitor ds_cpl vmx smx est tm2 ssse3 cx16 xtpr pdcm sse4_1 lahf_lm dts tpr_shadow vnmi flexpriority
bogomips : 5588.00
clflush size : 64
cache_alignment : 64
address sizes : 36 bits physical, 48 bits virtual
power management:
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: 32-bit qemu on current x86-64 kernel segfauls very early
2010-11-02 16:02 ` Christoph Hellwig
@ 2010-11-02 19:10 ` Avi Kivity
0 siblings, 0 replies; 6+ messages in thread
From: Avi Kivity @ 2010-11-02 19:10 UTC (permalink / raw)
To: Christoph Hellwig; +Cc: kvm
On 11/02/2010 12:02 PM, Christoph Hellwig wrote:
> On Tue, Nov 02, 2010 at 11:59:48AM -0400, Avi Kivity wrote:
> > > "KVM: Fix fs/gs reload oops with invalid ldt"
> > >
> >
> > Interesting, I guess we corrupt %fs on x86_64.
> >
> > Intel or AMD?
>
> Intel:
Thanks, reproduced and have a fix. Will send it out later.
--
I have a truly marvellous patch that fixes the bug which this
signature is too narrow to contain.
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: 32-bit qemu on current x86-64 kernel segfauls very early
2010-11-02 15:11 ` Christoph Hellwig
2010-11-02 15:59 ` Avi Kivity
@ 2010-11-03 12:37 ` Michael S. Tsirkin
1 sibling, 0 replies; 6+ messages in thread
From: Michael S. Tsirkin @ 2010-11-03 12:37 UTC (permalink / raw)
To: Christoph Hellwig; +Cc: kvm, avi
On Tue, Nov 02, 2010 at 11:11:03AM -0400, Christoph Hellwig wrote:
> On Sun, Oct 31, 2010 at 09:06:29AM -0400, Christoph Hellwig wrote:
> > With Linus' git tree from today I can't boot qemu when using kvm. It
> > seems to do fine, just glacially slow without -enable-kvm. The command
> > simplest command line that fails is:
> >
> > /opt/qemu/bin/qemu-system-x86_64 -enable-kvm
>
> This issue was caused by commit 9581d442b9058d3699b4be568b6e5eae38a41493
>
> "KVM: Fix fs/gs reload oops with invalid ldt"
I saw this issue too and I can confirm reverting this patch helps.
Will test the proper fix when it appears.
> --
> To unsubscribe from this list: send the line "unsubscribe kvm" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at http://vger.kernel.org/majordomo-info.html
^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2010-11-03 12:37 UTC | newest]
Thread overview: 6+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2010-10-31 13:06 32-bit qemu on current x86-64 kernel segfauls very early Christoph Hellwig
2010-11-02 15:11 ` Christoph Hellwig
2010-11-02 15:59 ` Avi Kivity
2010-11-02 16:02 ` Christoph Hellwig
2010-11-02 19:10 ` Avi Kivity
2010-11-03 12:37 ` Michael S. Tsirkin
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).