Xen devel - Feb 2006 - [PATCH] Fix qemu-dm segfault when multiple HVM domains ---Was: qemu-dm segfault with multiple HVM domains?

Hi,  John
	Can you try the attached patch ? 

	This issue can be reproduced on SMP platform, while the domain 0
is UP. The reason is, after finishing a dma request, the dma thread will
trigger the interrupt and then clear the call back function. When guest
get the interrupt , it will try to check the call back function, if it
is set, then it will trigger a dma request again. So if the checking for
the callbackfunction happens between trigger interrupt and clear
callback function on dma thread, it will cause NULL function calling.
After with domain 0 UP and smp platform, this situation can be
reproduced easily.

Thanks
Yunhong Jiang


This patch fix this issue by placing the interupt request in the end of
dma thread.
>-----Original Message-----
>From: xen-devel-bounces@lists.xensource.com 
>[mailto:xen-devel-bounces@lists.xensource.com] On Behalf Of 
>John Clemens
>Sent: Thursday, February 23, 2006 6:12 AM
>To: Li, Xin B
>Cc: xen-devel@lists.xensource.com
>Subject: RE: [Xen-devel] qemu-dm segfault with multiple HVM domains?
>
>
>Thanks, glad to know I''m not the only one seeing this... 
I''ve opened
>bug 542.
>
>http://bugzilla.xensource.com/bugzilla/show_bug.cgi?id=542
>
>john.c
>
>- --
>John Clemens			jclemens@virtualiron.com
>
>On Thu, 23 Feb 2006, Li, Xin B wrote:
>
>>> Just verifying that with cs 8932 I still see this problem.
>>> I''m able to
>>> start multiple windows domains, but either immediately or over
>>> time all
>>> but one qemu-dm processes segfaults.  This only appears to be
>>> a problem
>>> when I start multiple windows domains, a single domain seems
>>> to work fine.
>>>
>>> qemu-dm[4961]: segfault at 0000000000000000 rip 0000000000000000
rsp
>>> 0000000040800198 error 14
>>> qemu-dm[4963]: segfault at 0000000000000000 rip 0000000000000000
rsp
>>> 0000000040800198 error 14
>>>
>>
>> Thanks, I ever met this issue too, but did not pay much attention to
>> this :-(
>> Can you pls fire a bug?
>> -Xin
>>
>>> john.c
>>>
>>> - --
>>> John Clemens			jclemens@virtualiron.com
>>>
>>>
>>> _______________________________________________
>>> Xen-devel mailing list
>>> Xen-devel@lists.xensource.com
>>> http://lists.xensource.com/xen-devel
>>>
>>
>
>_______________________________________________
>Xen-devel mailing list
>Xen-devel@lists.xensource.com
>http://lists.xensource.com/xen-devel
>

_______________________________________________
Xen-devel mailing list
Xen-devel@lists.xensource.com
http://lists.xensource.com/xen-devel

So far, so good.. This patch seems to fix things for me.. I have 4 domains 
running right now, 2 mostly idle, one running an ''ls -R /''
loop in cygwin,
and the fourth trudging through a chkdsk so it too is hitting the disk 
hard.  Domains have been up for about an hour now without any problems, 
which is a lot longer than before.

Please check it in when you can, and thanks.
john.c

- --
John Clemens			jclemens@virtualiron.com

On Mon, 27 Feb 2006, Jiang, Yunhong wrote:
> Hi,  John
> 	Can you try the attached patch ?
>
> 	This issue can be reproduced on SMP platform, while the domain 0
> is UP. The reason is, after finishing a dma request, the dma thread will
> trigger the interrupt and then clear the call back function. When guest
> get the interrupt , it will try to check the call back function, if it
> is set, then it will trigger a dma request again. So if the checking for
> the callbackfunction happens between trigger interrupt and clear
> callback function on dma thread, it will cause NULL function calling.
> After with domain 0 UP and smp platform, this situation can be
> reproduced easily.
>
> Thanks
> Yunhong Jiang
>
>
> This patch fix this issue by placing the interupt request in the end of
> dma thread.
>> -----Original Message-----
>> From: xen-devel-bounces@lists.xensource.com
>> [mailto:xen-devel-bounces@lists.xensource.com] On Behalf Of
>> John Clemens
>> Sent: Thursday, February 23, 2006 6:12 AM
>> To: Li, Xin B
>> Cc: xen-devel@lists.xensource.com
>> Subject: RE: [Xen-devel] qemu-dm segfault with multiple HVM domains?
>>
>>
>> Thanks, glad to know I''m not the only one seeing this... 
I''ve opened
>> bug 542.
>>
>> http://bugzilla.xensource.com/bugzilla/show_bug.cgi?id=542
>>
>> john.c
>>
>> - --
>> John Clemens			jclemens@virtualiron.com
>>
>> On Thu, 23 Feb 2006, Li, Xin B wrote:
>>
>>>> Just verifying that with cs 8932 I still see this problem.
>>>> I''m able to
>>>> start multiple windows domains, but either immediately or over
>>>> time all
>>>> but one qemu-dm processes segfaults.  This only appears to be
>>>> a problem
>>>> when I start multiple windows domains, a single domain seems
>>>> to work fine.
>>>>
>>>> qemu-dm[4961]: segfault at 0000000000000000 rip
0000000000000000 rsp
>>>> 0000000040800198 error 14
>>>> qemu-dm[4963]: segfault at 0000000000000000 rip
0000000000000000 rsp
>>>> 0000000040800198 error 14
>>>>
>>>
>>> Thanks, I ever met this issue too, but did not pay much attention
to
>>> this :-(
>>> Can you pls fire a bug?
>>> -Xin
>>>
>>>> john.c
>>>>
>>>> - --
>>>> John Clemens			jclemens@virtualiron.com
>>>>
>>>>
>>>> _______________________________________________
>>>> Xen-devel mailing list
>>>> Xen-devel@lists.xensource.com
>>>> http://lists.xensource.com/xen-devel
>>>>
>>>
>>
>> _______________________________________________
>> Xen-devel mailing list
>> Xen-devel@lists.xensource.com
>> http://lists.xensource.com/xen-devel
>>
>
_______________________________________________
Xen-devel mailing list
Xen-devel@lists.xensource.com
http://lists.xensource.com/xen-devel