From mboxrd@z Thu Jan  1 00:00:00 1970
From: "Zhai, Edwin" <edwin.zhai@intel.com>
Subject: Re: [patch] Fix xm pci-detach for inactive devices
Date: Tue, 26 May 2009 14:28:52 +0800
Message-ID: <4A1B8C24.2040608@intel.com>
References: <20090526043821.GA24218@verge.net.au> <4A1B7B07.1080709@intel.com>
	<20090526062547.GA4521@verge.net.au>
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To: Simon Horman <horms@verge.net.au>
Cc: "xen-devel@lists.xensource.com" <xen-devel@lists.xensource.com>, Masaki Kanno <kanno.masaki@jp.fujitsu.com>
List-Id: xen-devel@lists.xenproject.org

I see.
Looks fine for me.

Thanks,


Simon Horman wrote:
> On Tue, May 26, 2009 at 01:15:51PM +0800, Zhai, Edwin wrote:
>   
>> Simon,
>> What does inactive domain means?
>> How does it lead an invalid vslot?
>>     
>
> Hi Edwin,
>
> An inactive domain means one that has been created
> but is stopped. An invalid vslot can occur in this case
> if the vslot is to be automatically assigned by qemu-dm.
> This is because the request will not be sent to qemu-dm
> until the domain is started.
>
> e.g.:
>
> $ xm new hvm.conf
> $ xm pci-attach hvm 00:1d.0
> $ xm pci-list hvm
> -    0x0      0x00  0x1d   0x0   <- '-' means the vslot has not been determined
> $ xm pci-detach hvm 00:1d.0      <- will fail without this change
>
> Or alternatively:
>
> $ xm new hvm.conf
> $ xm pci-attach hvm 00:1d.0
> $ xm pci-list hvm
> -    0x0      0x00  0x1d   0x0   <- '-' means the vslot has not been determined
> $ xm start hvm
> $ xm pci-list hvm
> 0x7  0x0      0x00  0x1d   0x0   <- vslot 0x7 was allocated after the
>                                     domain started
> $ xm pci-detach hvm 00:1d.0      <- will work with or without this patch
>
> Attaching devices to inactive domains was recently
> fixed (added?) by Kanno-san.
>
>   
>> Simon Horman wrote:
>>     
>>> In the case where a device is attached to an inactive domain
>>> and then removed before the domain is activated it won't have
>>> a vslot assigned, but it should still be valid to remove it.
>>>
>>> I don't think that there are any other cases where vslot can
>>> be invalid.
>>>
>>> Lightly tested
>>>
>>> Cc: Zhai Edwin <edwin.zhai@intel.com>
>>> Cc: Masaki Kanno <kanno.masaki@jp.fujitsu.com>
>>> Signed-off-by: Simon Horman <horms@verge.net.au>
>>>
>>> Index: xen-unstable.hg/tools/python/xen/xend/XendDomainInfo.py
>>> ===================================================================
>>> --- xen-unstable.hg.orig/tools/python/xen/xend/XendDomainInfo.py	2009-05-26 14:37:15.000000000 +1000
>>> +++ xen-unstable.hg/tools/python/xen/xend/XendDomainInfo.py	2009-05-26 14:37:18.000000000 +1000
>>> @@ -1130,9 +1130,6 @@ class XendDomainInfo:
>>>          if devnum >= pci_len:
>>>              raise VmError("Device @ vslot 0x%x doesn't exist." % (vslot))
>>>  -        if vslot == AUTO_PHP_SLOT:
>>> -            raise VmError("Device @ vslot 0x%x doesn't support hotplug." % (vslot))
>>> -
>>>          # Check the co-assignment.
>>>          # To pci-detach a device D from domN, we should ensure: for each DD in the
>>>          # list of D's co-assignment devices, DD is not assigned (to domN).
>>>
>>>   
>>>       
>> -- 
>> best rgds,
>> edwin
>>     
>
>   

-- 
best rgds,
edwin