From mboxrd@z Thu Jan  1 00:00:00 1970
From: Zhenzhong Duan <zhenzhong.duan@oracle.com>
Subject: Re: [PATCH] qemu-xen-trad: free all the pirqs for
 msi/msix when driver unloads
Date: Fri, 04 Jul 2014 09:29:38 +0800
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To: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: xen-devel@lists.xenproject.org, Ian Jackson <Ian.Jackson@eu.citrix.com>, stefano.stabellini@eu.citrix.com
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On 2014-7-4 1:54, Konrad Rzeszutek Wilk wrote:
> On Thu, Jul 03, 2014 at 11:12:18AM +0800, Zhenzhong Duan wrote:
>> There is a patch dependency missed.
> Is that one upstream as well? Or does it not need to be?
> If it is upstream, what is the title/commit id of that one?
>
> Thank you!
It's upstream, see detail below
>> commit adf74189dd58014744a4b8c9d64407d629da5e2f
>> Author: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
>> Date:   Mon Dec 10 12:43:33 2012 +0000
>>
>>      qemu-xen-trad/pt_msi_disable: do not clear all MSI flags
>>
>>      "qemu-xen-trad: fix msi_translate with PV event delivery" added a
>>      pt_msi_disable() call into pt_msgctrl_reg_write, clearing the MSI flags
>>      as a consequence. MSIs get enabled again soon after by calling
>>      pt_msi_setup.
>>
>>      However the MSI flags are only setup once in the pt_msgctrl_reg_init
>>      function, so from the QEMU point of view the device has lost some
>>      important properties, like for example PCI_MSI_FLAGS_64BIT.
>>
>>      This patch fixes the bug by clearing only the MSI
>>      enabled/mapped/initialized flags in pt_msi_disable.
>>
>>      Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
>>      Tested-by: G.R. <firemeteor@users.sourceforge.net>
>>      Xen-devel: http://marc.info/?l=xen-devel&m=135489879503075
>>
>> diff --git a/hw/pt-msi.c b/hw/pt-msi.c
>> index 73f737d..b03b989 100644
>> --- a/hw/pt-msi.c
>> +++ b/hw/pt-msi.c
>> @@ -213,7 +213,7 @@ void pt_msi_disable(struct pt_dev *dev)
>>
>>   out:
>>       /* clear msi info */
>> -    dev->msi->flags = 0;
>> +    dev->msi->flags &= ~(MSI_FLAG_UNINIT | PT_MSI_MAPPED |
>> PCI_MSI_FLAGS_ENABLE);
>>       dev->msi->pirq = -1;
>>       dev->msi_trans_en = 0;
>>   }
>>
>> On 2014-7-2 23:06, Ian Jackson wrote:
>>> Konrad Rzeszutek Wilk writes ("[Xen-devel] [PATCH] qemu-xen-trad: free all the pirqs for msi/msix when driver unloads"):
>>>> From: Zhenzhong Duan<zhenzhong.duan@oracle.com>
>>>>
>>>> Pirqs are not freed when driver unloads, then new pirqs are allocated when
>>>> driver reloads. This could exhaust pirqs if do it in a loop.
>>>>
>>>> This patch fixes the bug by freeing pirqs when ENABLE bit is cleared in
>>>> msi/msix control reg.
>>> I have backported this to 4.4 and 4.3.  It did not apply cleanly to
>>> 4.2 (and I have not investgated why).
>>>
>>> Thanks,
>>> Ian.