Re: [Xen-devel] [PATCH v10] VT-d: use correct BDF for VF to search VT-d unit

["Crawford, Eric R" <eric.r.crawford@xxxxxxxxx>]

Sorry for the delay, it looks like this patch resolves the issue.

Tested-by: Crawford, Eric R <Eric.R.Crawford@xxxxxxxxx>

-Eric

-----Original Message-----
From: Gao, Chao 
Sent: Monday, August 28, 2017 12:27 AM
To: Crawford, Eric R <eric.r.crawford@xxxxxxxxx>
Cc: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>; Roger Pau Monné 
<roger.pau@xxxxxxxxxx>; Wei Liu <wei.liu2@xxxxxxxxxx>; George Dunlap 
<George.Dunlap@xxxxxxxxxxxxx>; Ian Jackson <ian.jackson@xxxxxxxxxxxxx>; 
Crawford, Eric R <eric.r.crawford@xxxxxxxxx>; Tian, Kevin 
<kevin.tian@xxxxxxxxx>; Stefano Stabellini <sstabellini@xxxxxxxxxx>; 
xen-devel@xxxxxxxxxxxxx; Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx>; Tim 
Deegan <tim@xxxxxxx>; Jan Beulich <JBeulich@xxxxxxxx>
Subject: Re: [PATCH v10] VT-d: use correct BDF for VF to search VT-d unit

On Mon, Aug 28, 2017 at 02:16:18AM -0600, Jan Beulich wrote:
>>>> On 28.08.17 at 04:42, <chao.gao@xxxxxxxxx> wrote:
>> When SR-IOV is enabled, 'Virtual Functions' of a 'Physical Function'
>> are under the scope of the same VT-d unit as the 'Physical Function'.
>> A 'Physical Function' can be a 'Traditional Function' or an ARI 
>> 'Extended Function'. And furthermore, 'Extended Functions' on an 
>> endpoint are under the scope of the same VT-d unit as the 
>> 'Traditional Functions' on the endpoint. To search VT-d unit for a 
>> VF, if its PF isn't an extended function, the BDF of PF should be 
>> used. Otherwise the BDF of a traditional function in the same device 
>> with the PF should be used.
>> 
>> Current code uses PCI_SLOT() to recognize an ARI 'Extended Funcion'.
>> But it is conceptually wrong w/o checking whether PF is an extended 
>> function and would lead to match VFs of a RC integrated PF to a wrong 
>> VT-d unit.
>> 
>> This patch overrides VF 'is_extfn' field and uses this field to 
>> indicate whether the PF of this VF is an extended function. The field 
>> helps to use correct BDF to search VT-d unit.
>> 
>> Reported-by: Crawford, Eric R <Eric.R.Crawford@xxxxxxxxx>
>> Signed-off-by: Chao Gao <chao.gao@xxxxxxxxx>
>
>Acked-by: Jan Beulich <jbeulich@xxxxxxxx> albeit ...
>
>> --- a/xen/drivers/passthrough/vtd/dmar.c
>> +++ b/xen/drivers/passthrough/vtd/dmar.c
>> @@ -211,15 +211,15 @@ struct acpi_drhd_unit 
>> *acpi_find_matched_drhd_unit(const struct pci_dev *pdev)
>>      if ( pdev == NULL )
>>          return NULL;
>>  
>> -    if ( pdev->info.is_extfn )
>> +    if ( pdev->info.is_virtfn )
>>      {
>> -        bus = pdev->bus;
>> -        devfn = 0;
>> +        bus = pdev->info.physfn.bus;
>> +        devfn = (!pdev->info.is_extfn) ? pdev->info.physfn.devfn : 
>> + 0;
>
>... if I end up committing this and if I don't forget, I'll likely take 
>the liberty to remove the pointless parentheses here.
>

Hi, Eric.

Could you test this patch again and give your Tested-by if it fixes the problem 
you reported?

Thanks
Chao

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