Re: [PATCH 1/1 V2] x86/AMD: Fix setup ssss:bb:dd:f for d0 failed

[Suravee Suthikulanit <suravee.suthikulpanit@amd.com>]

On 9/4/2013 3:51 AM, Jan Beulich wrote:
>>>> On 31.08.13 at 02:41, <suravee.suthikulpanit@amd.com> wrote:
>>>>
>> --- a/xen/drivers/passthrough/vtd/intremap.c
>> +++ b/xen/drivers/passthrough/vtd/intremap.c
>> @@ -453,6 +453,7 @@ static void set_msi_source_id(struct pci_dev *pdev,
>> struct iremap_entry *ire)
>>           break;
>>   
>>       case DEV_TYPE_PCI:
>> +    case DEV_TYPE_PCI_HOST_BRIDGE:
>>       case DEV_TYPE_LEGACY_PCI_BRIDGE:
>>       case DEV_TYPE_PCI2PCIe_BRIDGE:
>>           ret = find_upstream_bridge(seg, &bus, &devfn, &secbus);
> There shouldn't be an upstream bridge to a host bridge, and
> hence adding the case here (rather than above) is at least
> pointlessly running more complex code (all under the unlikely but
> not impossible assumption that a host bridge would have MSI set
> up for it in the first place).
I put it here because the original code (before introducing the 
DEV_TYPE_PCI_HOST_BRIDGE) would have classified the host bridge device 
as "DEV_TYPE_PCI".  Therefore, I was trying to keep the logic the same 
for Intel.   However, I agree that there should not be upstream bridge 
from host bridge.  But I am not sure that the case below would be 
appropriate.

     case DEV_TYPE_PCIe_ENDPOINT:
     case DEV_TYPE_PCIe_BRIDGE:
     case DEV_TYPE_PCIe2PCI_BRIDGE:
         switch ( pdev->phantom_stride )
         {
         case 1: sq = SQ_13_IGNORE_3; break;
         case 2: sq = SQ_13_IGNORE_2; break;
         case 4: sq = SQ_13_IGNORE_1; break;
         default: sq = SQ_ALL_16; break;
         }
         set_ire_sid(ire, SVT_VERIFY_SID_SQ, sq, PCI_BDF2(bus, devfn));
         break;

Do we need to call set_ire_sid() for host bridge device?  Or should we 
just have it's own case which does nothing.
>> --- a/xen/drivers/passthrough/vtd/iommu.c
>> +++ b/xen/drivers/passthrough/vtd/iommu.c
>> @@ -1451,6 +1451,7 @@ static int domain_context_mapping(
>>           break;
>>   
>>       case DEV_TYPE_PCI:
>> +    case DEV_TYPE_PCI_HOST_BRIDGE:
>>           if ( iommu_verbose )
>>               dprintk(VTDPREFIX, "d%d:PCI: map %04x:%02x:%02x.%u\n",
>>                       domain->domain_id, seg, bus,
>> @@ -1580,6 +1581,7 @@ static int domain_context_unmap(
>>           break;
>>   
>>       case DEV_TYPE_PCI:
>> +    case DEV_TYPE_PCI_HOST_BRIDGE:
>>           if ( iommu_verbose )
>>               dprintk(VTDPREFIX, "d%d:PCI: unmap %04x:%02x:%02x.%u\n",
>>                       domain->domain_id, seg, bus, PCI_SLOT(devfn), PCI_FUNC(devfn));
> Host bridges would so far have gone through the respective default
> cases, not setting up any mapping, but logging a message. I think
> the change ought to be that host bridges result in both functions to
> fail, but without the log message saying "unknown" (and perhaps
> with -EPERM or -EACCES rather than -EINVAL).
I could do that.
> But in any event - you forgot to Cc the VT-d maintainer, who will
> need to ack the change anyway.
Sorry and thanks :)
>
> Jan
>
>