Re: [PATCH v2] xen: add support for MSI message groups

["Roger Pau Monné" <roger.pau@citrix.com>]

On 28/02/14 18:20, Boris Ostrovsky wrote:
> On 02/27/2014 01:45 PM, Boris Ostrovsky wrote:
>> On 02/27/2014 01:15 PM, Roger Pau Monne wrote:
>>> Add support for MSI message groups for Xen Dom0 using the
>>> MAP_PIRQ_TYPE_MULTI_MSI pirq map type.
>>>
>>> In order to keep track of which pirq is the first one in the group all
>>> pirqs in the MSI group except for the first one have the newly
>>> introduced PIRQ_MSI_GROUP flag set. This prevents calling
>>> PHYSDEVOP_unmap_pirq on them, since the unmap must be done with the
>>> first pirq in the group.
>>
>> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
>>
>>
> 
> 
> I was just looking at xen_setup_msi_irqs() (for a different reason) and
> I am no longer sure this patch does anything:
> 
> static int xen_setup_msi_irqs(struct pci_dev *dev, int nvec, int type)
> {
>         int irq, ret, i;
>         struct msi_desc *msidesc;
>         int *v;
> 
>         if (type == PCI_CAP_ID_MSI && nvec > 1)
>                 return 1;
> ....
> 
> Same thing for xen_hvm_setup_msi_irqs().

As said in the commit message this is only for Dom0, so the function
modified is xen_initdom_setup_msi_irqs (were this check is removed).

Roger.