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

[Boris Ostrovsky <boris.ostrovsky@oracle.com>]

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().

Take a look at commit 884ac2978a295b7df3c4a686d3bff6932bbbb460.


-boris