On Wed, Nov 16, 2022 at 11:38:52PM +0100, Thomas Gleixner wrote:
> >> +bool pci_setup_msi_device_domain(struct pci_dev *pdev)
> >> +{
> >> + if (WARN_ON_ONCE(pdev->msix_enabled))
> >> + return false;
> >> +
> >> + if (pci_match_device_domain(pdev, DOMAIN_BUS_PCI_DEVICE_MSI))
> >> + return true;
> >> + if (pci_match_device_domain(pdev, DOMAIN_BUS_PCI_DEVICE_MSIX))
> >> + msi_remove_device_irq_domain(&pdev->dev, MSI_DEFAULT_DOMAIN);
> >> +
> >> + return pci_create_device_domain(pdev, &pci_msi_template, 1);
> >
> > Hardwired to one 1? What about multi-msi?
>
> MSI has exactly ONE descriptor whether it's single or multi-MSI.
>
> Multi-MSI can have several interrupts hanging off the same descriptor,
> but that's not how MSI looks at it because you write ONE message and the
> hardware does the substitution of the low bits depending on which vector
> is raised.
Okay, that is very clear, maybe this in a comment right here ?
Jason
