Re: [PATCH v4 4/5] [FUTURE] xen/arm: enable vPCI for domUs

[Jan Beulich <jbeulich@suse.com>]

On 31.10.2023 00:52, Stewart Hildebrand wrote:
> --- a/xen/drivers/passthrough/pci.c
> +++ b/xen/drivers/passthrough/pci.c
> @@ -1618,6 +1618,16 @@ int iommu_do_pci_domctl(
>          bus = PCI_BUS(machine_sbdf);
>          devfn = PCI_DEVFN(machine_sbdf);
>  
> +        if ( IS_ENABLED(CONFIG_ARM) &&
> +             !is_hardware_domain(d) &&
> +             !is_system_domain(d) &&
> +             (!IS_ENABLED(CONFIG_HAS_VPCI_GUEST_SUPPORT) || !has_vpci(d)) )

I don't think you need the explicit ARM check; that's redundant with
checking !HAS_VPCI_GUEST_SUPPORT. It's also not really clear why you
need to check for the system domain here.

> +        {
> +            printk(XENLOG_G_WARNING "Cannot assign %pp to %pd: vPCI support not enabled\n",
> +                   &PCI_SBDF(seg, bus, devfn), d);

ret = -EPERM;

(or some other suitable error indicator)

Jan

> +            break;
> +        }
> +
>          pcidevs_lock();
>          ret = device_assigned(seg, bus, devfn);
>          if ( domctl->cmd == XEN_DOMCTL_test_assign_device )