On 31.10.2023 15:15, Stewart Hildebrand wrote: > On 10/31/23 09:17, Julien Grall wrote: >> On 31/10/2023 11:03, Jan Beulich wrote: >>> 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. > > Currently that is true. However, this is allowing for the possibility that we > eventually may want to enable PCI passthrough for PVH domU using vPCI (e.g. > hyperlaunch, or eliminating qemu backend), in which case we may want to > enable CONFIG_HAS_VPCI_GUEST_SUPPORT=y on x86.
That's precisely why I'd like to see the ARM check go away here. >>> It's also not really clear why you >>> need to check for the system domain here. > > xl pci-assignable-add will assign the device to domIO, which doesn't have > vPCI, but it is still a valid assignment. Perhaps an in code comment would be > helpful for clarity? And/or specifically check for DomIO, not any system domain. Jan
