On 02.07.2025 09:10, Mykyta Poturai wrote:
> From: Stewart Hildebrand <stewart.hildebr...@amd.com>
>
> Enable the use of IOMMU + PCI in dom0 without having to specify
> "pci-passthrough=yes". Due to possible platform specific dependencies
> of the PCI host, we rely on dom0 to initialize it and perform
> a PHYSDEVOP_pci_device_add/remove call to add each device to SMMU.
> PHYSDEVOP_pci_device_reset is left untouched as it does not have the
> pci_passthrough_enabled check.
This last sentence looks to be stale, now that ...
> Because pci_passthrough is not always enabled on all architectures, add
> a new function arch_pci_device_physdevop that checks if we need to enable
> a subset of the PCI subsystem related to managing IOMMU configuration
> for PCI devices.
>
> Enable pci_init() for initializing Xen's internal PCI subsystem, and
> allow PHYSDEVOP_pci_device_add when pci-passthrough is disabled.
>
> Signed-off-by: Stewart Hildebrand <stewart.hildebr...@amd.com>
> Signed-off-by: Mykyta Poturai <mykyta_potu...@epam.com>
> Reviewed-by: Stefano Stabellini <sstabell...@kernel.org>
> ---
> hmm. Since
> dec9e02f3190 ("xen: avoid generation of stub <asm/pci.h> header")
> Should we also move is_pci_passthrough_enabled() back to
> xen/arch/arm/include/asm/pci.h ?
> Not sure if PPC/RISC-V will plan on using this check.
>
> v11->v12:
> * add enabled checks to pci_device_reset
... you've done this. Which imo would better be a separate change (where
here you'd then consistently alter all three places. In no case can the
addition of that check go without justification, imo.
Jan
