On Tue, Jul 27, 2021 at 02:06:49AM +0800, Boqun Feng wrote: > Hi, > > This is the v6 for the preparation of virtual PCI support on Hyper-V > ARM64, Previous versions: > > v1: https://lore.kernel.org/lkml/20210319161956.2838291-1-boqun.feng@xxxxxxxxx/ > v2: https://lore.kernel.org/lkml/20210503144635.2297386-1-boqun.feng@xxxxxxxxx/ > v3: https://lore.kernel.org/lkml/20210609163211.3467449-1-boqun.feng@xxxxxxxxx/ > v4: https://lore.kernel.org/lkml/20210714102737.198432-1-boqun.feng@xxxxxxxxx/ > v5: https://lore.kernel.org/lkml/20210720134429.511541-1-boqun.feng@xxxxxxxxx/ > > Changes since last version: > > * Rebase to 5.14-rc3 > > * Comment fixes as suggested by Bjorn. > > The basic problem we need to resolve is that ARM64 is an arch with > PCI_DOMAINS_GENERIC=y, so the bus sysdata is pci_config_window. However, > Hyper-V PCI provides a paravirtualized PCI interface, so there is no > actual pci_config_window for a PCI host bridge, so no information can be > retrieve from the pci_config_window of a Hyper-V virtual PCI bus. Also > there is no corresponding ACPI device for the Hyper-V PCI root bridge, > which introduces a special case when trying to find the ACPI device from > the sysdata (see patch #3). > > With this patchset, we could enable the virtual PCI on Hyper-V ARM64 > guest with other code under development. > > Comments and suggestions are welcome. > > Regards, > Boqun > > Arnd Bergmann (1): > PCI: hv: Generify PCI probing > > Boqun Feng (7): > PCI: Introduce domain_nr in pci_host_bridge > PCI: Support populating MSI domains of root buses via bridges > arm64: PCI: Restructure pcibios_root_bridge_prepare() > arm64: PCI: Support root bridge preparation for Hyper-V > PCI: hv: Set ->domain_nr of pci_host_bridge at probing time > PCI: hv: Set up MSI domain at bridge probing time > PCI: hv: Turn on the host bridge probing on ARM64 > > arch/arm64/kernel/pci.c | 29 +++++++--- > drivers/pci/controller/pci-hyperv.c | 86 +++++++++++++++++------------ > drivers/pci/probe.c | 12 +++- > include/linux/pci.h | 11 ++++ > 4 files changed, 93 insertions(+), 45 deletions(-) If we take this series via the PCI tree we'd need Catalin/Will ACKs on patches 3-4. I need some time to look into [1] (thanks for that). Without [1] patch 8 is ugly, that's no news. The question is whether it is worth waiting for a kernel cycle to integrate [1] into this series or not. Is it really a problem if we postpone this series for another kernel cycle so that we can look into it ? [1] https://lore.kernel.org/lkml/20210811153619.88922-1-boqun.feng@xxxxxxxxx/