Hi Bjorn, In an earlier version[0], I sought to apply the existing jailhouse special case for isolated PCI functions to s390. As Bjorn noted in[1] there appears to be some potential for cleaning things up and removing duplication. This series attempts to do this cleanup (Patches 1 through 3) followed by enabling isolated PCI functions for s390 (Patches 4 and 5). Testing: - On s390 with SR-IOV and a ConnectX NIC with PF 1 but not PF 0 passed throug i.e. the isolated function case. Also of course with just VFs and an NVMe. - On x86_64 on a desktop system where ARI is disabled and with an SR-IOV NIC with non-contiguous VFs as well as the usual other PCI devices. Thanks, Niklas [0] https://lore.kernel.org/linux-pci/20220404095346.2324666-1-schnelle@xxxxxxxxxxxxx/ [1] https://lore.kernel.org/linux-pci/20220408224514.GA353445@bhelgaas/ Changes v5 -> v6: - Added a patch (2) which separates the ARI case into its own function - Some whitespace changes to remove unnecesssary empty lines Changes v4 -> v5: - Remove unintended whitespace change in patch 1 Changes v3 -> v4: - Use a do {} while loop in pci_scan_slot() as it is simpler (Bjorn) - Explicitly check "fn == 0" as it is not a pointer or bool (Bjorn) - Keep the "!dev" check in the ARI branch of next_fn() (Bjorn) - Moved the "fn == 0 && !dev" condition out of next_fn() into pci_scan_slot(). This allows us to keep the "!dev" case in the ARI branch and means there are no new conditions in next_fn() making it easier to verify that its behavior is equivalent to the existing code. - Guard the assignment of dev->multifunction with "fn > 0" instead of "nr > 0". This matches the existing logic more closely and works for the jailhouse case which unconditionally sets dev->multifunction for "fn > 0". This also means fn == 0 is the single "first iteration" test. - Remove some unneeded whitespace in patch 2 Changes v2 -> v3: - Removed now unused nr_devs variable (kernel test robot) Niklas Schnelle (5): PCI: Clean up pci_scan_slot() PCI: Split out next_ari_fn() from next_fn() PCI: Move jailhouse's isolated function handling to pci_scan_slot() PCI: Extend isolated function probing to s390 s390/pci: allow zPCI zbus without a function zero arch/s390/pci/pci_bus.c | 82 +++++++++--------------------------- drivers/pci/probe.c | 86 ++++++++++++++++++-------------------- include/linux/hypervisor.h | 8 ++++ 3 files changed, 68 insertions(+), 108 deletions(-) -- 2.32.0
