Chandan Kumar (raukadah)
c523612230
CentOS Stream 10 ships kernel 6.12 but backports IOMMU and VFIO API changes from upstream 6.15+. The existing compat header gates on LINUX_VERSION_CODE alone, which selects the wrong (old) API on CentOS because the kernel reports 6.12 while the actual signatures are 6.15-style. This prevents the module from compiling on RHEL-family kernels. The compat header now defines a single PCI_SIM_HAS_615_API predicate that checks LINUX_VERSION_CODE >= 6.15 or RHEL_RELEASE_CODE >= RHEL_RELEASE_VERSION(10, 3), and all five feature macros alias it. Adding future distro gates is a one-line edit. The QEMU test scripts hardcoded qemu-system-x86_64, which does not exist on CentOS/RHEL where the binary is /usr/libexec/qemu-kvm. All five QEMU-related scripts now auto-detect the binary via a QEMU_BIN environment variable with PATH-based fallback. The DevStack build_pci_sim() function used raw apt-get calls. It now uses devstack's is_ubuntu/is_fedora helpers with install_package for distro-aware package selection. Build and test documentation is updated with CentOS/Fedora install commands and CentOS Stream 10 as a compatibility target. A cyborg-tempest-centos-10-stream Zuul CI job is added to the weekly-periodic and experimental pipeline to validate pci-sim on CentOS Stream 10. Assisted-By: Claude Code (claude-opus-4-6) Change-Id: I7ecae754465510be9efc55667bb5ed1d5f9a5f68 Signed-off-by: Chandan Kumar (raukadah) <chkumar@redhat.com>
Fake PCI SR-IOV VFIO test fixture
fake_pci_sriov.ko is a self-contained module for testing
SR-IOV control-plane flows without physical SR-IOV hardware. It creates
fake PCI host bridges with physical functions and software-created
virtual functions. The VFs can be bound to VFIO and assigned to QEMU
guests.
For the standalone repository build from the repository root with:
makeor from this directory with:
make -C /lib/modules/$(uname -r)/build M=$PWD modulesThe built module is fake_pci_sriov.ko.
Local helpers
The helper scripts are intentionally kept next to the out-of-tree module so relative paths work in standalone development checkouts and DevStack jobs.
cleanup_fake_pci_sriov.sh-
Best-effort cleanup for fake VFs, fake PFs, driver overrides, and the loaded module. DevStack and smoke tests use this to make repeated runs deterministic.
test_pci_sim_loopback.py-
Host-side loopback test. It loads the module, enables VFs, waits for
/dev/ttyPCI_SIM<N>, and checks that bytes written to each TTY are read back from the same TTY. run_fake_pci_multi_pf_smoke.sh-
Host-side multi-PF smoke test. It verifies multiple fake PFs, expected class codes, VF creation, and cleanup.
run_fake_pci_qemu_vfio_smoke.sh-
Bounded QEMU/VFIO smoke test. It verifies that a fake VF can bind to
pci_sim_vfio_pciand that QEMU can start with the VF assigned. run_cirros_vfio_guest_probe.sh-
CirrOS guest probe test. It logs in over the serial console and runs guest-side PCI and TTY discovery commands.
run_cirros_vfio_userdata_echo.sh-
CirrOS config-drive end-to-end test. Guest user-data probes the VF and verifies the emulated UART loopback path inside the guest.
cirros_vfio_userdata_echo.sh-
Guest-side user-data script copied into the config-drive generated by
run_cirros_vfio_userdata_echo.sh.
Common test targets are available from this directory after building the module:
make test-loopback
make test-multi-pf