Add a utility, proc_irq_set_smp_affinity(), to set the CPU affinity of a
Linux host IRQ via the proc filesystem. Use smp_affinity_list instead of
smp_affinity to avoid having to convert the single CPU to a bitmask.
The helper will be used by the eventfd IRQ test to verify delivery of IRQs
when the affinity is randomized/modified.
Signed-off-by: Josh Hilke <jrhilke@google.com>
[sean: make the utility self-contained, drop "list", massage changelog]
Link: https://patch.msgid.link/20260626213534.3866178-11-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
Introduce proc_util.c and proc_util.h to house utility functions for
interacting with the proc filesystem.
Add vfio_msix_to_host_irq(), which parses /proc/interrupts, to get the host
Linux IRQ for a given VFIO device BDF and MSI-X vector.
This helper will be used by the eventfd IRQ test to print the host IRQ
number when triggering IRQs via VFIO device, e.g. to aid in debugging if
the test fails.
Suggested-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: David Matlack <dmatlack@google.com>
Co-developed-by: Josh Hilke <jrhilke@google.com>
Signed-off-by: Josh Hilke <jrhilke@google.com>
[sean: massage changelog]
Link: https://patch.msgid.link/20260626213534.3866178-9-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
