vfio: selftests: mlx5 driver - add send_msi support

Wire an MSI-X vector to a dedicated EQ so the mlx5 driver supports
send_msi().

Each EQ can be linked to an MSI-X vector, and the CQ can be set up
to deliver an event to the EQ. Thus, when everything is armed, an
RDMA WRITE posted to the QP generates a CQE, which generates an
EQE, which generates an MSI-X.

To keep things simple this just re-uses all the existing QPs and
CQs, so they generate single MSIs during memcpy.

send_msi() drains any accumulated MSI EQ events from prior memcpy
completions, posts a small signaled RDMA Write, then polls the CQ to
consume the resulting CQE (avoiding stale completions on subsequent
test cycles).

Assisted-by: Claude:claude-opus-4.6
Acked-by: David Matlack <dmatlack@google.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/10-v7-c6d30e8ce1e4+3dfa6-mlx5st_jgg@nvidia.com
Signed-off-by: Alex Williamson <alex@shazbot.org>

0 files changed, 0 insertions, 0 deletions