Files
kata-containers/src
Fabiano Fidêncio 91df041803 agent: expose guest InfiniBand devices to VFIO containers
When a VF is cold-plugged in guest-kernel mode, mlx5_core binds to the
PCI device inside the VM and mlx5_ib creates IB character devices under
/dev/infiniband/ (uverbs*, rdma_cm, umad*). The container cannot reach
these devices unless they are explicitly added to its OCI spec.

Add expose_guest_infiniband_devices(), called from create_devices() when
the container carries at least one VFIO device entry. The function:

  - Walks /dev/infiniband/ inside the guest VM.
  - Appends each char device to spec.linux.devices.
  - Inserts matching cgroup allow rules (rwm).
  - Is a no-op if /dev/infiniband/ is absent or empty (no IB driver,
    or VF not yet rebound), so non-RDMA pods are unaffected.

Gate the call on container_has_vfio_device() so unrelated containers
sharing the sandbox do not get IB device access widened.

Add is_vfio_device_type() and snapshot_infiniband() to
kata-sys-util/pcilibs. is_vfio_device_type() lets the agent check
device type strings against the VFIO driver name constants without
duplication. snapshot_infiniband() summarises /sys/class/infiniband,
/sys/class/infiniband_verbs, and /dev/infiniband as a single diagnostic
string for log context; it lives in pcilibs because it has no
agent-specific dependencies (pure sysfs/devfs reads).

Signed-off-by: Fabiano Fidêncio <ffidencio@nvidia.com>
Assisted-by: Cursor <cursoragent@cursor.com>
2026-05-29 13:07:45 +02:00
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