RDMA/mana_ib: Disable RX steering on RSS QP destroy

In the Linux kernel, the following vulnerability has been resolved:

RDMA/mana_ib: Disable RX steering on RSS QP destroy

When an RSS QP is destroyed (e.g. DPDK exit), mana_ib_destroy_qp_rss()

destroys the RX WQ objects but does not disable vPort RX steering in

firmware. This leaves stale steering configuration that still points to

the destroyed RX objects.

If traffic continues to arrive (e.g. peer VM is still transmitting) and

the VF interface is subsequently brought up (mana_open), the firmware

may deliver completions using stale CQ IDs from the old RX objects.

These CQ IDs can be reused by the ethernet driver for new TX CQs,

causing RX completions to land on TX CQs:

WARNING: mana_poll_tx_cq+0x1b8/0x220 [mana] (is_sq == false)

WARNING: mana_gd_process_eq_events+0x209/0x290 (cq_table lookup fails)

Fix this by disabling vPort RX steering before destroying RX WQ objects.

Note that mana_fence_rqs() cannot be used here because the fence

completion is delivered on the CQ, which is polled by user-mode (e.g.

DPDK) and not visible to the kernel driver.

Refactor the disable logic into a shared mana_disable_vport_rx() in

mana_en, exported for use by mana_ib, replacing the duplicate code.

The ethernet driver's mana_dealloc_queues() is also updated to call

this common function.