sema-svc: gate per-push/per-doorbell/RPC tracing behind default-off sema_dbg

A healthy run left dmesg dominated by per-operation lines (sema-push,
sema-lda, sema-chan rel-apply, sema-grce, DOORBELL/BAR writes, GSPRM
per-RPC lines, the teardown garbage-element stream). Introduce the
module parameter sema_dbg (default 0) and route every high-frequency
diagnostic through it; the finer-grained watch knobs (sema_ops_log,
sema_copy_watch, sema_copy_pat, sema_copy_dst, sema_copy_dst2) only
take effect while it is on. Boot stats, channel registrations, pin
events and state changes stay unconditional.

Also carries the per-side translation provenance (op_tr_src, printed
as prov= in the destination-window watch) and the 16 KB destination
window used to observe the guest's page-table writes.

Verified: fresh boot + full cdt2 smoke test (64/64, ALL OK) leaves a
520-line dmesg with zero per-push/per-doorbell/per-RPC lines.

0 files changed, 0 insertions, 0 deletions