Linux kernel (drivers/gpu/drm/xe): A tenant's jobs can occupy the same copy engines the driver needs to service GPU

Impact

A tenant's jobs can occupy the same copy engines the driver needs to service GPU page faults, and the GuC scheduling queue is only two deep. The migration path ends up waiting behind a fault it is itself required to resolve, the GPU deadlocks, and every tenant sharing that device stops making progress until the node is reset.

Who can reach it

Tenant container holding /dev/dri/renderD* on an Intel xe device with recoverable GPU page faults enabled (USM/SVM platforms): submit sustained blitter (BCS) work so user jobs and the migration queue contend for the same engine instances. No capabilities required.

What to do

Update to a kernel carrying the fix (stable commits below; no fixed_in published). Interim: disable recoverable page faults / USM on shared xe devices, or give each tenant its own device rather than sharing engines.

References