Mesa 26.0 Adds GPU Hardware Replay Support for Intel Xe Driver

The Mesa 3D graphics library has merged critical functionality enabling GPU hardware replay support for Intel's modern Xe kernel driver in the upcoming Mesa 26.0 release. This enhancement bridges a significant gap between Intel's legacy i915 driver and its next-generation Xe driver, providing developers and power users identical debugging capabilities across both driver stacks.

Hardware replay allows precise reproduction of GPU hangs by capturing engine state snapshots during failures. When a hang occurs, the system saves hardware registers and command stream data to disk. Developers then reload this "hang dump" file to replay the exact GPU commands that caused the failure, bypassing application-level reproduction steps. This accelerates debugging cycles exponentially - what previously required hours of manual reproduction now resolves in minutes through deterministic replay.

The implementation required coordinated kernel and userspace changes. Mesa's intel_hang_replay tool gained Xe compatibility after eight months of development, while kernel-side dependencies will land in Linux 6.20 or later. Compatibility testing confirms functionality across Intel's upcoming discrete and integrated GPUs:

Hardware Generation	Architecture	Driver Support
Battlemage	Xe2	Xe driver only
Lunar Lake	Xe2	Xe driver only
Panther Lake	Xe3	Xe driver only
Arc Alchemist	Xe HPG	i915 only

For performance-focused builders, this tool proves invaluable when stress testing overclocks or validating stability. The replay mechanism captures power state transitions and clock frequencies during hangs, helping correlate instability with specific power/performance states. Homelab users can generate standardized hang scenarios to:

1. Validate cooling solution efficacy during sustained compute workloads
2. Detect memory errors during VRAM-intensive operations
3. Profile driver overhead in failure recovery paths

Implementation requires Mesa 26.0 (scheduled for February release) paired with Linux kernel 6.20+ on Xe-supported hardware. Build recommendations for debugging setups:

• Enable CONFIG_DRM_XE_CAPTURE in kernel configuration
• Allocate ≥2GB persistent storage for hang dump files
• Use INTEL_HANG_REPLAY_DUMP_PATH environment variable to specify dump location
• Combine with Mesa's INTEL_DEBUG flags for concurrent event tracing

This parity feature completes Intel's driver transition roadmap, ensuring debugging workflows remain consistent as hardware migrates exclusively to Xe. The merged code currently resides in Mesa's main branch for early adopters.