Linux 5.12 To Allow Disabling Intel Graphics Security Mitigations

The Linux 5.12 kernel will allow optional, run-time disabling of Intel graphics driver security mitigations, which so far is just in regards to last year's iGPU Leak vulnerability. This i915.mitigations= module parameter control is being added as part of finally fixing the Haswell GT1 graphics support that was fallout from this mitigaion.

The drm-intel-gt-next pull request to DRM-Next for Linux 5.12 was sent in. Most notable is that fixing of the Haswell GT1 support that came from the clear residual security mitigations. Since that iGPU Leak mitigation for Gen7/Gen7.5 graphics was merged last year, Haswell GT1 graphics have resulted in hangs at boot. That's finally fixed up. Besides being in Linux 5.12, it should also get back-ported to recent stable kernel series as well.

Plus it goes a step further for allowing the Intel graphics driver security mitigations to be disabled. This is separate from the CPU security mitigation controls and is via the i915.mitigations= kernel module parameter. By default the graphics security mitigations will still be applied by default where relevant.

Besides those changes, this pull request also has a wide variety of other bug fixes and code improvements as well as some new workarounds for current and forthcoming Intel graphics hardware.

The full list of patches can be found via this pull request.