Hi, if Linux is running as a guest and the host is doing igd-pass-thorugh with VT-d enabled, the i915 driver does not work all that great. The most obvious problem is that there are dozens of 'Fault errors on pipe A' errrors logged per second, but depending on the hardware there can be other issues, too. I will send a patch to rate-limit that message in a separate mail. The i915 has various quirks for VT-d and these should be enabled even if Linux is running as a guest and does itself have iommu enabled. I have checked that making intel_vtd_active() form i915_drv.h return true makes the error messages go away. How could Linux detect this situation? Maybe simply check the Hypervisor cpuid bit? Or would you prefer a module parameter, or a combination of both? Or is there another way to detect that VT-d is enabled for the igd device? Cheers, Stefan _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/intel-gfx
