Nico Huber has posted comments on this change. ( https://review.coreboot.org/c/coreboot/+/32432 )
Change subject: soc/intel/cnl: Enable VT-d ......................................................................
Patch Set 4:
(2 comments)
https://review.coreboot.org/#/c/32432/3/src/soc/intel/cannonlake/acpi.c File src/soc/intel/cannonlake/acpi.c:
https://review.coreboot.org/#/c/32432/3/src/soc/intel/cannonlake/acpi.c@364 PS3, Line 364: any platform initiated DMA : * is restricted
The statement was simply copied/pasted from the VT-d specification.
Yes, I know. So what does "restricted" mean in this context? That the IOMMU restricts it or that all drivers in the firmware are written to comply with RMRRs?
If it's the latter, how could coreboot know, given its payload model?
https://review.coreboot.org/#/c/32432/4/src/soc/intel/common/Kconfig File src/soc/intel/common/Kconfig:
https://review.coreboot.org/#/c/32432/4/src/soc/intel/common/Kconfig@67 PS4, Line 67: default n Thank you for moving it to Kconfig.
Shouldn't this default to y and have a prompt? Without a prompt, it would have similar semantics as the device- tree setting, i.e. you have to edit the code to change it.
Um, but now that I think about it: if it had a prompt, it should be declared in cannonlake/Kconfig and not here. Otherwise, we would show the prompt for all SoCs using the common/ code.