On 2017-05-15 14:33, Corbin Bird wrote: > Gigabyte has long been known to ship 'broken for Linux' e820 firmware. > 'e820' is basically the APG Aperature setup in the firmware. > Gigabyte kills OR overrides the IOMMU support in the firmware, to setup > the AGP Aperature. > > Closed source / binary video drivers WANT an AGP Aperature.
So is _that_ what it's all about? Is the default assumption that I run non-free video drivers? Why? I _never_ use these, and if you bet on me using them in the future and win the bet, you can probably make a cool million or two. > The kernel wants an IOMMU on x86_64, as an IOMMU. But it has one! The GART_IOMMU. It was even added specifically for Linux, according to kernel.org discussions I remember seeing but can't locate now. I also found [1] , which I think is the clearest and most human-oriented explanation of this issue, yet. And ... the recommendation is pretty much the opposite of yours. The ball is in your court, sir. > > CONFIG_X86_X2APIC=y I did this long ago, and it has no effect - still only one is found, according to dmesg. As I wrote in the earlier thread. Also, the Kconfig help for this option says it does something quite different. > > CONFIG_X86_MPPARSE=y Ok, this one I have not set so far. Will read up on it and try, [1] http://bogdan.org.ua/2009/09/30/iommu-this-costs-you-64-mb-of-ram.html -- Please *no* private Cc: on mailing lists and newsgroups Personal signed mail: please _encrypt_ and sign Don't clear-text sign: http://primate.net/~itz/blog/the-problem-with-gpg-signatures.html
