On Mon, May 23, 2016 at 4:16 PM, Joonas Lahtinen <joonas.lahtinen@xxxxxxxxxxxxxxx> wrote: > On ma, 2016-05-23 at 07:03 +0000, Wang, Zhi A wrote: >> Hi Guys: >> I'm trying to make GVT-g as a sub-module of i915 in the next >> version patchset. The basic idea is to introduce a "gvt-g pre-enabled >> state" in i915. I think it should be a kernel option. >> > > Could not the GGTT partitioning be done ad hoc by moving objects out of > the memory areas to be ballooned? This way gvt module could just be > loaded and it would work, instead of having to reboot and change kernel > parameters. Yeah, if we want to make gvt loadable, then it should indeed not reserve anything if it's not loaded. Otherwise there's no point in that option, and it's no better than just a static Kconfig+ maybe i915 module option. If dynamic loading is too hard for v1, then I'd say we should postpone it to post-merging. GVT-g is already tricky to integrate as-is. >> When this kernel option is enabled by user, i915 will do GGTT >> partition and save HW initial MMIO snapshot for gvt-g module during >> loading. > > Like discussed in the F2F, I really think taking a MMIO snapshot in > Dom0 at boot sounds a little suspicious to me as changing Dom0 BIOS > settings could very obscurely break VM booting, especially if migration > is at some point wanted. It will also leak the Dom0 boot state to a VM, > which I do not like either. > > I would be more comfortable if the VMs are booting to a driver-fixed > MMIO state. > > Any thoughts by others on these? Golden MMIO state sounds like a good idea. -Daniel -- Daniel Vetter Software Engineer, Intel Corporation +41 (0) 79 365 57 48 - http://blog.ffwll.ch _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/intel-gfx
