On Tue, Feb 26, 2013 at 08:43:13PM +0100, Jan Kiszka wrote: > On 2013-02-26 15:11, Nadav Har'El wrote: > > On Thu, Feb 14, 2013, Nakajima, Jun wrote about "Re: [Bug 53611] New: nVMX: Add nested EPT": > >> We have started looking at the pataches first. But I couldn't > >> reproduce the results by simply applying the original patches to v3.6: > >> - L2 Ubuntu 12.04 (64-bit) (smp 2) > >> - L1 Ubuntu 12.04 (64-bit) KVM (smp 2) > >> - L0 Ubuntu 12.04 (64-bit)-based. kernel/KVM is v3.6 + patches (the > >> ones in nept-v2.tgz). > >> https://bugzilla.kernel.org/attachment.cgi?id=93101 > >> > >> Without the patches, the L2 guest works. With it, it hangs at boot > >> time (just black screen): > >> - EPT was detected by L1 KVM. > >> - UP L2 didn't help. > >> - Looks like it's looping at EPT_walk_add_generic at the same address in L0. > >> > >> Will take a closer look. It would be helpful if the test configuration > >> (e.g kernel/commit id used, L1/L2 guests) was documented as well. > > > > I sent the patches in August 1st, and they applied to commit > > ade38c311a0ad8c32e902fe1d0ae74d0d44bc71e from a week earlier. > > > > In most of my tests, L1 and L2 were old images - L1 had Linux 2.6.33, > > while L2 had Linux 2.6.28. In most of my tests both L1 and L2 were UP. > > > > I've heard another report of my patch not working with newer L1/L2 - > > the report said that L2 failed to boot (like you reported), and also > > that L1 became unstable (running anything in it gave a memory fault). > > So it is very likely that this code still has bugs - but since I already > > know of errors and holes that need to be plugged (see the announcement file > > together with the patches), it's not very surprising :( These patches > > definitely need some lovin', but it's easier than starting from scratch. > > FWIW, I'm playing with them on top of kvm-3.6-2 (second pull request for > 3.6) for a while. They work OK for my use case (static mapping) but > apparently lock up L2 when starting KVM on KVM, just as reported. I > didn't look into any details there, still busy with fixing other issues > like CR0/CR4 handling (which I came across while adding unrestricted > guest support on top of EPT). > > Given that I'm porting now patches between that branch and "next" back > and forth (I depend on EPT), it would be really great if someone > familiar with the KVM MMU (or enough time) could port the series to the > current git head. That would not solve remaining bugs but could trigger > more development, maybe also help me jumping into this. > I'd like to do that. See if I'll have time... -- Gleb. -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
