It was attached in my sent mail. Maybe it's being blocked by something? I'm hunting down another problem so I don't want to move my tree around too much, but once that's done I'll post it as a review.
Gabe On Tue, Dec 9, 2014 at 4:51 PM, Dutu, Alexandru via gem5-dev < gem5-dev@gem5.org> wrote: > I haven't received any attachment to your email. So I don't have your > patch. > > Alex > > -----Original Message----- > From: gem5-dev [mailto:gem5-dev-boun...@gem5.org] On Behalf Of Gabe Black > via gem5-dev > Sent: Tuesday, December 09, 2014 6:42 PM > To: gem5 Developer List > Subject: Re: [gem5-dev] x86 SE kvm functionality (AMD vs Intel) > > And... it turns out the KVM change wasn't necessary. If you're working > from my patch, get rid of where the segment limit is divided by PageBytes. > That was only necessary because I wasn't adding 0xFFF to the limit when the > granularity bit was set. > > Gabe > > On Tue, Dec 9, 2014 at 4:31 PM, Gabe Black <gabebl...@google.com> wrote: > > > Oh, also segment limits weren't being computed correctly in the > > installSegDesc function, although I don't think that was from the KVM > > stuff. Once it was fixed it required adjusting the KVM stuff a little, > > though. > > > > Gabe > > > > On Tue, Dec 9, 2014 at 4:29 PM, Gabe Black <gabebl...@google.com> wrote: > > > >> Here is my patch so far. There were a few things wrong, although I > >> didn't really keep notes. The limits were mixed up, the long mode bit > >> was set on all descriptors when it's only valid for the code segment, > >> privilege level > >> 0 is the OS and 3 is for applications and not the other way around, > >> and I think the type was being set wrong for one of the segments. > >> Also, the syscall and sysenter registers (star and friends) require > >> the segments in the GDT to be in a particular order which I don't think > they were. > >> > >> Gabe > >> > >> On Tue, Dec 9, 2014 at 4:22 PM, Dutu, Alexandru via gem5-dev < > >> gem5-dev@gem5.org> wrote: > >> > >>> So, I am doing this on an AMD system and I have SE working and am > >>> able to get FS entering into virtualized mode. However, in FS I get > >>> an early exception while the kernel is booting. This seems a bit > >>> different from what Nilay and Adrian observed for FS. Could you > >>> please share the diffs that got FS working? > >>> > >>> Thanks, > >>> Alex > >>> > >>> -----Original Message----- > >>> From: gem5-dev [mailto:gem5-dev-boun...@gem5.org] On Behalf Of Gabe > >>> Black via gem5-dev > >>> Sent: Tuesday, December 09, 2014 6:07 PM > >>> To: gem5 Developer List > >>> Subject: Re: [gem5-dev] x86 SE kvm functionality (AMD vs Intel) > >>> > >>> Oh, I see you have FS working again and not SE. NM, I'll keep looking. > >>> > >>> Gabe > >>> > >>> On Tue, Dec 9, 2014 at 4:04 PM, Gabe Black <gabebl...@google.com> > wrote: > >>> > >>> > I have FS working again which is good, but I'm still having > >>> > problems with SE. If you could let me know what you did to get > >>> > things going that would be very helpful. > >>> > > >>> > Gabe > >>> > > >>> > On Tue, Dec 9, 2014 at 10:06 AM, Dutu, Alexandru via gem5-dev < > >>> > gem5-dev@gem5.org> wrote: > >>> > > >>> >> Hi Adrian, > >>> >> > >>> >> Sorry for missing your first email. I do see the interchanged > >>> >> segment limits for full system mode, though I get a different > >>> >> behaviour on my system. The simulation seems to hang in the > following manner: > >>> >> > >>> >> Processor #0 (Bootup-CPU) > >>> >> I/O APIC #1 at 0xFEC00000. > >>> >> Setting APIC routing to flat > >>> >> Processors: 1 > >>> >> PANIC: early exception rip ffffffff807909a9 error 9 cr2 > >>> >> ffffffffff5fd020 > >>> >> > >>> >> Can please provide a patch with all the modifications that fixed > >>> >> the issue on your system? > >>> >> > >>> >> Thank you, > >>> >> Alex > >>> >> ________________________________________ > >>> >> From: gem5-dev [gem5-dev-boun...@gem5.org] on behalf of Adrián > >>> >> Colaso Diego via gem5-dev [gem5-dev@gem5.org] > >>> >> Sent: Tuesday, December 09, 2014 2:09 AM > >>> >> To: gem5 Developer List > >>> >> Subject: Re: [gem5-dev] x86 SE kvm functionality (AMD vs Intel) > >>> >> > >>> >> You are right Nilay. I sent an email last week but nobody has > replied. > >>> >> > >>> >> It seems that descriptors (cdDesc, dsDesc and tssDesc) located in > >>> >> src/arch/x86/system.cc file are not well-initialized and as a > >>> >> consequence kvm does not work when running in full-system mode. > >>> >> > >>> >> Segment limits values (limitHigh and limitLow) are interchanged > >>> >> and several segment descriptor values are wrong too. If these > >>> >> values are corrected kvm works again as before. > >>> >> > >>> >> Adrian > >>> >> > >>> >> El lun, 08-12-2014 a las 22:50 -0600, Nilay Vaish via gem5-dev > >>> escribió: > >>> >> > I also faced problem in getting KVM CPU to run in FS mode. I > >>> >> > figured > >>> >> that > >>> >> > the following changeset causes problems: > >>> >> > > >>> >> > author Alexandru Dutu <alexandru.d...@amd.com> > >>> >> > Sun Nov 23 18:01:08 2014 -0800 (2 weeks ago) > >>> >> > changeset 10554 fe2e2f06a7c8 > >>> >> > > >>> >> > I saw the hardware reason 0x80000021, but did not try to figure > >>> >> > what was going on wrong. > >>> >> > > >>> >> > -- > >>> >> > Nilay > >>> >> > > >>> >> > On Mon, 8 Dec 2014, Gabe Black via gem5-dev wrote: > >>> >> > > >>> >> > > I'm pretty sure entering 64 bit mode is the same between AMD > >>> >> > > and Intel CPUs. I vaguely remember there being some subtle > >>> >> > > page table difference though, and gem5 is building the page > >>> >> > > tables in SE mode instead of the kernel. > >>> >> > > > >>> >> > > Gabe > >>> >> > > > >>> >> > > On Mon, Dec 8, 2014 at 7:44 PM, Dutu, Alexandru via gem5-dev > >>> >> > > < gem5-dev@gem5.org> wrote: > >>> >> > > > >>> >> > >> Hi Mike, > >>> >> > >> > >>> >> > >> trace-cmd is a very handy tool to get an overview of what > >>> >> > >> the kvm > >>> >> kernel > >>> >> > >> module is doing before going into gdb. In extreme cases > >>> >> > >> ftrace can be useful as well. > >>> >> > >> What is the error that you are seeing? Is it still failing > >>> >> > >> to enter virtualized mode? > >>> >> > >> > >>> >> > >> If that is the case and the hardware reason is 0x80000021, > >>> >> > >> that > >>> >> seems to > >>> >> > >> be an unrecoverable exception (drivers/hv/hyperv_vmbus.h in > >>> >> > >> linux > >>> >> kernel > >>> >> > >> source code). When running in SE mode, we are trying to > >>> >> > >> bring the > >>> >> machine > >>> >> > >> state to full 64bit mode without going through legacy modes. > >>> >> > >> It > >>> >> might be > >>> >> > >> that Intel machines have a different way of going to 64bit > >>> >> > >> mode than > >>> >> AMD > >>> >> > >> machines (different CR4, different way of enabling 64bit > >>> >> > >> mode page > >>> >> tables > >>> >> > >> etc.). I remember dealing with these issue for AMD platforms > >>> >> > >> by going through System Programming manual and making sure > >>> >> > >> gem5 gets all the > >>> >> bits > >>> >> > >> right as there is not much the KVM kernel model will tell > >>> >> > >> about the > >>> >> cause > >>> >> > >> of failure. > >>> >> > >> > >>> >> > >> Best regards, > >>> >> > >> Alex > >>> >> > >> ________________________________________ > >>> >> > >> From: gem5-dev [gem5-dev-boun...@gem5.org] on behalf of Gabe > >>> >> > >> Black > >>> >> via > >>> >> > >> gem5-dev [gem5-dev@gem5.org] > >>> >> > >> Sent: Monday, December 08, 2014 7:08 PM > >>> >> > >> To: gem5 Developer List > >>> >> > >> Subject: Re: [gem5-dev] x86 SE kvm functionality (AMD vs > >>> >> > >> Intel) > >>> >> > >> > >>> >> > >> I'm not an expert either, but I did have problems running > >>> >> > >> KVM in SE > >>> >> mode on > >>> >> > >> an Intel CPU. I didn't look into it that much, but I think > >>> >> > >> things > >>> >> failed in > >>> >> > >> the kernel somewhere. What might be happening is that the > >>> >> > >> different > >>> >> vendors > >>> >> > >> hardware virtualization mechanisms are more or less picky > >>> >> > >> about > >>> >> various > >>> >> > >> things. Something might be set up incorrectly, and one > >>> >> implementation gets > >>> >> > >> more upset about it than the other. I believe there are > >>> >> > >> tools which > >>> >> will > >>> >> > >> help you determine whether your VM state is legal. Perhaps > >>> >> > >> Andreas > >>> >> can tell > >>> >> > >> you more about those? > >>> >> > >> > >>> >> > >> Gabe > >>> >> > >> > >>> >> > >> On Mon, Dec 8, 2014 at 4:29 PM, mike upton via gem5-dev < > >>> >> gem5-dev@gem5.org > >>> >> > >>> > >>> >> > >> wrote: > >>> >> > >> > >>> >> > >>> I have verified that x86 kvm works fine on AMD platforms, > >>> >> > >>> but fails > >>> >> on > >>> >> > >>> Intel platforms. > >>> >> > >>> > >>> >> > >>> Any hints about how to narrow down the cause (other than > >>> >> > >>> diving > >>> >> into gdb, > >>> >> > >>> which I will do). > >>> >> > >>> > >>> >> > >>> I am not an expert in KVM or how gem5 hooks up to libkvm. > >>> >> > >>> _______________________________________________ > >>> >> > >>> gem5-dev mailing list > >>> >> > >>> gem5-dev@gem5.org > >>> >> > >>> http://m5sim.org/mailman/listinfo/gem5-dev > >>> >> > >>> > >>> >> > >> _______________________________________________ > >>> >> > >> gem5-dev mailing list > >>> >> > >> gem5-dev@gem5.org > >>> >> > >> http://m5sim.org/mailman/listinfo/gem5-dev > >>> >> > >> _______________________________________________ > >>> >> > >> gem5-dev mailing list > >>> >> > >> gem5-dev@gem5.org > >>> >> > >> http://m5sim.org/mailman/listinfo/gem5-dev > >>> >> > >> > >>> >> > > _______________________________________________ > >>> >> > > gem5-dev mailing list > >>> >> > > gem5-dev@gem5.org > >>> >> > > http://m5sim.org/mailman/listinfo/gem5-dev > >>> >> > > > >>> >> > _______________________________________________ > >>> >> > gem5-dev mailing list > >>> >> > gem5-dev@gem5.org > >>> >> > http://m5sim.org/mailman/listinfo/gem5-dev > >>> >> > >>> >> > >>> >> _______________________________________________ > >>> >> gem5-dev mailing list > >>> >> gem5-dev@gem5.org > >>> >> http://m5sim.org/mailman/listinfo/gem5-dev > >>> >> _______________________________________________ > >>> >> gem5-dev mailing list > >>> >> gem5-dev@gem5.org > >>> >> http://m5sim.org/mailman/listinfo/gem5-dev > >>> >> > >>> > > >>> > > >>> _______________________________________________ > >>> gem5-dev mailing list > >>> gem5-dev@gem5.org > >>> http://m5sim.org/mailman/listinfo/gem5-dev > >>> _______________________________________________ > >>> gem5-dev mailing list > >>> gem5-dev@gem5.org > >>> http://m5sim.org/mailman/listinfo/gem5-dev > >>> > >> > >> > > > _______________________________________________ > gem5-dev mailing list > gem5-dev@gem5.org > http://m5sim.org/mailman/listinfo/gem5-dev > _______________________________________________ > gem5-dev mailing list > gem5-dev@gem5.org > http://m5sim.org/mailman/listinfo/gem5-dev > _______________________________________________ gem5-dev mailing list gem5-dev@gem5.org http://m5sim.org/mailman/listinfo/gem5-dev
