Now out of the blue I'm hitting errors having to do with setting GIC "attributes" of some sort with code that was working a few hours earlier. Any idea what it's upset about?
gem5 Simulator System. http://gem5.org gem5 is copyrighted software; use the --copyright option for details. gem5 compiled Mar 30 2018 03:08:57 gem5 started Mar 30 2018 03:13:05 gem5 executing on localhost, pid 9033 command line: build/ARM/gem5.debug gem5/google/configs/kvm.py INFO:root:Disk 0: /home/gabeblack/dist/m5/system/disks/disk.img INFO:root:Add GPU: NoMali GPU model... INFO:root:Kernel: /home/gabeblack/dist/m5/system/binaries/vmlinux INFO:root:Device tree: /home/gabeblack/dist/m5/system/binaries/armv8_1440x2560_google_v1_2cpu.dtb Global frequency set at 1000000000000 ticks per second warn: system.pci_ide adopting orphan SimObject param 'disks' info: kernel located at: /home/gabeblack/dist/m5/system/binaries/vmlinux warn: Highest ARM exception-level set to AArch32 but bootloader is for AArch64. Assuming you wanted these to match. Listening for system connection on port 5900 Listening for system connection on port 3456 Listening for uart1 connection on port 3457 0: system.remote_gdb: listening for remote gdb on port 7000 0: system.remote_gdb: listening for remote gdb on port 7001 warn: CoherentXBar system.membus has no snooping ports attached! info: Using bootloader at address 0x10 info: Using kernel entry physical address at 0x80080000 info: Loading DTB file: /home/gabeblack/dist/m5/system/binaries/armv8_1440x2560_google_v1_2cpu.dtb at address 0x88000000 info: KVM: Coalesced MMIO disabled by config. info: KVM: Coalesced MMIO disabled by config. warn: Existing EnergyCtrl, but no enabled DVFSHandler found. panic: Failed to set attribute (group: 2, attr: 9, errno: 6) Memory Usage: 3516676 KBytes Program aborted at tick 0 --- BEGIN LIBC BACKTRACE --- build/ARM/gem5.debug(_Z15print_backtracev+0x2c)[0x1a3e750] build/ARM/gem5.debug(_Z12abortHandleri+0x7c)[0x1a47070] [0x7988061510] /lib/aarch64-linux-gnu/libc.so.6(gsignal+0x38)[0x798771b528] --- END LIBC BACKTRACE --- Aborted (core dumped) On Wed, Mar 28, 2018 at 5:14 PM, Gabe Black <gabebl...@google.com> wrote: > Ok, I think I figured it out, and it all has to do with the simulation > quantum. If the quantum is too big, the kernel might poke hardware and > expect to get an interrupt within a certain period of time. It could be > that the CPU gets to the end of its timeout before the simulated hardware > has had a chance to trigger an interrupt, even though the interrupt would > happen first if the event queues were held in tighter sync. If I decrease > the size of the quantum from 500ms (per your suggestion) to 1ms, then I see > the errors from the keyboard/mouse drivers and the ATA driver go away, at > least in the one CPU/multiple event queue configuration. > > I'm going to do some more testing to make sure there isn't some other > problem that pops up, and also to characterize the performance impact which > I'm hopeful won't be too bad. > > Also, I was thinking it would be nice if KVM CPUs could set up their event > queues in some more automatic, less error prone way. Before I knew that > they needed their own event queue (which I think is just institutional > knowledge that isn't documented/warned about/etc.?), I had no idea what was > going wrong when just dropping in some KVM CPUs in place of regular CPUs. I > don't have a fully fleshed out plan for how to do that, but it doesn't > *seem* like something that should be that hard to do. > > Gabe > > On Mon, Mar 26, 2018 at 7:06 PM, Gabe Black <gabebl...@google.com> wrote: > >> I looked into this a little further, and I see the same problem happen >> with one CPU but with the CPU and the devices in different event queues. I >> haven't figured out exactly where things go wrong, but it looks like a >> write DMA is set up but doesn't happen for some reason. I'm not sure if the >> DMA starts but then gets stuck, or if it never starts at all. It could also >> be that the DMA happens, but the completion event (which is what doesn't >> seem to happen) is mishandled because of the additional event queue. >> >> I turned on the DMA debug flag, but that produced so much debug output >> that my tools are crashing. I'll have to see what I can do to narrow things >> down a bit. >> >> Gabe >> >> On Thu, Mar 22, 2018 at 11:28 AM, Gabe Black <gabebl...@google.com> >> wrote: >> >>> Ok, thanks. We're deciding internally what approach to use to tackle >>> this. >>> >>> Gabe >>> >>> On Wed, Mar 21, 2018 at 3:01 AM, Andreas Sandberg < >>> andreas.sandb...@arm.com> wrote: >>> >>>> Hi Gabe, >>>> >>>> There are issues with the IDE model that prevent it from working with >>>> in-kernel GIC emulation. I believe the model doesn't clear interrupts >>>> correctly, which confuses the host kernel. I tried to debug this at some >>>> point, but wasn't able to do much immaediate progress and decided it wasn't >>>> worth the effort. The VirtIO block devices doesn't suffer from this >>>> problem. >>>> >>>> Using the VirtIO device by default seems like a good idea to me. It >>>> doesn't simulate any timing, but that might not be a huge deal since the >>>> IDE device doesn't provide realistic timing anyway. It would be really >>>> awesome if we had a modern storage controller (e.g., NVMe or AHCI) and >>>> proper storage timing models. >>>> >>>> Cheers, >>>> Andreas >>>> >>>> On 20/03/2018 23:38, Gabe Black wrote: >>>> >>>> My next question is about disks. I see that the fs_bigLITTLE.py script >>>> uses PciVirtIO to set up its disks, where I'm using IDE which I inherited >>>> from the fs.py scripts I used as reference. The problem I'm seeing is that >>>> the IDE controllers seem to be mangling commands and dropping interrupts, >>>> so this difference looks particularly suspicious. Is there a KVM related >>>> reason you're using PciVirtIO? Is this something that *should* work with >>>> IDE bug doesn't, or do I have to use PciVirtIO for things to work properly? >>>> I'm not familiar with PciVirtIO beyond briefly skimming the source for it >>>> in gem5. Is this something we should consider using globally as a >>>> replacement for IDE, even in simulations where we're trying to be really >>>> realistic? >>>> >>>> Thanks again for all the help. >>>> >>>> Gabe >>>> >>>> On Tue, Mar 20, 2018 at 3:14 PM, Gabe Black <gabebl...@google.com> >>>> wrote: >>>> >>>>> Ok, that (multiple event queues) made things way better. There are >>>>> still some glitches to figure out, but at least it makes good forward >>>>> progress at a reasonable speed. Thanks! >>>>> >>>>> Gabe >>>>> >>>>> On Mon, Mar 19, 2018 at 5:12 PM, Gabe Black <gabebl...@google.com> >>>>> wrote: >>>>> >>>>>> This is on an chromebook based on the RK3399 with only ~4GB of RAM >>>>>> which is not ideal, although we have a bigger machine in the works for >>>>>> the >>>>>> future. I agree with your reasoning and don't think option 1 is a >>>>>> problem. >>>>>> We're using static DTBs so I don't think that's an issue either. In my >>>>>> script, I'm not doing anything smart with the event queues, so that's >>>>>> likely at least part of the problem. When I tried using fs_bigLITTLE.py I >>>>>> ran into what looked like a similar issue so that might not be the whole >>>>>> story, but it's definitely something I should fix up. I'll let you know >>>>>> how >>>>>> that goes! >>>>>> >>>>>> Gabe >>>>>> >>>>>> On Mon, Mar 19, 2018 at 4:30 AM, Andreas Sandberg < >>>>>> andreas.sandb...@arm.com> wrote: >>>>>> >>>>>>> Hmm, OK, this is very strange. >>>>>>> >>>>>>> What type of hardware are you running on? Is it an A57-based chip or >>>>>>> something else? Also, what's your simulation quantum? I have been able >>>>>>> to >>>>>>> run with a 0.5ms quantum (5e8 ticks). >>>>>>> I think the following trace of two CPUs running in KVM should be >>>>>>> roughly equivalent to the trace you shared earlier. It was generated on >>>>>>> a >>>>>>> commercially available 8xA57 (16GiB ram) using the following command >>>>>>> (gem5 >>>>>>> rev 9dc44b417): >>>>>>> >>>>>>> gem5.opt -r --debug-flags Kvm,KvmIO,KvmRun >>>>>>> configs/example/arm/fs_bigLITTLE.py \ >>>>>>> --sim-quantum '0.5ms' \ >>>>>>> --cpu-type kvm --big-cpus 0 --little-cpus 2 \ >>>>>>> --dtb system/arm/dt/armv8_gem5_v1_2cpu.dtb --kernel >>>>>>> vmlinux.aarch64.4.4-d318f95d0c >>>>>>> >>>>>>> Note that the tick counts are a bit weird since we have three >>>>>>> different event queues at play (1 for devices and one per CPU). >>>>>>> >>>>>>> 0: system.littleCluster.cpus0: KVM: Executing for 500000000 ticks >>>>>>> 0: system.littleCluster.cpus1: KVM: Executing for 500000000 ticks >>>>>>> 0: system.littleCluster.cpus0: KVM: Executed 79170 instructions >>>>>>> in 176363 cycles (88181504 ticks, sim cycles: 176363). >>>>>>> 88182000: system.littleCluster.cpus0: handleKvmExit (exit_reason: 6) >>>>>>> 88182000: system.littleCluster.cpus0: KVM: Handling MMIO (w: 1, addr: >>>>>>> 0x1c090024, len: 4) >>>>>>> 88332000: system.littleCluster.cpus0: Entering KVM... >>>>>>> 88332000: system.littleCluster.cpus0: KVM: Executing for 411668000 ticks >>>>>>> 88332000: system.littleCluster.cpus0: KVM: Executed 4384 instructions >>>>>>> in 16854 cycles (8427000 ticks, sim cycles: 16854). >>>>>>> 96759000: system.littleCluster.cpus0: handleKvmExit (exit_reason: 6) >>>>>>> 96759000: system.littleCluster.cpus0: KVM: Handling MMIO (w: 1, addr: >>>>>>> 0x1c090030, len: 4) >>>>>>> 0: system.littleCluster.cpus1: KVM: Executed 409368 instructions >>>>>>> in 666400 cycles (333200000 ticks, sim cycles: 666400). >>>>>>> 333200000: system.littleCluster.cpus1: Entering KVM... >>>>>>> 333200000: system.littleCluster.cpus1: KVM: Executing for 166800000 >>>>>>> ticks >>>>>>> 96909000: system.littleCluster.cpus0: Entering KVM... >>>>>>> 96909000: system.littleCluster.cpus0: KVM: Executing for 403091000 ticks >>>>>>> 96909000: system.littleCluster.cpus0: KVM: Executed 4384 instructions >>>>>>> in 15257 cycles (7628500 ticks, sim cycles: 15257). >>>>>>> 104538000: system.littleCluster.cpus0: handleKvmExit (exit_reason: 6) >>>>>>> 104538000: system.littleCluster.cpus0: KVM: Handling MMIO (w: 1, addr: >>>>>>> 0x1c0100a0, len: 4) >>>>>>> 333200000: system.littleCluster.cpus1: KVM: Executed 47544 instructions >>>>>>> in 200820 cycles (100410000 ticks, sim cycles: 200820). >>>>>>> 433610000: system.littleCluster.cpus1: Entering KVM... >>>>>>> 433610000: system.littleCluster.cpus1: KVM: Executing for 66390000 ticks >>>>>>> 104688000: system.littleCluster.cpus0: Entering KVM... >>>>>>> 104688000: system.littleCluster.cpus0: KVM: Executing for 395312000 >>>>>>> ticks >>>>>>> 104688000: system.littleCluster.cpus0: KVM: Executed 4382 instructions >>>>>>> in 14942 cycles (7471000 ticks, sim cycles: 14942). >>>>>>> >>>>>>> Comparing this trace to yours, I'd say that there the frequent KVM >>>>>>> exits look a bit suspicious. I would expect secondary CPUs to make very >>>>>>> little process while the main CPU initializes the system and starts the >>>>>>> early boot code. >>>>>>> >>>>>>> There area couple of possibilities that might be causing issues: >>>>>>> >>>>>>> 1) There is some CPU ID weirdness that confuses the boot code and >>>>>>> puts both CPUs in the holding pen. This seems unlikely since there are >>>>>>> some >>>>>>> writes to the UART. >>>>>>> >>>>>>> 2) Some device is incorrectly mapped to the CPU event queues and >>>>>>> causes frequent KVM exits. Have a look at _build_kvm in >>>>>>> fs_bigLITTLE.py, it >>>>>>> doesn't use configs/common, so no need to tear your eyes out. ;) Do you >>>>>>> map >>>>>>> event queues in the same way? It's mapping all simulated devices to one >>>>>>> event queue and the CPUs to private event queues. It's important to >>>>>>> remap >>>>>>> CPU child devices to the device queue instead of the CPU queue. Failing >>>>>>> to >>>>>>> do this will cause chaos, madness, and quite possibly result in >>>>>>> Armageddon. >>>>>>> >>>>>>> 3) You're using DTB autogeneration. This doesn't work for KVM guests >>>>>>> due to issues with the timer interrupt specification. We have a patch >>>>>>> for >>>>>>> the timer that we are testing internally. Sorry. :( >>>>>>> >>>>>>> Regards, >>>>>>> Andreas >>>>>>> On 16/03/2018 23:20, Gabe Black wrote: >>>>>>> >>>>>>> Ok, diving into this a little deeper, it looks like execution is >>>>>>> progressing but is making very slow progress for some reason. I added a >>>>>>> call to "dump()" before each ioctl invocation which enters the VM and >>>>>>> looked at the PC to get an idea of what it was up to. I made sure to put >>>>>>> that before the timers to avoid taking up VM time with printing debug >>>>>>> stuff. In any case, I see that neither CPU gets off of PC 0 for about >>>>>>> 2ms >>>>>>> simulated time (~500Hz), and that's EXTREMELY slow for a CPU which is >>>>>>> supposed to be running in the ballpark of 2GHz. It's not clear to me why >>>>>>> it's making such slow progress, but that would explain why I'm getting >>>>>>> very >>>>>>> little out on the simulated console. It's just taking forever to make it >>>>>>> that far. >>>>>>> >>>>>>> Any idea why it's going so slow, or how to debug further? >>>>>>> >>>>>>> Gabe >>>>>>> >>>>>>> On Wed, Mar 14, 2018 at 7:42 PM, Gabe Black <gabebl...@google.com> >>>>>>> wrote: >>>>>>> >>>>>>>> Some output which I think is suspicious: >>>>>>>> >>>>>>>> 55462000: system.cpus0: Entering KVM... >>>>>>>> 55462000: system.cpus0: KVM: Executing for 1506000 ticks >>>>>>>> 55462000: system.cpus0: KVM: Executed 5159 instructions in 13646 >>>>>>>> cycles (6823000 ticks, sim cycles: 13646). >>>>>>>> 56968000: system.cpus1: Entering KVM... >>>>>>>> 56968000: system.cpus1: KVM: Executing for 5317000 ticks >>>>>>>> 56968000: system.cpus1: KVM: Executed 7229 instructions in 14379 >>>>>>>> cycles (7189500 ticks, sim cycles: 14379). >>>>>>>> 62285000: system.cpus0: Entering KVM... >>>>>>>> 62285000: system.cpus0: KVM: Executing for 1872500 ticks >>>>>>>> 62285000: system.cpus0: KVM: Executed 5159 instructions in 13496 >>>>>>>> cycles (6748000 ticks, sim cycles: 13496). >>>>>>>> 64157500: system.cpus1: Entering KVM... >>>>>>>> 64157500: system.cpus1: KVM: Executing for 4875500 ticks >>>>>>>> 64157500: system.cpus1: KVM: Executed 6950 instructions in 13863 >>>>>>>> cycles (6931500 ticks, sim cycles: 13863). >>>>>>>> 69033000: system.cpus0: Entering KVM... >>>>>>>> 69033000: system.cpus0: KVM: Executing for 2056000 ticks >>>>>>>> 69033000: system.cpus0: KVM: Executed 5159 instructions in 13454 >>>>>>>> cycles (6727000 ticks, sim cycles: 13454). >>>>>>>> 71089000: system.cpus1: Entering KVM... >>>>>>>> 71089000: system.cpus1: KVM: Executing for 4671000 ticks >>>>>>>> 71089000: system.cpus1: KVM: Executed 6950 instructions in 13861 >>>>>>>> cycles (6930500 ticks, sim cycles: 13861). >>>>>>>> 75760000: system.cpus0: Entering KVM... >>>>>>>> 75760000: system.cpus0: KVM: Executing for 2259500 ticks >>>>>>>> 75760000: system.cpus0: KVM: Executed 5159 instructions in 13688 >>>>>>>> cycles (6844000 ticks, sim cycles: 13688). >>>>>>>> >>>>>>>> [...] >>>>>>>> >>>>>>>> 126512000: system.cpus0: handleKvmExit (exit_reason: 6) >>>>>>>> 126512000: system.cpus0: KVM: Handling MMIO (w: 1, addr: >>>>>>>> 0x1c090024, len: 4) >>>>>>>> 126512000: system.cpus0: In updateThreadContext(): >>>>>>>> >>>>>>>> [...] >>>>>>>> >>>>>>>> 126512000: system.cpus0: PC := 0xd8 (t: 0, a64: 1) >>>>>>>> >>>>>>>> On Wed, Mar 14, 2018 at 7:37 PM, Gabe Black <gabebl...@google.com> >>>>>>>> wrote: >>>>>>>> >>>>>>>>> I tried it just now, and I still don't see anything on the >>>>>>>>> console. I switched back to using my own script since it's a bit >>>>>>>>> simpler >>>>>>>>> (it doesn't use all the configs/common stuff), and started looking at >>>>>>>>> the >>>>>>>>> KVM debug output. I see that both cpus claim to execute instructions, >>>>>>>>> although cpu1 didn't take an exit in the output I was looking at. >>>>>>>>> cpu0 took >>>>>>>>> four exits, two which touched some UART registers, and two which >>>>>>>>> touched >>>>>>>>> RealView registes, the V2M_SYS_CFGDATA and V2M_SYS_CFGCTRL registers >>>>>>>>> judging by the comments in the bootloader assembly file. >>>>>>>>> >>>>>>>>> After that they claim to be doing stuff, although I see no further >>>>>>>>> console output or KVM exits. The accesses themselves and their PCs >>>>>>>>> are from >>>>>>>>> the bootloader blob, and so I'm pretty confident that it's starting >>>>>>>>> that >>>>>>>>> and executing some of those instructions. One thing that looks very >>>>>>>>> odd now >>>>>>>>> that I think about it, is that the KVM messages about entering and >>>>>>>>> executing instructions (like those below) seem to say that cpu0 has >>>>>>>>> executed thousands of instructions, but the exits I see seem to >>>>>>>>> correspond >>>>>>>>> to the first maybe 50 instructions it should be seeing in the >>>>>>>>> bootloader >>>>>>>>> blob. Are those values bogus for some reason? Is there some existing >>>>>>>>> debug >>>>>>>>> output which would let me see where KVM thinks it is periodically to >>>>>>>>> see if >>>>>>>>> it's in the kernel or if it went bananas and is executing random >>>>>>>>> memory >>>>>>>>> somewhere? Or if it just got stuck waiting for some event that's not >>>>>>>>> going >>>>>>>>> to show up? >>>>>>>>> >>>>>>>>> Are there any important CLs which haven't made their way into >>>>>>>>> upstream somehow? >>>>>>>>> >>>>>>>>> Gabe >>>>>>>>> >>>>>>>>> On Wed, Mar 14, 2018 at 4:28 AM, Andreas Sandberg < >>>>>>>>> andreas.sandb...@arm.com> wrote: >>>>>>>>> >>>>>>>>>> Have you tried using the fs_bigLITTLE script in >>>>>>>>>> configs/examples/arm? >>>>>>>>>> That's the script I have been using for testing. >>>>>>>>>> >>>>>>>>>> I just tested the script with 8 little CPUs and 0 big CPUs and it >>>>>>>>>> seems >>>>>>>>>> to work. Timing is a bit temperamental though, so you might need >>>>>>>>>> to >>>>>>>>>> override the simulation quantum. The default is 1ms, you might >>>>>>>>>> need to >>>>>>>>>> decrease it to something slightly smaller (I'm currently using >>>>>>>>>> 0.5ms). >>>>>>>>>> Another caveat is that there seem to be some issues related to dtb >>>>>>>>>> auto-generation that affect KVM guests. We are currently testing a >>>>>>>>>> solution for this issue. >>>>>>>>>> >>>>>>>>>> Cheers, >>>>>>>>>> Andreas >>>>>>>>>> >>>>>>>>>> >>>>>>>>>> >>>>>>>>>> On 12/03/2018 22:26, Gabe Black wrote: >>>>>>>>>> >>>>>>>>>>> I'm trying to run in FS mode, to boot android/linux. >>>>>>>>>>> >>>>>>>>>>> Gabe >>>>>>>>>>> >>>>>>>>>>> On Mon, Mar 12, 2018 at 3:26 PM, Dutu, Alexandru < >>>>>>>>>>> alexandru.d...@amd.com> >>>>>>>>>>> wrote: >>>>>>>>>>> >>>>>>>>>>> Hi Gabe, >>>>>>>>>>>> >>>>>>>>>>>> Are you running SE or FS mode? >>>>>>>>>>>> >>>>>>>>>>>> Thanks, >>>>>>>>>>>> Alex >>>>>>>>>>>> >>>>>>>>>>>> -----Original Message----- >>>>>>>>>>>> From: gem5-dev [mailto:gem5-dev-boun...@gem5.org] On Behalf Of >>>>>>>>>>>> Gabe Black >>>>>>>>>>>> Sent: Friday, March 9, 2018 5:46 PM >>>>>>>>>>>> To: gem5 Developer List <gem5-dev@gem5.org> >>>>>>>>>>>> Subject: [gem5-dev] Multicore ARM v8 KVM based simulation >>>>>>>>>>>> >>>>>>>>>>>> Hi folks. I have a config script set up where I can run a KVM >>>>>>>>>>>> based ARM v8 >>>>>>>>>>>> simulation just fine when I have a single CPU in it, but when I >>>>>>>>>>>> try running >>>>>>>>>>>> with more than one CPU, it just seems to get lost and not do >>>>>>>>>>>> anything. Is >>>>>>>>>>>> this a configuration that's supported? If so, are there any >>>>>>>>>>>> caveats to how >>>>>>>>>>>> it's set up? I may be missing something simple, but it's not >>>>>>>>>>>> apparent to me >>>>>>>>>>>> at the moment. >>>>>>>>>>>> >>>>>>>>>>>> Gabe >>>>>>>>>>>> _______________________________________________ >>>>>>>>>>>> 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 >>>>>>>>>>> >>>>>>>>>> >>>>>>>>>> IMPORTANT NOTICE: The contents of this email and any attachments >>>>>>>>>> are confidential and may also be privileged. If you are not the >>>>>>>>>> intended >>>>>>>>>> recipient, please notify the sender immediately and do not disclose >>>>>>>>>> the >>>>>>>>>> contents to any other person, use it for any purpose, or store or >>>>>>>>>> copy the >>>>>>>>>> information in any medium. Thank you. >>>>>>>>>> >>>>>>>>> >>>>>>>>> >>>>>>>> >>>>>>> >>>>>>> IMPORTANT NOTICE: The contents of this email and any attachments are >>>>>>> confidential and may also be privileged. If you are not the intended >>>>>>> recipient, please notify the sender immediately and do not disclose the >>>>>>> contents to any other person, use it for any purpose, or store or copy >>>>>>> the >>>>>>> information in any medium. Thank you. >>>>>>> >>>>>> >>>>>> >>>>> >>>> >>>> IMPORTANT NOTICE: The contents of this email and any attachments are >>>> confidential and may also be privileged. If you are not the intended >>>> recipient, please notify the sender immediately and do not disclose the >>>> contents to any other person, use it for any purpose, or store or copy the >>>> information in any medium. Thank you. >>>> >>> >>> >> > _______________________________________________ gem5-dev mailing list gem5-dev@gem5.org http://m5sim.org/mailman/listinfo/gem5-dev
