On Wed, Sep 28, 2016 at 1:29 PM, Martin Schrodt <mar...@schrodt.org> wrote:
> Dear community, > > after buying a new rig a week ago, I noticed several problems with the > mainboard I chose, so I am going to send it back. It's an ASRock Z 170 > Extreme 4. > > Problems I have: > > 1) The board does not like the RAM I ordered. I have a kit DDR4-3200 > DIMM CL14-14-14-34 from G-Skill that will crap out when running at it's > specified speed, right now it's stable at 2800. > > 2) It won't suspend correctly if I leave it's USB-3.1 controller to > Linux (will wake up immediately, complaining that the USB controller > prevented proper suspend) (ASMedia Technology Inc. ASM1142) > A poorly behaving ASMedia device, shocking </sarcasm> 3) The first and the second PCIe-slot are in the same IOMMU-group, > preventing me to use a second GPU for the host in slot 2 without > ACS-override. (*1) > Of course, you need a certain class of processors to have ACS, Z170 doesn't support any of those processors. See http://vfio.blogspot.com/2015/10/intel-processors-with-acs-support.html You need an X99 motherboard for that. > 4) When resuming from suspend, the BIOS (I presume, someone with another > board from ASRock has the same problems) fucks up TSC, which causes the > kernel to turn it off, and the VM to stutter badly afterwards. I have to > reboot to get a performing VM. (*2) > > 5) The VM is dead after I suspend/resume the host. > Hmm, if you're thinking a VM with assigned devices should survive a host suspend/resume, I'm not sure that's a reasonable expectation right now. > I need help in finding a good board quickly, so my downtime won't be too > much. So I reach out to y'all. Is someone out there who can suggest a > mainboard that does provide remedy for the points above? > > I am very grateful for your help! > > (*1) script to list IOMMU group with contained device: > > for iommu_group in $(find /sys/kernel/iommu_groups/ -maxdepth 1 > -mindepth 1 -type d); do echo "IOMMU group $(basename "$iommu_group")"; > for device in $(\ls -1 "$iommu_group"/devices/); do echo -n $'\t'; lspci > -nns "$device"; done; done > > (*2) To check whether tsc is enabled: > > cat /sys/devices/system/clocksource/clocksource0/available_clocksource > > The output should contain "tsc" before and after suspend to ram. > > _______________________________________________ > vfio-users mailing list > vfio-users@redhat.com > https://www.redhat.com/mailman/listinfo/vfio-users >
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