On Thursday, November 26, 2020 6:26 PM, Alex Smirnoff <arke...@gmail.com> wrote:
> It is rather a xen issue, but I did not find xen groups alive enough, so.. > > I have a 6-core cpu, so.. xen thinks there are two "CPU's" per core, probably > due to HT. > And it does, apparently, cause a lot of confusion. > > from "xenpm start 1: > > Socket 0 > Core 0 CPU 0 > Core 1 CPU 2 > Core 2 CPU 4 > Core 3 CPU 6 > Core 4 CPU 8 > Core 5 CPU 10 > > But, when I try to get CPU states, xenpm assumes the core count to the cpu > count! thus, it tries to get status of CPU0-CPU5, which succeeds only for > even CPUs, odd CPUs get dropped and return error when xenp tries to control > them, and CPU6-CPU10 are ingored. > > also, xenpm get-cpufreq-para returns obviously incorrect values (for even > CPUs only, again, for odd ones it just "falied to get cpufreq parameter" and > 6-10 are igored), as well as xentop. At the same time, values at > get-cpufreq-average are apparently right. > > Is it a known issue? Yes, similar things mentioned here https://github.com/QubesOS/qubes-issues/issues/4252 and here https://github.com/QubesOS/qubes-issues/issues/4456 Additional logical cores have been disabled in Qubes OS to mitigate serious vulnerability https://www.qubes-os.org/news/2018/09/02/qsb-43/ , in this QSB it is also shown how to re-enable Hyper-Threading (SMT), though it's not recommended. To make xenpm show only physical cores disable Hyper-Threading in UEFI (suggested in issue 4252). But to make it show correct frequencies it may be needed 1) disable GT in UEFI 2) re-enable SMT in xen.cfg (it shouldn't have adverse effects since HT already disabled in UEFI) -- You received this message because you are subscribed to the Google Groups "qubes-users" group. To unsubscribe from this group and stop receiving emails from it, send an email to qubes-users+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/qubes-users/7c3rcBhFbpqWMYUhjpDGlx-ivKcbr52kbICSb_JRt0jkSq2BPEnIodHtSq8_0G8wnzked9Pfltx9zRn9JOfd_NqlmNJJddTAhDlOxfkIVJU%3D%40protonmail.com.
