http://bugzilla.suse.com/show_bug.cgi?id=1092035 http://bugzilla.suse.com/show_bug.cgi?id=1092035#c7 --- Comment #7 from Fei Li <fli@suse.com> --- (In reply to Fei Li from comment #5)

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Hi. I used geekbench benchmark. Here is my general result: https://browser.geekbench.com/v4/cpu/8134716 And here after cpu performance drop: https://browser.geekbench.com/v4/cpu/8134665

CPU performance drop is present right after starting VM with *-IBRS profile and restores only with CPU power reset (reboot or suspend/resume). Even stopping all VM's not solves the problem. So your problem is stopping the VM with *-IBRS can not restore the host CPU

(In reply to magist3r sergei from comment #4) performance, and instead the performance can only be restored by rebooting the host, right? This sounds not like the same with this bug's title. :) Will try to reproduce it on my environment then and see what's wrong with this.

I use the geekbench-tool you shared to do the tests, and did not reproduce your phenomenon. In my environment[1] (my machine is Skylake, currently I do not have a Ivybridge one), CPU downgrades not so obvious[2]. [1] My environment: host # rpm -qa | grep ucode-intel ucode-intel-20180312-22.1.x86_64 host # uname -a Linux linux 4.4.126-48-default #1 SMP Sat Apr 7 05:22:50 UTC 2018 (f24992c) x86_64 x86_64 x86_64 GNU/Linux host # grep -H . /sys/devices/system/cpu/vulnerabilities/* /sys/devices/system/cpu/vulnerabilities/meltdown:Mitigation: PTI /sys/devices/system/cpu/vulnerabilities/spectre_v1:Mitigation: __user pointer sanitization /sys/devices/system/cpu/vulnerabilities/spectre_v2:Mitigation: IBRS+IBPB host # dmesg | grep spec //no message means fully applied And qemu (2.9.1-41.1.x86_64) libvirt (3.3.0-15.1) are up to date, too. guest # cat /proc/cpuinfo Model name: Intel Xeon E3-12xx v2 (Ivy Bridge, IBRS) ... flags: fpu vme ... spec_ctl ... ... guest # grep -H . /sys/devices/system/cpu/vulnerabilities/* /sys/devices/system/cpu/vulnerabilities/meltdown:Mitigation: PTI /sys/devices/system/cpu/vulnerabilities/spectre_v1:Mitigation: __user pointer sanitization /sys/devices/system/cpu/vulnerabilities/spectre_v2:Mitigation: Full generic retpoline + IBPB [2] My test results 1. In the host without any vm is running, run `./geekbench4` under the decompressed Geekbench-4.2.2-Linux, result is 4544/15058, see https://browser.geekbench.com/v4/cpu/8284798 2. `virsh start opensuse42.3`, run `./geekbench4`, result is 4541/14357, see https://browser.geekbench.com/v4/cpu/8285056 3. `virsh destroy opensuse42.3`, run `./geekbench4`, result is 4501/14143, see https://browser.geekbench.com/v4/cpu/8285106 BTW, I use same steps on a Haswell v2 machine to do the tests too. The result is also not obvious before starting a vm and destroy a vm. FYI, pls see 8284586/8284623/8284656. Umm, have no idea what is the difference between our environments.. But at least, the config you have attached are same. -- You are receiving this mail because: You are on the CC list for the bug.