https://bugzilla.kernel.org/show_bug.cgi?id=205151 Bug ID: 205151 Summary: "user requested TSC rate below hardware speed" warning Product: Virtualization Version: unspecified Kernel Version: 5.3 Hardware: x86-64 OS: Linux Tree: Mainline Status: NEW Severity: normal Priority: P1 Component: kvm Assignee: virtualization_kvm@xxxxxxxxxxxxxxxxxxxx Reporter: v.zubkov87@xxxxxxxxx Regression: Yes 5.3 seems to have broken TSC, at least for qemu/kvm VMs. After 5.3 upgrade starting a VM gets me "user requested TSC rate below hardware speed" warnings (1 per assigned core). I'm not quite sure when kind of data I could provide, however after a short while (several minutes) drift becomes quite noticable (severe audio/video desync). Relevant(?) dmesg entries from 5.3: [Sun Oct 6 16:59:21 2019] tsc: Detected 4000.000 MHz processor [Sun Oct 6 16:59:21 2019] tsc: Detected 3999.984 MHz TSC [Sun Oct 6 16:59:22 2019] tsc: Refined TSC clocksource calibration: 4008.064 MHz [Sun Oct 6 17:00:48 2019] user requested TSC rate below hardware speed [Sun Oct 6 17:00:48 2019] user requested TSC rate below hardware speed And 5.2: [Thu Oct 3 21:56:01 2019] tsc: Detected 4000.000 MHz processor [Thu Oct 3 21:56:01 2019] tsc: Detected 4008.000 MHz TSC (no refined calibration here) My CPU is Intel(R) Core(TM) i7-6700K CPU @ 4.00GHz (family: 0x6, model: 0x5e, stepping: 0x3). Revering commit 604dc9170f2435d27da5039a3efd757dceadc684 fixes the problem. -- You are receiving this mail because: You are watching the assignee of the bug.
