http://bugzilla.opensuse.org/show_bug.cgi?id=1092035 Bug ID: 1092035 Summary: VM CPU model with *-IBRS causing host cpu performance degradation Classification: openSUSE Product: openSUSE Distribution Version: Leap 42.3 Hardware: x86-64 OS: Other Status: NEW Severity: Normal Priority: P5 - None Component: KVM Assignee: kvm-bugs@forge.provo.novell.com Reporter: magist3r@gmail.com QA Contact: qa-bugs@suse.de Found By: --- Blocker: --- After I run a virtual machine using libvirt, the CPU performance is significantly degraded (about 2 times). I double checked this using various benchmarks. This issue is only reproduced when I use 'IvyBridge-IBRS' CPU model. With 'IvyBridge' all works fine. Performance degradation remains after VM shutdown. To reset CPU to original performance, I need to reboot or suspend/resume my machine. My system information: PROCESSOR: Intel Core i7-3770 @ 4.10GHz (8 Cores) GRAPHICS: NVIDIA GeForce GTX 660 Ti 2048MB MOTHERBOARD: ASUS P8Z77-V LE PLUS OPERATING SYSTEM: openSUSE 42.3 with latest updates -- You are receiving this mail because: You are on the CC list for the bug.