Here is test #9 (#8 is the same as #4 from my previous tests. And not of much help since Disco-updates QEMU (v=1:3.1+dfsg-2ubuntu3.3) does not have cap-ibs=workaround):
*** 9- Bionic-proposed kernel + Disco-proposed QEMU $ uname -r; qemu-system-ppc64 --version | head -n 1 4.15.0-60-generic QEMU emulator version 3.1.0 (Debian 1:3.1+dfsg-2ubuntu3.4) $ dmesg | grep count-cache [ 0.000000] count-cache-flush: hardware assisted flush sequence enabled $ qemu-system-ppc64 -machine pseries,? 2>&1 | grep "\|ibs\|ccf" cap-ibs=string (Indirect Branch Speculation (broken, workaround, fixed-ibs,fixed-ccd, fixed-na)) cap-ccf-assist=bool (Count Cache Flush Assist via HW Instruction) - cap-ibs=broken $ dmesg | grep count-cache [ 0.000000] count-cache-flush: software flush disabled. - cap-ibs=workaround $ dmesg | grep count-cache [ 0.000000] count-cache-flush: full software flush sequence enabled. - cap-ibs=fixed-ccd qemu-system-ppc64: Requested safe indirect branch capability level not supported by kvm, try cap-ibs=workaround - cap-ibs=fixed-ibs qemu-system-ppc64: Requested safe indirect branch capability level not supported by kvm, try cap-ibs=workaround - cap-ccf-assist=off $ dmesg | grep count-cache [ 0.000000] count-cache-flush: software flush disabled. - cap-ccf-assist=on $ dmesg | grep count-cache [ 0.000000] count-cache-flush: software flush disabled. - cap-ibs=workaround,cap-ccf-assist=on $ dmesg | grep count-cache [ 0.000000] count-cache-flush: hardware assisted flush sequence enabled - cap-ibs=workaround,cap-ccf-assist=off $ dmesg | grep count-cache [ 0.000000] count-cache-flush: full software flush sequence enabled. So my interpretation of the results is that the Disco kernel is indeed to blame for cap-ibs=workaround not working with QEMU 1:3.1+dfsg-2ubuntu3.4 and a DD 2.3 machine. -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1832622 Title: QEMU - count cache flush Spectre v2 mitigation (CVE) (required for POWER9 DD2.3) To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu-power-systems/+bug/1832622/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
