TL;DR only occurs with HWE kernel - odd Results of: $ cat /sys/devices/system/cpu/vulnerabilities/mds
Host Bionic: 4.18.0-20-generic / 2.11+dfsg-1ubuntu7.13 Guest-lvl1: 3.13.0-170-generic / 2.0.0+dfsg-2ubuntu1.46 Vulnerable: Clear CPU buffers attempted, SMT Host state unknown Guest-lvl2: 3.13.0-170-generic Vulnerable: Clear CPU buffers attempted, no microcode; SMT Host state unknown It is "ok" that without passthrough it hits "Clear CPU buffers attempted" Using passthrough: Guest-lvl1: 3.13.0-170-generic / 2.0.0+dfsg-2ubuntu1.46 + passthrough Mitigation: Clear CPU buffers; SMT Host state unknown Guest-lvl2: 3.13.0-170-generic + passthrough Mitigation: Clear CPU buffers; SMT Host state unknown So this does not trigger witrh 3.13 kernels for me. Upgrading to 4.4 in both trusty levels now. Guest-lvl1: 4.4.0-148-generic / 2.0.0+dfsg-2ubuntu1.46 + passthrough Mitigation: Clear CPU buffers; SMT Host state unknown Guest-lvl1: 4.4.0-148-generic $ cat /sys/devices/system/cpu/vulnerabilities/mds Not affected -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1829555 Title: nested virtualization w/first level trusty guests has odd MDS behavior To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1829555/+subscriptions -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
