Public bug reported: Problem description: We turn on device IOTLB via VIRTIO_F_IOMMU_PLATFORM unconditionally on platform without IOMMU support. This can lead unnecessary IOTLB transactions which will damage the performance.
Fixing this by check whether the device is backed by IOMMU and disable device IOTLB. The patch can be found at https://lists.gnu.org/archive/html/qemu-devel/2020-03/msg00074.html. ** Affects: qemu (Ubuntu) Importance: Undecided Assignee: Skipper Bug Screeners (skipper-screen-team) Status: New ** Tags: architecture-s39064 bugnameltc-184022 severity-high targetmilestone-inin2004 ** Tags added: architecture-s39064 bugnameltc-184022 severity-high targetmilestone-inin2004 ** Changed in: ubuntu Assignee: (unassigned) => Skipper Bug Screeners (skipper-screen-team) ** Package changed: ubuntu => qemu (Ubuntu) -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1866207 Title: [Ubuntu 20.04] vhost_set_features not supported in qemu-system-s390x To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/qemu/+bug/1866207/+subscriptions -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
