Public bug reported: This is a bit of a race, many of the relevant changes like [1][2] have landed upstream and are already in qmeu 9.2 that we have in plucky. But for a particular set of cards, I know of the Nvidia H100 there is an issue in regard to memory handling which makes this "almost there but unusable".
It is a race as AMD works on fully upstreaming things, but given the feature freezes of Ubuntu things might not fit perfectly. There is a temporary stop gap in [3][4] that seems ok to be carried in 25.04. It is unblocking the usage of a new technology and only changing a use case that is otherwise impossible to be "kind of ok, based on a hack and with extra memory consumption". Until fully worked out and upstreamed I reject backporting this to active Ubuntu releases. I do furthermore not agree to just carry this change indefinitely (we will drop it in 25.10 and rely on what is upstream by then). Things will diverge and cause problems, this is really just a stop-gap to avoid users to wait another 6 months. It should be a change landing before 25.04 is in Feature-Freeze, which we are still in time for as of today. I pre-checked and the patches: - They are meaningful, but of small size making them relatively easy to review (implications are larger than the code size though). - They apply cleanly as-is. - They furthermore are only relevant for a very specific use case that has still a very small user base and should therefore even less affect the majority of qemu users even if it would be bad. Therefore I plan to add this to qemu 9.2 in qemu 25.04 soon. [1]: https://github.com/qemu/qemu/commit/60de433d4cb17211dbea5c1e6b74d476dec16370 [2]: https://github.com/qemu/qemu/commit/586d708c1e3e5e29a0b3c05c347290aed9478854 [3]: https://github.com/AMDESE/qemu/commit/0c9ae28d3e199de9a40876a492e0f03a11c6f5d8 [4]: https://github.com/AMDESE/qemu/commit/5256c41fb3055961ea7ac368acc0b86a6632d095 ** Affects: qemu (Ubuntu) Importance: Undecided Assignee: Christian Ehrhardt (paelzer) Status: New ** Affects: qemu (Ubuntu Noble) Importance: Undecided Status: Won't Fix ** Affects: qemu (Ubuntu Oracular) Importance: Undecided Status: Won't Fix ** Tags: server-todo ** Also affects: qemu (Ubuntu Noble) Importance: Undecided Status: New ** Also affects: qemu (Ubuntu Oracular) Importance: Undecided Status: New ** Changed in: qemu (Ubuntu Noble) Status: New => Won't Fix ** Changed in: qemu (Ubuntu Oracular) Status: New => Won't Fix ** Changed in: qemu (Ubuntu) Assignee: (unassigned) => Christian Ehrhardt (paelzer) ** Tags added: server-todo -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/2097517 Title: Close the gap to support AMD SEV SNP for Nvidia H100 cards in plucky To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/qemu/+bug/2097517/+subscriptions -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
