So after we talked on MM, I think maybe you and Simon have been testing this instead, so for now is do I need to do this?
Thanks Jeff On Tue, Mar 19, 2024 at 3:10 PM Sergio Durigan Junior < 2012...@bugs.launchpad.net> wrote: > Hi Jeff, > > Thanks for the offer. Actually there is! > > - If you could test Noble and double/triple check that we don't need to > do anything else there in order to support maxcpus, that'd be great. > Just use the "ubuntu" machine type and check if QEMU starts correct with > more than 288 vCPUs. > > - Once the Jammy/Mantic SRUs are accepted, we will need to perform a > verification for both uploads. I can do it my side, but it would be > very helpful if you could also verify the uploads on your side. > > Thanks. > > -- > You received this bug notification because you are subscribed to the bug > report. > https://bugs.launchpad.net/bugs/2012763 > > Title: > qemu-system-amd64 max cpus is too low for latest processors > > Status in lxd package in Ubuntu: > New > Status in qemu package in Ubuntu: > Confirmed > Status in lxd source package in Jammy: > New > Status in qemu source package in Jammy: > New > Status in lxd source package in Lunar: > Invalid > Status in qemu source package in Lunar: > Invalid > Status in lxd source package in Mantic: > New > Status in qemu source package in Mantic: > Confirmed > Status in lxd source package in Noble: > New > Status in qemu source package in Noble: > Confirmed > > Bug description: > [ Impact ] > > QEMU users on Ubuntu Jammy/Mantic who try to spawn a VM with more than > 288 vCPUs will not be able to do so, because the machine types > available don't support such scenario. The following error will > happen: > > qemu-system-x86_64: Invalid SMP CPUs 300. The max CPUs supported by > machine 'pc-q35-jammy' is 288 > > [ Test Plan ] > > Ideally, the test should be performed in a machine with more than 288 > physical CPUs available. However, due to the difficulty in finding > such systems, it is possible to emulate the usage of more than 288 > vCPUs. > > On a Jammy/Mantic machine, making sure to adjust the machine type > accordingly, you can do: > > $ sudo qemu-system-x86_64 -M pc-q35-jammy,accel=kvm,kernel- > irqchip=split -device intel-iommu,intremap=on -smp > cpus=300,maxcpus=300 -enable-kvm -net none -m 4096M -nographic -kernel > /boot/vmlinuz -initrd /boot/initrd.img -chardev stdio,mux=on,id=char0 > -mon chardev=char0,mode=readline -serial chardev:char0 -append > "console=ttyS0" > > You will notice that the command will fail, as expected. > > The proposed fix is to create a new machine type on Jammy/Mantic, in > order to minimize the possibility of regressions in deployments using > the existing machine types. This new type is named > pc-{q35,i440fx}-{jammy,mantic}-maxcpus. When doing the test, make > sure to provide this new machine type (as part of the "-M" argument). > > [ Where problems could occur ] > > As explained above, a new machine type was created in order to > minimize the possibility of regressions. As such, the existing > "pc-{q35,i440fx}-{jammy,mantic}" machine types should continue to work > as before, without any change. > > [ Original Description ] > > During testing of an AMD Genoa CPU, it was discovered that qemu- > system-amd64 doesn't support enough cpus. > > The specific error the tester received was: > > qemu-system-x86_64: Invalid SMP CPUs 384. The max supported by machine > 'pc-q35-7.1' is 288 > > Looking at the sournce that seems to be an easy fix at first glance: > > https://github.com/qemu/qemu/blob/master/hw/i386/pc_q35.c > 372 machine_class_allow_dynamic_sysbus_dev(m, TYPE_VMBUS_BRIDGE); > 373 m->max_cpus = 288; > > To manage notifications about this bug go to: > https://bugs.launchpad.net/ubuntu/+source/lxd/+bug/2012763/+subscriptions > > Launchpad-Notification-Type: bug > Launchpad-Bug: distribution=ubuntu; sourcepackage=lxd; component=universe; > status=New; importance=Undecided; assignee=None; > Launchpad-Bug: distribution=ubuntu; sourcepackage=qemu; component=main; > status=Confirmed; importance=Critical; assignee= > sergio.duri...@canonical.com; > Launchpad-Bug: distribution=ubuntu; distroseries=jammy; sourcepackage=lxd; > component=None; status=New; importance=Undecided; assignee=None; > Launchpad-Bug: distribution=ubuntu; distroseries=jammy; > sourcepackage=qemu; component=main; status=New; importance=Undecided; > assignee=sergio.duri...@canonical.com; > Launchpad-Bug: distribution=ubuntu; distroseries=lunar; sourcepackage=lxd; > component=None; status=Invalid; importance=Undecided; assignee=None; > Launchpad-Bug: distribution=ubuntu; distroseries=lunar; > sourcepackage=qemu; component=main; status=Invalid; importance=Undecided; > assignee=sergio.duri...@canonical.com; > Launchpad-Bug: distribution=ubuntu; distroseries=mantic; > sourcepackage=lxd; component=None; status=New; importance=Undecided; > assignee=None; > Launchpad-Bug: distribution=ubuntu; distroseries=mantic; > sourcepackage=qemu; component=main; status=Confirmed; importance=Critical; > assignee=sergio.duri...@canonical.com; > Launchpad-Bug: distribution=ubuntu; distroseries=noble; sourcepackage=lxd; > component=None; status=New; importance=Undecided; assignee=None; > Launchpad-Bug: distribution=ubuntu; distroseries=noble; > sourcepackage=qemu; component=main; status=Confirmed; importance=Critical; > assignee=sergio.duri...@canonical.com; > Launchpad-Bug-Information-Type: Public > Launchpad-Bug-Private: no > Launchpad-Bug-Security-Vulnerability: no > Launchpad-Bug-Commenters: anilchabba bladernr goujm1 junggyumkim mcoskey > mjt+launchpad-tls paelzer racb rodsmith sergiodj > Launchpad-Bug-Reporter: Jeff Lane (bladernr) > Launchpad-Bug-Modifier: Sergio Durigan Junior (sergiodj) > Launchpad-Message-Rationale: Subscriber > Launchpad-Message-For: bladernr > > -- Jeff Lane Engineering Manager IHV/OEM Alliances and Server Certification "Entropy isn't what it used to be." -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/2012763 Title: qemu-system-amd64 max cpus is too low for latest processors To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/lxd/+bug/2012763/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
