On Monday, December 16th, 2024 at 16:50, Sean Christopherson <seanjc@xxxxxxxxxx> wrote: > > On Mon, Dec 16, 2024, Juri Lelli wrote: > > > On 14/12/24 19:52, Peter Zijlstra wrote: > > > > > On Sat, Dec 14, 2024 at 06:32:57AM +0000, Ranguvar wrote: > > > > > > > I have in kernel cmdline `iommu=pt isolcpus=1-7,17-23 rcu_nocbs=1-7,17-23 nohz_full=1-7,17-23`. Removing iommu=pt does not produce a change, and > > > > dropping the core isolation freezes the host on VM startup. > > As in, dropping all of isolcpus, rcu_nocbs, and nohz_full? Or just dropping > isolcpus? Thanks for looking. I had dropped all three, but not altered the VM guest config, which is: <cputune> <vcpupin vcpu='0' cpuset='2'/> <vcpupin vcpu='1' cpuset='18'/> ... <vcpupin vcpu='11' cpuset='23'/> <emulatorpin cpuset='1,17'/> <iothreadpin iothread='1' cpuset='1,17'/> <vcpusched vcpus='0' scheduler='fifo' priority='95'/> ... <iothreadsched iothreads='1' scheduler='fifo' priority='50'/> </cputune> CPU mode is host-passthrough, cache mode is passthrough. The 24GB VRAM did cause trouble when setting up resizeable BAR months ago as well. It necessitated a special qemu config: <qemu:commandline> <qemu:arg value='-fw_cfg'/> <qemu:arg value='opt/ovmf/PciMmio64Mb,string=65536'/> </qemu:commandline>
