I was bumping up to the config you had (but with one PT device). - Host phys bits machine type for larger mappings - more CPUS 1->32
Adding/removing a PT device in the configs above doesn't change a lot. As assumed none of these increased the time tremendously. Then I went to bump up the memory size. T1: use 1.2 TB but no PT device #1: 6 sec #2: 21 sec #3: 16 sec This only very slightly increases in #2 due to more memory that needs to be set up. T2: use 1.2 TB with one PT device #1: 253 sec #2: 20 sec #3: 18 sec The time consuming part is a single process, with kernel side load. Associated userpace is qemu, but the load i in the kernel close to 100%. Samples: 62K of event 'cycles:ppp', Event count (approx.): 34521154809 Overhead Shared Object Symbol 73.91% [kernel] [k] clear_page_erms 9.53% [kernel] [k] clear_huge_page 1.65% [kernel] [k] follow_trans_huge_pmd -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1838575 Title: passthrough devices cause >17min boot delay To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/qemu/+bug/1838575/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs