On Mon, 07 Mar 2022 22:13:01 +0000 "Bronek Kozicki" <b...@incorrekt.com> wrote:
> I know, this is such an old topic ... > > I have today upgraded my hypervisor from intel Ivy-Bridge to AMD Epyc > Milan and, after making the necessary adjustments in vfio > configuration to make my virtual machines work again, I found that > there's immense amount of crackling (like, many times per second) in > audio, both in Linux and in Windows guests. The audio is USB DAC > connected through USB, and USB is on passed-through PCI (dedicated > for guest). > > The host has two AMD 7413 CPUs, with lots of cores dedicated to > guests: > > video=efifb:off iommu=pt amd_iommu=on add_efi_memmap > nohz_full=6-35,54-83 rcu_nocbs=6-35,54-83 isolcpus=6-35,54-83 > nvme.poll_queues=12 > Getting interrupt bypass to work on AMD (AVIC) is rather more finicky than the equivalent on Intel (APICv). Have a look at this pointer and see if you can get it working: https://forum.level1techs.com/t/svm-avic-iommu-avic-improves-interrupt-performance-on-zen-2-etc-based-processors/155226 When working correctly, you should essentially stop seeing interrupt counts increase in /proc/interrupts on the host for any vfio MSI vectors. Thanks, Alex _______________________________________________ vfio-users mailing list vfio-users@redhat.com https://listman.redhat.com/mailman/listinfo/vfio-users
