Gpu passtrhough lag since apt upgrade this week

[sshanee]

WIndows 10 VM with a 5950x, 20Gb ram dedicated and rx 6800 pass through working perfectly. Now since updating proxmox, it lags horribly in league of legends. Almost a slideshow while the fps hovers over 90fps and lowest graphics settings do not improve anything audio is perfect. Desktop feels perfect.

Not using ballooning, not using any disk cache on my virt-io gen4 nvme storage (writeback caused lag very similar to this before but at desktop also). Can't figure out where to even start troubleshooting this... using on-demand or performance scheduler makes no difference.

 

[dcsapak]

i'll move the thread since it's in the wrong subforum

to your problem:

can you post the vm config?
and is there anything noteworthy in your host journal? (you can also post it then we can look through)

did the upgrade entail also a kernel upgrade? if yes, to which one and does booting with the older kernel fix it?

 

[sshanee]

i'll move the thread since it's in the wrong subforum

to your problem:

can you post the vm config?
and is there anything noteworthy in your host journal? (you can also post it then we can look through)

did the upgrade entail also a kernel upgrade? if yes, to which one and does booting with the older kernel fix it?

nothing odd in journalctl or syslog.

here is the config:

agent: 1,fstrim_cloned_disks=1
balloon: 0
bios: ovmf
boot: order=scsi0
cores: 24
cpu: host
efidisk0: local-lvm:vm-200-disk-3,efitype=4m,pre-enrolled-keys=1,size=4M
hostpci0: 0000:0f:00.0,pcie=1,x-vga=1
hostpci1: 0000:0f:00.1,pcie=1
machine: pc-q35-7.1
memory: 21384
meta: creation-qemu=7.1.0,ctime=1675317754
name: poop
net0: virtio=6A:19:8E:23:4F:2A,bridge=vmbr0,firewall=1,queues=64
numa: 1
onboot: 1
ostype: win10
scsi0: local-lvm:vm-200-disk-1,discard=on,iothread=1,size=1250G,ssd=1
scsihw: virtio-scsi-single
smbios1: uuid=911ae355-1d9e-4aa2-92c6-a90da6da51f4
sockets: 1
tpmstate0: local-lvm:vm-200-disk-2,size=4M,version=v2.0
unused0: local-lvm:vm-200-disk-0
usb0: host=1b1c:0a42
usb1: host=1b1c:1b49
usb2: host=046d:c24a
vga: none
vmgenid: 5f10f716-ea03-4837-8b25-7e77bbf7564a

 

[leesteken]

My generic observations:

here is the config:
hostpci0: 0000:0f:00.0,pcie=1,x-vga=1 hostpci1: 0000:0f:00.1,pcie=1

Unless the GPU has more than two functions, usually you would combine them: hostpci0: 0000:0f:00,pcie=1,x-vga=1 (or remove the second one in the Proxmox GUI and enable All Functions on the first one).

machine: pc-q35-7.1

Some Windows 10 drivers work better with machine: pc-q35-6.2 (or Machine version 6.2 in the Proxmox GUI).

memory: 21384

Some VMs work better when the memory is a multiply of GiB like memory: 20480. Note that all VM memory must be pinned into host RAM. Any other VMs running that might cause swapping?

Maybe something changed in the machine emulation (for version 7.1) or in the USB passthrough (which does not work well for high-bandwidth or low-latency) since the update. If it is the latter, you could try PCIe passthrough of a whole USB controller.
Are you using any special work-arounds or options in the files in /etc/modprobe.d/? What is the output of cat /proc/cmdline?

 

[sshanee]

My generic observations:

Unless the GPU has more than two functions, usually you would combine them: hostpci0: 0000:0f:00,pcie=1,x-vga=1 (or remove the second one in the Proxmox GUI and enable All Functions on the first one).

Some Windows 10 drivers work better with machine: pc-q35-6.2 (or Machine version 6.2 in the Proxmox GUI).

Some VMs work better when the memory is a multiply of GiB like memory: 20480. Note that all VM memory must be pinned into host RAM. Any other VMs running that might cause swapping?

Maybe something changed in the machine emulation (for version 7.1) or in the USB passthrough (which does not work well for high-bandwidth or low-latency) since the update. If it is the latter, you could try PCIe passthrough of a whole USB controller.
Are you using any special work-arounds or options in the files in /etc/modprobe.d/? What is the output of cat /proc/cmdline?

Thanks for the reply. This issue magically fixed itself today... I do appreciate your observations and will be making a couple changes.

The reason for passing through the video and audio individually is because it doesnt work with the entire device. there's a USB C and it also has pcie bus/hosts connected to it which i dont understand... it does work like this