GPU passthrough making host crash

[paul20]

I've passed through my AMD RX 570 to a VM. It works fine for a few hours, then screen turns off and host load goes up to 300. Logs are spammed with
DMAR: DRHD: handling fault status reg 600
DMAR: DRHD: handling fault status reg 640
watchdog BUG: soft lockup - CPU #11 stuck for 30s!

I'm unable to stop the VM after that, I must hard reset my node.
What's wrong here?
Thanks!