Hi Kevin, On Wed, Jun 08, 2022 at 11:48:27PM +0000, Tian, Kevin wrote: > > > > The KVM mechanism for controlling wbinvd is only triggered during > > > > kvm_vfio_group_add(), meaning it is a one-shot test done once the > > devices > > > > are setup. > > > > > > It's not one-shot. kvm_vfio_update_coherency() is called in both > > > group_add() and group_del(). Then the coherency property is > > > checked dynamically in wbinvd emulation: > > > > From the perspective of managing the domains that is still > > one-shot. It doesn't get updated when individual devices are > > added/removed to domains. > > It's unchanged per-domain but dynamic per-vm when multiple > domains are added/removed (i.e. kvm->arch.noncoherent_dma_count). > It's the latter being checked in the kvm. I am going to send a v2, yet not quite getting the point here. Meanwhile, Jason is on leave. What, in your opinion, would be an accurate description here? Thanks Nic
