Joerg, On 1/22/19 5:44 PM, j...@8bytes.org wrote: > Hi Suravee, > > On Thu, Jan 17, 2019 at 08:44:36AM +0000, Suthikulpanit, Suravee wrote: >> Then, in __domain_flush_pages, we issue command when the dev_iommu[] >= 0. >> This should preserve previous behavior, and only add flushing condition to >> the specific IOMMU in detached state. Please let me know what you think. > > I think the whole point why VFIO is detaching all devices first and then > goes into unmapping pages is that there are no flushes needed anymore > when devices are detached. > > But when we follow your proposal we would still do IOTLB flushes even > when no devices are attached anymore. So I'd like to avoid this, given > the implications on unmapping performance. We should just flush the > IOMMU TLB at detach time and be done with it. > > Makes sense? > > Regards, > > Joerg >
Thanks for the detail. Alright then, let's just go with the version you sent on 1/16/19. Do you want me to resend V3 with that changes, or would you be taking care of that? Thanks, Suravee
