On 01/03/2018 11:33, Liu, Yi L wrote: > This patch adds pci_device_notify_iommu() for notify virtual IOMMU > emulator when assigned device is added. And adds a new notify_func > in PCIBus. vIOMMU emulator provides the instance of this notify_func. > > Reason: > When virtual IOMMU is exposed to guest, vIOMMU emulator needs to > programm host IOMMU to setup DMA mapping for assigned devices. This > is a per-device operation, to be efficient, vIOMMU emulator needs > to record the assigned devices. > > Example: devices assigned thru vfio, vfio_realize would call > pci_device_notify_iommu() to notify vIOMMU emulator to record necessary > info for assigned device.
I think the notification should not be left to the individual device. Instead, the add notification should be done in pci_setup_sva_ops, and the delete notification should be done in pci_qdev_unrealize, before calling pc->exit, and only if dev->sva_ops is not NULL. In general I think it's better to change your names from "assigned_dev" to "sva_dev", because the point of the list is to only iterate over devices that might be interested in using SVA. Paolo
