Hi, > Note that usb_packet_map() invokes dma_memory_map() with a NULL invalidate > callback function. When IOMMU support is added, this will mean that > usb_packet_map() and the corresponding usb_packet_unmap() must be called in > close proximity without dropping the qemu device lock
Well, that isn't guaranteed ... > - otherwise the guest > might invalidate IOMMU mappings while they are still in use by the device > code. Guest tearing down mapping while usb packets using them are still in flight would be a guest bug. Still not impossible to happen though. How is this case supposed to be handled? cheers, Gerd
