On 05/24/2018 12:51 PM, Ram Pai wrote: > On Wed, May 23, 2018 at 09:50:02PM +0300, Michael S. Tsirkin wrote: >> subj: s/virito/virtio/ >> > ..snip.. >>> machine_subsys_initcall_sync(pseries, tce_iommu_bus_notifier_init); >>> + >>> +bool platform_forces_virtio_dma(struct virtio_device *vdev) >>> +{ >>> + /* >>> + * On protected guest platforms, force virtio core to use DMA >>> + * MAP API for all virtio devices. But there can also be some >>> + * exceptions for individual devices like virtio balloon. >>> + */ >>> + return (of_find_compatible_node(NULL, NULL, "ibm,ultravisor") != NULL); >>> +} >> >> Isn't this kind of slow? vring_use_dma_api is on >> data path and supposed to be very fast. > > Yes it is slow and not ideal. This won't be the final code. The final > code will cache the information in some global variable and used > in this function. Right this will be a simple check based on a global variable. _______________________________________________ Virtualization mailing list Virtualization@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linuxfoundation.org/mailman/listinfo/virtualization