On Tue, Apr 11, 2023 at 1:14 PM Christoph Hellwig <hch@xxxxxxxxxxxxx> wrote: > > On Tue, Apr 11, 2023 at 12:54:46PM +0800, Jason Wang wrote: > > Ok, just to clarify, I meant there could be a case where the virtqueue > > is emulated by software, in this case we need check whether the > > virtqueue has a dma device or not in vring_use_dma_api(). If not we > > need return false. > > Well, that's what vring_use_dma_api basically does. Such devics > just should never have VIRTIO_F_ACCESS_PLATFORM set. If there is > a really good reason for such a device to have VIRTIO_F_ACCESS_PLATFORM > set we'd need an extra quirk in vring_use_dma_api indeed. > This is useful for some vDPA devices where the control virtqueue is emulated by the vDPA parent (who will decode the control virtqueue commands to vendor specific control commands). Thanks _______________________________________________ Virtualization mailing list Virtualization@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linuxfoundation.org/mailman/listinfo/virtualization
