On Tue, Feb 06, 2018 at 03:23:02PM +0100, Gerd Hoffmann wrote: > > Creation of shareable buffer by guest > > ------------------------------------------------- > > > > 1. Client requests virtio driver to create a buffer suitable for sharing > > with host (DRM_VIRTGPU_RESOURCE_CREATE) > > client or guest proxy? > > > 4. QEMU maps that buffer to the guest's address space > > (KVM_SET_USER_MEMORY_REGION), passes the guest PFN to the virtio driver > > That part is problematic. The host can't simply allocate something in > the physical address space, because most physical address space > management is done by the guest. All pci bars are mapped by the guest > firmware for example (or by the guest OS in case of hotplug). > > > 4. QEMU pops data+buffers from the virtqueue, looks up shmem FD for each > > resource, sends data + FDs to the compositor with SCM_RIGHTS If you squint hard, this sounds a bit like a use-case for vhost-user-gpu, does it not? > BTW: Is there a 1:1 relationship between buffers and shmem blocks? Or > does the wayland protocol allow for offsets in buffer meta data, so you > can place multiple buffers in a single shmem block? > > cheers, > Gerd _______________________________________________ Virtualization mailing list Virtualization@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linuxfoundation.org/mailman/listinfo/virtualization
