Viresh Kumar <viresh.ku...@linaro.org> writes:
> The current model of memory mapping at the back-end works fine where a > standard call to mmap() (for the respective file descriptor) is enough > before the front-end can start accessing the guest memory. > > There are other complex cases though where the back-end needs more > information and simple mmap() isn't enough. For example Xen, a type-1 > hypervisor, currently supports memory mapping via two different methods, > foreign-mapping (via /dev/privcmd) and grant-dev (via /dev/gntdev). In > both these cases, the back-end needs to call mmap() and ioctl(), with > extra information like the Xen domain-id of the guest whose memory we > are trying to map. > > Add a new protocol feature, 'VHOST_USER_PROTOCOL_F_XEN_MMAP', which lets > the back-end know about the additional memory mapping requirements. > When this feature is negotiated, the front-end will send the additional > information within the memory regions themselves. > > Signed-off-by: Viresh Kumar <viresh.ku...@linaro.org> Reviewed-by: Alex Bennée <alex.ben...@linaro.org> -- Alex Bennée Virtualisation Tech Lead @ Linaro
