Il 25/07/2012 21:16, Boaz Harrosh ha scritto: > The picture confused me. It looked like the first element is the virtio_scsi_cmd_req > not an sgilist-element that points to the struct's buffer. > > In that case then yes your plan of making a two-elements fragment that points to the > original scsi-sglist is perfect. All you have to do is that, and all you have to do > at virtio is use the sg_for_each macro and you are done. > > You don't need any sglist allocation or reshaping. And you can easily support > chaining. Looks like order of magnitude more simple then what you do now It is. > So what is the problem? That not all architectures have ARCH_HAS_SG_CHAIN (though all those I care about do). So I need to go through all architectures and make sure they use for_each_sg, or at least to change ARCH_HAS_SG_CHAIN to a Kconfig define so that dependencies can be expressed properly. > And BTW you won't need that new __sg_set_page API anymore. Kind of. sg_init_table(sg, 2); sg_set_buf(sg[0], req, sizeof(req)); sg_chain(sg[1], scsi_out(sc)); is still a little bit worse than __sg_set_buf(sg[0], req, sizeof(req)); __sg_chain(sg[1], scsi_out(sc)); Paolo -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
