On 25/04/17 12:30 AM, Knut Omang wrote: > Yes, that's why I used 'significant'. One good thing is that given resources > it can easily be done in parallel with other development, and will give additional > insight of some form. Yup, well if someone wants to start working on an emulated RDMA device that actually simulates proper DMA transfers that would be great! >> I also imagine it would be quite difficult to develop those models >> given the array of hardware that needs to be supported and the deep >> functional knowledge required to figure out appropriate restrictions. > > From my naive perspective it seems it need not even be a full model to get some benefits, > just low level functionality tests with some instances of a > device that offers some MMIO space 'playground'. Yes, the nvme device in qemu has a CMB buffer which is a good choice to test with but we don't have code to use it for p2p transfers in the kernel so it is a bit awkward. We also posted [1] to qemu which was also handy to test with using a small out of tree module. But I don't see a lot of value in it if you completely ignore any hardware quirks. Logan [1] https://lists.gnu.org/archive/html/qemu-devel/2016-10/msg04331.html
