On Mon, Jun 06, 2016 at 04:29:11PM +0800, Dong Jia wrote: > On Sun, 5 Jun 2016 23:27:42 -0700 > Neo Jia <c...@nvidia.com> wrote: > > 2. VFIO_DEVICE_CCW_CMD_REQUEST > This intends to handle an intercepted channel I/O instruction. It > basically need to do the following thing:
May I ask how and when QEMU knows that he needs to issue such VFIO ioctl at first place? Thanks, Neo > a. Copy the raw data of the CCW program (a group of chained CCWs) from > user into kernel space buffers. > b. Do CCW program translation based on the raw data to get a > real-device runnable CCW program. We'd pin pages for those CCWs > which have memory space pointers for their offload, and update the > CCW program with the pinned results (phys). > c. Issue the translated CCW program to a real-device to perform the > I/O operation, and wait for the I/O result interrupt. > d. Once we got the I/O result, copy the result back to user, and > unpin the pages. > > Step c could only be done by the physical device driver, since it's it > that the int_handler belongs to. > Step b and d should be done by the physical device driver. Or we'd > pin/unpin pages in the mediated device driver? > > That's why I asked for the new callback. >
