Merge tag 'char-misc-4.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh...

[mirror_ubuntu-zesty-kernel.git] / Documentation / mic / mic_overview.txt

diff --git a/Documentation/mic/mic_overview.txt b/Documentation/mic/mic_overview.txt
index 73f44fc3e71569f98bf14283239af7d1f310c9d9..074adbdf83a44205cf9378a953865df791d1e8fb 100644 (file)
--- a/Documentation/mic/mic_overview.txt
+++ b/Documentation/mic/mic_overview.txt
@@ -12,10 +12,19 @@ for the X100 devices.
 
 Since it is a PCIe card, it does not have the ability to host hardware
 devices for networking, storage and console. We provide these devices
-on X100 coprocessors thus enabling a self-bootable equivalent environment
-for applications. A key benefit of our solution is that it leverages
-the standard virtio framework for network, disk and console devices,
-though in our case the virtio framework is used across a PCIe bus.
+on X100 coprocessors thus enabling a self-bootable equivalent
+environment for applications. A key benefit of our solution is that it
+leverages the standard virtio framework for network, disk and console
+devices, though in our case the virtio framework is used across a PCIe
+bus. A Virtio Over PCIe (VOP) driver allows creating user space
+backends or devices on the host which are used to probe virtio drivers
+for these devices on the MIC card. The existing VRINGH infrastructure
+in the kernel is used to access virtio rings from the host. The card
+VOP driver allows card virtio drivers to communicate with their user
+space backends on the host via a device page. Ring 3 apps on the host
+can add, remove and configure virtio devices. A thin MIC specific
+virtio_config_ops is implemented which is borrowed heavily from
+previous similar implementations in lguest and s390.
 
 MIC PCIe card has a dma controller with 8 channels. These channels are
 shared between the host s/w and the card s/w. 0 to 3 are used by host
@@ -38,7 +47,6 @@ single threaded performance for the host compared to MIC, the ability of
 the host to initiate DMA's to/from the card using the MIC DMA engine and
 the fact that the virtio block storage backend can only be on the host.
 
-                                      |
                +----------+           |             +----------+
                | Card OS  |           |             | Host OS  |
                +----------+           |             +----------+
@@ -47,27 +55,25 @@ the fact that the virtio block storage backend can only be on the host.
         | Virtio| |Virtio  | |Virtio| | |Virtio   |  |Virtio  | |Virtio  |
         | Net   | |Console | |Block | | |Net      |  |Console | |Block   |
         | Driver| |Driver  | |Driver| | |backend  |  |backend | |backend |
-        +-------+ +--------+ +------+ | +---------+  +--------+ +--------+
+        +---+---+ +---+----+ +--+---+ | +---------+  +----+---+ +--------+
             |         |         |     |      |            |         |
             |         |         |     |User  |            |         |
-            |         |         |     |------|------------|---------|-------
-            +-------------------+     |Kernel +--------------------------+
-                      |               |       | Virtio over PCIe IOCTLs  |
-                      |               |       +--------------------------+
-+-----------+         |               |                   |  +-----------+
-| MIC DMA   |         |      +------+ | +------+ +------+ |  | MIC DMA   |
-| Driver    |         |      | SCIF | | | SCIF | | COSM | |  | Driver    |
-+-----------+         |      +------+ | +------+ +--+---+ |  +-----------+
-      |               |         |     |    |        |     |        |
-+---------------+     |      +------+ | +--+---+ +--+---+ | +----------------+
-|MIC virtual Bus|     |      |SCIF  | | |SCIF  | | COSM | | |MIC virtual Bus |
-+---------------+     |      |HW Bus| | |HW Bus| | Bus  | | +----------------+
-      |               |      +------+ | +--+---+ +------+ |              |
-      |               |         |     |       |     |     |              |
-      |   +-----------+---+     |     |       |    +---------------+     |
-      |   |Intel MIC      |     |     |       |    |Intel MIC      |     |
-      +---|Card Driver    |     |     |       |    |Host Driver    |     |
-          +------------+--------+     |       +----+---------------+-----+
+            |         |         |     |------|------------|--+------|-------
+            +---------+---------+     |Kernel                |
+                      |               |                      |
+  +---------+     +---+----+ +------+ | +------+ +------+ +--+---+  +-------+
+  |MIC DMA  |     |  VOP   | | SCIF | | | SCIF | | COSM | | VOP  |  |MIC DMA|
+  +---+-----+     +---+----+ +--+---+ | +--+---+ +--+---+ +------+  +----+--+
+      |               |         |     |    |        |                    |
+  +---+-----+     +---+----+ +--+---+ | +--+---+ +--+---+ +------+  +----+--+
+  |MIC      |     |  VOP   | |SCIF  | | |SCIF  | | COSM | | VOP  |  | MIC   |
+  |HW Bus   |     |  HW Bus| |HW Bus| | |HW Bus| | Bus  | |HW Bus|  |HW Bus |
+  +---------+     +--------+ +--+---+ | +--+---+ +------+ +------+  +-------+
+      |               |         |     |       |     |                    |
+      |   +-----------+--+      |     |       |    +---------------+     |
+      |   |Intel MIC     |      |     |       |    |Intel MIC      |     |
+      |   |Card Driver   |      |     |       |    |Host Driver    |     |
+      +---+--------------+------+     |       +----+---------------+-----+
                  |                    |                   |
              +-------------------------------------------------------------+
              |                                                             |