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-rw-r--r--Documentation/mic/mic_overview.txt54
1 files changed, 30 insertions, 24 deletions
diff --git a/Documentation/mic/mic_overview.txt b/Documentation/mic/mic_overview.txt
index 73f44fc3e715..074adbdf83a4 100644
--- 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 | |
+ +---+--------------+------+ | +----+---------------+-----+
| | |
+-------------------------------------------------------------+
| |