Re: [Qemu-devel] [PATCH v7 4/4] docs: Add Documentation for Mediated devices

2016-09-03 Thread Kirti Wankhede 
Adding Eric.

Eric,
This is the v7 version of patch. I'll incorporate changes that you
suggested here.

Kirti.

On 8/25/2016 9:23 AM, Kirti Wankhede wrote:
> Add file Documentation/vfio-mediated-device.txt that include details of
> mediated device framework.
> 
> Signed-off-by: Kirti Wankhede 
> Signed-off-by: Neo Jia 
> Change-Id: I137dd646442936090d92008b115908b7b2c7bc5d
> Reviewed-on: http://git-master/r/1182512
> Reviewed-by: Automatic_Commit_Validation_User
> ---
>  Documentation/vfio-mediated-device.txt | 203 
> +
>  1 file changed, 203 insertions(+)
>  create mode 100644 Documentation/vfio-mediated-device.txt
> 
> diff --git a/Documentation/vfio-mediated-device.txt 
> b/Documentation/vfio-mediated-device.txt
> new file mode 100644
> index ..237d8eb630b7
> --- /dev/null
> +++ b/Documentation/vfio-mediated-device.txt
> @@ -0,0 +1,203 @@
> +VFIO Mediated devices [1]
> +---
> +
> +There are more and more use cases/demands to virtualize the DMA devices which
> +doesn't have SR_IOV capability built-in. To do this, drivers of different
> +devices had to develop their own management interface and set of APIs and 
> then
> +integrate it to user space software. We've identified common requirements and
> +unified management interface for such devices to make user space software
> +integration easier.
> +
> +The VFIO driver framework provides unified APIs for direct device access. It 
> is
> +an IOMMU/device agnostic framework for exposing direct device access to
> +user space, in a secure, IOMMU protected environment. This framework is
> +used for multiple devices like GPUs, network adapters and compute 
> accelerators.
> +With direct device access, virtual machines or user space applications have
> +direct access of physical device. This framework is reused for mediated 
> devices.
> +
> +Mediated core driver provides a common interface for mediated device 
> management
> +that can be used by drivers of different devices. This module provides a 
> generic
> +interface to create/destroy mediated device, add/remove it to mediated bus
> +driver, add/remove device to IOMMU group. It also provides an interface to
> +register bus driver, for example, Mediated VFIO mdev driver is designed for
> +mediated devices and supports VFIO APIs. Mediated bus driver add/delete 
> mediated
> +device to VFIO Group.
> +
> +Below is the high Level block diagram, with NVIDIA, Intel and IBM devices
> +as example, since these are the devices which are going to actively use
> +this module as of now.
> +
> + +---+
> + |   |
> + | +---+ |  mdev_register_driver() +--+
> + | |   | +<+  |
> + | |  mdev | | |  |
> + | |  bus  | +>+ vfio_mdev.ko |<-> VFIO user
> + | |  driver   | | probe()/remove()|  |APIs
> + | |   | | +--+
> + | +---+ |
> + |   |
> + |  MDEV CORE|
> + |   MODULE  |
> + |   mdev.ko |
> + | +---+ |  mdev_register_device() +--+
> + | |   | +<+  |
> + | |   | | |  nvidia.ko   |<-> physical
> + | |   | +>+  |device
> + | |   | |callbacks+--+
> + | | Physical  | |
> + | |  device   | |  mdev_register_device() +--+
> + | | interface | |<+  |
> + | |   | | |  i915.ko |<-> physical
> + | |   | +>+  |device
> + | |   | |callbacks+--+
> + | |   | |
> + | |   | |  mdev_register_device() +--+
> + | |   | +<+  |
> + | |   | | | ccw_device.ko|<-> physical
> + | |   | +>+  |device
> + | |   | |callbacks+--+
> + | +---+ |
> + +---+
> +
> +
> +Registration Interfaces
> +---
> +
> +Mediated core driver provides two types of registration interfaces:
> +
> +1. Registration interface for mediated bus driver:
> +-
> + /*
> +  * struct mdev_driver [2] - Mediated device's driver
> +  * @name: driver name
> +  * @probe: called when new device created
> +  * @remove: called when device removed
> +  * @driver: device driver structure
> +  */
> + struct mdev_

[Qemu-devel] [PATCH v7 4/4] docs: Add Documentation for Mediated devices

2016-08-24 Thread Kirti Wankhede 
Add file Documentation/vfio-mediated-device.txt that include details of
mediated device framework.

Signed-off-by: Kirti Wankhede 
Signed-off-by: Neo Jia 
Change-Id: I137dd646442936090d92008b115908b7b2c7bc5d
Reviewed-on: http://git-master/r/1182512
Reviewed-by: Automatic_Commit_Validation_User
---
 Documentation/vfio-mediated-device.txt | 203 +
 1 file changed, 203 insertions(+)
 create mode 100644 Documentation/vfio-mediated-device.txt

diff --git a/Documentation/vfio-mediated-device.txt 
b/Documentation/vfio-mediated-device.txt
new file mode 100644
index ..237d8eb630b7
--- /dev/null
+++ b/Documentation/vfio-mediated-device.txt
@@ -0,0 +1,203 @@
+VFIO Mediated devices [1]
+---
+
+There are more and more use cases/demands to virtualize the DMA devices which
+doesn't have SR_IOV capability built-in. To do this, drivers of different
+devices had to develop their own management interface and set of APIs and then
+integrate it to user space software. We've identified common requirements and
+unified management interface for such devices to make user space software
+integration easier.
+
+The VFIO driver framework provides unified APIs for direct device access. It is
+an IOMMU/device agnostic framework for exposing direct device access to
+user space, in a secure, IOMMU protected environment. This framework is
+used for multiple devices like GPUs, network adapters and compute accelerators.
+With direct device access, virtual machines or user space applications have
+direct access of physical device. This framework is reused for mediated 
devices.
+
+Mediated core driver provides a common interface for mediated device management
+that can be used by drivers of different devices. This module provides a 
generic
+interface to create/destroy mediated device, add/remove it to mediated bus
+driver, add/remove device to IOMMU group. It also provides an interface to
+register bus driver, for example, Mediated VFIO mdev driver is designed for
+mediated devices and supports VFIO APIs. Mediated bus driver add/delete 
mediated
+device to VFIO Group.
+
+Below is the high Level block diagram, with NVIDIA, Intel and IBM devices
+as example, since these are the devices which are going to actively use
+this module as of now.
+
+ +---+
+ |   |
+ | +---+ |  mdev_register_driver() +--+
+ | |   | +<+  |
+ | |  mdev | | |  |
+ | |  bus  | +>+ vfio_mdev.ko |<-> VFIO user
+ | |  driver   | | probe()/remove()|  |APIs
+ | |   | | +--+
+ | +---+ |
+ |   |
+ |  MDEV CORE|
+ |   MODULE  |
+ |   mdev.ko |
+ | +---+ |  mdev_register_device() +--+
+ | |   | +<+  |
+ | |   | | |  nvidia.ko   |<-> physical
+ | |   | +>+  |device
+ | |   | |callbacks+--+
+ | | Physical  | |
+ | |  device   | |  mdev_register_device() +--+
+ | | interface | |<+  |
+ | |   | | |  i915.ko |<-> physical
+ | |   | +>+  |device
+ | |   | |callbacks+--+
+ | |   | |
+ | |   | |  mdev_register_device() +--+
+ | |   | +<+  |
+ | |   | | | ccw_device.ko|<-> physical
+ | |   | +>+  |device
+ | |   | |callbacks+--+
+ | +---+ |
+ +---+
+
+
+Registration Interfaces
+---
+
+Mediated core driver provides two types of registration interfaces:
+
+1. Registration interface for mediated bus driver:
+-
+ /*
+  * struct mdev_driver [2] - Mediated device's driver
+  * @name: driver name
+  * @probe: called when new device created
+  * @remove: called when device removed
+  * @driver: device driver structure
+  */
+ struct mdev_driver {
+const char *name;
+int  (*probe)  (struct device *dev);
+void (*remove) (struct device *dev);
+struct device_driverdriver;
+ };
+
+Mediated bus driver for mdev should use this interface to register and
+unregister with core driver respectively:
+
+extern int  mdev_register_driver(struct mdev_driver *drv, s