vfio-mediated-device.txt: standardize document format
Each text file under Documentation follows a different format. Some doesn't even have titles! In this specific document, the title, copyright and authorship are added as if it were a C file! Change its representation to follow the adopted standard, using ReST markups for it to be parseable by Sphinx: - convert document preambule to the proper format; - mark literal blocks; - adjust identation; - use numbered lists for references. Reviewed by: Kirti Wankhede <kwankhede@nvidia.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
This commit is contained in:
Mauro Carvalho Chehab
Jonathan Corbet
parent
c6ebaf6bdb
commit
2a26ed8e4a
|
|
@ -1,14 +1,17 @@
|
|||
/*
|
||||
* VFIO Mediated devices
|
||||
*
|
||||
* Copyright (c) 2016, NVIDIA CORPORATION. All rights reserved.
|
||||
* Author: Neo Jia <cjia@nvidia.com>
|
||||
* Kirti Wankhede <kwankhede@nvidia.com>
|
||||
*
|
||||
* This program is free software; you can redistribute it and/or modify
|
||||
* it under the terms of the GNU General Public License version 2 as
|
||||
* published by the Free Software Foundation.
|
||||
*/
|
||||
.. include:: <isonum.txt>
|
||||
|
||||
=====================
|
||||
VFIO Mediated devices
|
||||
=====================
|
||||
|
||||
:Copyright: |copy| 2016, NVIDIA CORPORATION. All rights reserved.
|
||||
:Author: Neo Jia <cjia@nvidia.com>
|
||||
:Author: Kirti Wankhede <kwankhede@nvidia.com>
|
||||
|
||||
This program is free software; you can redistribute it and/or modify
|
||||
it under the terms of the GNU General Public License version 2 as
|
||||
published by the Free Software Foundation.
|
||||
|
||||
|
||||
Virtual Function I/O (VFIO) Mediated devices[1]
|
||||
===============================================
|
||||
|
|
@ -42,7 +45,7 @@ removes it from a VFIO group.
|
|||
|
||||
The following high-level block diagram shows the main components and interfaces
|
||||
in the VFIO mediated driver framework. The diagram shows NVIDIA, Intel, and IBM
|
||||
devices as examples, as these devices are the first devices to use this module.
|
||||
devices as examples, as these devices are the first devices to use this module::
|
||||
|
||||
+---------------+
|
||||
| |
|
||||
|
|
@ -91,7 +94,7 @@ Registration Interface for a Mediated Bus Driver
|
|||
------------------------------------------------
|
||||
|
||||
The registration interface for a mediated bus driver provides the following
|
||||
structure to represent a mediated device's driver:
|
||||
structure to represent a mediated device's driver::
|
||||
|
||||
/*
|
||||
* struct mdev_driver [2] - Mediated device's driver
|
||||
|
|
@ -110,14 +113,14 @@ structure to represent a mediated device's driver:
|
|||
A mediated bus driver for mdev should use this structure in the function calls
|
||||
to register and unregister itself with the core driver:
|
||||
|
||||
* Register:
|
||||
* Register::
|
||||
|
||||
extern int mdev_register_driver(struct mdev_driver *drv,
|
||||
extern int mdev_register_driver(struct mdev_driver *drv,
|
||||
struct module *owner);
|
||||
|
||||
* Unregister:
|
||||
* Unregister::
|
||||
|
||||
extern void mdev_unregister_driver(struct mdev_driver *drv);
|
||||
extern void mdev_unregister_driver(struct mdev_driver *drv);
|
||||
|
||||
The mediated bus driver is responsible for adding mediated devices to the VFIO
|
||||
group when devices are bound to the driver and removing mediated devices from
|
||||
|
|
@ -152,15 +155,15 @@ The callbacks in the mdev_parent_ops structure are as follows:
|
|||
* mmap: mmap emulation callback
|
||||
|
||||
A driver should use the mdev_parent_ops structure in the function call to
|
||||
register itself with the mdev core driver:
|
||||
register itself with the mdev core driver::
|
||||
|
||||
extern int mdev_register_device(struct device *dev,
|
||||
const struct mdev_parent_ops *ops);
|
||||
extern int mdev_register_device(struct device *dev,
|
||||
const struct mdev_parent_ops *ops);
|
||||
|
||||
However, the mdev_parent_ops structure is not required in the function call
|
||||
that a driver should use to unregister itself with the mdev core driver:
|
||||
that a driver should use to unregister itself with the mdev core driver::
|
||||
|
||||
extern void mdev_unregister_device(struct device *dev);
|
||||
extern void mdev_unregister_device(struct device *dev);
|
||||
|
||||
|
||||
Mediated Device Management Interface Through sysfs
|
||||
|
|
@ -183,30 +186,32 @@ with the mdev core driver.
|
|||
Directories and files under the sysfs for Each Physical Device
|
||||
--------------------------------------------------------------
|
||||
|
||||
|- [parent physical device]
|
||||
|--- Vendor-specific-attributes [optional]
|
||||
|--- [mdev_supported_types]
|
||||
| |--- [<type-id>]
|
||||
| | |--- create
|
||||
| | |--- name
|
||||
| | |--- available_instances
|
||||
| | |--- device_api
|
||||
| | |--- description
|
||||
| | |--- [devices]
|
||||
| |--- [<type-id>]
|
||||
| | |--- create
|
||||
| | |--- name
|
||||
| | |--- available_instances
|
||||
| | |--- device_api
|
||||
| | |--- description
|
||||
| | |--- [devices]
|
||||
| |--- [<type-id>]
|
||||
| |--- create
|
||||
| |--- name
|
||||
| |--- available_instances
|
||||
| |--- device_api
|
||||
| |--- description
|
||||
| |--- [devices]
|
||||
::
|
||||
|
||||
|- [parent physical device]
|
||||
|--- Vendor-specific-attributes [optional]
|
||||
|--- [mdev_supported_types]
|
||||
| |--- [<type-id>]
|
||||
| | |--- create
|
||||
| | |--- name
|
||||
| | |--- available_instances
|
||||
| | |--- device_api
|
||||
| | |--- description
|
||||
| | |--- [devices]
|
||||
| |--- [<type-id>]
|
||||
| | |--- create
|
||||
| | |--- name
|
||||
| | |--- available_instances
|
||||
| | |--- device_api
|
||||
| | |--- description
|
||||
| | |--- [devices]
|
||||
| |--- [<type-id>]
|
||||
| |--- create
|
||||
| |--- name
|
||||
| |--- available_instances
|
||||
| |--- device_api
|
||||
| |--- description
|
||||
| |--- [devices]
|
||||
|
||||
* [mdev_supported_types]
|
||||
|
||||
|
|
@ -219,12 +224,12 @@ Directories and files under the sysfs for Each Physical Device
|
|||
|
||||
The [<type-id>] name is created by adding the device driver string as a prefix
|
||||
to the string provided by the vendor driver. This format of this name is as
|
||||
follows:
|
||||
follows::
|
||||
|
||||
sprintf(buf, "%s-%s", dev_driver_string(parent->dev), group->name);
|
||||
|
||||
(or using mdev_parent_dev(mdev) to arrive at the parent device outside
|
||||
of the core mdev code)
|
||||
of the core mdev code)
|
||||
|
||||
* device_api
|
||||
|
||||
|
|
@ -239,7 +244,7 @@ Directories and files under the sysfs for Each Physical Device
|
|||
* [device]
|
||||
|
||||
This directory contains links to the devices of type <type-id> that have been
|
||||
created.
|
||||
created.
|
||||
|
||||
* name
|
||||
|
||||
|
|
@ -253,21 +258,25 @@ created.
|
|||
Directories and Files Under the sysfs for Each mdev Device
|
||||
----------------------------------------------------------
|
||||
|
||||
|- [parent phy device]
|
||||
|--- [$MDEV_UUID]
|
||||
::
|
||||
|
||||
|- [parent phy device]
|
||||
|--- [$MDEV_UUID]
|
||||
|--- remove
|
||||
|--- mdev_type {link to its type}
|
||||
|--- vendor-specific-attributes [optional]
|
||||
|
||||
* remove (write only)
|
||||
|
||||
Writing '1' to the 'remove' file destroys the mdev device. The vendor driver can
|
||||
fail the remove() callback if that device is active and the vendor driver
|
||||
doesn't support hot unplug.
|
||||
|
||||
Example:
|
||||
Example::
|
||||
|
||||
# echo 1 > /sys/bus/mdev/devices/$mdev_UUID/remove
|
||||
|
||||
Mediated device Hot plug:
|
||||
Mediated device Hot plug
|
||||
------------------------
|
||||
|
||||
Mediated devices can be created and assigned at runtime. The procedure to hot
|
||||
|
|
@ -277,13 +286,13 @@ Translation APIs for Mediated Devices
|
|||
=====================================
|
||||
|
||||
The following APIs are provided for translating user pfn to host pfn in a VFIO
|
||||
driver:
|
||||
driver::
|
||||
|
||||
extern int vfio_pin_pages(struct device *dev, unsigned long *user_pfn,
|
||||
int npage, int prot, unsigned long *phys_pfn);
|
||||
extern int vfio_pin_pages(struct device *dev, unsigned long *user_pfn,
|
||||
int npage, int prot, unsigned long *phys_pfn);
|
||||
|
||||
extern int vfio_unpin_pages(struct device *dev, unsigned long *user_pfn,
|
||||
int npage);
|
||||
extern int vfio_unpin_pages(struct device *dev, unsigned long *user_pfn,
|
||||
int npage);
|
||||
|
||||
These functions call back into the back-end IOMMU module by using the pin_pages
|
||||
and unpin_pages callbacks of the struct vfio_iommu_driver_ops[4]. Currently
|
||||
|
|
@ -304,81 +313,80 @@ card.
|
|||
|
||||
This step creates a dummy device, /sys/devices/virtual/mtty/mtty/
|
||||
|
||||
Files in this device directory in sysfs are similar to the following:
|
||||
Files in this device directory in sysfs are similar to the following::
|
||||
|
||||
# tree /sys/devices/virtual/mtty/mtty/
|
||||
/sys/devices/virtual/mtty/mtty/
|
||||
|-- mdev_supported_types
|
||||
| |-- mtty-1
|
||||
| | |-- available_instances
|
||||
| | |-- create
|
||||
| | |-- device_api
|
||||
| | |-- devices
|
||||
| | `-- name
|
||||
| `-- mtty-2
|
||||
| |-- available_instances
|
||||
| |-- create
|
||||
| |-- device_api
|
||||
| |-- devices
|
||||
| `-- name
|
||||
|-- mtty_dev
|
||||
| `-- sample_mtty_dev
|
||||
|-- power
|
||||
| |-- autosuspend_delay_ms
|
||||
| |-- control
|
||||
| |-- runtime_active_time
|
||||
| |-- runtime_status
|
||||
| `-- runtime_suspended_time
|
||||
|-- subsystem -> ../../../../class/mtty
|
||||
`-- uevent
|
||||
# tree /sys/devices/virtual/mtty/mtty/
|
||||
/sys/devices/virtual/mtty/mtty/
|
||||
|-- mdev_supported_types
|
||||
| |-- mtty-1
|
||||
| | |-- available_instances
|
||||
| | |-- create
|
||||
| | |-- device_api
|
||||
| | |-- devices
|
||||
| | `-- name
|
||||
| `-- mtty-2
|
||||
| |-- available_instances
|
||||
| |-- create
|
||||
| |-- device_api
|
||||
| |-- devices
|
||||
| `-- name
|
||||
|-- mtty_dev
|
||||
| `-- sample_mtty_dev
|
||||
|-- power
|
||||
| |-- autosuspend_delay_ms
|
||||
| |-- control
|
||||
| |-- runtime_active_time
|
||||
| |-- runtime_status
|
||||
| `-- runtime_suspended_time
|
||||
|-- subsystem -> ../../../../class/mtty
|
||||
`-- uevent
|
||||
|
||||
2. Create a mediated device by using the dummy device that you created in the
|
||||
previous step.
|
||||
previous step::
|
||||
|
||||
# echo "83b8f4f2-509f-382f-3c1e-e6bfe0fa1001" > \
|
||||
# echo "83b8f4f2-509f-382f-3c1e-e6bfe0fa1001" > \
|
||||
/sys/devices/virtual/mtty/mtty/mdev_supported_types/mtty-2/create
|
||||
|
||||
3. Add parameters to qemu-kvm.
|
||||
3. Add parameters to qemu-kvm::
|
||||
|
||||
-device vfio-pci,\
|
||||
sysfsdev=/sys/bus/mdev/devices/83b8f4f2-509f-382f-3c1e-e6bfe0fa1001
|
||||
-device vfio-pci,\
|
||||
sysfsdev=/sys/bus/mdev/devices/83b8f4f2-509f-382f-3c1e-e6bfe0fa1001
|
||||
|
||||
4. Boot the VM.
|
||||
|
||||
In the Linux guest VM, with no hardware on the host, the device appears
|
||||
as follows:
|
||||
as follows::
|
||||
|
||||
# lspci -s 00:05.0 -xxvv
|
||||
00:05.0 Serial controller: Device 4348:3253 (rev 10) (prog-if 02 [16550])
|
||||
Subsystem: Device 4348:3253
|
||||
Physical Slot: 5
|
||||
Control: I/O+ Mem- BusMaster- SpecCycle- MemWINV- VGASnoop- ParErr-
|
||||
Stepping- SERR- FastB2B- DisINTx-
|
||||
Status: Cap- 66MHz- UDF- FastB2B- ParErr- DEVSEL=medium >TAbort-
|
||||
<TAbort- <MAbort- >SERR- <PERR- INTx-
|
||||
Interrupt: pin A routed to IRQ 10
|
||||
Region 0: I/O ports at c150 [size=8]
|
||||
Region 1: I/O ports at c158 [size=8]
|
||||
Kernel driver in use: serial
|
||||
00: 48 43 53 32 01 00 00 02 10 02 00 07 00 00 00 00
|
||||
10: 51 c1 00 00 59 c1 00 00 00 00 00 00 00 00 00 00
|
||||
20: 00 00 00 00 00 00 00 00 00 00 00 00 48 43 53 32
|
||||
30: 00 00 00 00 00 00 00 00 00 00 00 00 0a 01 00 00
|
||||
# lspci -s 00:05.0 -xxvv
|
||||
00:05.0 Serial controller: Device 4348:3253 (rev 10) (prog-if 02 [16550])
|
||||
Subsystem: Device 4348:3253
|
||||
Physical Slot: 5
|
||||
Control: I/O+ Mem- BusMaster- SpecCycle- MemWINV- VGASnoop- ParErr-
|
||||
Stepping- SERR- FastB2B- DisINTx-
|
||||
Status: Cap- 66MHz- UDF- FastB2B- ParErr- DEVSEL=medium >TAbort-
|
||||
<TAbort- <MAbort- >SERR- <PERR- INTx-
|
||||
Interrupt: pin A routed to IRQ 10
|
||||
Region 0: I/O ports at c150 [size=8]
|
||||
Region 1: I/O ports at c158 [size=8]
|
||||
Kernel driver in use: serial
|
||||
00: 48 43 53 32 01 00 00 02 10 02 00 07 00 00 00 00
|
||||
10: 51 c1 00 00 59 c1 00 00 00 00 00 00 00 00 00 00
|
||||
20: 00 00 00 00 00 00 00 00 00 00 00 00 48 43 53 32
|
||||
30: 00 00 00 00 00 00 00 00 00 00 00 00 0a 01 00 00
|
||||
|
||||
In the Linux guest VM, dmesg output for the device is as follows:
|
||||
In the Linux guest VM, dmesg output for the device is as follows:
|
||||
|
||||
serial 0000:00:05.0: PCI INT A -> Link[LNKA] -> GSI 10 (level, high) -> IRQ
|
||||
10
|
||||
0000:00:05.0: ttyS1 at I/O 0xc150 (irq = 10) is a 16550A
|
||||
0000:00:05.0: ttyS2 at I/O 0xc158 (irq = 10) is a 16550A
|
||||
serial 0000:00:05.0: PCI INT A -> Link[LNKA] -> GSI 10 (level, high) -> IRQ 10
|
||||
0000:00:05.0: ttyS1 at I/O 0xc150 (irq = 10) is a 16550A
|
||||
0000:00:05.0: ttyS2 at I/O 0xc158 (irq = 10) is a 16550A
|
||||
|
||||
|
||||
5. In the Linux guest VM, check the serial ports.
|
||||
5. In the Linux guest VM, check the serial ports::
|
||||
|
||||
# setserial -g /dev/ttyS*
|
||||
/dev/ttyS0, UART: 16550A, Port: 0x03f8, IRQ: 4
|
||||
/dev/ttyS1, UART: 16550A, Port: 0xc150, IRQ: 10
|
||||
/dev/ttyS2, UART: 16550A, Port: 0xc158, IRQ: 10
|
||||
# setserial -g /dev/ttyS*
|
||||
/dev/ttyS0, UART: 16550A, Port: 0x03f8, IRQ: 4
|
||||
/dev/ttyS1, UART: 16550A, Port: 0xc150, IRQ: 10
|
||||
/dev/ttyS2, UART: 16550A, Port: 0xc158, IRQ: 10
|
||||
|
||||
6. Using minicom or any terminal emulation program, open port /dev/ttyS1 or
|
||||
/dev/ttyS2 with hardware flow control disabled.
|
||||
|
|
@ -388,14 +396,14 @@ card.
|
|||
|
||||
Data is loop backed from hosts mtty driver.
|
||||
|
||||
8. Destroy the mediated device that you created.
|
||||
8. Destroy the mediated device that you created::
|
||||
|
||||
# echo 1 > /sys/bus/mdev/devices/83b8f4f2-509f-382f-3c1e-e6bfe0fa1001/remove
|
||||
# echo 1 > /sys/bus/mdev/devices/83b8f4f2-509f-382f-3c1e-e6bfe0fa1001/remove
|
||||
|
||||
References
|
||||
==========
|
||||
|
||||
[1] See Documentation/vfio.txt for more information on VFIO.
|
||||
[2] struct mdev_driver in include/linux/mdev.h
|
||||
[3] struct mdev_parent_ops in include/linux/mdev.h
|
||||
[4] struct vfio_iommu_driver_ops in include/linux/vfio.h
|
||||
1. See Documentation/vfio.txt for more information on VFIO.
|
||||
2. struct mdev_driver in include/linux/mdev.h
|
||||
3. struct mdev_parent_ops in include/linux/mdev.h
|
||||
4. struct vfio_iommu_driver_ops in include/linux/vfio.h
|
||||
|
|
|
|||
Loading…
Reference in New Issue