556eb8b791
Here is the large set of driver core changes for 6.4-rc1. Once again, a busy development cycle, with lots of changes happening in the driver core in the quest to be able to move "struct bus" and "struct class" into read-only memory, a task now complete with these changes. This will make the future rust interactions with the driver core more "provably correct" as well as providing more obvious lifetime rules for all busses and classes in the kernel. The changes required for this did touch many individual classes and busses as many callbacks were changed to take const * parameters instead. All of these changes have been submitted to the various subsystem maintainers, giving them plenty of time to review, and most of them actually did so. Other than those changes, included in here are a small set of other things: - kobject logging improvements - cacheinfo improvements and updates - obligatory fw_devlink updates and fixes - documentation updates - device property cleanups and const * changes - firwmare loader dependency fixes. All of these have been in linux-next for a while with no reported problems. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> -----BEGIN PGP SIGNATURE----- iG0EABECAC0WIQT0tgzFv3jCIUoxPcsxR9QN2y37KQUCZEp7Sw8cZ3JlZ0Brcm9h aC5jb20ACgkQMUfUDdst+ykitQCfamUHpxGcKOAGuLXMotXNakTEsxgAoIquENm5 LEGadNS38k5fs+73UaxV =7K4B -----END PGP SIGNATURE----- Merge tag 'driver-core-6.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core Pull driver core updates from Greg KH: "Here is the large set of driver core changes for 6.4-rc1. Once again, a busy development cycle, with lots of changes happening in the driver core in the quest to be able to move "struct bus" and "struct class" into read-only memory, a task now complete with these changes. This will make the future rust interactions with the driver core more "provably correct" as well as providing more obvious lifetime rules for all busses and classes in the kernel. The changes required for this did touch many individual classes and busses as many callbacks were changed to take const * parameters instead. All of these changes have been submitted to the various subsystem maintainers, giving them plenty of time to review, and most of them actually did so. Other than those changes, included in here are a small set of other things: - kobject logging improvements - cacheinfo improvements and updates - obligatory fw_devlink updates and fixes - documentation updates - device property cleanups and const * changes - firwmare loader dependency fixes. All of these have been in linux-next for a while with no reported problems" * tag 'driver-core-6.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (120 commits) device property: make device_property functions take const device * driver core: update comments in device_rename() driver core: Don't require dynamic_debug for initcall_debug probe timing firmware_loader: rework crypto dependencies firmware_loader: Strip off \n from customized path zram: fix up permission for the hot_add sysfs file cacheinfo: Add use_arch[|_cache]_info field/function arch_topology: Remove early cacheinfo error message if -ENOENT cacheinfo: Check cache properties are present in DT cacheinfo: Check sib_leaf in cache_leaves_are_shared() cacheinfo: Allow early level detection when DT/ACPI info is missing/broken cacheinfo: Add arm64 early level initializer implementation cacheinfo: Add arch specific early level initializer tty: make tty_class a static const structure driver core: class: remove struct class_interface * from callbacks driver core: class: mark the struct class in struct class_interface constant driver core: class: make class_register() take a const * driver core: class: mark class_release() as taking a const * driver core: remove incorrect comment for device_create* MIPS: vpe-cmp: remove module owner pointer from struct class usage. ... |
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|---|---|---|
| .. | ||
| Makefile | ||
| mbochs.c | ||
| mdpy-defs.h | ||
| mdpy-fb.c | ||
| mdpy.c | ||
| mtty.c | ||
| README.rst | ||
Using the mtty vfio-mdev sample code
====================================
mtty is a sample vfio-mdev driver that demonstrates how to use the mediated
device framework.
The sample driver creates an mdev device that simulates a serial port over a PCI
card.
1. Build and load the mtty.ko module.
This step creates a dummy device, /sys/devices/virtual/mtty/mtty/
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
2. Create a mediated device by using the dummy device that you created in the
previous step::
# echo "83b8f4f2-509f-382f-3c1e-e6bfe0fa1001" > \
/sys/devices/virtual/mtty/mtty/mdev_supported_types/mtty-2/create
3. Add parameters to qemu-kvm::
-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::
# 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:
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::
# 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.
7. Type data on the minicom terminal or send data to the terminal emulation
program and read the data.
Data is loop backed from hosts mtty driver.
8. Destroy the mediated device that you created::
# echo 1 > /sys/bus/mdev/devices/83b8f4f2-509f-382f-3c1e-e6bfe0fa1001/remove