f5d74d4e9c
The "test_gpio_process_events_multi_success" test currently hangs with an update to a newer version of Rust. The code here tries to read the value, locked, for each GPIO one by one. The values are updated in another thread with the help of write lock. More discussion around this issue can be found here. https://github.com/rust-lang/rust/issues/101194 Taking the lock only once fixes it for now. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> |
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| Cargo.toml | ||
| README.md | ||
vhost-device-gpio - GPIO emulation backend daemon
Description
This program is a vhost-user backend that emulates a VirtIO GPIO device. This program takes a list of gpio devices on the host OS and then talks to them via the /dev/gpiochip{X} interface when a request comes from the guest OS for an GPIO device.
This program is tested with QEMU's -device vhost-user-gpio-pci but should
work with any virtual machine monitor (VMM) that supports vhost-user. See the
Examples section below.
Synopsis
vhost-device-gpio [OPTIONS]
Options
.. program:: vhost-device-gpio
.. option:: -h, --help
Print help.
.. option:: -s, --socket-path=PATH
Location of vhost-user Unix domain sockets, this path will be suffixed with 0,1,2..socket_count-1.
.. option:: -c, --socket-count=INT
Number of guests (sockets) to attach to, default set to 1.
.. option:: -l, --device-list=GPIO-DEVICES
GPIO device list at the host OS in the format: [:]
Example: --device-list "2:4:7"
Here, each GPIO devices correspond to a separate guest instance, i.e. the number of devices in the device-list must match the number of sockets in the --socket-count. For example, the GPIO device 0 will be allocated to the guest with "0" path.
Examples
The daemon should be started first:
::
host# vhost-device-gpio --socket-path=gpio.sock --socket-count=1 --device-list 0:3
The QEMU invocation needs to create a chardev socket the device can use to communicate as well as share the guests memory over a memfd.
::
host# qemu-system
-chardev socket,path=vgpio.sock,id=vgpio
-device vhost-user-gpio-pci,chardev=vgpio,id=gpio
-m 4096
-object memory-backend-file,id=mem,size=4G,mem-path=/dev/shm,share=on
-numa node,memdev=mem
...