|
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] Re: [Xen-devel] [PATCH V5 0/7] xen pvusb toolstack work
On 06/25/2015 12:07 PM, Chunyan Liu wrote: This patch series is to add pvusb toolstack work, supporting hot add|remove USB device to|from guest and specify USB device in domain configuration file. Patches 1-6: Tested-by: Juergen Gross <jgross@xxxxxxxx> Juergen Changes to v4: * use DEFINE_DEVICE_ADD and DEFINE_DEVICES_ADD to handle usbctrl adding and usb adding, define extended macro DEFINE_DEVICE_REMOVE_EXT to handle usbctrl remove. * Change interfaces: libxl_device_usb only includes bus.addr, removing busid. 'xl usb-detach' uses <ctrl,port> to specify usb device instead of bus.addr. Adjusting all related codes. * Other changes addring all other comments in v4. V3 is here: http://lists.xenproject.org/archives/html/xen-devel/2015-06/msg01327.html Related Discussion Threads: http://www.redhat.com/archives/libvir-list/2014-June/msg00038.html http://lists.xen.org/archives/html/xen-devel/2014-06/msg00086.html <<< pvusb work introduction >>> 1. Overview There are two general methods for passing through individual host devices to a guest. The first is via an emulated USB device controller; the second is PVUSB. Additionally, there are two ways to add USB devices to a guest: via the config file at domain creation time, and via hot-plug while the VM is running. * Emulated USB In emulated USB, the device model (qemu) presents an emulated USB controller to the guest. The device model process then grabs control of the device from domain 0 and and passes the USB commands between the guest OS and the host USB device. This method is only available to HVM domains, and is not available for domains running with device model stubdomains. * PVUSB PVUSB uses a paravirtialized front-end/back-end interface, similar to the traditional Xen PV network and disk protocols. In order to use PVUSB, you need usbfront in your guest OS, and usbback in dom0 (or your USB driver domain). 2. Specifying a host USB device QEMU qmp commands allows USB devices to be specified either by their bus address (in the form bus.device) or their device tag (in the form vendorid:deviceid). Each way of specifying has its advantages: Specifying by device tag will always get the same device, regardless of where the device ends up in the USB bus topology. However, if there are two identical devices, it will not allow you to specify which one. Specifying by bus address will always allow you to choose a specific device, even if you have duplicates. However, the bus address may change depending on which port you plugged the device into, and possibly also after a reboot. To avoid duplication of vendorid:deviceid, we'll use bus address to specify host USB device in xl toolstack. You can use lsusb to list the USB devices on the system: Bus 001 Device 003: ID 0424:2514 Standard Microsystems Corp. USB 2.0 Hub Bus 003 Device 002: ID f617:0905 Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub Bus 001 Device 004: ID 0424:2640 Standard Microsystems Corp. USB 2.0 Hub Bus 001 Device 005: ID 0424:4060 Standard Microsystems Corp. Ultra Fast Media Reader Bus 001 Device 006: ID 046d:c016 Logitech, Inc. Optical Wheel Mouse To pass through the Logitec mouse, for instance, you could specify 1.6 (remove leading zeroes). Note: USB hubs can not be assigned to guest. 3. PVUSB toolstack * Specify USB device in xl config file You can just specify usb devices, like: usbdev=['1.6'] Then it will create a USB controller automatically and attach the USB device to the first available USB controller:port. or, you can explicitly specify usb controllers and usb devices, like: usbctrl=['verison=1, ports=4', 'version=2, ports=8', ] usbdev=['1.6, controller=0, port=1'] Then it will create two USB controllers as you specified. And if controller and port are specified in usb config, then it will attach the USB device to that controller:port. About the controller and port value: Each USB controller has a index (or called devid) based on 0. The 1st controller has index 0, the 2nd controller has index 1, ... Under controller, each port has a port number based on 1. In above configuration, the 1st controller will have port 1,2,3,4. * Hot-Plug USB device To attach a USB device, you should first create a USB controller. e.g. xl usb-ctrl-attach domain [version=1|2] [ports=value] By default, it will create a USB2.0 controller with 8 ports. Then you could attach a USB device. e.g. xl usb-attach domain 1.6 [controller=index port=number] By default, it will find the 1st available controller:port to attach the USB device. You could view USB device status of the domain by usb-list. e.g. xl usb-list domain It will list USB controllers and USB devices under each controller. You could detach a USB device with usb-detach command. e.g. xl usb-detach domain 1.6 You can also remove the whole USB controller by usb-ctrl-detach command. e.g. xl usb-ctrl-detach domain 0 It will remove the USB controller with index 0 and all USB devices under it. 4. PVUSB Libxl implementation * usb-ctrl-attach To create a usb controller, we need: 1) generate usb controler related information 2) write usb controller frontend/backend info to xenstore PVUSB frontend and backend driver will probe xenstore paths and build connection between frontend and backend. * usb-ctrl-detach To remove a usb controller, we need: 1) check if the usb controller exists or not 2) remove all usb devices under controller 3) remove usb controller info from xenstore * usb-attach To attach a usb device, we need: 1) check if the usb device type is assignable 2) check if the usb device is already assigned to a domain 3) add 'busid' of the usb device to xenstore contoller/port/. PVUSB driver watches the xenstore changes and detects that, and needs to use 'busid' to do following work. 4) unbind usb device from original driver and bind to usbback. If usb device has many interfaces, then: - unbind each interface from its original driver and bind to usbback. - store the original driver to xenstore for later rebinding when detaching the device. * usb-detach To detach a usb device, we need: 1) check if the usb device is assigned to the domain 2) remove the usb device from xenstore controller/port. 3) unbind usb device from usbback and rebind to its original driver. If usb device has many interfaces, do it to each interface. * usb-list List all USB controllers and USB devices under each controller. 5. PVUSB xenstore information PVUSB xenstore information includes three parts: frontend, backend and /libxl part. A USB controller is corresponding to a "vusb" device in xenstore. Adding a USB controller will add a new "vusb" device, removing a USB controller will delete the related "vusb" device. Following is an example xenstore values of a USB controller. Backend: backend = "" vusb = "" 1 = "" 0 = "" frontend = "/local/domain/1/device/vusb/0" frontend-id = "1" online = "1" state = "4" type = "pv" usb-ver = "1" num-ports = "4" port = "" 1 = "" 2 = "" 3 = "" 4 = "" Frontend: device = "" vusb = "" 0 = "" backend = "/local/domain/0/backend/vusb/1/0" backend-id = "0" state = "4" urb-ring-ref = "348" conn-ring-ref = "346" event-channel = "20" Adding a USB device won't create a new "vusb" device, but only write the USB device busid to one port of USB controller. For example, attaching a USB device (busid is 2-1.6) to above USB controller port 1, it only need write 2-1.6 to port 1 of this USB controller: Backend: backend = "" vusb = "" 1 = "" 0 = "" frontend = "/local/domain/1/device/vusb/0" frontend-id = "1" online = "1" state = "4" type = "pv" usb-ver = "1" num-ports = "4" port = "" 1 = "2-1.6" 2 = "" 3 = "" 4 = "" Frontend doesn't change. Since assign a host USB device to guest, we'll unbind USB interfaces from their original drivers and bind them to usbback. After detaching this USB device from guest, one would hope the USB interfaces could be rebind to their original drivers, so there should some place to get the original driver info. To support that, when attaching a USB device to guest, we'll save the original driver info in xenstore too, the place is /libxl/usbback, for example: libxl = "" 1 = "" dm-version = "qemu_xen" usbback = "" 3-11 = "" 3-11-1_0 = "" driver_path = "/sys/bus/usb/drivers/btusb" In this example, USB device (busid is 3-11, /sys/bus/usb/devices/3-11). It has interface 3-11:1.0, whose original dirver is btusb. Since xenstore doesn't allow ':' and '.' in a key, so we encode the interface by changing ':' to '-' and changing '.' to '_'. When detaching the USB device from guest, we can rebind 3-11:1.0 to btusb driver. Chunyan Liu (7): libxl: export some functions for pvusb use libxl_read_file_contents: add new entry to read sysfs file libxl: add pvusb API libxl: add libxl_device_usb_assignable_list API xl: add pvusb commands xl: add usb-assignable-list command domcreate: support pvusb in configuration file docs/man/xl.cfg.pod.5 | 75 ++ docs/man/xl.pod.1 | 40 + tools/libxl/Makefile | 2 +- tools/libxl/libxl.c | 57 +- tools/libxl/libxl.h | 67 ++ tools/libxl/libxl_create.c | 73 +- tools/libxl/libxl_device.c | 8 + tools/libxl/libxl_internal.h | 33 +- tools/libxl/libxl_osdeps.h | 13 + tools/libxl/libxl_pvusb.c | 1358 ++++++++++++++++++++++++++++++++++ tools/libxl/libxl_types.idl | 50 ++ tools/libxl/libxl_types_internal.idl | 1 + tools/libxl/libxl_utils.c | 53 +- tools/libxl/libxl_utils.h | 5 + tools/libxl/xl.h | 6 + tools/libxl/xl_cmdimpl.c | 401 +++++++++- tools/libxl/xl_cmdtable.c | 29 + 17 files changed, 2255 insertions(+), 16 deletions(-) create mode 100644 tools/libxl/libxl_pvusb.c _______________________________________________ Xen-devel mailing list Xen-devel@xxxxxxxxxxxxx http://lists.xen.org/xen-devel
|
 |
Lists.xenproject.org is hosted with RackSpace, monitoring our |