[libvirt] [PATCH 00/13] Add support for send keys to guest

[Lai Jiangshan]

On 05/26/2011 12:36 AM, Daniel P. Berrange wrote:
> On Wed, May 25, 2011 at 05:37:42PM +0800, Lai Jiangshan wrote:
>> Add API virDomainSendKey() and virsh send-key command.
>>
>> # virsh help send-key
>>   NAME
>>     send-key - Send keycodes to the guest
>>
>>   SYNOPSIS
>>     send-key <domain> [--codeset <string>] [--holdtime <number>] <keycode>...
>>
>>   DESCRIPTION
>>     Send keycodes to the guest, the keycodes must be integers
>>     or the qemu-style key strings for the "xt:keystring" codeset
>>     or the KEY_* strings listed below for the "linux" codeset.
>>
>>     Available codeset:
>>         linux          the keycodes specified in 
>>                         /usr/include/linux/input.h(default)
>>         default        linux codeset will be used
>>         driver_default the hypervisor default codeset will be used
>>         xt             XT(set1) scancode of standard AT keyboards and PS/2 keyboards
>>         atset1         set1 scancode of standard AT keyboards and PS/2 keyboards
>>         atset2         set2 scancode of standard AT keyboards and PS/2 keyboards
>>         atset3         set3 scancode of standard AT keyboards and PS/2 keyboards
>>         xt:keystring   XT scancode, but <keycode>... must be the qemu-style key strings
> 
> I was thinking we'd just use the Linux keycode set in the API, but I guess
> if the client app already has things in XT codeset, it isn't too nice to
> force them to convert to Linux keycodes, only for libvirt to convert them
> straight back for QEMU. So I think it was a good idea to add different
> codesets.
> 
> I don't think that 'driver_default' makes sense though. For that to be
> usable, the person invoking the API must somehow know what the driver
> default codeset is. If they know that, then they can trivially just
> specify that already, so 'driver_default' doesn't seem to add any
> benefit.

OK, it will be removed.

> 
> 
> As for 'xt:keystring', if you think it is worth being able to use
> key strings, then perhaps we should have 2 apis. One API that takes
> a list of keycodes as ints, and one API that takes a list of keycodes
> as strings.

I don't think it is a good idea to add a second API, virDomainSendKey()
is not used directly by human, integer is enough. 2 apis will make the user of
the lib confused.

virsh send-key command is a human interface,
I think it is good if it accepts strings, so I allow KEY_XXX strings.

And this command should wrap all things(convert strings to integers).

If you deny 'xt:keystring', I can remove the patch, but KEY_XXX strings will
still stay.

> 
> This would avoid the need for every client application to maintain
> a mapping table of strings <-> ints. eg, all the mapping tables
> would be contained within libvirt.

qemu monitor don't require "ints-->names" conversions, it just needs
very trivial conversions "ints-->0xNN", this conversion will not need
when qmp send-key is implemented.

I don't know other hypervisors, but I think virDomainSendKey() taking
a list of keycode as ints is the best api for all hypervisors.

> 
>>
>>     Examples:
>>
>>         virsh # send-key <domain> 37 18 21
>>         virsh # send-key <domain> --holdtime 1000 0x15 18 0xf
>>         virsh # send-key <domain> KEY_LEFTCTRL KEY_LEFTALT KEY_F1
>>         virsh # send-key <domain> --codeset xt:keystring alt-sysrq h
>>
>>     KEY_XXX strings for the "linux" codeset:
> 
> For virsh, perhaps it should default to always using the strings
> for the keys, and only use integers if given a special flag. I
> think most admins using virsh would just be using strings. The
> integer keycodes are mostly useful for apps using the API directly.
> 
> eg, perhaps
> 
>          virsh # send-key <domain> KEY_LEFTCTRL KEY_LEFTALT KEY_F1
>          virsh # send-key <domain> --codeset linux KEY_LEFTCTRL KEY_LEFTALT KEY_F1
>          virsh # send-key <domain> --codeset xt alt-sysrq h
>          virsh # send-key <domain> --num 37 18 21
>          virsh # send-key <domain> --num --holdtime 1000 0x15 18 0xf
>          virsh # send-key <domain> --num --codeset linux --holdtime 1000 0x15 18 0xf

It is good for me, but I may want to wrap the strings->ints conversions in virsh
instead of in hypervisors.

> 
>> .
>> .
>> .
>>   OPTIONS
>>     [--domain] <string>  domain name, id or uuid
>>     --codeset <string>   the codeset of keycodes, default:linux
>       --num                the keys are specified as integer values,
>>     --holdtime <number>  the time (in millsecond) how long the keys will be held
>>     <keycode>            the key string (or value if --num is set)
> 
> 
> Daniel