[libvirt] [PATCH 3/3] libxl: add .domainSendKey

[Daniel P. Berrange]

On Tue, Dec 09, 2014 at 11:19:22PM -0700, Chun Yan Liu wrote:
> 
> 
> >>> On 12/9/2014 at 05:44 PM, in message <20141209094444.GB29167 at redhat.com>,
> "Daniel P. Berrange" <berrange at redhat.com> wrote: 
> > On Tue, Dec 09, 2014 at 11:27:46AM +0800, Chunyan Liu wrote: 
> > > libxl supports sysrq. Add .domainSendKey function to support 
> > > sending sysrq key. 
> >  
> > I think this is really bending the semantics of the virDomainSendKey 
> > API too much.  This API is documented to inject *any* scancodes into 
> > the guest operating system. Implementing it in such a way that you 
> > can only send sysrq key sequences to the guest kernel is not what 
> > applications will expect when they try to use this API. So NACK to 
> > this patch 
> >  
> > I'm open to the idea of adding an explicit API for triggering the 
> > sysrq sequence though. eg virDomainSendSysRequest or something 
> > like that, if you really want access to sysrq via the API.
> 
> Libxl now has no ability to send any key sequence to guest kernel
> but supports sending sysrq key. We just want a way to send sysrq key,
> so adding new  virDomainSendSysRequest API is OK to me.
> 
> Meanwhile, that means:
> Adding .domainSendSysRequest to virHypervisorDriver?
> And in virsh, add a new 'virsh sysrq' command or update code of
> cmdSendKey to handle sysrq key sequence? (like if .domainSendKey is
> not supported by driver, check if it is sysrq key sequence, if yes, try
> virDomainSysRequest if driver supports that.)

Yes pretty much, but I wouldn't do anything with domainSendKey. Apps can
choose to try to use domainSendKey if domainSysRequest isn't supported.

Regards,
Daniel
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