Unimplemented VM.send_sysrq method about xen-api

[psafont]

Looking at the code history I can see that it has been like that for at least 14 years. I can see, however that there's an implementation in xenopsd to send the request using xenstore interface, so using it needs a guest tools that supports this.

First the guest tools need to be checked whether they support the protocol and the protocol is reasonable (@ydirson is an interested partiy, probably). Then it can be a matter of plumbing the request from the http request to xenopsd and fix whatever is necessary to follow the reasonable protocol.

xen-api/ocaml/xenopsd/xc/domain.ml

Line 626 in c074cb6

let sysrq ~xs domid key =

[andyhhp]

there's no guest tools interaction at all. It's the Linux kernel which watches that xenstore key.

And yes, it means the toolstack doesn't know if the guest kernel understands it or not, but xl sysrq $domid and xm before that does work to a first approximation.