Re: [PATCH 0/4] HVM Virtual S3

[Keir Fraser <Keir.Fraser@cl.cam.ac.uk>]

On 21/5/07 04:10, "Yu, Ke" <ke.yu@intel.com> wrote:

> 1. For HVM without PV, QEMU call xc_save, qemu_savevm,... at the virtual S3
> final stage.

In this case S3 should somehow be an option to 'xm save', so an alternative
to doing an immediate remote shutdown on the HVM guest. Instead we would
inject a S3 event and when the guest enters S3 qemu would do the remote
shutdown at that point. This has to be an option to 'xm save', or perhaps a
domain config option, because not all guests will respond to PM events to
enter S3 state.

> 2. For HVM with PV, need also add PV driver suspend/resume interface to
> disconnect/reconnect xenbus connection.

Possibly we can leave the S3 kickoff to the PV drivers. So xend notifies PV
drivers to suspend, they do their thing, kick S3 code in a guest-OS-specific
way, guest enters S3, qemu does remote shutdown. Then on wakeup the S3
restore code runs before PV-driver restore.

 -- Keir

> - I implement the basic Virtual S3 code and leave interface for save/restore
> - You or the PV maintainer add the above save/restore logic upon the  basic
> virtual S3 code.