[Qemu-devel] cross version compatibility and qemu version

["Michael S. Tsirkin" <mst@redhat.com>]

I was looking at cross-version migration issues, in the
hope that we can fix most of them for release 1.6.
I noticed that we still use QEMU_VERSION in hardware.

hw/scsi/megasas.c:    snprintf(info.package_version, 0x60, "%s-QEMU", QEMU_VERSION);
hw/usb/redirect.c:#define VERSION "qemu usb-redir guest " QEMU_VERSION

These look like a bug that will break cross version
compatibility - I think need to change both instances
to qemu_get_version()?

megasas also includes the build date/time of QEMU - this
clearly removed any hope to be exactly compatible.
I'm not sure what to do with respect to this:
let's stop the clock at an arbitrary date?
Add property for management to control this as well?

We also probably want to fix this in -stable versions.