Re: device compatibility interface for live migration with assigned devices
> As you indicate, the vendor driver is responsible for checking
version
> information embedded within the migration stream. Therefore a
> migration should fail early if the devices are incompatible. Is it
but as I know, currently in VFIO migration protocol, we have no way to
get vendor specific compatibility checking string in migration setup stage
(i.e. .save_setup stage) before the device is set to _SAVING state.
In this way, for devices who does not save device data in precopy stage,
the migration compatibility checking is as late as in stop-and-copy
stage, which is too late.
do you think we need to add the getting/checking of vendor specific
compatibility string early in save_setup stage?
hi Alex,
after an offline discussion with Kevin, I realized that it may not be a
problem if migration compatibility check in vendor driver occurs late in
stop-and-copy phase for some devices, because if we report device
compatibility attributes clearly in an interface, the chances for
libvirt/openstack to make a wrong decision is little.
so, do you think we are now arriving at an agreement that we'll give up
the read-and-test scheme and start to defining one interface (perhaps in
json format), from which libvirt/openstack is able to parse and find out
compatibility list of a source mdev/physical device?
Thanks
Yan