On 9/28/2021 2:12 AM, Jason Gunthorpe wrote:
On Mon, Sep 27, 2021 at 04:46:48PM -0600, Alex Williamson wrote:
+ enum { MAX_STATE = VFIO_DEVICE_STATE_RESUMING };
+ static const u8 vfio_from_state_table[MAX_STATE + 1][MAX_STATE + 1] = {
+ [VFIO_DEVICE_STATE_STOP] = {
+ [VFIO_DEVICE_STATE_RUNNING] = 1,
+ [VFIO_DEVICE_STATE_RESUMING] = 1,
+ },
Our state transition diagram is pretty weak on reachable transitions
out of the _STOP state, why do we select only these two as valid?
I have no particular opinion on specific states here, however adding
more states means more stuff for drivers to implement and more risk
driver writers will mess up this uAPI.
_STOP == 000b => Device Stopped, not saving or resuming (from UAPI).
This is the default initial state and not RUNNING.
The user application should move device from STOP => RUNNING or STOP =>
RESUMING.
Maybe we need to extend the comment in the UAPI file.
So only on those grounds I'd suggest to keep this to the minimum
needed instead of the maximum logically possible..
Also, probably the FSM comment from the uapi header file should be
moved into a function comment above this function?
Jason
