> From: Alex Williamson <alex.williamson@xxxxxxxxxx> > Sent: Thursday, April 20, 2023 10:09 PM [...] > > > Whereas dev-id < 0 > > > (== -1) is an affected device which prevents hot-reset, ex. an un-owned > > > device, device configured within a different iommufd_ctx, or device > > > opened outside of the vfio cdev API." Is that about right? Thanks, > > > > Do you mean to have separate err-code for the three possibilities? As > > the devid is generated by iommufd and it is u32. I'm not sure if we can > > have such err-code definition without reserving some ids in iommufd. > > Yes, if we're going to report the full dev-set, I think we need at > least two unique error codes or else the user has no way to determine > the subset of invalid dev-ids which block the reset. I think Jason is > proposing the set of valid dev-ids are >0, a dev-id of zero indicates > some form of non-blocking, while <0 (or maybe specifically -1) > indicates a blocking device. I was trying to get consensus on a formal > definition of each of those error codes in my previous reply. Thanks, Seems like RESETTABLE flag is not needed if we report -1 for the devices that block hotreset. Userspace can deduce if the calling device is resettable or not by checking if there is any -1 in the affected device list. Regards, Yi Liu