On Mon, Apr 17, 2023 at 12:34:31PM +0200, Jan Beulich wrote: > On 17.04.2023 12:17, Roger Pau Monné wrote: > > On Fri, Apr 14, 2023 at 01:30:39AM +0000, Volodymyr Babchuk wrote: > >> Above I have proposed another view on this. I hope, it will work for > >> you. Just to reiterate, idea is to allow "harmless" refcounts to be left > >> after returning from pci_remove_device(). By "harmless" I mean that > >> owners of those refcounts will not try to access the physical PCI > >> device if pci_remove_device() is already finished. > > > > I'm not strictly a maintainer of this piece code, albeit I have an > > opinion. I will like to also hear Jans opinion, since he is the > > maintainer. > > I'm afraid I can't really appreciate the term "harmless refcounts". Whoever > holds a ref is entitled to access the device. As stated before, I see only > two ways of getting things consistent: Either pci_remove_device() is > invoked upon dropping of the last ref,
With this approach, what would be the implementation of PHYSDEVOP_manage_pci_remove? Would it just check whether the pdev exist and either return 0 or -EBUSY? > or it checks that it is dropping the > last one. The former looks architecturally cleaner to me, but I can accept > that moving there might be more of a change, so wouldn't object to going > the latter route. One of my concerns is what is expected of PHYSDEVOP_manage_pci_remove, I don't think it's expected for PHYSDEVOP_manage_pci_remove to return 0 while there are users inside the hypervisor still holding a reference to the pdev. Thanks, Roger.
