On Tue, Oct 08, 2019 at 03:32:25PM +0200, Jan Beulich wrote: > On 08.10.2019 15:14, Roger Pau Monné wrote: > > On Tue, Oct 08, 2019 at 01:28:49PM +0200, Jan Beulich wrote: > >> On 08.10.2019 13:09, Roger Pau Monné wrote: > >>> Given that as you correctly point out maskall is unset after device > >>> reset, I feel that option 4 is the best one since it matches the state > >>> of the hardware after reset. > >> > >> Right, that's the variant coming closest to what hardware state > >> ought to be at that point. We'd need to double check that the > >> per-entry mask bits are all set at that point. > > > > I'm not saying such check is not worth doing, but why do it in this > > case but not when also clearing the maskall (in msix_capability_init) > > when called from prepare_msix? > > By "double check" I meant inspect the source, not to add checking logic.
Oh, I implied you wanted to iterate over all entries and check that the mask bit is set for each. It's my understanding that Xen relies on dom0 having done a device reset before it being assigned, which masks all entries. I've checked the pciback code and the reset is performed when the device is assigned to dom0 (ie: guest shutdown or hot-unplug), and hence when the device is assigned to a different domain the state of it should be the after reset one. I can add a comment in assign_device that Xen expects the device state to be the after reset one, and hence host_maskall = guest_maskall = false and all entries should have the mask bit set. Roger. _______________________________________________ Xen-devel mailing list [email protected] https://lists.xenproject.org/mailman/listinfo/xen-devel
