Hi Zenghui, On 1/14/20 8:10 AM, Zenghui Yu wrote: > Hi Eric, > > On 2020/1/10 16:37, Auger Eric wrote: >> Hi Zenghui, >> >> On 12/25/19 2:30 PM, Zenghui Yu wrote: >>> DISCARD command error occurs if any of the following apply: >>> >>> - [ ... (those which we have already handled) ] >> nit: I would remove the above and simply say the discard is supposed to >> fail if the collection is not mapped to any target redistributor. If an >> ITE exists then the ite->collection is non NULL. > > I think this is not always true. Let's talk about the following scenario > (a bit insane, though): > > 1. First map a LPI to an unmapped Collection, then ite->collection is > non NULL and its target_addr is COLLECTION_NOT_MAPPED. > > 2. Then issue MAPC and unMAPC(V=0) commands on this Collection, the > ite->collection will be NULL, see vgic_its_free_collection(). You're right I missed that case. > > Discard the LPI mapping after "1" or "2", we will both encounter the > unmapped collection command error. > >> What needs to be checked is its_is_collection_mapped(). >> >> By the way update_affinity_collection() also tests ite->collection. I >> think this is useless or do I miss something? > > Yeah, I agree. We managed to invoke update_affinity_collection(,, coll), > ensure that the 'coll' can _not_ be NULL. > So '!ite->collection' is already a subcase of 'coll != ite->collection'. > We can safely get rid of it. OK. But that's not for the (wrong) reason I mentioned above. So it is a minor cleanup and you may just leave it as is and just focus on this fix. Thanks Eric > >> >> Reviewed-by: Eric Auger <eric.auger@xxxxxxxxxx> >> > > Thanks for that. I'll change the commit message with your suggestion and > add your R-b in v2. > > > Thanks, > Zenghui > > > _______________________________________________ > linux-arm-kernel mailing list > linux-arm-kernel@xxxxxxxxxxxxxxxxxxx > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel > _______________________________________________ kvmarm mailing list kvmarm@xxxxxxxxxxxxxxxxxxxxx https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
