On Wed, May 04, 2022 at 03:42:09PM +0100, Robin Murphy wrote: > > This fixes an oops with VFIO and SMMUv3 because VFIO will call > > iommu_detach_group() and then immediately iommu_domain_free(), but > > SMMUv3 has no way to know that the domain it is holding a pointer to > > has been freed. Now the iommu_detach_group() will assign the blocking > > domain and SMMUv3 will no longer hold a stale domain reference. > > Thanks for taking this on! I do like the overall structure and naming much > more than my initial sketch :)
Thanks, no problem! > > /* > > - * If the group has been claimed already, do not re-attach the default > > - * domain. > > + * A NULL domain means to call the detach_dev() op. New drivers should > > + * use a IOMMU_DOMAIN_IDENTITY domain instead of a NULL default_domain > > Nit: IOMMU_DOMAIN_DMA is the baseline of default domain support, passthrough > is more of an optional extra. Can you elaborate on this a bit more for the comment, I'm not sure I understand all the historical stuff here. Here we are looking at a case where group->domain becomes NULL - what does this mean in the historical world? ie what should the iommu driver do when detach_dev is called? I had guessed it was remove all translation - ie IOMMU_DOMAIN_IDENTITY? > > + * and detatch_dev(). > > Nit: detach_dev > > Otherwise, modulo the other things already pointed out, this looks OK to me. Done, thanks Jason _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu
