On Wed, Jun 20, 2018 at 06:42:58PM +1000, Alexey Kardashevskiy wrote: > When attaching a hardware table to LIOBN in KVM, we match table parameters > such as page size, table offset and table size. However the tables are > created via very different paths - VFIO and KVM - and the VFIO path goes > through the platform code which has minimum TCE page size requirement > (which is 4K but since we allocate memory by pages and cannot avoid > alignment anyway, we align to 64k pages for powernv_defconfig). > > So when we match the tables, one might be bigger that the other which > means the hardware table cannot get attached to LIOBN and DMA mapping > fails. > > This removes the table size alignment from the guest visible table. > This does not affect the memory allocation which is still aligned - > kvmppc_tce_pages() takes care of this. > > This relaxes the check we do when attaching tables to allow the hardware > table be bigger than the guest visible table. > > Ideally we want the KVM table to cover the same space as the hardware > table does but since the hardware table may use multiple levels, and > all levels must use the same table size (IODA2 design), the area it can > actually cover might get very different from the window size which > the guest requested, even though the guest won't map it all. > > Fixes: ca1fc489cf "KVM: PPC: Book3S: Allow backing bigger guest IOMMU pages with smaller physical pages" > Signed-off-by: Alexey Kardashevskiy <aik@xxxxxxxxx> Thanks, patch applied to my kvm-ppc-next branch. Paul. -- To unsubscribe from this list: send the line "unsubscribe kvm-ppc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
