On 05/02/2020 10:22, Jan Beulich wrote: > On 03.02.2020 15:43, Andrew Cooper wrote: >> The MMIO registers as already byte offsets. By masking out the reserved bits >> suitably in guest_iommu_mmio_write64(), we can use the values directly, >> instead of masking/shifting on every use. > I guess it's unclear whether such masking matches real hardware > behavior, but it's certainly within spec with all other bits > there reserved. > >> Store the buffer size, rather than the number of entries, to keep the same >> units for comparison purposes. >> >> This simplifies guest_iommu_get_table_mfn() by dropping the entry_size >> parameter, and simplifies the map_domain_page() handling by being able to >> drop >> the log_base variables. >> >> No functional change. > Well, not exactly - reads of those head/tail registers previously > returned the last written value afaict.
It is actually a bugfix, because the spec prohibits preservation of reserved bits. I'll adjust the commit message to indicate this. > >> Signed-off-by: Andrew Cooper <andrew.coop...@citrix.com> > Acked-by: Jan Beulich <jbeul...@suse.com> _______________________________________________ Xen-devel mailing list Xen-devel@lists.xenproject.org https://lists.xenproject.org/mailman/listinfo/xen-devel
