On Tue, Dec 12, 2017 at 12:59:39PM -0700, Alex Williamson wrote: > The vfio_info_add_capability() helper requires the caller to pass a > capability ID, which it then uses to fill in header fields, assuming > hard coded versions. This makes for an awkward and rigid interface. > The only thing we want this helper to do is allocate sufficient > space in the caps buffer and chain this capability into the list. > Reduce it to that simple task. > > Signed-off-by: Alex Williamson <alex.williamson@xxxxxxxxxx> Reviewed-by: Peter Xu <peterx@xxxxxxxxxx> Though during review I had a question related to the function msix_sparse_mmap_cap(): Is it possible that one PCI device BAR is very small (e.g., 4K) that only contains the MSI-X table (and another small PBA area)? If so, should we just mark that region unmappable instead of setting vfio_region_info_cap_sparse_mmap.nr_areas to 1 in msix_sparse_mmap_cap()? /* If MSI-X table is aligned to the start or end, only one area */ if (((vdev->msix_offset & PAGE_MASK) == 0) || (PAGE_ALIGN(vdev->msix_offset + vdev->msix_size) >= end)) nr_areas = 1; Thanks, -- Peter Xu
