On 03.09.2021 12:08, Oleksandr Andrushchenko wrote:
> @@ -37,12 +41,28 @@ static int map_range(unsigned long s, unsigned long e,
> void *data,
> unsigned long *c)
> {
> const struct map_data *map = data;
> + gfn_t start_gfn;
> int rc;
>
> for ( ; ; )
> {
> unsigned long size = e - s + 1;
>
> + /*
> + * Any BAR may have holes in its memory we want to map, e.g.
> + * we don't want to map MSI regions which may be a part of that BAR,
> + * e.g. when a single BAR is used for both MMIO and MSI.
> + * In this case MSI regions are subtracted from the mapping, but
> + * map->start_gfn still points to the very beginning of the BAR.
> + * So if there is a hole present then we need to adjust start_gfn
> + * to reflect the fact of that substraction.
> + */
> + start_gfn = gfn_add(map->start_gfn, s - mfn_x(map->start_mfn));
I may be missing something, but don't you need to adjust "size" then
as well? And don't you need to account for the "hole" not being at
the start? (As an aside - do you mean "MSI-X regions" everywhere you
say just "MSI" above?)
Jan
