On 20.01.25 11:28, Claudio Imbrenda wrote:
On Mon, 20 Jan 2025 10:43:15 +0100
David Hildenbrand <david@xxxxxxxxxx> wrote:
+static inline unsigned long gmap_pgste_get_index(unsigned long *pgt)
+{
+ unsigned long *pgstes, res;
+
+ pgstes = pgt + _PAGE_ENTRIES;
+
+ res = (pgstes[0] & PGSTE_ST2_MASK) << 16;
+ res |= pgstes[1] & PGSTE_ST2_MASK;
+ res |= (pgstes[2] & PGSTE_ST2_MASK) >> 16;
+ res |= (pgstes[3] & PGSTE_ST2_MASK) >> 32;
+
+ return res;
+}
I have to think about that change for a bit before I post an opinion.
I'm wondering if we should just do what Willy suggested and use ptdesc
-> pt_index instead?
we will need to store more stuff in the future; putting things in the
PGSTEs gives us 512 bytes per table (although I admit it looks... weird)
With memdesc/ptdesc you'll be able to allocate more without playing many
tricks.
Storing more information could be done today by allocating a separate
structure for these page tables and linking it via ptindex. Not that I
would suggest that just now. :)
But this is not something I am to decide, just pointing it out that it
likely can be done in a simpler+cleaner way and there is no way to rush
the pt_index removal.
--
Cheers,
David / dhildenb
