On 21.04.2021 16:15, Hongyan Xia wrote:
> From: Wei Liu <wei.l...@citrix.com>
>
> Rewrite those functions to use the new APIs. Modify its callers to unmap
> the pointer returned. Since alloc_xen_pagetable_new() is almost never
> useful unless accompanied by page clearing and a mapping, introduce a
> helper alloc_map_clear_xen_pt() for this sequence.
>
> Signed-off-by: Wei Liu <wei.l...@citrix.com>
> Signed-off-by: Hongyan Xia <hongy...@amazon.com>
Reviewed-by: Jan Beulich <jbeul...@suse.com>
albeit ...
> @@ -4941,33 +4961,33 @@ static l3_pgentry_t *virt_to_xen_l3e(unsigned long v)
> if ( !(l4e_get_flags(*pl4e) & _PAGE_PRESENT) )
> {
> bool locking = system_state > SYS_STATE_boot;
> - l3_pgentry_t *l3t = alloc_xen_pagetable();
> + mfn_t l3mfn;
> + l3_pgentry_t *l3t = alloc_mapped_pagetable(&l3mfn);
>
> if ( !l3t )
> return NULL;
> - clear_page(l3t);
> + UNMAP_DOMAIN_PAGE(l3t);
... this immediate unmapping (and then re-mapping below) will imo
want re-doing down the road as well. Even if it's not a severe
performance hit, it's simply odd, at least to me.
Jan
