x86/paravirt: add a pgd_alloc/free hooks
Add hooks which are called at pgd_alloc/free time. The pgd_alloc hook
may return an error code, which if non-zero, causes the pgd allocation
to be failed. The hooks may be used to allocate/free auxillary
per-pgd information.
also fix:
> * Ingo Molnar <mingo@elte.hu> wrote:
>
> include/asm/pgalloc.h: In function ‘paravirt_pgd_free':
> include/asm/pgalloc.h:14: error: parameter name omitted
> arch/x86/kernel/entry_64.S: In file included from
> arch/x86/kernel/traps_64.c:51:include/asm/pgalloc.h: In function ‘paravirt_pgd_free':
> include/asm/pgalloc.h:14: error: parameter name omitted
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Cc: xen-devel <xen-devel@lists.xensource.com>
Cc: Stephen Tweedie <sct@redhat.com>
Cc: Eduardo Habkost <ehabkost@redhat.com>
Cc: Mark McLoughlin <markmc@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/arch/x86/mm/pgtable.c b/arch/x86/mm/pgtable.c
index 45b99ac..418c443 100644
--- a/arch/x86/mm/pgtable.c
+++ b/arch/x86/mm/pgtable.c
@@ -215,13 +215,15 @@
/* so that alloc_pmd can use it */
mm->pgd = pgd;
- if (pgd)
+ if (pgd) {
pgd_ctor(pgd);
- if (pgd && !pgd_prepopulate_pmd(mm, pgd)) {
- pgd_dtor(pgd);
- free_page((unsigned long)pgd);
- pgd = NULL;
+ if (paravirt_pgd_alloc(mm) != 0 ||
+ !pgd_prepopulate_pmd(mm, pgd)) {
+ pgd_dtor(pgd);
+ free_page((unsigned long)pgd);
+ pgd = NULL;
+ }
}
return pgd;
@@ -231,6 +233,7 @@
{
pgd_mop_up_pmds(mm, pgd);
pgd_dtor(pgd);
+ paravirt_pgd_free(mm, pgd);
free_page((unsigned long)pgd);
}