From: Julien Grall <jgr...@amazon.com>
xen_{un,}map_table() already uses the helper to map/unmap pages
on-demand (note this is currently a NOP on arm64). So switching to
domheap don't have any disavantage.
But this as the benefit:
- to keep the page tables unmapped if an arch decided to do so
- reduce xenheap use on arm32 which can be pretty small
Signed-off-by: Julien Grall <jgr...@amazon.com>
Acked-by: Stefano Stabellini <sstabell...@kernel.org>
---
Changes in v3:
- Add Stefano's acked-by
Changes in v2:
- New patch
---
xen/arch/arm/mm.c | 36 +++++++++++++++++++++---------------
1 file changed, 21 insertions(+), 15 deletions(-)
diff --git a/xen/arch/arm/mm.c b/xen/arch/arm/mm.c
index 1e5c2c45dcf9..58364bb6c820 100644
--- a/xen/arch/arm/mm.c
+++ b/xen/arch/arm/mm.c
@@ -972,21 +972,6 @@ void *ioremap(paddr_t pa, size_t len)
return ioremap_attr(pa, len, PAGE_HYPERVISOR_NOCACHE);
}
-static int create_xen_table(lpae_t *entry)
-{
- void *p;
- lpae_t pte;
-
- p = alloc_xenheap_page();
- if ( p == NULL )
- return -ENOMEM;
- clear_page(p);
- pte = mfn_to_xen_entry(virt_to_mfn(p), MT_NORMAL);
- pte.pt.table = 1;
- write_pte(entry, pte);
- return 0;
-}
-
static lpae_t *xen_map_table(mfn_t mfn)
{
/*
@@ -1027,6 +1012,27 @@ static void xen_unmap_table(const lpae_t *table)
unmap_domain_page(table);
}
+static int create_xen_table(lpae_t *entry)
+{
+ struct page_info *pg;
+ void *p;
+ lpae_t pte;
+
+ pg = alloc_domheap_page(NULL, 0);
+ if ( pg == NULL )
+ return -ENOMEM;
+
+ p = xen_map_table(page_to_mfn(pg));
+ clear_page(p);
+ xen_unmap_table(p);
+
+ pte = mfn_to_xen_entry(page_to_mfn(pg), MT_NORMAL);
+ pte.pt.table = 1;
+ write_pte(entry, pte);
+
+ return 0;
+}
+
#define XEN_TABLE_MAP_FAILED 0
#define XEN_TABLE_SUPER_PAGE 1
#define XEN_TABLE_NORMAL_PAGE 2
--
2.32.0
