[PATCH for-next] xen/arm: mm: flush_page_to_ram() only need to clean to PoC

[Julien Grall <julien@xxxxxxx>]

From: Julien Grall <jgrall@xxxxxxxxxx>

At the moment, flush_page_to_ram() is both cleaning and invalidate to
PoC the page. However, the cache line can be speculated and pull in the
cache right after as it is part of the direct map.

So it is pointless to try to invalidate the line in the data cache.

Signed-off-by: Julien Grall <jgrall@xxxxxxxxxx>
---
 xen/arch/arm/mm.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/xen/arch/arm/mm.c b/xen/arch/arm/mm.c
index 59f8a3f15fd1..2f11d214e184 100644
--- a/xen/arch/arm/mm.c
+++ b/xen/arch/arm/mm.c
@@ -529,7 +529,7 @@ void flush_page_to_ram(unsigned long mfn, bool sync_icache)
 {
     void *v = map_domain_page(_mfn(mfn));
 
-    clean_and_invalidate_dcache_va_range(v, PAGE_SIZE);
+    clean_dcache_va_range(v, PAGE_SIZE);
     unmap_domain_page(v);
 
     /*
-- 
2.17.1