On 08/23/2017 03:08 PM, Andre Przywara wrote:
Hi,
On 14/08/17 15:24, Julien Grall wrote:
Currently, the flags used to update page tables (i.e PAGE_HYPERVISOR_*)
only contains the memory attribute index. Follow-up patches will add
more information in it.
At the same time introduce PAGE_AI_MASK to get the memory attribute
index easily.
Signed-off-by: Julien Grall <julien.gr...@arm.com>
I wonder if that should be merged with the next patch, to explain the
reason for it. As it stands now it just applies a mask to some existing
call, which looks a bit suspicious.
But that's just a nit and the patch itself is fine, so:
Not really it just documents the current behavior rather than hiding
what is going on.
Cheers,
Reviewed-by: Andre Przywara <andre.przyw...@arm.com>
Cheers,
Andre.
---
xen/arch/arm/mm.c | 2 +-
xen/include/asm-arm/page.h | 7 +++++++
2 files changed, 8 insertions(+), 1 deletion(-)
diff --git a/xen/arch/arm/mm.c b/xen/arch/arm/mm.c
index 411fe02842..cd7bcf7aca 100644
--- a/xen/arch/arm/mm.c
+++ b/xen/arch/arm/mm.c
@@ -1021,7 +1021,7 @@ static int create_xen_entries(enum xenmap_operation op,
}
if ( op == RESERVE )
break;
- pte = mfn_to_xen_entry(mfn, flags);
+ pte = mfn_to_xen_entry(mfn, PAGE_AI_MASK(flags));
pte.pt.table = 1;
write_pte(entry, pte);
break;
diff --git a/xen/include/asm-arm/page.h b/xen/include/asm-arm/page.h
index d9dac92e73..1bf8e9d012 100644
--- a/xen/include/asm-arm/page.h
+++ b/xen/include/asm-arm/page.h
@@ -63,6 +63,13 @@
#define MAIR0VAL (MAIRVAL & 0xffffffff)
#define MAIR1VAL (MAIRVAL >> 32)
+/*
+ * Layout of the flags used for updating the hypervisor page tables
+ *
+ * [0:2] Memory Attribute Index
+ */
+#define PAGE_AI_MASK(x) ((x) & 0x7U)
+
#define PAGE_HYPERVISOR (MT_NORMAL)
#define PAGE_HYPERVISOR_NOCACHE (MT_DEVICE_nGnRE)
#define PAGE_HYPERVISOR_WC (MT_NORMAL_NC)
--
Julien Grall
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