Hi,
On 05/06/2019 12:07, Jan Beulich wrote:
On 03.06.19 at 18:03, <julien.gr...@arm.com> wrote:
At the moment, Arm is providing a dummy implementation for the M2P
helpers used in common code. However, they are quite isolated and could
be used by other architecture in the future. So move all the helpers in
xen/mm.h.
And where's the problem then adding ...
--- a/xen/include/xen/mm.h
+++ b/xen/include/xen/mm.h
@@ -655,4 +655,18 @@ static inline void share_xen_page_with_privileged_guests(
share_xen_page_with_guest(page, dom_xen, flags);
}
+/*
+ * Dummy implementation of M2P-related helpers for common code when
+ * the architecture doesn't have an M2P.
+ */
+#ifndef CONFIG_HAS_M2P
+
+#define INVALID_M2P_ENTRY (~0UL)
+#define SHARED_M2P_ENTRY (~0UL - 1UL)
+#define SHARED_M2P(_e) ((_e) == SHARED_M2P_ENTRY)
+
+static inline void set_pfn_from_mfn(mfn_t mfn, unsigned long pfn) {}
+
+#endif
... mfn_to_gmfn() to this set? Perhaps a declaration without any
definition anywhere?
The only purpose for this would be to make some code compile and expect the
compiler to remove it. So I am not in favor of defining mfn_to_gmfn() in any
form for Arm.
Also please take the opportunity and drop the unnecessary underscore
from _e. And actually, shouldn't this uniformly return false? At which
point you don't even need SHARED_M2P_ENTRY.
I thought about it. But I wasn't sure if there would be any issue with that
implementation. I am happy to implement SHARED_M2P this way.
Cheers,
--
Julien Grall
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