[PATCH v4 6/8] xen/arm: set up shared memory foreign mapping for borrower domain

[Penny Zheng <Penny.Zheng@arm.com>]

This commit sets up shared memory foreign mapping for borrower domain.

If owner domain is the default dom_io, all shared domain are treated as
borrower domain.

Signed-off-by: Penny Zheng <penny.zheng@arm.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
---
v4 changes:
- no change
---
v3 change:
- use map_regions_p2mt instead
---
v2 change:
- remove guest_physmap_add_shm, since for borrower domain, we only
do P2M foreign memory mapping now.
---
 xen/arch/arm/domain_build.c | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/xen/arch/arm/domain_build.c b/xen/arch/arm/domain_build.c
index 3a20247836..fcdd87468d 100644
--- a/xen/arch/arm/domain_build.c
+++ b/xen/arch/arm/domain_build.c
@@ -957,6 +957,15 @@ static int __init process_shm(struct domain *d,
             if ( ret )
                 return ret;
         }
+
+        if ( owner_dom_io || (strcmp(role_str, "borrower") == 0) )
+        {
+            /* Set up P2M foreign mapping for borrower domain. */
+            ret = map_regions_p2mt(d, _gfn(PFN_UP(gbase)), PFN_DOWN(psize),
+                                   _mfn(PFN_UP(pbase)), p2m_map_foreign_rw);
+            if ( ret )
+                return ret;
+        }
     }
 
     return 0;
-- 
2.25.1