[Xen-devel] [PATCH v7 07/14] xen/arm: map_regions_rw_cache: Map the region with p2m->default_access

[Julien Grall <julien.grall@xxxxxxx>]

The parameter 'access' is used by memaccess to restrict temporarily the
permission. This parameter should not be used for other purpose (such
as restricting permanently the permission).

Instead, we should use the default access requested by memacess. When it
is not enabled, the access will be p2m_access_rwx (i.e no restriction
applied).

The type p2m_mmio_direct will map the region read-write and
non-executable before any further restriction by memaccess. Note that
this is already the resulting permission with the curreent combination
of the type and the access. So there is no functional change.

Signed-off-by: Julien Grall <julien.grall@xxxxxxx>

---
Cc: Shannon Zhao <shannon.zhao@xxxxxxxxxx>

    This patch is a candidate for Xen 4.7. Currently this function is
    only used to map ACPI regions.

    I am wondering if we should introduce a new p2m type for it. And map
    this region RO (I am not sure why a guest would want to
    modify this region).

    Changes in v2:
        - Reword the commit message

    Changes in v4:
        - Patch added
---
 xen/arch/arm/p2m.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/xen/arch/arm/p2m.c b/xen/arch/arm/p2m.c
index 1cfb62b..fcc4513 100644
--- a/xen/arch/arm/p2m.c
+++ b/xen/arch/arm/p2m.c
@@ -1231,7 +1231,7 @@ int map_regions_rw_cache(struct domain *d,
                              pfn_to_paddr(start_gfn + nr),
                              pfn_to_paddr(mfn),
                              MATTR_MEM, 0, p2m_mmio_direct,
-                             p2m_access_rw);
+                             d->arch.p2m.default_access);
 }
 
 int unmap_regions_rw_cache(struct domain *d,
@@ -1244,7 +1244,7 @@ int unmap_regions_rw_cache(struct domain *d,
                              pfn_to_paddr(start_gfn + nr),
                              pfn_to_paddr(mfn),
                              MATTR_MEM, 0, p2m_invalid,
-                             p2m_access_rw);
+                             d->arch.p2m.default_access);
 }
 
 int map_mmio_regions(struct domain *d,
-- 
1.9.1


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