[RFC PATCH v6 33/43] arm/altp2m: Add altp2m_set_view_visibility{,_locked} support

[Rose.Spangler@xxxxxxxxxxxxxx]

From: Rose Spangler <Rose.Spangler@xxxxxxxxxxxxxx>

This commit adds the altp2m_set_view_visibility and
altp2m_set_view_visibility_locked functions on ARM. This makes it possible
to set the altp2m view visibility in common altp2m routines (namely,
altp2m_flush).

This is commit 4/5 of the altp2m view validity/visibility phase.

Signed-off-by: Rose Spangler <Rose.Spangler@xxxxxxxxxxxxxx>
---
v6: Introduced this patch.
---
 xen/arch/arm/altp2m.c             | 30 ++++++++++++++++++++++++++++++
 xen/arch/arm/include/asm/altp2m.h |  8 ++++++++
 2 files changed, 38 insertions(+)

diff --git a/xen/arch/arm/altp2m.c b/xen/arch/arm/altp2m.c
index 0e19e197e826..aa48c17e11a3 100644
--- a/xen/arch/arm/altp2m.c
+++ b/xen/arch/arm/altp2m.c
@@ -37,6 +37,36 @@ bool altp2m_view_is_visible(struct domain *d, unsigned int 
idx)
     return d->arch.altp2m_state[array_index_nospec(idx, d->nr_altp2m)] == 
ALTP2M_VISIBLE;
 }
 
+int altp2m_set_view_visibility(struct domain *d, unsigned int altp2m_idx,
+                               uint8_t visible)
+{
+    int rc;
+
+    altp2m_lock(d);
+    rc = altp2m_set_view_visibility_locked(d, altp2m_idx, visible);
+    altp2m_unlock(d);
+
+    return rc;
+}
+
+int altp2m_set_view_visibility_locked(struct domain *d, unsigned int 
altp2m_idx,
+                                      uint8_t visible)
+{
+    int rc = 0;
+
+    if ( altp2m_idx >= d->nr_altp2m || !altp2m_view_is_valid(d, altp2m_idx) )
+        rc = -EINVAL;
+    else if ( visible )
+        d->arch.altp2m_state[array_index_nospec(altp2m_idx, d->nr_altp2m)] =
+            ALTP2M_VISIBLE;
+    else
+        d->arch.altp2m_state[array_index_nospec(altp2m_idx, d->nr_altp2m)] =
+            ALTP2M_INVISIBLE;
+
+    return rc;
+}
+
+
 /*
  * Local variables:
  * mode: C
diff --git a/xen/arch/arm/include/asm/altp2m.h 
b/xen/arch/arm/include/asm/altp2m.h
index fbe66ad5536d..f8d0dd799a4a 100644
--- a/xen/arch/arm/include/asm/altp2m.h
+++ b/xen/arch/arm/include/asm/altp2m.h
@@ -40,6 +40,14 @@ enum altp2m_view_state {
     ALTP2M_INVISIBLE,
 };
 
+/* Set a specific p2m view visibility */
+int altp2m_set_view_visibility(struct domain *d, unsigned int altp2m_idx,
+                               uint8_t visible);
+
+/* Set a specific p2m view visibility (with lock already held) */
+int altp2m_set_view_visibility_locked(struct domain *d, unsigned int 
altp2m_idx,
+                                      uint8_t visible);
+
 #else /* CONFIG_ALTP2M */
 
 static inline bool altp2m_supported(void)
-- 
2.34.1