[RFC PATCH v6 22/43] arm/p2m: Introduce p2m_is_{hostp2m,altp2m}

[Rose Spangler <Rose.Spangler@xxxxxxxxxxxxxx>]

From: Sergej Proskurin <proskurin@xxxxxxxxxxxxx>

This commit adds a p2m class to the struct p2m_domain to distinguish
between the host's original p2m and alternate p2m's. The need for this
functionality will be shown in the following commits.

This is commit 11/12 of the altp2m_init/altp2m_teardown routines phase.

Signed-off-by: Sergej Proskurin <proskurin@xxxxxxxxxxxxx>
---
v4: Change return type of p2m_is_(hostp2m|altp2m) from bool_t to bool.
---
 xen/arch/arm/include/asm/p2m.h | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

diff --git a/xen/arch/arm/include/asm/p2m.h b/xen/arch/arm/include/asm/p2m.h
index 62261d41e780..8ae0cd7ff589 100644
--- a/xen/arch/arm/include/asm/p2m.h
+++ b/xen/arch/arm/include/asm/p2m.h
@@ -32,6 +32,11 @@ struct domain;
 
 extern void memory_type_changed(struct domain *d);
 
+typedef enum {
+    p2m_host,
+    p2m_alternate,
+} p2m_class_t;
+
 /* Per-p2m-table state */
 struct p2m_domain {
     /*
@@ -111,6 +116,9 @@ struct p2m_domain {
 
     /* Keeping track on which CPU this p2m was used and for which vCPU */
     uint8_t last_vcpu_ran[NR_CPUS];
+
+    /* Choose between: host/alternate. */
+    p2m_class_t p2m_class;
 };
 
 /*
@@ -424,6 +432,16 @@ static inline int get_page_and_type(struct page_info *page,
 /* get host p2m table */
 #define p2m_get_hostp2m(d) ((d)->arch.p2m)
 
+static inline bool p2m_is_hostp2m(const struct p2m_domain *p2m)
+{
+    return p2m->p2m_class == p2m_host;
+}
+
+static inline bool p2m_is_altp2m(const struct p2m_domain *p2m)
+{
+    return p2m->p2m_class == p2m_alternate;
+}
+
 static inline bool p2m_vm_event_sanity_check(struct domain *d)
 {
     return true;
-- 
2.34.1