xen/p2m: move xenmem_access_to_p2m_access() to common p2m.c

Memory access and ALTP2M are two seperate features, while both depending on
helper xenmem_access_to_p2m_access(). So it betters lives in common p2m.c,
other than mem_access.c which will be compiled out when VM_EVENT=n && ALTP2M=y.
Guard xenmem_access_to_p2m_access() with VM_EVENT || ALTP2M, otherwise it
will become unreachable when both VM_EVENT=n and ALTP2M=n, and hence
violating Misra rule 2.1.
Also move declaration from xen/mem_access.h to x86'es one, requiring to also
move the inclusion point and condition of asm/mem_access.h there.
An extra blank line is inserted after each case-block to correct coding
style at the same time.

Signed-off-by: Penny Zheng <Penny.Zheng@amd.com>
Acked-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Jason Andryuk <jason.andryuk@amd.com>
Acked-by: Tamas K Lengyel <tamas@tklengyel.com>

xen/arch/x86/include/asm/mem_access.h

@@ -34,6 +34,11 @@ bool p2m_mem_access_emulate_check(struct vcpu *v,
 /* Sanity check for mem_access hardware support */
 bool p2m_mem_access_sanity_check(const struct domain *d);
 
+struct p2m_domain;
+bool xenmem_access_to_p2m_access(const struct p2m_domain *p2m,
+                                 xenmem_access_t xaccess,
+                                 p2m_access_t *paccess);
+
 #endif /*__ASM_X86_MEM_ACCESS_H__ */
 
 /*

xen/arch/x86/mm/mem_access.c

@@ -298,42 +298,6 @@ static int set_mem_access(struct domain *d, struct p2m_domain *p2m,
     return rc;
 }
 
-bool xenmem_access_to_p2m_access(const struct p2m_domain *p2m,
-                                 xenmem_access_t xaccess,
-                                 p2m_access_t *paccess)
-{
-    static const p2m_access_t memaccess[] = {
-#define ACCESS(ac) [XENMEM_access_##ac] = p2m_access_##ac
-        ACCESS(n),
-        ACCESS(r),
-        ACCESS(w),
-        ACCESS(rw),
-        ACCESS(x),
-        ACCESS(rx),
-        ACCESS(wx),
-        ACCESS(rwx),
-        ACCESS(rx2rw),
-        ACCESS(n2rwx),
-        ACCESS(r_pw),
-#undef ACCESS
-    };
-
-    switch ( xaccess )
-    {
-    case 0 ... ARRAY_SIZE(memaccess) - 1:
-        xaccess = array_index_nospec(xaccess, ARRAY_SIZE(memaccess));
-        *paccess = memaccess[xaccess];
-        break;
-    case XENMEM_access_default:
-        *paccess = p2m->default_access;
-        break;
-    default:
-        return false;
-    }
-
-    return true;
-}
-
 /*
  * Set access type for a region of gfns.
  * If gfn == INVALID_GFN, sets the default access type.

xen/arch/x86/mm/p2m.c

@@ -2203,6 +2203,46 @@ void p2m_log_dirty_range(struct domain *d, unsigned long begin_pfn,
     guest_flush_tlb_mask(d, d->dirty_cpumask);
 }
 
+#if defined(CONFIG_VM_EVENT) || defined(CONFIG_ALTP2M)
+bool xenmem_access_to_p2m_access(const struct p2m_domain *p2m,
+                                 xenmem_access_t xaccess,
+                                 p2m_access_t *paccess)
+{
+    static const p2m_access_t memaccess[] = {
+#define ACCESS(ac) [XENMEM_access_##ac] = p2m_access_##ac
+        ACCESS(n),
+        ACCESS(r),
+        ACCESS(w),
+        ACCESS(rw),
+        ACCESS(x),
+        ACCESS(rx),
+        ACCESS(wx),
+        ACCESS(rwx),
+        ACCESS(rx2rw),
+        ACCESS(n2rwx),
+        ACCESS(r_pw),
+#undef ACCESS
+    };
+
+    switch ( xaccess )
+    {
+    case 0 ... ARRAY_SIZE(memaccess) - 1:
+        xaccess = array_index_nospec(xaccess, ARRAY_SIZE(memaccess));
+        *paccess = memaccess[xaccess];
+        break;
+
+    case XENMEM_access_default:
+        *paccess = p2m->default_access;
+        break;
+
+    default:
+        return false;
+    }
+
+    return true;
+}
+#endif /* VM_EVENT || ALTP2M */
+
 /*
  * Local variables:
  * mode: C

xen/include/xen/mem_access.h

@@ -33,10 +33,6 @@
  */
 struct vm_event_st;
 
-#ifdef CONFIG_VM_EVENT
-#include <asm/mem_access.h>
-#endif
-
 /*
  * Additional access types, which are used to further restrict
  * the permissions given my the p2m_type_t memory type.  Violations
@@ -73,10 +69,9 @@ typedef enum {
     /* NOTE: Assumed to be only 4 bits right now on x86. */
 } p2m_access_t;
 
-struct p2m_domain;
-bool xenmem_access_to_p2m_access(const struct p2m_domain *p2m,
-                                 xenmem_access_t xaccess,
-                                 p2m_access_t *paccess);
+#if defined(CONFIG_VM_EVENT) || defined(CONFIG_ALTP2M)
+#include <asm/mem_access.h>
+#endif
 
 /*
  * Set access type for a region of gfns.