[PATCH 5/5] tools/migration: unify type checking for data pfns in migration stream

[Andrew Cooper <andrew.cooper3@citrix.com>]

From: Olaf Hering <olaf@aepfle.de>

Introduce a helper which decides if a given pfn type has data
in the migration stream.

No change in behaviour intended, except for invalid page types which now
have a safer default.

Signed-off-by: Olaf Hering <olaf@aepfle.de>
---
 tools/libs/guest/xg_sr_common.h  | 27 +++++++++++++++++++++++++++
 tools/libs/guest/xg_sr_restore.c | 29 +++--------------------------
 tools/libs/guest/xg_sr_save.c    | 14 ++------------
 3 files changed, 32 insertions(+), 38 deletions(-)

diff --git a/tools/libs/guest/xg_sr_common.h b/tools/libs/guest/xg_sr_common.h
index 7f4b0439f6bd..36d45ef56fb8 100644
--- a/tools/libs/guest/xg_sr_common.h
+++ b/tools/libs/guest/xg_sr_common.h
@@ -513,6 +513,33 @@ static inline bool page_type_to_populate(uint32_t type)
     }
 }
 
+static inline bool page_type_has_stream_data(uint32_t type)
+{
+    switch ( type )
+    {
+    case XEN_DOMCTL_PFINFO_NOTAB:
+
+    case XEN_DOMCTL_PFINFO_L1TAB:
+    case XEN_DOMCTL_PFINFO_L1TAB | XEN_DOMCTL_PFINFO_LPINTAB:
+
+    case XEN_DOMCTL_PFINFO_L2TAB:
+    case XEN_DOMCTL_PFINFO_L2TAB | XEN_DOMCTL_PFINFO_LPINTAB:
+
+    case XEN_DOMCTL_PFINFO_L3TAB:
+    case XEN_DOMCTL_PFINFO_L3TAB | XEN_DOMCTL_PFINFO_LPINTAB:
+
+    case XEN_DOMCTL_PFINFO_L4TAB:
+    case XEN_DOMCTL_PFINFO_L4TAB | XEN_DOMCTL_PFINFO_LPINTAB:
+        return true;
+
+    case XEN_DOMCTL_PFINFO_XTAB:
+    case XEN_DOMCTL_PFINFO_BROKEN:
+    case XEN_DOMCTL_PFINFO_XALLOC:
+    default:
+        return false;
+    }
+}
+
 #endif
 /*
  * Local variables:
diff --git a/tools/libs/guest/xg_sr_restore.c b/tools/libs/guest/xg_sr_restore.c
index 3d63442d4537..aa4113d7f679 100644
--- a/tools/libs/guest/xg_sr_restore.c
+++ b/tools/libs/guest/xg_sr_restore.c
@@ -231,25 +231,8 @@ static int process_page_data(struct xc_sr_context *ctx, unsigned int count,
     {
         ctx->restore.ops.set_page_type(ctx, pfns[i], types[i]);
 
-        switch ( types[i] )
-        {
-        case XEN_DOMCTL_PFINFO_NOTAB:
-
-        case XEN_DOMCTL_PFINFO_L1TAB:
-        case XEN_DOMCTL_PFINFO_L1TAB | XEN_DOMCTL_PFINFO_LPINTAB:
-
-        case XEN_DOMCTL_PFINFO_L2TAB:
-        case XEN_DOMCTL_PFINFO_L2TAB | XEN_DOMCTL_PFINFO_LPINTAB:
-
-        case XEN_DOMCTL_PFINFO_L3TAB:
-        case XEN_DOMCTL_PFINFO_L3TAB | XEN_DOMCTL_PFINFO_LPINTAB:
-
-        case XEN_DOMCTL_PFINFO_L4TAB:
-        case XEN_DOMCTL_PFINFO_L4TAB | XEN_DOMCTL_PFINFO_LPINTAB:
-
+        if ( page_type_has_stream_data(types[i]) )
             mfns[nr_pages++] = ctx->restore.ops.pfn_to_gfn(ctx, pfns[i]);
-            break;
-        }
     }
 
     /* Nothing to do? */
@@ -269,14 +252,8 @@ static int process_page_data(struct xc_sr_context *ctx, unsigned int count,
 
     for ( i = 0, j = 0; i < count; ++i )
     {
-        switch ( types[i] )
-        {
-        case XEN_DOMCTL_PFINFO_XTAB:
-        case XEN_DOMCTL_PFINFO_BROKEN:
-        case XEN_DOMCTL_PFINFO_XALLOC:
-            /* No page data to deal with. */
+        if ( !page_type_has_stream_data(types[i]) )
             continue;
-        }
 
         if ( map_errs[j] )
         {
@@ -411,7 +388,7 @@ static int handle_page_data(struct xc_sr_context *ctx, struct xc_sr_record *rec)
             goto err;
         }
 
-        if ( type < XEN_DOMCTL_PFINFO_BROKEN )
+        if ( page_type_has_stream_data(type) )
             /* NOTAB and all L1 through L4 tables (including pinned) should
              * have a page worth of data in the record. */
             pages_of_data++;
diff --git a/tools/libs/guest/xg_sr_save.c b/tools/libs/guest/xg_sr_save.c
index c84a073e86f4..3fce41b6cfff 100644
--- a/tools/libs/guest/xg_sr_save.c
+++ b/tools/libs/guest/xg_sr_save.c
@@ -153,13 +153,8 @@ static int write_batch(struct xc_sr_context *ctx)
             goto err;
         }
 
-        switch ( types[i] )
-        {
-        case XEN_DOMCTL_PFINFO_BROKEN:
-        case XEN_DOMCTL_PFINFO_XALLOC:
-        case XEN_DOMCTL_PFINFO_XTAB:
+        if ( !page_type_has_stream_data(types[i]) )
             continue;
-        }
 
         mfns[nr_pages++] = mfns[i];
     }
@@ -177,13 +172,8 @@ static int write_batch(struct xc_sr_context *ctx)
 
         for ( i = 0, p = 0; i < nr_pfns; ++i )
         {
-            switch ( types[i] )
-            {
-            case XEN_DOMCTL_PFINFO_BROKEN:
-            case XEN_DOMCTL_PFINFO_XALLOC:
-            case XEN_DOMCTL_PFINFO_XTAB:
+            if ( !page_type_has_stream_data(types[i]) )
                 continue;
-            }
 
             if ( errors[p] )
             {
-- 
2.11.0