libxc: add p2m_size to xc_dom_image

Add a new field p2m_size to keep track of the number of pages covered by
p2m.  Change total_pages to p2m_size in functions which in fact need
the size of p2m.

This is needed because we are going to ditch the assumption that PV x86
has only one contiguous ram region. Originally the p2m size was always
equal to total_pages, but we will soon change that in later patch.

This patch doesn't change the behaviour of libxc.

Signed-off-by: Wei Liu <wei.liu2@citrix.com>
Reviewed-by: Dario Faggioli <dario.faggioli@citrix.com>
Cc: Ian Campbell <ian.campbell@citrix.com>
Cc: Ian Jackson <ian.jackson@eu.citrix.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>

tools/libxc/include/xc_dom.h

@@ -129,6 +129,7 @@ struct xc_dom_image {
      */
     xen_pfn_t rambase_pfn;
     xen_pfn_t total_pages;
+    xen_pfn_t p2m_size;         /* number of pfns covered by p2m */
     struct xc_dom_phys *phys_pages;
     int realmodearea_log;
 #if defined (__arm__) || defined(__aarch64__)

tools/libxc/xc_dom_arm.c

@@ -449,6 +449,7 @@ int arch_setup_meminit(struct xc_dom_image *dom)
     assert(dom->rambank_size[0] != 0);
     assert(ramsize == 0); /* Too much RAM is rejected above */
 
+    dom->p2m_size = p2m_size;
     dom->p2m_host = xc_dom_malloc(dom, sizeof(xen_pfn_t) * p2m_size);
     if ( dom->p2m_host == NULL )
         return -EINVAL;

tools/libxc/xc_dom_core.c

@@ -931,9 +931,9 @@ int xc_dom_update_guest_p2m(struct xc_dom_image *dom)
     {
     case 4:
         DOMPRINTF("%s: dst 32bit, pages 0x%" PRIpfn "",
-                  __FUNCTION__, dom->total_pages);
+                  __FUNCTION__, dom->p2m_size);
         p2m_32 = dom->p2m_guest;
-        for ( i = 0; i < dom->total_pages; i++ )
+        for ( i = 0; i < dom->p2m_size; i++ )
             if ( dom->p2m_host[i] != INVALID_P2M_ENTRY )
                 p2m_32[i] = dom->p2m_host[i];
             else
@@ -941,9 +941,9 @@ int xc_dom_update_guest_p2m(struct xc_dom_image *dom)
         break;
     case 8:
         DOMPRINTF("%s: dst 64bit, pages 0x%" PRIpfn "",
-                  __FUNCTION__, dom->total_pages);
+                  __FUNCTION__, dom->p2m_size);
         p2m_64 = dom->p2m_guest;
-        for ( i = 0; i < dom->total_pages; i++ )
+        for ( i = 0; i < dom->p2m_size; i++ )
             if ( dom->p2m_host[i] != INVALID_P2M_ENTRY )
                 p2m_64[i] = dom->p2m_host[i];
             else

tools/libxc/xc_dom_x86.c

@@ -122,11 +122,11 @@ static int count_pgtables(struct xc_dom_image *dom, int pae,
 
         try_pfn_end = (try_virt_end - dom->parms.virt_base) >> PAGE_SHIFT_X86;
 
-        if ( try_pfn_end > dom->total_pages )
+        if ( try_pfn_end > dom->p2m_size )
         {
             xc_dom_panic(dom->xch, XC_OUT_OF_MEMORY,
                          "%s: not enough memory for initial mapping (%#"PRIpfn" > %#"PRIpfn")",
-                         __FUNCTION__, try_pfn_end, dom->total_pages);
+                         __FUNCTION__, try_pfn_end, dom->p2m_size);
             return -ENOMEM;
         }
 
@@ -440,10 +440,11 @@ pfn_error:
 
 static int alloc_magic_pages(struct xc_dom_image *dom)
 {
-    size_t p2m_size = dom->total_pages * dom->arch_hooks->sizeof_pfn;
+    size_t p2m_alloc_size = dom->p2m_size * dom->arch_hooks->sizeof_pfn;
 
     /* allocate phys2mach table */
-    if ( xc_dom_alloc_segment(dom, &dom->p2m_seg, "phys2mach", 0, p2m_size) )
+    if ( xc_dom_alloc_segment(dom, &dom->p2m_seg, "phys2mach",
+                              0, p2m_alloc_size) )
         return -1;
     dom->p2m_guest = xc_dom_seg_to_ptr(dom, &dom->p2m_seg);
     if ( dom->p2m_guest == NULL )
@@ -777,8 +778,9 @@ int arch_setup_meminit(struct xc_dom_image *dom)
         int count = dom->total_pages >> SUPERPAGE_PFN_SHIFT;
         xen_pfn_t extents[count];
 
+        dom->p2m_size = dom->total_pages;
         dom->p2m_host = xc_dom_malloc(dom, sizeof(xen_pfn_t) *
-                                      dom->total_pages);
+                                      dom->p2m_size);
         if ( dom->p2m_host == NULL )
             return -EINVAL;
 
@@ -810,8 +812,9 @@ int arch_setup_meminit(struct xc_dom_image *dom)
                 return rc;
         }
         /* setup initial p2m */
+        dom->p2m_size = dom->total_pages;
         dom->p2m_host = xc_dom_malloc(dom, sizeof(xen_pfn_t) *
-                                      dom->total_pages);
+                                      dom->p2m_size);
         if ( dom->p2m_host == NULL )
             return -EINVAL;
         for ( pfn = 0; pfn < dom->total_pages; pfn++ )
@@ -860,7 +863,7 @@ static int map_grant_table_frames(struct xc_dom_image *dom)
     {
         rc = xc_domain_add_to_physmap(dom->xch, dom->guest_domid,
                                       XENMAPSPACE_grant_table,
-                                      i, dom->total_pages + i);
+                                      i, dom->p2m_size + i);
         if ( rc != 0 )
         {
             if ( (i > 0) && (errno == EINVAL) )
@@ -870,7 +873,7 @@ static int map_grant_table_frames(struct xc_dom_image *dom)
             }
             xc_dom_panic(dom->xch, XC_INTERNAL_ERROR,
                          "%s: mapping grant tables failed " "(pfn=0x%" PRIpfn
-                         ", rc=%d)", __FUNCTION__, dom->total_pages + i, rc);
+                         ", rc=%d)", __FUNCTION__, dom->p2m_size + i, rc);
             return rc;
         }
     }