--- qemu/xen-mapcache.c	2018/04/24 18:55:39	1.1.1.1
+++ qemu/xen-mapcache.c	2018/04/24 19:16:42	1.1.1.2
@@ -40,6 +40,13 @@
 #endif
 #define MCACHE_BUCKET_SIZE (1UL << MCACHE_BUCKET_SHIFT)
 
+/* This is the size of the virtual address space reserve to QEMU that will not
+ * be use by MapCache.
+ * From empirical tests I observed that qemu use 75MB more than the
+ * max_mcache_size.
+ */
+#define NON_MCACHE_MEMORY_SIZE (80 * 1024 * 1024)
+
 #define mapcache_lock()   ((void)0)
 #define mapcache_unlock() ((void)0)
 
@@ -87,20 +94,32 @@ void xen_map_cache_init(void)
     unsigned long size;
     struct rlimit rlimit_as;
 
-    mapcache = qemu_mallocz(sizeof (MapCache));
+    mapcache = g_malloc0(sizeof (MapCache));
 
     QTAILQ_INIT(&mapcache->locked_entries);
     mapcache->last_address_index = -1;
 
-    getrlimit(RLIMIT_AS, &rlimit_as);
-    if (rlimit_as.rlim_max < MCACHE_MAX_SIZE) {
-        rlimit_as.rlim_cur = rlimit_as.rlim_max;
+    if (geteuid() == 0) {
+        rlimit_as.rlim_cur = RLIM_INFINITY;
+        rlimit_as.rlim_max = RLIM_INFINITY;
+        mapcache->max_mcache_size = MCACHE_MAX_SIZE;
     } else {
-        rlimit_as.rlim_cur = MCACHE_MAX_SIZE;
+        getrlimit(RLIMIT_AS, &rlimit_as);
+        rlimit_as.rlim_cur = rlimit_as.rlim_max;
+
+        if (rlimit_as.rlim_max != RLIM_INFINITY) {
+            fprintf(stderr, "Warning: QEMU's maximum size of virtual"
+                    " memory is not infinity.\n");
+        }
+        if (rlimit_as.rlim_max < MCACHE_MAX_SIZE + NON_MCACHE_MEMORY_SIZE) {
+            mapcache->max_mcache_size = rlimit_as.rlim_max -
+                NON_MCACHE_MEMORY_SIZE;
+        } else {
+            mapcache->max_mcache_size = MCACHE_MAX_SIZE;
+        }
     }
 
     setrlimit(RLIMIT_AS, &rlimit_as);
-    mapcache->max_mcache_size = rlimit_as.rlim_cur;
 
     mapcache->nr_buckets =
         (((mapcache->max_mcache_size >> XC_PAGE_SHIFT) +
@@ -111,7 +130,7 @@ void xen_map_cache_init(void)
     size = (size + XC_PAGE_SIZE - 1) & ~(XC_PAGE_SIZE - 1);
     DPRINTF("%s, nr_buckets = %lx size %lu\n", __func__,
             mapcache->nr_buckets, size);
-    mapcache->entry = qemu_mallocz(size);
+    mapcache->entry = g_malloc0(size);
 }
 
 static void xen_remap_bucket(MapCacheEntry *entry,
@@ -126,8 +145,8 @@ static void xen_remap_bucket(MapCacheEnt
 
     trace_xen_remap_bucket(address_index);
 
-    pfns = qemu_mallocz(nb_pfn * sizeof (xen_pfn_t));
-    err = qemu_mallocz(nb_pfn * sizeof (int));
+    pfns = g_malloc0(nb_pfn * sizeof (xen_pfn_t));
+    err = g_malloc0(nb_pfn * sizeof (int));
 
     if (entry->vaddr_base != NULL) {
         if (munmap(entry->vaddr_base, entry->size) != 0) {
@@ -136,7 +155,7 @@ static void xen_remap_bucket(MapCacheEnt
         }
     }
     if (entry->valid_mapping != NULL) {
-        qemu_free(entry->valid_mapping);
+        g_free(entry->valid_mapping);
         entry->valid_mapping = NULL;
     }
 
@@ -154,7 +173,7 @@ static void xen_remap_bucket(MapCacheEnt
     entry->vaddr_base = vaddr_base;
     entry->paddr_index = address_index;
     entry->size = size;
-    entry->valid_mapping = (unsigned long *) qemu_mallocz(sizeof(unsigned long) *
+    entry->valid_mapping = (unsigned long *) g_malloc0(sizeof(unsigned long) *
             BITS_TO_LONGS(size >> XC_PAGE_SHIFT));
 
     bitmap_zero(entry->valid_mapping, nb_pfn);
@@ -164,8 +183,8 @@ static void xen_remap_bucket(MapCacheEnt
         }
     }
 
-    qemu_free(pfns);
-    qemu_free(err);
+    g_free(pfns);
+    g_free(err);
 }
 
 uint8_t *xen_map_cache(target_phys_addr_t phys_addr, target_phys_addr_t size,
@@ -201,7 +220,7 @@ uint8_t *xen_map_cache(target_phys_addr_
         entry = entry->next;
     }
     if (!entry) {
-        entry = qemu_mallocz(sizeof (MapCacheEntry));
+        entry = g_malloc0(sizeof (MapCacheEntry));
         pentry->next = entry;
         xen_remap_bucket(entry, __size, address_index);
     } else if (!entry->lock) {
@@ -223,7 +242,7 @@ uint8_t *xen_map_cache(target_phys_addr_
     mapcache->last_address_index = address_index;
     mapcache->last_address_vaddr = entry->vaddr_base;
     if (lock) {
-        MapCacheRev *reventry = qemu_mallocz(sizeof(MapCacheRev));
+        MapCacheRev *reventry = g_malloc0(sizeof(MapCacheRev));
         entry->lock++;
         reventry->vaddr_req = mapcache->last_address_vaddr + address_offset;
         reventry->paddr_index = mapcache->last_address_index;
@@ -237,7 +256,7 @@ uint8_t *xen_map_cache(target_phys_addr_
 
 ram_addr_t xen_ram_addr_from_mapcache(void *ptr)
 {
-    MapCacheEntry *entry = NULL, *pentry = NULL;
+    MapCacheEntry *entry = NULL;
     MapCacheRev *reventry;
     target_phys_addr_t paddr_index;
     target_phys_addr_t size;
@@ -263,7 +282,6 @@ ram_addr_t xen_ram_addr_from_mapcache(vo
 
     entry = &mapcache->entry[paddr_index % mapcache->nr_buckets];
     while (entry && (entry->paddr_index != paddr_index || entry->size != size)) {
-        pentry = entry;
         entry = entry->next;
     }
     if (!entry) {
@@ -302,7 +320,7 @@ void xen_invalidate_map_cache_entry(uint
         return;
     }
     QTAILQ_REMOVE(&mapcache->locked_entries, reventry, next);
-    qemu_free(reventry);
+    g_free(reventry);
 
     entry = &mapcache->entry[paddr_index % mapcache->nr_buckets];
     while (entry && (entry->paddr_index != paddr_index || entry->size != size)) {
@@ -323,8 +341,8 @@ void xen_invalidate_map_cache_entry(uint
         perror("unmap fails");
         exit(-1);
     }
-    qemu_free(entry->valid_mapping);
-    qemu_free(entry);
+    g_free(entry->valid_mapping);
+    g_free(entry);
 }
 
 void xen_invalidate_map_cache(void)
@@ -358,7 +376,7 @@ void xen_invalidate_map_cache(void)
         entry->paddr_index = 0;
         entry->vaddr_base = NULL;
         entry->size = 0;
-        qemu_free(entry->valid_mapping);
+        g_free(entry->valid_mapping);
         entry->valid_mapping = NULL;
     }