From: Jack Lange <jarusl@cs.northwestern.edu>
Date: Wed, 4 Aug 2010 23:18:41 +0000 (-0500)
Subject: added memory alignment option to vmm memory mangement initialization and allocation
X-Git-Url: http://v3vee.org/palacios/gitweb/gitweb.cgi?p=palacios.git;a=commitdiff_plain;h=293c0868149e908271dd349248ca67cd53930e7d

added memory alignment option to vmm memory mangement initialization and allocation
---

diff --git a/palacios/src/palacios/vmm_mem.c b/palacios/src/palacios/vmm_mem.c
index ab8fc2c..6a7b154 100644
--- a/palacios/src/palacios/vmm_mem.c
+++ b/palacios/src/palacios/vmm_mem.c
@@ -51,9 +51,23 @@ static int unhandled_err(struct guest_info * core, addr_t guest_va, addr_t guest
 }
 
 
+static inline uint32_t get_alignment(char * align_str) {
+    if (align_str != NULL) {
+	if (strncasecmp(align_str, "2MB", strlen("2MB")) == 0) {
+	    return PAGE_SIZE_2MB;
+	} else if (strncasecmp(align_str, "4MB", strlen("4MB")) == 0) {
+	    return PAGE_SIZE_4MB;
+	}
+    }
+    
+    // default is 4KB alignment
+    return PAGE_SIZE_4KB;
+}
 
 int v3_init_mem_map(struct v3_vm_info * vm) {
     struct v3_mem_map * map = &(vm->mem_map);
+    v3_cfg_tree_t * pg_cfg = v3_cfg_subtree(vm->cfg_data->cfg, "memory");
+    uint32_t alignment = get_alignment(v3_cfg_val(pg_cfg, "alignment"));
     addr_t mem_pages = vm->mem_size >> 12;
 
     memset(&(map->base_region), 0, sizeof(struct v3_mem_region));
@@ -66,7 +80,16 @@ int v3_init_mem_map(struct v3_vm_info * vm) {
 
     map->base_region.guest_start = 0;
     map->base_region.guest_end = mem_pages * PAGE_SIZE_4KB;
+
+#ifdef ALIGNED_PG_ALLOC
+    map->base_region.host_addr = (addr_t)V3_AllocAlignedPages(mem_pages, alignment);
+#else
+    if (alignment != PAGE_SIZE_4KB) {
+	PrintError("Aligned page allocations are not supported in this host (requested alignment=%d)\n", alignment);
+	PrintError("Ignoring alignment request\n");
+    }
     map->base_region.host_addr = (addr_t)V3_AllocPages(mem_pages);
+#endif
 
     map->base_region.flags.read = 1;
     map->base_region.flags.write = 1;
diff --git a/utils/guest_creator/default.xml b/utils/guest_creator/default.xml
index 6316742..db20b2c 100644
--- a/utils/guest_creator/default.xml
+++ b/utils/guest_creator/default.xml
@@ -3,7 +3,7 @@
 <vm class="PC"> 
 
 	<!-- Memory in MB -->
-	<memory>256</memory> 
+	<memory alignment="4KB">256</memory> 
 
 	<!-- Basic VMM system flags -->
 	<telemetry>enable</telemetry>