Added support for using large shadow pages with 32-bit 4MB page table entries

[palacios.releases.git] / palacios / src / palacios / vmm_config.c

diff --git a/palacios/src/palacios/vmm_config.c b/palacios/src/palacios/vmm_config.c
index 9ba0a11..7a596d2 100644 (file)
--- a/palacios/src/palacios/vmm_config.c
+++ b/palacios/src/palacios/vmm_config.c
@@ -183,12 +183,35 @@ static struct v3_config * parse_config(void * cfg_blob) {
     return cfg;
 }
 
+
+static inline uint32_t get_alignment(char * align_str) {
+    // default is 4KB alignment
+    uint32_t alignment = PAGE_SIZE_4KB;
+
+    if (align_str != NULL) {
+       if (strcasecmp(align_str, "2MB") == 0) {
+           alignment = PAGE_SIZE_2MB;
+       } else if (strcasecmp(align_str, "4MB") == 0) {
+           alignment = PAGE_SIZE_4MB;
+       }
+    }
+    
+#ifndef CONFIG_ALIGNED_PG_ALLOC
+    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");
+    }
+#endif 
+
+    return alignment;
+}
 static int pre_config_vm(struct v3_vm_info * vm, v3_cfg_tree_t * vm_cfg) {
 
 
     char * memory_str = v3_cfg_val(vm_cfg, "memory");
     char * schedule_hz_str = v3_cfg_val(vm_cfg, "schedule_hz");
     char * vm_class = v3_cfg_val(vm_cfg, "class");
+    char * align_str = v3_cfg_val(v3_cfg_subtree(vm_cfg, "memory"), "alignment");
     uint32_t sched_hz = 100;   // set the schedule frequency to 100 HZ
     
     if (!memory_str) {
@@ -197,10 +220,18 @@ static int pre_config_vm(struct v3_vm_info * vm, v3_cfg_tree_t * vm_cfg) {
     }
     
     PrintDebug("Memory=%s\n", memory_str);
+    if (align_str) {
+        PrintDebug("Alignment=%s\n", align_str);
+    } else {
+        PrintDebug("Alignment defaulted to 4KB.\n");
+    }
 
     // Amount of ram the Guest will have, always in MB
     vm->mem_size = atoi(memory_str) * 1024 * 1024;
-    
+    vm->mem_align = get_alignment(align_str);
+
+    PrintDebug("Alignment computed as 0x%x\n", vm->mem_align);
+
     if (strcasecmp(vm_class, "PC") == 0) {
        vm->vm_class = V3_PC_VM;
     } else {
@@ -270,6 +301,7 @@ static int determine_paging_mode(struct guest_info *info, v3_cfg_tree_t * core_c
        info->shdw_pg_mode = SHADOW_PAGING;
     }
 
+
     if (info->shdw_pg_mode == NESTED_PAGING) {
        PrintDebug("Guest Paging Mode: NESTED_PAGING\n");
     } else if (info->shdw_pg_mode == SHADOW_PAGING) {
@@ -278,6 +310,12 @@ static int determine_paging_mode(struct guest_info *info, v3_cfg_tree_t * core_c
        PrintError("Guest paging mode incorrectly set.\n");
        return -1;
     }
+
+    if (strcasecmp(v3_cfg_val(pg_tree, "large_pages"), "true") == 0) {
+       info->use_large_pages = 1;
+       PrintDebug("Use of large pages in memory virtualization enabled.\n");
+    }
+
     return 0;
 }