--- /dev/null
+#ifndef __VMM_MEM_H
+#define __VMM_MEM_H
+
+
+#include <palacios/vmm_types.h>
+
+typedef ulong_t addr_t;
+
+/*
+
+ Guest Shadow Host
+ Virtual Physical Virtual Physical Virtual Physical
+ OK OK
+ OK NOK
+ NOK OK
+ NOK NOK
+
+*/
+
+// These are the types of physical memory address regions
+// from the perspective of the guest
+typedef enum guest_region_type {
+ GUEST_REGION_NOTHING,
+ GUEST_REGION_PHYSICAL_MEMORY,
+ GUEST_REGION_MEMORY_MAPPED_DEVICE} guest_region_type_t;
+
+// These are the types of physical memory address regions
+// from the perspective of the HOST
+typedef enum host_region_type {
+ HOST_REGION_INVALID, // This region is INVALID (this is a return type, to denote errors)
+ HOST_REGION_NOTHING, // This region is mapped as not present (always generate page faults)
+ HOST_REGION_PHYSICAL_MEMORY, // Region is a section of host memory
+ HOST_REGION_MEMORY_MAPPED_DEVICE, // Region is allocated for DMA
+ HOST_REGION_UNALLOCATED, // Region is mapped on demand
+ HOST_REGION_REMOTE, // Region is located on a remote machine
+ HOST_REGION_SWAPPED, // Region is swapped
+} host_region_type_t;
+
+
+
+typedef struct shadow_region {
+ guest_region_type_t guest_type;
+ addr_t guest_start;
+ addr_t guest_end;
+
+ host_region_type_t host_type;
+ union host_addr_t {
+ struct physical_addr {
+ addr_t host_start;
+ } phys_addr;
+ // Other addresses, like on disk, etc, would go here
+ } host_addr;
+ struct shadow_region *next, *prev;
+} shadow_region_t;
+
+
+
+typedef struct shadow_map {
+ uint_t num_regions;
+
+ shadow_region_t * head;
+} shadow_map_t;
+
+
+void init_shadow_region(shadow_region_t * entry,
+ addr_t guest_addr_start,
+ addr_t guest_addr_end,
+ guest_region_type_t guest_region_type,
+ host_region_type_t host_region_type);
+
+void init_shadow_region_physical(shadow_region_t * entry,
+ addr_t guest_addr_start,
+ addr_t guest_addr_end,
+ guest_region_type_t guest_region_type,
+ addr_t host_addr_start,
+ host_region_type_t host_region_type);
+
+void init_shadow_map(shadow_map_t * map);
+void free_shadow_map(shadow_map_t * map);
+
+shadow_region_t * get_shadow_region_by_addr(shadow_map_t * map, addr_t guest_addr);
+
+shadow_region_t * get_shadow_region_by_index(shadow_map_t * map, uint_t index);
+
+host_region_type_t lookup_shadow_map_addr(shadow_map_t * map, addr_t guest_addr, addr_t * host_addr);
+
+
+// Semantics:
+// Adding a region that overlaps with an existing region results is undefined
+// and will probably fail
+int add_shadow_region(shadow_map_t * map, shadow_region_t * entry);
+
+// Semantics:
+// Deletions result in splitting
+int delete_shadow_region(shadow_map_t * map,
+ addr_t guest_start,
+ addr_t guest_end);
+
+
+void print_shadow_map(shadow_map_t * map);
+
+
+
+
+#endif
