5 #include <geekos/ktypes.h>
9 #include <geekos/vmm_mem.h>
10 #include <geekos/vmm_util.h>
14 In the following, when we say "page table", we mean the whole 2 or 4 layer
15 page table (PDEs, PTEs), etc.
18 guest-visible paging state
19 This is the state that the guest thinks the machine is using
21 - guest physical memory
22 The physical memory addresses the guest is allowed to use
23 (see shadow page maps, below)
25 (we care about when the current one changes)
26 - guest paging registers (these are never written to hardware)
32 This the state that the machine will actually use when the guest
33 is running. It consists of:
34 - current shadow page table
35 This is the page table actually useed when the guest is running.
36 It is changed/regenerated when the guest page table changes
37 It mostly reflects the guest page table, except that it restricts
38 physical addresses to those the VMM allocates to the guest.
40 This is a mapping from guest physical memory addresses to
41 the current location of the guest physical memory content.
42 It maps from regions of physical memory addresses to regions
43 located in physical memory or elsewhere.
44 (8192,16384) -> MEM(8912,...)
45 (0,8191) -> DISK(65536,..)
46 - guest paging registers (these are written to guest state)
51 This is the state we expect to be operative when the VMM is running.
52 Typically, this is set up by the host os into which we have embedded
53 the VMM, but we include the description here for clarity.
55 This is the page table we use when we are executing in
56 the VMM (or the host os)
62 The reason why the shadow paging state and the host paging state are
63 distinct is to permit the guest to use any virtual address it wants,
64 irrespective of the addresses the VMM or the host os use. These guest
65 virtual addresses are reflected in the shadow paging state. When we
66 exit from the guest, we switch to the host paging state so that any
67 virtual addresses that overlap between the guest and VMM/host now map
68 to the physical addresses epxected by the VMM/host. On AMD SVM, this
69 switch is done by the hardware. On Intel VT, the switch is done
70 by the hardware as well, but we are responsible for manually updating
71 the host state in the vmcs before entering the guest.
79 #define MAX_PAGE_TABLE_ENTRIES 1024
80 #define MAX_PAGE_DIR_ENTRIES 1024
82 #define MAX_PAGE_TABLE_ENTRIES_64 512
83 #define MAX_PAGE_DIR_ENTRIES_64 512
84 #define MAX_PAGE_DIR_PTR_ENTRIES_64 512
85 #define MAX_PAGE_MAP_ENTRIES_64 512
87 #define PAGE_DIRECTORY_INDEX(x) ((((uint_t)x) >> 22) & 0x3ff)
88 #define PAGE_TABLE_INDEX(x) ((((uint_t)x) >> 12) & 0x3ff)
89 #define PAGE_OFFSET(x) ((((uint_t)x) & 0xfff))
91 #define PAGE_ALIGNED_ADDR(x) (((uint_t) (x)) >> 12)
93 #define PAGE_ADDR(x) (PAGE_ALIGNED_ADDR(x) << 12)
105 #define GUEST_PAGE 0x0
106 #define SHARED_PAGE 0x1
113 uint_t large_pages : 1;
114 uint_t global_page : 1;
116 uint_t pt_base_addr : 20;
125 uint_t global_page : 1;
127 uint_t page_base_addr : 20;
132 typedef struct pte64 {
138 uint_t global_page : 1;
140 uint_t page_base_addr_lo : 20;
141 uint_t page_base_addr_hi : 20;
142 uint_t available : 11;
143 uint_t no_execute : 1;
146 typedef struct pde64 {
151 uint_t large_pages : 1;
152 uint_t reserved2 : 1;
154 uint_t pt_base_addr_lo : 20;
155 uint_t pt_base_addr_hi : 20;
156 uint_t available : 11;
157 uint_t no_execute : 1;
160 typedef struct pdpe64 {
168 uint_t large_pages : 1;
171 uint_t pd_base_addr_lo : 20;
172 uint_t pd_base_addr_hi : 20;
173 uint_t available : 11;
174 uint_t no_execute : 1;
178 typedef struct pml4e {
188 uint_t pdp_base_addr_lo : 20;
189 uint_t pdp_base_addr_hi : 20;
190 uint_t available : 11;
191 uint_t no_execute : 1;
196 typedef enum { PDE32 } page_directory_type_t;
199 typedef struct shadow_paging_state {
200 // these two reflect the top-level page directory
201 // of the guest page table
202 page_directory_type_t guest_page_directory_type;
203 void *guest_page_directory; // points to guest's current page table
205 // This reflects the guest physical to host physical mapping
206 shadow_map_t shadow_map;
208 // these two reflect the top-level page directory
209 // the shadow page table
210 page_directory_type_t shadow_page_directory_type;
211 void *shadow_page_directory;
213 } shadow_paging_state_t;
217 int init_shadow_paging_state(shadow_paging_state_t *state);
219 // This function will cause the shadow page table to be deleted
220 // and rewritten to reflect the guest page table and the shadow map
221 int wholesale_update_shadow_paging_state(shadow_paging_state_t *state);
223 //void free_guest_page_tables(vmm_pde_t * pde);
227 //vmm_pde_t * generate_guest_page_tables(shadow_map_t * map, vmm_mem_list_t * list);
228 //pml4e64_t * generate_guest_page_tables_64(shadow_map_t * map, vmm_mem_list_t * list);
231 void PrintDebugPageTables(vmm_pde_t * pde);