2 * This file is part of the Palacios Virtual Machine Monitor developed
3 * by the V3VEE Project with funding from the United States National
4 * Science Foundation and the Department of Energy.
6 * The V3VEE Project is a joint project between Northwestern University
7 * and the University of New Mexico. You can find out more at
10 * Copyright (c) 2008, Jack Lange <jarusl@cs.northwestern.edu>
11 * Copyright (c) 2008, The V3VEE Project <http://www.v3vee.org>
12 * All rights reserved.
14 * Author: Jack Lange <jarusl@cs.northwestern.edu>
16 * This is free software. You are permitted to use,
17 * redistribute, and modify it as specified in the file "V3VEE_LICENSE".
20 #include <palacios/vmm.h>
21 #include <palacios/vmm_dev_mgr.h>
22 #include <devices/lnx_virtio_blk.h>
23 #include <palacios/vmm_sym_swap.h>
25 #define SWAP_CAPACITY (150 * 1024 * 1024)
27 #ifdef CONFIG_SYMBIOTIC_SWAP_TELEMETRY
28 #include <palacios/vmm_telemetry.h>
32 /* This is the first page that linux writes to the swap area */
33 /* Taken from Linux */
36 char reserved[PAGE_SIZE - 10];
37 char magic[10]; /* SWAP-SPACE or SWAPSPACE2 */
40 char bootbits[1024]; /* Space for disklabel etc. */
44 unsigned char sws_uuid[16];
45 unsigned char sws_volume[16];
46 uint32_t type; // The index into the swap_map
47 uint32_t padding[116];
48 // uint32_t padding[117];
58 struct vm_device * blk_dev;
61 uint_t unswapped_pages;
64 union swap_header * hdr;
66 #ifdef CONFIG_SYMBIOTIC_SWAP_TELEMETRY
74 addr_t swap_base_addr;
76 uint8_t usage_map[0]; // This must be the last structure member
82 static inline void set_index_usage(struct swap_state * swap, uint32_t index, int used) {
83 int major = index / 8;
84 int minor = index % 8;
87 swap->usage_map[major] |= (1 << minor);
89 swap->usage_map[major] &= ~(1 << minor);
93 static inline int get_index_usage(struct swap_state * swap, uint32_t index) {
94 int major = index / 8;
95 int minor = index % 8;
97 return (swap->usage_map[major] & (1 << minor));
101 static inline uint32_t get_swap_index_from_offset(uint32_t offset) {
102 // CAREFUL: The index might be offset by 1, because the first 4K is the header
103 return (offset / 4096);
108 static inline uint32_t get_swap_index(uint32_t offset) {
109 // CAREFUL: The index might be offset by 1, because the first 4K is the header
110 return (swap_addr - swap->swap_space) / 4096;
115 static inline void * get_swap_entry(uint32_t pg_index, void * private_data) {
116 struct vm_device * dev = (struct vm_device *)private_data;
117 struct swap_state * swap = (struct swap_state *)(dev->private_data);
118 void * pg_addr = NULL;
121 // if ((ret = get_index_usage(swap, pg_index))) {
122 // CAREFUL: The index might be offset by 1, because the first 4K is the header
123 pg_addr = (void *)(swap->swap_space + (pg_index * 4096));
131 static uint64_t swap_get_capacity(void * private_data) {
132 struct vm_device * dev = (struct vm_device *)private_data;
133 struct swap_state * swap = (struct swap_state *)(dev->private_data);
135 PrintDebug("SymSwap: Getting Capacity %d\n", (uint32_t)(swap->capacity));
137 return swap->capacity / HD_SECTOR_SIZE;
141 static struct v3_swap_ops swap_ops = {
142 .get_swap_entry = get_swap_entry,
147 static int swap_read(uint8_t * buf, int sector_count, uint64_t lba, void * private_data) {
148 struct vm_device * dev = (struct vm_device *)private_data;
149 struct swap_state * swap = (struct swap_state *)(dev->private_data);
150 uint32_t offset = lba * HD_SECTOR_SIZE;
151 uint32_t length = sector_count * HD_SECTOR_SIZE;
155 PrintDebug("SymSwap: Reading %d bytes to %p from %p\n", length,
156 buf, (void *)(swap->swap_space + offset));
160 PrintError("Swapping in length that is not a page multiple\n");
163 memcpy(buf, swap->swap_space + offset, length);
165 swap->unswapped_pages += (length / 4096);
167 if ((swap->active == 1) && (offset != 0)) {
169 // Notify the shadow paging layer
171 #ifdef CONFIG_SYMBIOTIC_SWAP_TELEMETRY
172 swap->pages_in += length / 4096;
175 for (i = 0; i < length; i += 4096) {
176 set_index_usage(swap, get_swap_index_from_offset(offset + i), 0);
177 v3_swap_in_notify(dev->vm, get_swap_index_from_offset(offset + i), swap->hdr->info.type);
187 static int swap_write(uint8_t * buf, int sector_count, uint64_t lba, void * private_data) {
188 struct vm_device * dev = (struct vm_device *)private_data;
189 struct swap_state * swap = (struct swap_state *)(dev->private_data);
190 uint32_t offset = lba * HD_SECTOR_SIZE;
191 uint32_t length = sector_count * HD_SECTOR_SIZE;
194 PrintDebug("SymSwap: Writing %d bytes to %p from %p\n", length,
195 (void *)(swap->swap_space + offset), buf);
199 PrintError("Swapping out length that is not a page multiple\n");
202 if ((swap->active == 0) && (offset == 0)) {
203 // This is the swap header page
205 if (length != 4096) {
206 PrintError("Initializing Swap space by not writing page multiples. This sucks...\n");
212 PrintDebug("Swap Type=%d (magic=%s)\n", swap->hdr->info.type, swap->hdr->magic.magic);
214 if (v3_register_swap_disk(dev->vm, swap->hdr->info.type, &swap_ops, dev) == -1) {
215 PrintError("Error registering symbiotic swap disk\n");
220 memcpy(swap->swap_space + offset, buf, length);
222 swap->swapped_pages += (length / 4096);
224 if ((swap->active == 1) && (offset != 0)) {
227 #ifdef CONFIG_SYMBIOTIC_SWAP_TELEMETRY
228 swap->pages_out += length / 4096;
231 for (i = 0; i < length; i += 4096) {
232 set_index_usage(swap, get_swap_index_from_offset(offset + i), 1);
240 static int swap_free(struct vm_device * dev) {
245 static struct v3_hd_ops hd_ops = {
248 .get_capacity = swap_get_capacity,
253 static struct v3_device_ops dev_ops = {
261 #ifdef CONFIG_SYMBIOTIC_SWAP_TELEMETRY
262 static void telemetry_cb(struct guest_info * info, void * private_data, char * hdr) {
263 struct vm_device * dev = (struct vm_device *)private_data;
264 struct swap_state * swap = (struct swap_state *)(dev->private_data);
266 V3_Print("%sSwap Device:\n", hdr);
267 V3_Print("%s\tPages Swapped in=%d\n", hdr, swap->pages_in);
268 V3_Print("%s\tPages Swapped out=%d\n", hdr, swap->pages_out);
277 static int swap_init(struct guest_info * vm, void * cfg_data) {
278 struct swap_state * swap = NULL;
279 struct vm_device * virtio_blk = v3_find_dev(vm, (char *)cfg_data);
282 PrintError("could not find Virtio backend\n");
286 PrintDebug("Creating Swap Device\n");
288 if (virtio_blk == NULL) {
289 PrintError("Swap device requires a virtio block device\n");
293 swap = (struct swap_state *)V3_Malloc(sizeof(struct swap_state) + ((SWAP_CAPACITY / 4096) / 8));
295 swap->blk_dev = virtio_blk;
296 swap->capacity = SWAP_CAPACITY;
298 swap->swapped_pages = 0;
299 swap->unswapped_pages = 0;
302 swap->hdr = (union swap_header *)swap;
305 swap->swap_base_addr = (addr_t)V3_AllocPages(swap->capacity / 4096);
306 swap->swap_space = (uint8_t *)V3_VAddr((void *)(swap->swap_base_addr));
307 memset(swap->swap_space, 0, SWAP_CAPACITY);
309 memset(swap->usage_map, 0, ((SWAP_CAPACITY / 4096) / 8));
311 struct vm_device * dev = v3_allocate_device("SYM_SWAP", &dev_ops, swap);
313 if (v3_attach_device(vm, dev) == -1) {
314 PrintError("Could not attach device %s\n", "SYM_SWAP");
319 v3_virtio_register_harddisk(virtio_blk, &hd_ops, dev);
321 #ifdef CONFIG_SYMBIOTIC_SWAP_TELEMETRY
322 if (vm->enable_telemetry) {
323 v3_add_telemetry_cb(vm, telemetry_cb, dev);
330 device_register("SYM_SWAP", swap_init)