#include <palacios/vmm.h>
#include <palacios/vmm_dev_mgr.h>
#include <devices/lnx_virtio_blk.h>
+#include <palacios/vmm_sym_swap.h>
#define SWAP_CAPACITY (150 * 1024 * 1024)
+
/* This is the first page that linux writes to the swap area */
/* Taken from Linux */
union swap_header {
} info;
};
+
+
struct swap_state {
-
+ int active;
+
struct vm_device * blk_dev;
uint_t swapped_pages;
uint_t unswapped_pages;
+
uint64_t capacity;
uint8_t * swap_space;
addr_t swap_base_addr;
+
+ uint8_t usage_map[0]; // This must be the last structure member
};
+
+static inline void set_index_usage(struct swap_state * swap, uint32_t index, int used) {
+ int major = index / 8;
+ int minor = index % 8;
+
+ if (used) {
+ swap->usage_map[major] |= (1 << minor);
+ } else {
+ swap->usage_map[major] &= ~(1 << minor);
+ }
+}
+
+static inline int get_index_usage(struct swap_state * swap, uint32_t index) {
+ int major = index / 8;
+ int minor = index % 8;
+ return swap->usage_map[major] & (1 << minor);
+}
+
+
+static inline uint32_t get_swap_index_from_offset(uint32_t offset) {
+ // CAREFUL: The index might be offset by 1, because the first 4K is the header
+ return (offset / 4096);
+}
+
+
+/*
+ static inline uint32_t get_swap_index(uint32_t offset) {
+ // CAREFUL: The index might be offset by 1, because the first 4K is the header
+ return (swap_addr - swap->swap_space) / 4096;
+ }
+*/
+
+
+static inline void * get_swap_entry(uint32_t pg_index, void * private_data) {
+ struct swap_state * swap = (struct swap_state *)private_data;
+ void * pg_addr = NULL;
+
+ if (get_index_usage(swap, pg_index)) {
+ // CAREFUL: The index might be offset by 1, because the first 4K is the header
+ pg_addr = (void *)(swap->swap_space + (pg_index * 4096));
+ }
+
+ return pg_addr;
+}
+
+
+
static uint64_t swap_get_capacity(void * private_data) {
struct vm_device * dev = (struct vm_device *)private_data;
struct swap_state * swap = (struct swap_state *)(dev->private_data);
return swap->capacity / HD_SECTOR_SIZE;
}
+
+static struct v3_swap_ops swap_ops = {
+ .get_swap_entry = get_swap_entry,
+};
+
+
+
static int swap_read(uint8_t * buf, int sector_count, uint64_t lba, void * private_data) {
struct vm_device * dev = (struct vm_device *)private_data;
struct swap_state * swap = (struct swap_state *)(dev->private_data);
- int offset = lba * HD_SECTOR_SIZE;
- int length = sector_count * HD_SECTOR_SIZE;
+ uint32_t offset = lba * HD_SECTOR_SIZE;
+ uint32_t length = sector_count * HD_SECTOR_SIZE;
PrintDebug("SymSwap: Reading %d bytes to %p from %p\n", length,
swap->unswapped_pages += (length / 4096);
+ set_index_usage(swap, get_swap_index_from_offset(offset), 0);
+
+
+ // Notify the shadow paging layer
+
PrintDebug("Swapped in %d pages\n", length / 4096);
return 0;
}
+
+
+
static int swap_write(uint8_t * buf, int sector_count, uint64_t lba, void * private_data) {
struct vm_device * dev = (struct vm_device *)private_data;
struct swap_state * swap = (struct swap_state *)(dev->private_data);
- int offset = lba * HD_SECTOR_SIZE;
- int length = sector_count * HD_SECTOR_SIZE;
+ uint32_t offset = lba * HD_SECTOR_SIZE;
+ uint32_t length = sector_count * HD_SECTOR_SIZE;
+
/*
PrintDebug("SymSwap: Writing %d bytes to %p from %p\n", length,
(void *)(swap->swap_space + offset), buf);
*/
+
if (length % 4096) {
PrintError("Swapping out length that is not a page multiple\n");
}
- if (offset == 0) {
- // This is the swap header page
- union swap_header * hdr;
+ if ((swap->active == 0) && (offset == 0)) {
+ // This is the swap header page
+ union swap_header * hdr = (union swap_header *)buf;
+
if (length != 4096) {
PrintError("Initializing Swap space by not writing page multiples. This sucks...\n");
return -1;
}
- hdr = (union swap_header *)buf;
-
+ swap->active = 1;
PrintDebug("Swap Type=%d (magic=%s)\n", hdr->info.type, hdr->magic.magic);
+
+ if (v3_register_swap_disk(dev->vm, hdr->info.type, &swap_ops, dev) == -1) {
+ PrintError("Error registering symbiotic swap disk\n");
+ return -1;
+ }
+
}
memcpy(swap->swap_space + offset, buf, length);
swap->swapped_pages += (length / 4096);
+ set_index_usage(swap, get_swap_index_from_offset(offset), 1);
+
PrintDebug("Swapped out %d pages\n", length / 4096);
return 0;
+
+
static int swap_init(struct guest_info * vm, void * cfg_data) {
struct swap_state * swap = NULL;
struct vm_device * virtio_blk = v3_find_dev(vm, (char *)cfg_data);
return -1;
}
- swap = (struct swap_state *)V3_Malloc(sizeof(struct swap_state));
+ swap = (struct swap_state *)V3_Malloc(sizeof(struct swap_state) + ((SWAP_CAPACITY / 4096) / 8));
swap->blk_dev = virtio_blk;
swap->capacity = SWAP_CAPACITY;
swap->swapped_pages = 0;
swap->unswapped_pages = 0;
+ swap->active = 0;
+
swap->swap_base_addr = (addr_t)V3_AllocPages(swap->capacity / 4096);
swap->swap_space = (uint8_t *)V3_VAddr((void *)(swap->swap_base_addr));
memset(swap->swap_space, 0, SWAP_CAPACITY);
+ memset(swap->usage_map, 0, ((SWAP_CAPACITY / 4096) / 8));
struct vm_device * dev = v3_allocate_device("SYM_SWAP", &dev_ops, swap);
