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make size of primary CoW buffer configurable

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This commit is contained in:
Sergej Schumilo 2021-12-10 01:07:59 +01:00
parent 23a408e2cf
commit c9dac7704d
3 changed files with 58 additions and 15 deletions
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6
nyx/interface.c
View File

@ -76,6 +76,7 @@ typedef struct kafl_mem_state {
char* workdir;
uint32_t worker_id;
uint64_t cow_primary_size;
char* redqueen_workdir;
char* data_bar_fd_0;
@ -354,6 +355,10 @@ static void pci_kafl_guest_realize(DeviceState *dev, Error **errp){
abort();
}
if(s->cow_primary_size){
set_global_cow_cache_primary_size(s->cow_primary_size);
}
if (!s->workdir || !verify_workdir_state(s, errp)){
fprintf(stderr, "Invalid work dir...\n");
abort();
@ -407,6 +412,7 @@ static Property kafl_guest_properties[] = {
DEFINE_PROP_STRING("workdir", kafl_mem_state, workdir),
DEFINE_PROP_UINT32("worker_id", kafl_mem_state, worker_id, 0xFFFF),
DEFINE_PROP_UINT64("cow_primary_size", kafl_mem_state, cow_primary_size, 0),
/*
* Since DEFINE_PROP_UINT64 is somehow broken (signed/unsigned madness),
* let's use DEFINE_PROP_STRING and post-process all values by strtol...

47
nyx/snapshot/block/block_cow.c
View File

@ -14,6 +14,20 @@
//0x200
#define PAGE_MASK 0xFFFFFFFFFFFFF000
uint64_t global_cow_primary_size = COW_CACHE_PRIMARY_MINIMUM_SIZE;
bool global_cow_primary_size_adjustable = true;
void set_global_cow_cache_primary_size(uint64_t new_size){
if (global_cow_primary_size_adjustable && new_size > COW_CACHE_PRIMARY_MINIMUM_SIZE && (new_size & 0xFFF) == 0){
global_cow_primary_size = new_size;
global_cow_primary_size_adjustable = false;
}
}
static inline uint64_t get_global_cow_cache_primary_size(void){
return global_cow_primary_size;
}
cow_cache_t* cow_cache_new(const char* filename){
//printf("%s: \"%s\"\n", __func__, filename);
@ -23,9 +37,10 @@ cow_cache_t* cow_cache_new(const char* filename){
self->lookup_secondary = kh_init(COW_CACHE);
self->lookup_secondary_tmp = kh_init(COW_CACHE);
self->data_primary = mmap(NULL, COW_CACHE_SIZE, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS, 0, 0);
self->cow_primary_size = COW_CACHE_PRIMARY_MINIMUM_SIZE;
self->data_primary = mmap(NULL, self->cow_primary_size, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS, 0, 0);
assert(self->data_primary != MAP_FAILED);
//memset(self->data_primary, COW_CACHE_SIZE/CHUNK_SIZE, CHUNK_SIZE);
//memset(self->data_primary, COW_CACHE_PRIMARY_MINIMUM_SIZE/CHUNK_SIZE, CHUNK_SIZE);
self->data_secondary = mmap(NULL, COW_CACHE_SECONDARY_SIZE, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS, 0, 0);
assert(self->data_secondary != MAP_FAILED);
@ -80,6 +95,7 @@ static char* gen_file_name(cow_cache_t* self, const char* filename_prefix, const
void read_primary_buffer(cow_cache_t* self, const char* filename_prefix, bool switch_mode){
assert(!self->enabled_fuzz);
global_cow_primary_size_adjustable = false;
//printf("%s: %s\n", __func__, self->filename);
@ -98,6 +114,11 @@ void read_primary_buffer(cow_cache_t* self, const char* filename_prefix, bool sw
struct stat buffer;
assert(stat (tmp2, &buffer) == 0);
if (buffer.st_size > get_global_cow_cache_primary_size()){
fprintf(stderr, "ERROR: in-memory CoW buffer is too small compared to snapshot file (buffer: 0x%lx / file: 0x%lx)\n", get_global_cow_cache_primary_size(), buffer.st_size);
exit(1);
}
if(buffer.st_size){
self->lookup_primary = kh_load(COW_CACHE, tmp1);
}
@ -109,14 +130,24 @@ void read_primary_buffer(cow_cache_t* self, const char* filename_prefix, bool sw
//printf("TRY TO MMAP : %lx\n", buffer.st_size);
if(switch_mode){
self->data_primary = mmap(0, COW_CACHE_SIZE, PROT_READ, MAP_SHARED, fd, 0);
munmap(self->data_primary, self->cow_primary_size);
self->cow_primary_size = get_global_cow_cache_primary_size();
self->data_primary = mmap(0, self->cow_primary_size, PROT_READ, MAP_SHARED, fd, 0);
assert(self->data_primary);
}
else{
void* ptr = mmap(0, COW_CACHE_SIZE, PROT_READ , MAP_SHARED, fd, 0);
if(get_global_cow_cache_primary_size() != self->cow_primary_size){
munmap(self->data_primary, self->cow_primary_size);
self->cow_primary_size = get_global_cow_cache_primary_size();
self->data_primary = mmap(NULL, self->cow_primary_size, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS, 0, 0);
assert(self->data_primary != MAP_FAILED);
}
void* ptr = mmap(0, COW_CACHE_PRIMARY_MINIMUM_SIZE, PROT_READ , MAP_SHARED, fd, 0);
assert(ptr);
memcpy(self->data_primary, ptr, buffer.st_size);
munmap(ptr, COW_CACHE_SIZE);
munmap(ptr, COW_CACHE_PRIMARY_MINIMUM_SIZE);
}
//printf("self->data_primary -> %p\n", self->data_primary );
close(fd);
@ -395,7 +426,7 @@ static inline void write_to_primary_buffer(cow_cache_t* self, BlockBackend *blk,
#endif
/* IN CASE THE BUFFER IS FULL -> ABORT! */
assert(self->offset_primary < COW_CACHE_SIZE);
assert(self->offset_primary < self->cow_primary_size);
}
#ifdef COW_CACHE_DEBUG
@ -515,8 +546,8 @@ static int cow_cache_write(cow_cache_t* self, BlockBackend *blk, int64_t offset,
void switch_to_fuzz_mode(cow_cache_t* self){
self->enabled_fuzz = true;
assert(!mprotect(self->data_primary, COW_CACHE_SIZE, PROT_READ));
printf("[qemu-nyx] switch to secondary CoW buffer\n");
assert(!mprotect(self->data_primary, self->cow_primary_size, PROT_READ));
printf("[qemu-nyx] switching to secondary CoW buffer\n");
}
void cow_cache_read_entry(void* opaque){

20
nyx/snapshot/block/block_cow.h
View File

@ -12,14 +12,16 @@
//#define DEBUG_COW_LAYER
/* 2GB Cache */
//#define COW_CACHE_SIZE 0x80000000
/* Minimum size of CoW buffer that stores data written to
* the block device between boot time and root snapshot (3GB)
*/
#define COW_CACHE_PRIMARY_MINIMUM_SIZE 0xC0000000
// 3GB
#define COW_CACHE_SIZE 0xC0000000
// 512MB
//#define COW_CACHE_SECONDARY_SIZE 0x20000000
/* Size of CoW buffer which stores data written to
* the block device between the root snapshot and the
* next snapshot restore (3GB). This buffer is allocated
* twice to store the incremental snapshot delta.
*/
#define COW_CACHE_SECONDARY_SIZE 0xC0000000
@ -34,6 +36,8 @@ typedef struct cow_cache_s{
void* data_secondary;
void* data_secondary_tmp;
uint64_t cow_primary_size;
char* filename;
uint64_t offset_primary;
uint64_t offset_secondary;
@ -70,3 +74,5 @@ void cow_cache_disable(cow_cache_t* self);
void cow_cache_enable_tmp_mode(cow_cache_t* self);
void cow_cache_disable_tmp_mode(cow_cache_t* self);
void set_global_cow_cache_primary_size(uint64_t new_size);