[RFC PATCH 2/6] ram_blocks: Convert to a QLIST

Alex Williamson
2010-06-08T19:21:45Z

This makes the RAM block list easier to manipulate. Also incorporate
relevant variables into the RAMList struct.

Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
---

arch_init.c | 14 ++++++-----
cpu-all.h | 28 ++++++++++++++++-------
exec.c | 72 ++++++++++++++++++-----------------------------------------
3 files changed, 49 insertions(+), 65 deletions(-)

diff --git a/arch_init.c b/arch_init.c
index 8e849a8..43e42ba 100644
--- a/arch_init.c
+++ b/arch_init.c
@@ -110,7 +110,7 @@ static int ram_save_block(QEMUFile *f)
ram_addr_t addr = 0;
int bytes_sent = 0;

- while (addr < last_ram_offset) {
+ while (addr < ram.last_offset) {
if (cpu_physical_memory_get_dirty(current_addr, MIGRATION_DIRTY_FLAG)) {
uint8_t *p;

@@ -133,7 +133,7 @@ static int ram_save_block(QEMUFile *f)
break;
}
addr += TARGET_PAGE_SIZE;
- current_addr = (saved_addr + addr) % last_ram_offset;
+ current_addr = (saved_addr + addr) % ram.last_offset;
}

return bytes_sent;
@@ -146,7 +146,7 @@ static ram_addr_t ram_save_remaining(void)
ram_addr_t addr;
ram_addr_t count = 0;

- for (addr = 0; addr < last_ram_offset; addr += TARGET_PAGE_SIZE) {
+ for (addr = 0; addr < ram.last_offset; addr += TARGET_PAGE_SIZE) {
if (cpu_physical_memory_get_dirty(addr, MIGRATION_DIRTY_FLAG)) {
count++;
}
@@ -167,7 +167,7 @@ uint64_t ram_bytes_transferred(void)

uint64_t ram_bytes_total(void)
{
- return last_ram_offset;
+ return ram.last_offset;
}

int ram_save_live(Monitor *mon, QEMUFile *f, int stage, void *opaque)
@@ -191,7 +191,7 @@ int ram_save_live(Monitor *mon, QEMUFile *f, int stage, void *opaque)
bytes_transferred = 0;

/* Make sure all dirty bits are set */
- for (addr = 0; addr < last_ram_offset; addr += TARGET_PAGE_SIZE) {
+ for (addr = 0; addr < ram.last_offset; addr += TARGET_PAGE_SIZE) {
if (!cpu_physical_memory_get_dirty(addr, MIGRATION_DIRTY_FLAG)) {
cpu_physical_memory_set_dirty(addr);
}
@@ -200,7 +200,7 @@ int ram_save_live(Monitor *mon, QEMUFile *f, int stage, void *opaque)
/* Enable dirty memory tracking */
cpu_physical_memory_set_dirty_tracking(1);

- qemu_put_be64(f, last_ram_offset | RAM_SAVE_FLAG_MEM_SIZE);
+ qemu_put_be64(f, ram.last_offset | RAM_SAVE_FLAG_MEM_SIZE);
}

bytes_transferred_last = bytes_transferred;
@@ -259,7 +259,7 @@ int ram_load(QEMUFile *f, void *opaque, int version_id)
addr &= TARGET_PAGE_MASK;

if (flags & RAM_SAVE_FLAG_MEM_SIZE) {
- if (addr != last_ram_offset) {
+ if (addr != ram.last_offset) {
return -EINVAL;
}
}
diff --git a/cpu-all.h b/cpu-all.h
index 77eaf85..458cb4b 100644
--- a/cpu-all.h
+++ b/cpu-all.h
@@ -859,9 +859,21 @@ target_phys_addr_t cpu_get_phys_page_debug(CPUState *env, target_ulong addr);
/* memory API */

extern int phys_ram_fd;
-extern uint8_t *phys_ram_dirty;
extern ram_addr_t ram_size;
-extern ram_addr_t last_ram_offset;
+
+typedef struct RAMBlock {
+ uint8_t *host;
+ ram_addr_t offset;
+ ram_addr_t length;
+ QLIST_ENTRY(RAMBlock) next;
+} RAMBlock;
+
+typedef struct RAMList {
+ uint8_t *phys_dirty;
+ ram_addr_t last_offset;
+ QLIST_HEAD(ram, RAMBlock) blocks;
+} RAMList;
+extern RAMList ram;

extern const char *mem_path;
extern int mem_prealloc;
@@ -891,29 +903,29 @@ extern int mem_prealloc;
/* read dirty bit (return 0 or 1) */
static inline int cpu_physical_memory_is_dirty(ram_addr_t addr)
{
- return phys_ram_dirty[addr >> TARGET_PAGE_BITS] == 0xff;
+ return ram.phys_dirty[addr >> TARGET_PAGE_BITS] == 0xff;
}

static inline int cpu_physical_memory_get_dirty_flags(ram_addr_t addr)
{
- return phys_ram_dirty[addr >> TARGET_PAGE_BITS];
+ return ram.phys_dirty[addr >> TARGET_PAGE_BITS];
}

static inline int cpu_physical_memory_get_dirty(ram_addr_t addr,
int dirty_flags)
{
- return phys_ram_dirty[addr >> TARGET_PAGE_BITS] & dirty_flags;
+ return ram.phys_dirty[addr >> TARGET_PAGE_BITS] & dirty_flags;
}

static inline void cpu_physical_memory_set_dirty(ram_addr_t addr)
{
- phys_ram_dirty[addr >> TARGET_PAGE_BITS] = 0xff;
+ ram.phys_dirty[addr >> TARGET_PAGE_BITS] = 0xff;
}

static inline int cpu_physical_memory_set_dirty_flags(ram_addr_t addr,
int dirty_flags)
{
- return phys_ram_dirty[addr >> TARGET_PAGE_BITS] |= dirty_flags;
+ return ram.phys_dirty[addr >> TARGET_PAGE_BITS] |= dirty_flags;
}

static inline void cpu_physical_memory_mask_dirty_range(ram_addr_t start,
@@ -925,7 +937,7 @@ static inline void cpu_physical_memory_mask_dirty_range(ram_addr_t start,

len = length >> TARGET_PAGE_BITS;
mask = ~dirty_flags;
- p = phys_ram_dirty + (start >> TARGET_PAGE_BITS);
+ p = ram.phys_dirty + (start >> TARGET_PAGE_BITS);
for (i = 0; i < len; i++) {
p[i] &= mask;
}
diff --git a/exec.c b/exec.c
index c60f9e7..d785de3 100644
--- a/exec.c
+++ b/exec.c
@@ -116,21 +116,9 @@ uint8_t *code_gen_ptr;

#if !defined(CONFIG_USER_ONLY)
int phys_ram_fd;
-uint8_t *phys_ram_dirty;
static int in_migration;

-typedef struct RAMBlock {
- uint8_t *host;
- ram_addr_t offset;
- ram_addr_t length;
- struct RAMBlock *next;
-} RAMBlock;
-
-static RAMBlock *ram_blocks;
-/* TODO: When we implement (and use) ram deallocation (e.g. for hotplug)
- then we can no longer assume contiguous ram offsets, and external uses
- of this variable will break. */
-ram_addr_t last_ram_offset;
+RAMList ram = { .blocks = QLIST_HEAD_INITIALIZER(ram) };
#endif

CPUState *first_cpu;
@@ -2795,18 +2783,17 @@ ram_addr_t qemu_ram_map(ram_addr_t size, void *host)

new_block->host = host;

- new_block->offset = last_ram_offset;
+ new_block->offset = ram.last_offset;
new_block->length = size;

- new_block->next = ram_blocks;
- ram_blocks = new_block;
+ QLIST_INSERT_HEAD(&ram.blocks, new_block, next);

- phys_ram_dirty = qemu_realloc(phys_ram_dirty,
- (last_ram_offset + size) >> TARGET_PAGE_BITS);
- memset(phys_ram_dirty + (last_ram_offset >> TARGET_PAGE_BITS),
+ ram.phys_dirty = qemu_realloc(ram.phys_dirty,
+ (ram.last_offset + size) >> TARGET_PAGE_BITS);
+ memset(ram.phys_dirty + (ram.last_offset >> TARGET_PAGE_BITS),
0xff, size >> TARGET_PAGE_BITS);

- last_ram_offset += size;
+ ram.last_offset += size;

if (kvm_enabled())
kvm_setup_guest_memory(new_block->host, size);
@@ -2864,31 +2851,17 @@ void qemu_ram_free(ram_addr_t addr)
*/
void *qemu_get_ram_ptr(ram_addr_t addr)
{
- RAMBlock *prev;
- RAMBlock **prevp;
RAMBlock *block;

- prev = NULL;
- prevp = &ram_blocks;
- block = ram_blocks;
- while (block && (block->offset > addr
- || block->offset + block->length <= addr)) {
- if (prev)
- prevp = &prev->next;
- prev = block;
- block = block->next;
- }
- if (!block) {
- fprintf(stderr, "Bad ram offset %" PRIx64 "\n", (uint64_t)addr);
- abort();
- }
- /* Move this entry to to start of the list. */
- if (prev) {
- prev->next = block->next;
- block->next = *prevp;
- *prevp = block;
+ QLIST_FOREACH(block, &ram.blocks, next) {
+ if (addr - block->offset < block->length) {
+ QLIST_REMOVE(block, next);
+ QLIST_INSERT_HEAD(&ram.blocks, block, next);
+ return block->host + (addr - block->offset);
+ }
}
- return block->host + (addr - block->offset);
+
+ return NULL;
}

int do_qemu_ram_addr_from_host(void *ptr, ram_addr_t *ram_addr)
@@ -2896,15 +2869,14 @@ int do_qemu_ram_addr_from_host(void *ptr, ram_addr_t *ram_addr)
RAMBlock *block;
uint8_t *host = ptr;

- block = ram_blocks;
- while (block && (block->host > host
- || block->host + block->length <= host)) {
- block = block->next;
+ QLIST_FOREACH(block, &ram.blocks, next) {
+ if (host - block->host < block->length) {
+ *ram_addr = block->offset + (host - block->host);
+ return 0;
+ }
}
- if (!block)
- return -1;
- *ram_addr = block->offset + (host - block->host);
- return 0;
+
+ return -1;
}

/* Some of the softmmu routines need to translate from a host pointer