[RFC PATCH 4/6] Remove uses of ram.last_offset (aka last_ram_offset)

Alex Williamson
2010-06-08T19:22:18Z

We currently need this either to allocate the next ram_addr_t for a
new block, or for total memory to be migrated. Both of which we can
calculate without need of this to keep us in a contiguous address space.

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

arch_init.c | 23 ++++++++++++++++-------
cpu-all.h | 1 -
exec.c | 19 ++++++++++++++-----
3 files changed, 30 insertions(+), 13 deletions(-)

diff --git a/arch_init.c b/arch_init.c
index 43e42ba..6103461 100644
--- a/arch_init.c
+++ b/arch_init.c
@@ -108,9 +108,10 @@ static int ram_save_block(QEMUFile *f)
static ram_addr_t current_addr = 0;
ram_addr_t saved_addr = current_addr;
ram_addr_t addr = 0;
+ uint64_t total_ram = ram_bytes_total();
int bytes_sent = 0;

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

@@ -133,7 +134,7 @@ static int ram_save_block(QEMUFile *f)
break;
}
addr += TARGET_PAGE_SIZE;
- current_addr = (saved_addr + addr) % ram.last_offset;
+ current_addr = (saved_addr + addr) % total_ram;
}

return bytes_sent;
@@ -145,8 +146,9 @@ static ram_addr_t ram_save_remaining(void)
{
ram_addr_t addr;
ram_addr_t count = 0;
+ uint64_t total_ram = ram_bytes_total();

- for (addr = 0; addr < ram.last_offset; addr += TARGET_PAGE_SIZE) {
+ for (addr = 0; addr < total_ram; addr += TARGET_PAGE_SIZE) {
if (cpu_physical_memory_get_dirty(addr, MIGRATION_DIRTY_FLAG)) {
count++;
}
@@ -167,7 +169,13 @@ uint64_t ram_bytes_transferred(void)

uint64_t ram_bytes_total(void)
{
- return ram.last_offset;
+ RAMBlock *block;
+ uint64_t total = 0;
+
+ QLIST_FOREACH(block, &ram.blocks, next)
+ total += block->length;
+
+ return total;
}

int ram_save_live(Monitor *mon, QEMUFile *f, int stage, void *opaque)
@@ -188,10 +196,11 @@ int ram_save_live(Monitor *mon, QEMUFile *f, int stage, void *opaque)
}

if (stage == 1) {
+ uint64_t total_ram = ram_bytes_total();
bytes_transferred = 0;

/* Make sure all dirty bits are set */
- for (addr = 0; addr < ram.last_offset; addr += TARGET_PAGE_SIZE) {
+ for (addr = 0; addr < total_ram; addr += TARGET_PAGE_SIZE) {
if (!cpu_physical_memory_get_dirty(addr, MIGRATION_DIRTY_FLAG)) {
cpu_physical_memory_set_dirty(addr);
}
@@ -200,7 +209,7 @@ 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, ram.last_offset | RAM_SAVE_FLAG_MEM_SIZE);
+ qemu_put_be64(f, total_ram | RAM_SAVE_FLAG_MEM_SIZE);
}

bytes_transferred_last = bytes_transferred;
@@ -259,7 +268,7 @@ int ram_load(QEMUFile *f, void *opaque, int version_id)
addr &= TARGET_PAGE_MASK;

if (flags & RAM_SAVE_FLAG_MEM_SIZE) {
- if (addr != ram.last_offset) {
+ if (addr != ram_bytes_total()) {
return -EINVAL;
}
}
diff --git a/cpu-all.h b/cpu-all.h
index a5b886a..23b1d1d 100644
--- a/cpu-all.h
+++ b/cpu-all.h
@@ -871,7 +871,6 @@ typedef struct RAMBlock {

typedef struct RAMList {
uint8_t *phys_dirty;
- ram_addr_t last_offset;
QLIST_HEAD(ram, RAMBlock) blocks;
} RAMList;
extern RAMList ram;
diff --git a/exec.c b/exec.c
index dd57515..13c0ca0 100644
--- a/exec.c
+++ b/exec.c
@@ -2774,6 +2774,17 @@ static void *file_ram_alloc(ram_addr_t memory, const char *path)
}
#endif

+static ram_addr_t find_ram_offset(ram_addr_t size)
+{
+ RAMBlock *block;
+ ram_addr_t last = 0;
+
+ QLIST_FOREACH(block, &ram.blocks, next)
+ last = MAX(last, block->offset + block->length);
+
+ return last;
+}
+
ram_addr_t qemu_ram_map(const char *name, ram_addr_t size, void *host)
{
RAMBlock *new_block;
@@ -2785,18 +2796,16 @@ ram_addr_t qemu_ram_map(const char *name, ram_addr_t size, void *host)
snprintf(new_block->name, sizeof(new_block->name), "%s", strdup(name));
new_block->host = host;

- new_block->offset = ram.last_offset;
+ new_block->offset = find_ram_offset(size);
new_block->length = size;

QLIST_INSERT_HEAD(&ram.blocks, new_block, next);

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),
+ (new_block->offset + size) >> TARGET_PAGE_BITS);
+ memset(ram.phys_dirty + (new_block->offset >> TARGET_PAGE_BITS),
0xff, size >> TARGET_PAGE_BITS);

- ram.last_offset += size;
-
if (kvm_enabled())
kvm_setup_guest_memory(new_block->host, size);