[PATCH 6/6] qemu-kvm: Use cpu_physical_memory_get_dirty_range() to check multiple dirty pages.

Yoshiaki Tamura
2010-03-16T10:56:21Z

Modifies ram_save_block() and ram_save_remaining() to use
cpu_physical_memory_get_dirty_range() to check multiple dirty and non-dirty
pages at once.

Signed-off-by: Yoshiaki Tamura <tamura.yoshiaki@lab.ntt.co.jp>
Signed-off-by: OHMURA Kei <ohmura.kei@lab.ntt.co.jp>
---
vl.c | 55 +++++++++++++++++++++++++++++++++++--------------------
1 files changed, 35 insertions(+), 20 deletions(-)

diff --git a/vl.c b/vl.c
index 6e35cc6..e9ad7c9 100644
--- a/vl.c
+++ b/vl.c
@@ -2779,7 +2779,8 @@ 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;
- int found = 0;
+ ram_addr_t dirty_rams[HOST_LONG_BITS];
+ int i, found = 0;

while (addr < last_ram_offset) {
if (kvm_enabled() && current_addr == 0) {
@@ -2791,28 +2792,35 @@ static int ram_save_block(QEMUFile *f)
return 0;
}
}
- if (cpu_physical_memory_get_dirty(current_addr, MIGRATION_DIRTY_FLAG)) {
+ if ((found = cpu_physical_memory_get_dirty_range(
+ current_addr, last_ram_offset, dirty_rams, HOST_LONG_BITS,
+ MIGRATION_DIRTY_FLAG))) {
uint8_t *p;

- cpu_physical_memory_reset_dirty(current_addr,
- current_addr + TARGET_PAGE_SIZE,
- MIGRATION_DIRTY_FLAG);
+ for (i = 0; i < found; i++) {
+ ram_addr_t page_addr = dirty_rams[i];
+ cpu_physical_memory_reset_dirty(page_addr,
+ page_addr + TARGET_PAGE_SIZE,
+ MIGRATION_DIRTY_FLAG);

- p = qemu_get_ram_ptr(current_addr);
+ p = qemu_get_ram_ptr(page_addr);

- if (is_dup_page(p, *p)) {
- qemu_put_be64(f, current_addr | RAM_SAVE_FLAG_COMPRESS);
- qemu_put_byte(f, *p);
- } else {
- qemu_put_be64(f, current_addr | RAM_SAVE_FLAG_PAGE);
- qemu_put_buffer(f, p, TARGET_PAGE_SIZE);
+ if (is_dup_page(p, *p)) {
+ qemu_put_be64(f, (page_addr) |
+ RAM_SAVE_FLAG_COMPRESS);
+ qemu_put_byte(f, *p);
+ } else {
+ qemu_put_be64(f, (page_addr) |
+ RAM_SAVE_FLAG_PAGE);
+ qemu_put_buffer(f, p, TARGET_PAGE_SIZE);
+ }
}
-
- found = 1;
+
break;
+ } else {
+ addr += dirty_rams[0];
+ current_addr = (saved_addr + addr) % last_ram_offset;
}
- addr += TARGET_PAGE_SIZE;
- current_addr = (saved_addr + addr) % last_ram_offset;
}

return found;
@@ -2822,12 +2830,19 @@ static uint64_t bytes_transferred;

static ram_addr_t ram_save_remaining(void)
{
- ram_addr_t addr;
+ ram_addr_t addr = 0;
ram_addr_t count = 0;
+ ram_addr_t dirty_rams[HOST_LONG_BITS];
+ int found = 0;

- for (addr = 0; addr < last_ram_offset; addr += TARGET_PAGE_SIZE) {
- if (cpu_physical_memory_get_dirty(addr, MIGRATION_DIRTY_FLAG))
- count++;
+ while (addr < last_ram_offset) {
+ if ((found = cpu_physical_memory_get_dirty_range(addr, last_ram_offset,
+ dirty_rams, HOST_LONG_BITS, MIGRATION_DIRTY_FLAG))) {
+ count += found;
+ addr = dirty_rams[found - 1] + TARGET_PAGE_SIZE;
+ } else {
+ addr += dirty_rams[0];
+ }
}

return count;
--
1.7.0.31.g1df487