From c2688bae4f871f4ed17f7f415d1e08e8d5d3c18d Mon Sep 17 00:00:00 2001
From: Alex Williamson <alex.williamson@redhat.com>
Date: Tue, 6 Jul 2010 22:28:51 -0300
Subject: [PATCH 13/24] savevm: Use RAM blocks for basis of migration
RH-Author: Alex Williamson <alex.williamson@redhat.com>
Message-id: <20100706222851.1033.84328.stgit@localhost.localdomain>
Patchwork-id: 10516
O-Subject: [RHEL6.0 qemu-kvm PATCH 13/17] savevm: Use RAM blocks for basis of
migration
Bugzilla: 596328
RH-Acked-by: Juan Quintela <quintela@redhat.com>
RH-Acked-by: Amit Shah <amit.shah@redhat.com>
RH-Acked-by: Jes Sorensen <Jes.Sorensen@redhat.com>
Bugzilla: 596328
Upstream commit: e44359c35efbcd5ba9abf94bdd544a744046925a
We don't want to assume a contiguous address space, so migrate based
on RAM blocks instead of a fixed linear address map. This will allow
us to have holes in the ram_addr_t namespace, so we can implement
qemu_ram_free().
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
---
vl.c | 67 +++++++++++++++++++++++++++++++++++++++++-------------------------
1 files changed, 42 insertions(+), 25 deletions(-)
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
---
vl.c | 67 +++++++++++++++++++++++++++++++++++++++++------------------------
1 files changed, 42 insertions(+), 25 deletions(-)
diff --git a/vl.c b/vl.c
index 8947b4a..4e6f293 100644
--- a/vl.c
+++ b/vl.c
@@ -3047,13 +3047,19 @@ static int is_dup_page(uint8_t *page, uint8_t ch)
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();
+ static RAMBlock *last_block = NULL;
+ static ram_addr_t last_offset = 0;
+ RAMBlock *block = last_block;
+ ram_addr_t offset = last_offset;
+ ram_addr_t current_addr;
int found = 0;
- while (addr < total_ram) {
+ if (!block)
+ block = QLIST_FIRST(&ram_list.blocks);
+
+ current_addr = block->offset + offset;
+
+ do {
if (kvm_enabled() && current_addr == 0) {
int r;
r = kvm_update_dirty_pages_log();
@@ -3064,19 +3070,12 @@ static int ram_save_block(QEMUFile *f)
}
}
if (cpu_physical_memory_get_dirty(current_addr, MIGRATION_DIRTY_FLAG)) {
- RAMBlock *block;
- ram_addr_t offset;
uint8_t *p;
cpu_physical_memory_reset_dirty(current_addr,
current_addr + TARGET_PAGE_SIZE,
MIGRATION_DIRTY_FLAG);
- QLIST_FOREACH(block, &ram_list.blocks, next) {
- if (current_addr - block->offset < block->length)
- break;
- }
- offset = current_addr - block->offset;
p = block->host + offset;
if (is_dup_page(p, *p)) {
@@ -3096,9 +3095,21 @@ static int ram_save_block(QEMUFile *f)
found = 1;
break;
}
- addr += TARGET_PAGE_SIZE;
- current_addr = (saved_addr + addr) % total_ram;
- }
+
+ offset += TARGET_PAGE_SIZE;
+ if (offset >= block->length) {
+ offset = 0;
+ block = QLIST_NEXT(block, next);
+ if (!block)
+ block = QLIST_FIRST(&ram_list.blocks);
+ }
+
+ current_addr = block->offset + offset;
+
+ } while (current_addr != last_block->offset + last_offset);
+
+ last_block = block;
+ last_offset = offset;
return found;
}
@@ -3107,13 +3118,16 @@ static uint64_t bytes_transferred;
static ram_addr_t ram_save_remaining(void)
{
- ram_addr_t addr;
+ RAMBlock *block;
ram_addr_t count = 0;
- uint64_t total_ram = ram_bytes_total();
- for (addr = 0; addr < total_ram; addr += TARGET_PAGE_SIZE) {
- if (cpu_physical_memory_get_dirty(addr, MIGRATION_DIRTY_FLAG))
- count++;
+ QLIST_FOREACH(block, &ram_list.blocks, next) {
+ ram_addr_t addr;
+ for (addr = block->offset; addr < block->offset + block->length;
+ addr += TARGET_PAGE_SIZE) {
+ if (cpu_physical_memory_get_dirty(addr, MIGRATION_DIRTY_FLAG))
+ count++;
+ }
}
return count;
@@ -3159,19 +3173,22 @@ static int ram_save_live(Monitor *mon, QEMUFile *f, int stage, void *opaque)
if (stage == 1) {
RAMBlock *block;
- uint64_t total_ram = ram_bytes_total();
bytes_transferred = 0;
/* Make sure all dirty bits are set */
- 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);
+ QLIST_FOREACH(block, &ram_list.blocks, next) {
+ for (addr = block->offset; addr < block->offset + block->length;
+ addr += TARGET_PAGE_SIZE) {
+ if (!cpu_physical_memory_get_dirty(addr,
+ MIGRATION_DIRTY_FLAG))
+ cpu_physical_memory_set_dirty(addr);
+ }
}
/* Enable dirty memory tracking */
cpu_physical_memory_set_dirty_tracking(1);
- qemu_put_be64(f, total_ram | RAM_SAVE_FLAG_MEM_SIZE);
+ qemu_put_be64(f, ram_bytes_total() | RAM_SAVE_FLAG_MEM_SIZE);
QLIST_FOREACH(block, &ram_list.blocks, next) {
qemu_put_byte(f, strlen(block->idstr));
--
1.7.0.3