Following patch introduces a mutex to protect the migration thread against the
removal of memslots during the guest migration iteration.
Signed-off-by: Umesh Deshpande <udeshpan@xxxxxxxxxx>
---
arch_init.c | 10 ++++++++++
buffered_file.c | 4 ++++
cpu-all.h | 2 ++
cpus.c | 12 ++++++++++++
exec.c | 10 ++++++++++
qemu-common.h | 2 ++
6 files changed, 40 insertions(+), 0 deletions(-)
diff --git a/arch_init.c b/arch_init.c
index 484b39d..f0ddda6 100644
--- a/arch_init.c
+++ b/arch_init.c
@@ -298,6 +298,11 @@ int ram_save_live(Monitor *mon, QEMUFile *f, int stage, void *opaque)
bytes_transferred_last = bytes_transferred;
bwidth = qemu_get_clock_ns(rt_clock);
+ if (stage != 3) {
+ qemu_mutex_lock_ramlist();
+ qemu_mutex_unlock_iothread();
+ }
+
while (!qemu_file_rate_limit(f)) {
int bytes_sent;
@@ -308,6 +313,11 @@ int ram_save_live(Monitor *mon, QEMUFile *f, int stage, void *opaque)
}
}
+ if (stage != 3) {
+ qemu_mutex_lock_iothread();
+ qemu_mutex_unlock_ramlist();
+ }
+
bwidth = qemu_get_clock_ns(rt_clock) - bwidth;
bwidth = (bytes_transferred - bytes_transferred_last) / bwidth;
diff --git a/buffered_file.c b/buffered_file.c
index b64ada7..5735e18 100644
--- a/buffered_file.c
+++ b/buffered_file.c
@@ -243,7 +243,9 @@ static void *migrate_vm(void *opaque)
while (!s->closed) {
if (s->freeze_output) {
+ qemu_mutex_unlock_iothread();
s->wait_for_unfreeze(s);
+ qemu_mutex_lock_iothread();
s->freeze_output = 0;
continue;
}
@@ -255,7 +257,9 @@ static void *migrate_vm(void *opaque)
current_time = qemu_get_clock_ms(rt_clock);
if (!s->closed && (expire_time > current_time)) {
tv.tv_usec = 1000 * (expire_time - current_time);
+ qemu_mutex_unlock_iothread();
select(0, NULL, NULL, NULL, &tv);
+ qemu_mutex_lock_iothread();
continue;
}
diff --git a/cpu-all.h b/cpu-all.h
index e839100..6a5dbb3 100644
--- a/cpu-all.h
+++ b/cpu-all.h
@@ -21,6 +21,7 @@
#include "qemu-common.h"
#include "cpu-common.h"
+#include "qemu-thread.h"
/* some important defines:
*
@@ -931,6 +932,7 @@ typedef struct RAMBlock {
} RAMBlock;
typedef struct RAMList {
+ QemuMutex mutex;
uint8_t *phys_dirty;
QLIST_HEAD(ram, RAMBlock) blocks;
} RAMList;
diff --git a/cpus.c b/cpus.c
index de70e02..6090c44 100644
--- a/cpus.c
+++ b/cpus.c
@@ -666,6 +666,7 @@ int qemu_init_main_loop(void)
qemu_cond_init(&qemu_work_cond);
qemu_mutex_init(&qemu_fair_mutex);
qemu_mutex_init(&qemu_global_mutex);
+ qemu_mutex_init(&ram_list.mutex);
qemu_mutex_lock(&qemu_global_mutex);
qemu_thread_get_self(&io_thread);
@@ -919,6 +920,17 @@ void qemu_mutex_unlock_iothread(void)
qemu_mutex_unlock(&qemu_global_mutex);
}
+void qemu_mutex_lock_ramlist(void)
+{
+ qemu_mutex_lock(&ram_list.mutex);
+}
+
+void qemu_mutex_unlock_ramlist(void)
+{
+ qemu_mutex_unlock(&ram_list.mutex);
+}
+
+
static int all_vcpus_paused(void)
{
CPUState *penv = first_cpu;
diff --git a/exec.c b/exec.c
index 0e2ce57..7bfb36f 100644
--- a/exec.c
+++ b/exec.c
@@ -2972,6 +2972,8 @@ ram_addr_t qemu_ram_alloc_from_ptr(DeviceState *dev, const char *name,
}
new_block->length = size;
+ qemu_mutex_lock_ramlist();
+
QLIST_INSERT_HEAD(&ram_list.blocks, new_block, next);
ram_list.phys_dirty = qemu_realloc(ram_list.phys_dirty,
@@ -2979,6 +2981,8 @@ ram_addr_t qemu_ram_alloc_from_ptr(DeviceState *dev, const char *name,
memset(ram_list.phys_dirty + (new_block->offset >> TARGET_PAGE_BITS),
0xff, size >> TARGET_PAGE_BITS);
+ qemu_mutex_unlock_ramlist();
+
if (kvm_enabled())
kvm_setup_guest_memory(new_block->host, size);
@@ -2996,7 +3000,9 @@ void qemu_ram_free_from_ptr(ram_addr_t addr)
QLIST_FOREACH(block, &ram_list.blocks, next) {
if (addr == block->offset) {
+ qemu_mutex_lock_ramlist();
QLIST_REMOVE(block, next);
+ qemu_mutex_unlock_ramlist();
qemu_free(block);
return;
}
@@ -3009,7 +3015,9 @@ void qemu_ram_free(ram_addr_t addr)
QLIST_FOREACH(block, &ram_list.blocks, next) {
if (addr == block->offset) {
+ qemu_mutex_lock_ramlist();
QLIST_REMOVE(block, next);
+ qemu_mutex_unlock_ramlist();
if (block->flags & RAM_PREALLOC_MASK) {
;
} else if (mem_path) {
@@ -3117,8 +3125,10 @@ void *qemu_get_ram_ptr(ram_addr_t addr)
if (addr - block->offset < block->length) {
/* Move this entry to to start of the list. */
if (block != QLIST_FIRST(&ram_list.blocks)) {
+ qemu_mutex_lock_ramlist();
QLIST_REMOVE(block, next);
QLIST_INSERT_HEAD(&ram_list.blocks, block, next);
+ qemu_mutex_unlock_ramlist();
}
if (xen_mapcache_enabled()) {
/* We need to check if the requested address is in the RAM
diff --git a/qemu-common.h b/qemu-common.h
index abd7a75..b802883 100644
--- a/qemu-common.h
+++ b/qemu-common.h
@@ -212,6 +212,8 @@ char *qemu_strndup(const char *str, size_t size);
void qemu_mutex_lock_iothread(void);
void qemu_mutex_unlock_iothread(void);
+void qemu_mutex_lock_ramlist(void);
+void qemu_mutex_unlock_ramlist(void);
int qemu_open(const char *name, int flags, ...);
ssize_t qemu_write_full(int fd, const void *buf, size_t count)
--
1.7.4.1
--
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