* [Qemu-devel] [PATCH v17 0/9] XBZRLE delta for live migration of large memory app
@ 2012-07-10 9:37 Orit Wasserman
2012-07-10 9:37 ` [Qemu-devel] [PATCH v17 1/9] Add migration capabilities Orit Wasserman
` (8 more replies)
0 siblings, 9 replies; 11+ messages in thread
From: Orit Wasserman @ 2012-07-10 9:37 UTC (permalink / raw)
To: qemu-devel
Cc: peter.maydell, aliguori, quintela, stefanha, mdroth, blauwirbel,
Orit Wasserman, chegu_vinod, avi, pbonzini, eblake
Changes from v16:
- Change QMP migrate_set_cachesize to migrate-set-cache-size
Changes from v15:
- Fix example in documentation
- Fix identation in qmp-commands.hx
- Fix missing comments from v13
- Fix other comments by Eric Blake
Changes from v14:
- rebase on top on Juan's patches
- Use clz64 to calculate pow2floor (round down to power of 2)
- Fix xbzrle_encode_buffer and xbzrle_decode_buffer
- Fix QMP commands documentation
Changes from v13:
- Fix round to power of 2 of cache size
- Add more checks to the XBZRLE encoding.
- use comparison instead of XOR when calculating zrun_len
- use strcmp trick for calculating nzrun_len (algorithm from Eric Blake)
- Fix other comments by Eric Blake
- Fix comments from Blue Swirl
- Display migration statics after migration completes
Changes from v12:
- use bool for blk and shared params
- use long when decoding buffer
- fix QMP commands
- always display migration parameters in "info migrate"
- update current_addr inside the while loop in ram_save_block
- display statistics after migration completes
- fix other review comments from Eric Blake
Changes from v11:
- divide patch 7 to several smaller patches.
- Use an array for setting migration parameters QMP only (there
is not support for arrays in HMP commands). parameters can be enabled
or disabled.
- Do not use XBZRLE in stage 3 , it is a very sensitive stage and CPU
can be an issue.
- Fix review comments by Juan Quintela and Eric Blake
Changes from v10:
- Cache size will be in bytes, in case it is not a power of 2 it will be
reduced to the nearest power of 2.
- fix documentation
- use cache_init with number of pages not cache size.
Changes from v9:
- move cache implementation to separate files. Kept our own implementation because GCache or GHashTable have no size limit.
- Add migrate_set_parameter function
- removed XBZRLE option from migrate command
- add cache size information to query_migrate command
- add documantation file
- write/read the exact XBZRLE header format
- fix other review comments by Anthony and Juan
Changes from v8:
Implement more effiecent cache_resize method
fix set_cachesize command
Changes from v7:
Copy current page before encoding it, this will prevents page content
change during the encoding.
Allow changing the cache size during an active migration.
Fix comments by Avi.
Changes from v6:
1) add assert checks to ULEB encoding/decoding
2) no need to send last zero run
Changes from v5:
1) Add migration capabilities
2) Use ULEB to encode run length
3) Do not send unmodified (dirty) page
3) Fix other patch comments
Using GCache or GHashTable requires allocating new buffer on every content change and have no size limit ,
so I decided to keep the simple cache implementation.
Changes from v4:
1) Rebase
2) divide patch into 9 patches
3) move memory allocation into cache_insert
Future work :
Use SSE for encoding.
Page ranking acording to their dirty rate and automatic activation/deactivation of the feature - will be sent in a separate patch series.
By using XBZRLE (Xor Based Zero Run Length Encoding) we can reduce VM downtime
and total live-migration time of VMs running memory write intensive workloads
typical of large enterprise applications such as SAP ERP Systems, and generally
speaking for any application with a sparse memory update pattern.
The compression format uses the fact that we will have many zero (zero represents
an unchanged value).
We repesent the page data delta by zero and non zero runs.
We represent a zero run with it's length (in bytes).
We represent a non zero run with it's length (in bytes) and the data.
The run length is encoded using ULEB128 (http://en.wikipedia.org/wiki/LEB128)
page = zrun nzrun
| zrun nzrun page
zrun = length
nzrun = length byte...
length = uleb128 encoded integer
On the sender side XBZRLE is used as a compact delta encoding of page updates,
retrieving the old page content from an LRU cache (default size of 512 MB). The
receiving side uses the existing page content and XBZRLE to decode the new page
content.
This is a more compact way to store the delta than the previous version.
This work was originally based on research results published VEE 2011: Evaluation of
Delta Compression Techniques for Efficient Live Migration of Large Virtual
Machines by Benoit, Svard, Tordsson and Elmroth. Additionally the delta encoder
XBRLE was improved further using XBZRLE instead.
XBZRLE has a sustained bandwidth of 2-2.5 GB/s for typical workloads making it
ideal for in-line, real-time encoding such as is needed for live-migration.
A typical usage scenario:
On incoming QEMU:
{qemu} migrate_set_parameter xbzrle on
On outgoing QEMU:
{qemu} migrate_set_parameter xbzrle on
{qemu} migrate_set_cachesize 256m
{qemu} migrate -d tcp:destination.host:4444
{qemu} info migrate
...
cache size : 64 MBytes
transferred ram: A kbytes
remaining ram: B kbytes
total ram: C kbytes
cache size: D bytes
xbzrle transferred: E kbytes
xbzrle pages: F pages
xbzrle cache miss: G
xbzrle overflow : H
Testing: live migration with XBZRLE completed in 110 seconds, without live
migration was not able to complete.
A simple synthetic memory r/w load generator:
.. include <stdlib.h>
.. include <stdio.h>
.. int main()
.. {
.. char *buf = (char *) calloc(4096, 4096);
.. while (1) {
.. int i;
.. for (i = 0; i < 4096 * 4; i++) {
.. buf[i * 4096 / 4]++;
.. }
.. printf(".");
.. }
.. }
Orit Wasserman (9):
Add migration capabilities
Add XBZRLE documentation
Add cache handling functions
Add uleb encoding/decoding functions
Change ram_save_block to return -1 if there are no more changes
Add xbzrle_encode_buffer and xbzrle_decode_buffer functions
Add XBZRLE to ram_save_block and ram_save_live
Add migrate_set_cachesize command
Add XBZRLE statistics
Makefile.objs | 1 +
arch_init.c | 272 ++++++++++++++++++++++++++++++++++++++++++++++++++++--
cutils.c | 42 +++++++++
docs/xbzrle.txt | 136 +++++++++++++++++++++++++++
hmp-commands.hx | 36 +++++++
hmp.c | 90 ++++++++++++++++++
hmp.h | 3 +
migration.c | 159 +++++++++++++++++++++++++++++++-
migration.h | 21 ++++
monitor.c | 7 ++
qapi-schema.json | 102 +++++++++++++++++++-
qemu-common.h | 21 ++++
qmp-commands.hx | 127 +++++++++++++++++++++++++-
savevm.c | 159 +++++++++++++++++++++++++++++++
14 files changed, 1158 insertions(+), 18 deletions(-)
create mode 100644 docs/xbzrle.txt
--
1.7.7.6
^ permalink raw reply [flat|nested] 11+ messages in thread
* [Qemu-devel] [PATCH v17 1/9] Add migration capabilities
2012-07-10 9:37 [Qemu-devel] [PATCH v17 0/9] XBZRLE delta for live migration of large memory app Orit Wasserman
@ 2012-07-10 9:37 ` Orit Wasserman
2012-07-10 9:37 ` [Qemu-devel] [PATCH v17 2/9] Add XBZRLE documentation Orit Wasserman
` (7 subsequent siblings)
8 siblings, 0 replies; 11+ messages in thread
From: Orit Wasserman @ 2012-07-10 9:37 UTC (permalink / raw)
To: qemu-devel
Cc: peter.maydell, aliguori, quintela, stefanha, mdroth, blauwirbel,
Orit Wasserman, chegu_vinod, avi, pbonzini, eblake
Add migration capabilities that can be queried by the management.
The management can query the source QEMU and the destination QEMU in order to
verify both support some migration capability (currently only XBZRLE).
The management can enable a capability for the next migration by using
migrate_set_parameter command.
Signed-off-by: Orit Wasserman <owasserm@redhat.com>
---
hmp-commands.hx | 16 ++++++++++++
hmp.c | 64 ++++++++++++++++++++++++++++++++++++++++++++++++
hmp.h | 2 +
migration.c | 72 ++++++++++++++++++++++++++++++++++++++++++++++++++++-
migration.h | 2 +
monitor.c | 7 +++++
qapi-schema.json | 53 ++++++++++++++++++++++++++++++++++++++-
qmp-commands.hx | 71 +++++++++++++++++++++++++++++++++++++++++++++++++++--
8 files changed, 280 insertions(+), 7 deletions(-)
diff --git a/hmp-commands.hx b/hmp-commands.hx
index f5d9d91..9245bef 100644
--- a/hmp-commands.hx
+++ b/hmp-commands.hx
@@ -861,6 +861,20 @@ Set maximum tolerated downtime (in seconds) for migration.
ETEXI
{
+ .name = "migrate_set_parameter",
+ .args_type = "capability:s,state:b",
+ .params = "",
+ .help = "Enable/Disable the usage of a capability for migration",
+ .mhandler.cmd = hmp_migrate_set_parameter,
+ },
+
+STEXI
+@item migrate_set_parameter @var{capability} @var{state}
+@findex migrate_set_parameter
+Enable/Disable the usage of a capability @var{capability} for migration.
+ETEXI
+
+ {
.name = "client_migrate_info",
.args_type = "protocol:s,hostname:s,port:i?,tls-port:i?,cert-subject:s?",
.params = "protocol hostname port tls-port cert-subject",
@@ -1419,6 +1433,8 @@ show CPU statistics
show user network stack connection states
@item info migrate
show migration status
+@item info migration_capabilities
+show migration capabilities
@item info balloon
show balloon information
@item info qtree
diff --git a/hmp.c b/hmp.c
index 4c6d4ae..b0440e6 100644
--- a/hmp.c
+++ b/hmp.c
@@ -131,9 +131,19 @@ void hmp_info_mice(Monitor *mon)
void hmp_info_migrate(Monitor *mon)
{
MigrationInfo *info;
+ MigrationCapabilityInfoList *cap;
info = qmp_query_migrate(NULL);
+ if (info->has_capabilities && info->capabilities) {
+ monitor_printf(mon, "capabilities: ");
+ for (cap = info->capabilities; cap; cap = cap->next) {
+ monitor_printf(mon, "%s: %s ",
+ MigrationCapability_lookup[cap->value->capability],
+ cap->value->state ? "on" : "off");
+ }
+ monitor_printf(mon, "\n");
+ }
if (info->has_status) {
monitor_printf(mon, "Migration status: %s\n", info->status);
}
@@ -161,6 +171,25 @@ void hmp_info_migrate(Monitor *mon)
qapi_free_MigrationInfo(info);
}
+void hmp_info_migration_capabilities(Monitor *mon)
+{
+ MigrationCapabilityInfoList *caps_list, *cap;
+
+ caps_list = qmp_query_migration_capabilities(NULL);
+ if (!caps_list) {
+ monitor_printf(mon, "No migration capabilities found\n");
+ return;
+ }
+
+ for (cap = caps_list; cap; cap = cap->next) {
+ monitor_printf(mon, "%s: %s ",
+ MigrationCapability_lookup[cap->value->capability],
+ cap->value->state ? "on" : "off");
+ }
+
+ qapi_free_MigrationCapabilityInfoList(caps_list);
+}
+
void hmp_info_cpus(Monitor *mon)
{
CpuInfoList *cpu_list, *cpu;
@@ -735,6 +764,41 @@ void hmp_migrate_set_speed(Monitor *mon, const QDict *qdict)
qmp_migrate_set_speed(value, NULL);
}
+void hmp_migrate_set_parameter(Monitor *mon, const QDict *qdict)
+{
+ const char *cap = qdict_get_str(qdict, "capability");
+ bool state = qdict_get_bool(qdict, "state");
+ Error *err = NULL;
+ MigrationCapabilityInfoList *params = NULL;
+ int i;
+
+ for (i = 0; i < MIGRATION_CAPABILITY_MAX; i++) {
+ if (strcmp(cap, MigrationCapability_lookup[i]) == 0) {
+ if (!params) {
+ params = g_malloc0(sizeof(*params));
+ }
+ params->value = g_malloc0(sizeof(*params->value));
+ params->value->capability = i;
+ params->value->state = state;
+ params->next = NULL;
+ qmp_migrate_set_parameters(params, &err);
+ break;
+ }
+ }
+
+ if (i == MIGRATION_CAPABILITY_MAX) {
+ error_set(&err, QERR_INVALID_PARAMETER, cap);
+ }
+
+ qapi_free_MigrationCapabilityInfoList(params);
+
+ if (err) {
+ monitor_printf(mon, "migrate_set_parameter: %s\n",
+ error_get_pretty(err));
+ error_free(err);
+ }
+}
+
void hmp_set_password(Monitor *mon, const QDict *qdict)
{
const char *protocol = qdict_get_str(qdict, "protocol");
diff --git a/hmp.h b/hmp.h
index 79d138d..09ba198 100644
--- a/hmp.h
+++ b/hmp.h
@@ -25,6 +25,7 @@ void hmp_info_uuid(Monitor *mon);
void hmp_info_chardev(Monitor *mon);
void hmp_info_mice(Monitor *mon);
void hmp_info_migrate(Monitor *mon);
+void hmp_info_migration_capabilities(Monitor *mon);
void hmp_info_cpus(Monitor *mon);
void hmp_info_block(Monitor *mon);
void hmp_info_blockstats(Monitor *mon);
@@ -51,6 +52,7 @@ void hmp_snapshot_blkdev(Monitor *mon, const QDict *qdict);
void hmp_migrate_cancel(Monitor *mon, const QDict *qdict);
void hmp_migrate_set_downtime(Monitor *mon, const QDict *qdict);
void hmp_migrate_set_speed(Monitor *mon, const QDict *qdict);
+void hmp_migrate_set_parameter(Monitor *mon, const QDict *qdict);
void hmp_set_password(Monitor *mon, const QDict *qdict);
void hmp_expire_password(Monitor *mon, const QDict *qdict);
void hmp_eject(Monitor *mon, const QDict *qdict);
diff --git a/migration.c b/migration.c
index 8db1b43..fd004d7 100644
--- a/migration.c
+++ b/migration.c
@@ -117,12 +117,36 @@ MigrationInfo *qmp_query_migrate(Error **errp)
{
MigrationInfo *info = g_malloc0(sizeof(*info));
MigrationState *s = migrate_get_current();
+ int i;
switch (s->state) {
case MIG_STATE_SETUP:
- /* no migration has happened ever */
+ /* no migration has ever happened; show enabled capabilities */
+ for (i = 0; i < MIGRATION_CAPABILITY_MAX; i++) {
+ if (!info->has_capabilities) {
+ info->capabilities = g_malloc0(sizeof(*info->capabilities));
+ info->has_capabilities = true;
+ }
+ info->capabilities->value =
+ g_malloc(sizeof(*info->capabilities->value));
+ info->capabilities->value->capability = i;
+ info->capabilities->value->state = s->enabled_capabilities[i];
+ info->capabilities->next = NULL;
+ }
break;
case MIG_STATE_ACTIVE:
+ for (i = 0; i < MIGRATION_CAPABILITY_MAX; i++) {
+ if (!info->has_capabilities) {
+ info->capabilities = g_malloc0(sizeof(*info->capabilities));
+ info->has_capabilities = true;
+ }
+ info->capabilities->value =
+ g_malloc(sizeof(*info->capabilities->value));
+ info->capabilities->value->capability = i;
+ info->capabilities->value->state = s->enabled_capabilities[i];
+ info->capabilities->next = NULL;
+ }
+
info->has_status = true;
info->status = g_strdup("active");
@@ -143,6 +167,18 @@ MigrationInfo *qmp_query_migrate(Error **errp)
}
break;
case MIG_STATE_COMPLETED:
+ for (i = 0; i < MIGRATION_CAPABILITY_MAX; i++) {
+ if (!info->has_capabilities) {
+ info->capabilities = g_malloc0(sizeof(*info->capabilities));
+ info->has_capabilities = true;
+ }
+ info->capabilities->value =
+ g_malloc(sizeof(*info->capabilities->value));
+ info->capabilities->value->capability = i;
+ info->capabilities->value->state = s->enabled_capabilities[i];
+ info->capabilities->next = NULL;
+ }
+
info->has_status = true;
info->status = g_strdup("completed");
@@ -166,6 +202,33 @@ MigrationInfo *qmp_query_migrate(Error **errp)
return info;
}
+MigrationCapabilityInfoList *qmp_query_migration_capabilities(Error **errp)
+{
+ MigrationCapabilityInfoList *caps_list = g_malloc0(sizeof(*caps_list));
+
+ caps_list->value = g_malloc(sizeof(*caps_list->value));
+ caps_list->value->capability = MIGRATION_CAPABILITY_XBZRLE;
+ caps_list->next = NULL;
+
+ return caps_list;
+}
+
+void qmp_migrate_set_parameters(MigrationCapabilityInfoList *params,
+ Error **errp)
+{
+ MigrationState *s = migrate_get_current();
+ MigrationCapabilityInfoList *cap;
+
+ if (s->state == MIG_STATE_ACTIVE) {
+ error_set(errp, QERR_MIGRATION_ACTIVE);
+ return;
+ }
+
+ for (cap = params; cap; cap = cap->next) {
+ s->enabled_capabilities[cap->value->capability] = cap->value->state;
+ }
+}
+
/* shared migration helpers */
static int migrate_fd_cleanup(MigrationState *s)
@@ -375,12 +438,17 @@ static MigrationState *migrate_init(const MigrationParams *params)
{
MigrationState *s = migrate_get_current();
int64_t bandwidth_limit = s->bandwidth_limit;
+ bool enabled_capabilities[MIGRATION_CAPABILITY_MAX];
+
+ memcpy(enabled_capabilities, s->enabled_capabilities,
+ sizeof(enabled_capabilities));
memset(s, 0, sizeof(*s));
s->bandwidth_limit = bandwidth_limit;
s->params = *params;
+ memcpy(s->enabled_capabilities, enabled_capabilities,
+ sizeof(enabled_capabilities));
- s->bandwidth_limit = bandwidth_limit;
s->state = MIG_STATE_SETUP;
s->total_time = qemu_get_clock_ms(rt_clock);
diff --git a/migration.h b/migration.h
index de13004..acc0b94 100644
--- a/migration.h
+++ b/migration.h
@@ -18,6 +18,7 @@
#include "qemu-common.h"
#include "notify.h"
#include "error.h"
+#include "qapi-types.h"
struct MigrationParams {
bool blk;
@@ -38,6 +39,7 @@ struct MigrationState
void *opaque;
MigrationParams params;
int64_t total_time;
+ bool enabled_capabilities[MIGRATION_CAPABILITY_MAX];
};
void process_incoming_migration(QEMUFile *f);
diff --git a/monitor.c b/monitor.c
index f6107ba..e2be6cd 100644
--- a/monitor.c
+++ b/monitor.c
@@ -2687,6 +2687,13 @@ static mon_cmd_t info_cmds[] = {
.mhandler.info = hmp_info_migrate,
},
{
+ .name = "migration_capabilities",
+ .args_type = "",
+ .params = "",
+ .help = "show migration capabilities",
+ .mhandler.info = hmp_info_migration_capabilities,
+ },
+ {
.name = "balloon",
.args_type = "",
.params = "",
diff --git a/qapi-schema.json b/qapi-schema.json
index 1ab5dbd..a8408fd 100644
--- a/qapi-schema.json
+++ b/qapi-schema.json
@@ -288,11 +288,15 @@
# status, only returned if status is 'active' and it is a block
# migration
#
-# Since: 0.14.0
+# @capabilities: #optional a list describing all the migration capabilities
+# state
+#
+# Since: 0.14.0, 'capabilities' since 1.2
##
{ 'type': 'MigrationInfo',
'data': {'*status': 'str', '*ram': 'MigrationStats',
- '*disk': 'MigrationStats'} }
+ '*disk': 'MigrationStats',
+ '*capabilities': ['MigrationCapabilityInfo']} }
##
# @query-migrate
@@ -306,6 +310,51 @@
{ 'command': 'query-migrate', 'returns': 'MigrationInfo' }
##
+# @MigrationCapability
+#
+# Migration capabilities enumeration
+#
+# @xbzrle: current migration supports xbzrle
+#
+# Since: 1.2
+##
+{ 'enum': 'MigrationCapability',
+ 'data': ['xbzrle'] }
+
+##
+# @MigrationCapabilityInfo
+#
+# Migration capability information
+#
+# @capability: capability enum
+#
+# Since: 1.2
+##
+{ 'type': 'MigrationCapabilityInfo',
+ 'data': { 'capability' : 'MigrationCapability', 'state' : 'bool' } }
+
+##
+# @query-migration-capabilities
+#
+# Returns information about current migration process capabilties.
+#
+# Returns: @MigrationCapabilityInfo list
+#
+# Since: 1.2
+##
+{ 'command': 'query-migration-capabilities', 'returns': ['MigrationCapabilityInfo'] }
+
+##
+# @migrate_set_parameters
+#
+# Enable/Disable the following migration capabilities (like xbzrle)
+#
+# Since: 1.2
+##
+{ 'command': 'migrate-set-parameters',
+ 'data': { 'capabilities': ['MigrationCapabilityInfo'] } }
+
+##
# @MouseInfo:
#
# Information about a mouse device.
diff --git a/qmp-commands.hx b/qmp-commands.hx
index 2e1a38e..3ee6e00 100644
--- a/qmp-commands.hx
+++ b/qmp-commands.hx
@@ -2075,18 +2075,31 @@ The main json-object contains the following:
- "transferred": amount transferred (json-int)
- "remaining": amount remaining (json-int)
- "total": total (json-int)
-
+- "capabilities": migration capabilities state
+ - "xbzrle" : XBZRLE state (json-bool)
Examples:
1. Before the first migration
-> { "execute": "query-migrate" }
-<- { "return": {} }
+<- { "return": {
+ "capabilities" : [ { "capability" : "xbzrle", "state" : false } ]
+ }
+ }
2. Migration is done and has succeeded
-> { "execute": "query-migrate" }
-<- { "return": { "status": "completed" } }
+<- { "return": {
+ "status": "completed",
+ "capabilities": [ { "capability" : "xbzrle", "state" : false } ],
+ "ram":{
+ "transferred":123,
+ "remaining":123,
+ "total":246
+ }
+ }
+ }
3. Migration is done and has failed
@@ -2099,6 +2112,7 @@ Examples:
<- {
"return":{
"status":"active",
+ "capabilities": [ { "capability" : "xbzrle", "state" : false } ],
"ram":{
"transferred":123,
"remaining":123,
@@ -2113,6 +2127,7 @@ Examples:
<- {
"return":{
"status":"active",
+ "capabilities": [ { "capability" : "xbzrle", "state" : false } ],
"ram":{
"total":1057024,
"remaining":1053304,
@@ -2135,6 +2150,56 @@ EQMP
},
SQMP
+query-migration-capabilities
+-------
+
+Query migration capabilities
+
+- "xbzrle": xbzrle support
+
+Arguments:
+
+Example:
+
+-> { "execute": "query-migration-capabilities"}
+<- { "return": [ { "capability": "xbzrle", "state": true },
+ { "capability": "foobar", "state": false } ] }
+
+EQMP
+
+ {
+ .name = "query-migration-capabilities",
+ .args_type = "",
+ .mhandler.cmd_new = qmp_marshal_input_query_migration_capabilities,
+ },
+
+SQMP
+migrate_set_parameters
+-------
+
+Enable/Disable migration capabilities
+
+- "xbzrle": xbzrle support
+
+Arguments:
+
+Example:
+
+-> { "execute": "migrate_set_parameters" , "arguments":
+ { "parameters": [ { "capability": "xbzrle", "state": true } ] } }
+
+EQMP
+
+ {
+ .name = "migrate_set_parameters",
+ .args_type = "parameters:O",
+ .params = "capability:s,state:b",
+ .mhandler.cmd_new = qmp_marshal_input_migrate_set_parameters,
+ },
+
+
+
+SQMP
query-balloon
-------------
--
1.7.7.6
^ permalink raw reply related [flat|nested] 11+ messages in thread
* [Qemu-devel] [PATCH v17 2/9] Add XBZRLE documentation
2012-07-10 9:37 [Qemu-devel] [PATCH v17 0/9] XBZRLE delta for live migration of large memory app Orit Wasserman
2012-07-10 9:37 ` [Qemu-devel] [PATCH v17 1/9] Add migration capabilities Orit Wasserman
@ 2012-07-10 9:37 ` Orit Wasserman
2012-07-10 9:37 ` [Qemu-devel] [PATCH v17 3/9] Add cache handling functions Orit Wasserman
` (6 subsequent siblings)
8 siblings, 0 replies; 11+ messages in thread
From: Orit Wasserman @ 2012-07-10 9:37 UTC (permalink / raw)
To: qemu-devel
Cc: peter.maydell, aliguori, quintela, stefanha, mdroth, blauwirbel,
Orit Wasserman, chegu_vinod, avi, pbonzini, eblake
Signed-off-by: Orit Wasserman <owasserm@redhat.com>
---
docs/xbzrle.txt | 136 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
1 files changed, 136 insertions(+), 0 deletions(-)
create mode 100644 docs/xbzrle.txt
diff --git a/docs/xbzrle.txt b/docs/xbzrle.txt
new file mode 100644
index 0000000..f70e851
--- /dev/null
+++ b/docs/xbzrle.txt
@@ -0,0 +1,136 @@
+XBZRLE (Xor Based Zero Run Length Encoding)
+===========================================
+
+Using XBZRLE (Xor Based Zero Run Length Encoding) allows for the reduction
+of VM downtime and the total live-migration time of Virtual machines.
+It is particularly useful for virtual machines running memory write intensive
+workloads that are typical of large enterprise applications such as SAP ERP
+Systems, and generally speaking for any application that uses a sparse memory
+update pattern.
+
+Instead of sending the changed guest memory page this solution will send a
+compressed version of the updates, thus reducing the amount of data sent during
+live migration.
+In order to be able to calculate the update, the previous memory pages need to
+be stored on the source. Those pages are stored in a dedicated cache
+(hash table) and are
+accessed by their address.
+The larger the cache size the better the chances are that the page has already
+been stored in the cache.
+A small cache size will result in high cache miss rate.
+Cache size can be changed before and during migration.
+
+Format
+=======
+
+The compression format performs a XOR between the previous and current content
+of the page, where zero represents an unchanged value.
+The page data delta is represented by zero and non zero runs.
+A zero run is represented by its length (in bytes).
+A non zero run is represented by its length (in bytes) and the new data.
+The run length is encoded using ULEB128 (http://en.wikipedia.org/wiki/LEB128)
+
+There can be more than one valid encoding, the sender may send a longer encoding
+for the benefit of reducing computation cost.
+
+page = zrun nzrun
+ | zrun nzrun page
+
+zrun = length
+
+nzrun = length byte...
+
+length = uleb128 encoded integer
+
+On the sender side XBZRLE is used as a compact delta encoding of page updates,
+retrieving the old page content from the cache (default size of 512 MB). The
+receiving side uses the existing page's content and XBZRLE to decode the new
+page's content.
+
+This work was originally based on research results published
+VEE 2011: Evaluation of Delta Compression Techniques for Efficient Live
+Migration of Large Virtual Machines by Benoit, Svard, Tordsson and Elmroth.
+Additionally the delta encoder XBRLE was improved further using the XBZRLE
+instead.
+
+XBZRLE has a sustained bandwidth of 2-2.5 GB/s for typical workloads making it
+ideal for in-line, real-time encoding such as is needed for live-migration.
+
+Example
+old buffer:
+1001 zeros
+05 06 07 08 09 0a 0b 0c 0d 0e 0f 10 11 12 13 68 00 00 6b 00 6d
+3074 zeros
+
+new buffer:
+1001 zeros
+01 02 03 04 05 06 07 08 09 0a 0b 0c 0d 0e 0f 68 00 00 67 00 69
+3074 zeros
+
+encoded buffer:
+
+encoded length 24
+e9 07 0f 01 02 03 04 05 06 07 08 09 0a 0b 0c 0d 0e 0f 03 01 67 01 01 69
+
+Migration Capabilities
+======================
+In order to use XBZRLE the destination QEMU version should be able to
+decode the new format.
+Adding a new migration capabilities command that will allow external management
+to query for it support.
+A typical use for the destination
+ {qemu} info migrate_capabilities
+ {qemu} xbzrle, ...
+
+In order to enable capabilities for future live migration,
+a new command migrate_set_parameter is introduced:
+ {qemu} migrate_set_parameter xbzrle
+
+Usage
+======
+
+1. Activate xbzrle
+2. Set the XBZRLE cache size - the cache size is in MBytes and should be a
+power of 2. The cache default value is 64MBytes.
+3. start outgoing migration
+
+A typical usage scenario:
+On the incoming QEMU:
+ {qemu} migrate_set_parameter xbzrle on
+On the outgoing QEMU:
+ {qemu} migrate_set_parameter xbzrle on
+ {qemu} migrate_set_cachesize 256m
+ {qemu} migrate -d tcp:destination.host:4444
+ {qemu} info migrate
+ ...
+ cache size: 67108864 bytes
+ transferred ram-duplicate: A kbytes
+ transferred ram-normal: B kbytes
+ transferred ram-xbrle: C kbytes
+ overflow ram-xbrle: D pages
+ cache-miss ram-xbrle: E pages
+
+cache-miss: the number of cache misses to date - high cache-miss rate
+indicates that the cache size is set too low.
+overflow: the number of overflows in the decoding which where the delta could
+not be compressed. This can happen if the changes in the pages are too large
+or there are many short changes; for example, changing every second byte (half a
+page).
+
+Testing: Testing indicated that live migration with XBZRLE was completed in 110
+seconds, whereas without it would not be able to complete.
+
+A simple synthetic memory r/w load generator:
+.. include <stdlib.h>
+.. include <stdio.h>
+.. int main()
+.. {
+.. char *buf = (char *) calloc(4096, 4096);
+.. while (1) {
+.. int i;
+.. for (i = 0; i < 4096 * 4; i++) {
+.. buf[i * 4096 / 4]++;
+.. }
+.. printf(".");
+.. }
+.. }
--
1.7.7.6
^ permalink raw reply related [flat|nested] 11+ messages in thread
* [Qemu-devel] [PATCH v17 3/9] Add cache handling functions
2012-07-10 9:37 [Qemu-devel] [PATCH v17 0/9] XBZRLE delta for live migration of large memory app Orit Wasserman
2012-07-10 9:37 ` [Qemu-devel] [PATCH v17 1/9] Add migration capabilities Orit Wasserman
2012-07-10 9:37 ` [Qemu-devel] [PATCH v17 2/9] Add XBZRLE documentation Orit Wasserman
@ 2012-07-10 9:37 ` Orit Wasserman
2012-07-10 19:16 ` Orit Wasserman
2012-07-10 9:37 ` [Qemu-devel] [PATCH v17 4/9] Add uleb encoding/decoding functions Orit Wasserman
` (5 subsequent siblings)
8 siblings, 1 reply; 11+ messages in thread
From: Orit Wasserman @ 2012-07-10 9:37 UTC (permalink / raw)
To: qemu-devel
Cc: peter.maydell, aliguori, quintela, Petter Svard, stefanha,
mdroth, Benoit Hudzia, blauwirbel, Orit Wasserman, chegu_vinod,
avi, Aidan Shribman, pbonzini, eblake
Add LRU page cache mechanism.
The page are accessed by their address.
Signed-off-by: Benoit Hudzia <benoit.hudzia@sap.com>
Signed-off-by: Petter Svard <petters@cs.umu.se>
Signed-off-by: Aidan Shribman <aidan.shribman@sap.com>
Signed-off-by: Orit Wasserman <owasserm@redhat.com>
---
Makefile.objs | 1 +
cutils.c | 9 +++++++++
qemu-common.h | 13 +++++++++++++
3 files changed, 23 insertions(+), 0 deletions(-)
diff --git a/Makefile.objs b/Makefile.objs
index 5ebbcfa..e0fb69b 100644
--- a/Makefile.objs
+++ b/Makefile.objs
@@ -77,6 +77,7 @@ common-obj-y += qemu-char.o #aio.o
common-obj-y += block-migration.o iohandler.o
common-obj-y += pflib.o
common-obj-y += bitmap.o bitops.o
+common-obj-y += page_cache.o
common-obj-$(CONFIG_POSIX) += migration-exec.o migration-unix.o migration-fd.o
common-obj-$(CONFIG_WIN32) += version.o
diff --git a/cutils.c b/cutils.c
index e2bc1b8..b0bdd4b 100644
--- a/cutils.c
+++ b/cutils.c
@@ -375,3 +375,12 @@ int qemu_parse_fd(const char *param)
}
return fd;
}
+
+/* round down to the nearest power of 2*/
+int64_t pow2floor(int64_t value)
+{
+ if (!is_power_of_2(value)) {
+ value = 0x8000000000000000ULL >> clz64(value);
+ }
+ return value;
+}
diff --git a/qemu-common.h b/qemu-common.h
index 09676f5..195bab5 100644
--- a/qemu-common.h
+++ b/qemu-common.h
@@ -1,3 +1,4 @@
+
/* Common header file that is included by all of qemu. */
#ifndef QEMU_COMMON_H
#define QEMU_COMMON_H
@@ -411,6 +412,18 @@ static inline uint64_t muldiv64(uint64_t a, uint32_t b, uint32_t c)
/* Round number up to multiple */
#define QEMU_ALIGN_UP(n, m) QEMU_ALIGN_DOWN((n) + (m) - 1, (m))
+static inline bool is_power_of_2(int64_t value)
+{
+ if (!value) {
+ return 0;
+ }
+
+ return !(value & (value - 1));
+}
+
+/* round down to the nearest power of 2*/
+int64_t pow2floor(int64_t value);
+
#include "module.h"
#endif
--
1.7.7.6
^ permalink raw reply related [flat|nested] 11+ messages in thread
* [Qemu-devel] [PATCH v17 4/9] Add uleb encoding/decoding functions
2012-07-10 9:37 [Qemu-devel] [PATCH v17 0/9] XBZRLE delta for live migration of large memory app Orit Wasserman
` (2 preceding siblings ...)
2012-07-10 9:37 ` [Qemu-devel] [PATCH v17 3/9] Add cache handling functions Orit Wasserman
@ 2012-07-10 9:37 ` Orit Wasserman
2012-07-10 9:37 ` [Qemu-devel] [PATCH v17 5/9] Change ram_save_block to return -1 if there are no more changes Orit Wasserman
` (4 subsequent siblings)
8 siblings, 0 replies; 11+ messages in thread
From: Orit Wasserman @ 2012-07-10 9:37 UTC (permalink / raw)
To: qemu-devel
Cc: peter.maydell, aliguori, quintela, stefanha, mdroth, blauwirbel,
Orit Wasserman, chegu_vinod, avi, pbonzini, eblake
Implement Unsigned Little Endian Base 128.
Signed-off-by: Orit Wasserman <owasserm@redhat.com>
---
cutils.c | 33 +++++++++++++++++++++++++++++++++
qemu-common.h | 8 ++++++++
2 files changed, 41 insertions(+), 0 deletions(-)
diff --git a/cutils.c b/cutils.c
index b0bdd4b..700f943 100644
--- a/cutils.c
+++ b/cutils.c
@@ -384,3 +384,36 @@ int64_t pow2floor(int64_t value)
}
return value;
}
+
+/*
+ * Implementation of ULEB128 (http://en.wikipedia.org/wiki/LEB128)
+ * Input is limited to 14-bit numbers
+ */
+int uleb128_encode_small(uint8_t *out, uint32_t n)
+{
+ g_assert(n <= 0x3fff);
+ if (n < 0x80) {
+ *out++ = n;
+ return 1;
+ } else {
+ *out++ = (n & 0x7f) | 0x80;
+ *out++ = n >> 7;
+ return 2;
+ }
+}
+
+int uleb128_decode_small(const uint8_t *in, uint32_t *n)
+{
+ if (!(*in & 0x80)) {
+ *n = *in++;
+ return 1;
+ } else {
+ *n = *in++ & 0x7f;
+ /* we exceed 14 bit number */
+ if (*in & 0x80) {
+ return -1;
+ }
+ *n |= *in++ << 7;
+ return 2;
+ }
+}
diff --git a/qemu-common.h b/qemu-common.h
index 195bab5..3188bdd 100644
--- a/qemu-common.h
+++ b/qemu-common.h
@@ -426,4 +426,12 @@ int64_t pow2floor(int64_t value);
#include "module.h"
+/*
+ * Implementation of ULEB128 (http://en.wikipedia.org/wiki/LEB128)
+ * Input is limited to 14-bit numbers
+ */
+
+int uleb128_encode_small(uint8_t *out, uint32_t n);
+int uleb128_decode_small(const uint8_t *in, uint32_t *n);
+
#endif
--
1.7.7.6
^ permalink raw reply related [flat|nested] 11+ messages in thread
* [Qemu-devel] [PATCH v17 5/9] Change ram_save_block to return -1 if there are no more changes
2012-07-10 9:37 [Qemu-devel] [PATCH v17 0/9] XBZRLE delta for live migration of large memory app Orit Wasserman
` (3 preceding siblings ...)
2012-07-10 9:37 ` [Qemu-devel] [PATCH v17 4/9] Add uleb encoding/decoding functions Orit Wasserman
@ 2012-07-10 9:37 ` Orit Wasserman
2012-07-10 9:37 ` [Qemu-devel] [PATCH v17 6/9] Add xbzrle_encode_buffer and xbzrle_decode_buffer functions Orit Wasserman
` (3 subsequent siblings)
8 siblings, 0 replies; 11+ messages in thread
From: Orit Wasserman @ 2012-07-10 9:37 UTC (permalink / raw)
To: qemu-devel
Cc: peter.maydell, aliguori, quintela, stefanha, mdroth, blauwirbel,
Orit Wasserman, chegu_vinod, avi, pbonzini, eblake
It will return 0 if the page is unmodifed.
Signed-off-by: Orit Wasserman <owasserm@redhat.com>
---
arch_init.c | 11 +++++++----
1 files changed, 7 insertions(+), 4 deletions(-)
diff --git a/arch_init.c b/arch_init.c
index 5b0f562..91e583f 100644
--- a/arch_init.c
+++ b/arch_init.c
@@ -188,7 +188,7 @@ static int ram_save_block(QEMUFile *f)
{
RAMBlock *block = last_block;
ram_addr_t offset = last_offset;
- int bytes_sent = 0;
+ int bytes_sent = -1;
MemoryRegion *mr;
if (!block)
@@ -349,8 +349,11 @@ int ram_save_live(QEMUFile *f, int stage, void *opaque)
int bytes_sent;
bytes_sent = ram_save_block(f);
- bytes_transferred += bytes_sent;
- if (bytes_sent == 0) { /* no more blocks */
+ /* bytes_sent 0 represent unchanged page,
+ bytes_sent -1 represent no more blocks*/
+ if (bytes_sent > 0) {
+ bytes_transferred += bytes_sent;
+ } else if (bytes_sent == -1) { /* no more blocks */
break;
}
/* we want to check in the 1st loop, just in case it was the 1st time
@@ -387,7 +390,7 @@ int ram_save_live(QEMUFile *f, int stage, void *opaque)
int bytes_sent;
/* flush all remaining blocks regardless of rate limiting */
- while ((bytes_sent = ram_save_block(f)) != 0) {
+ while ((bytes_sent = ram_save_block(f)) != -1) {
bytes_transferred += bytes_sent;
}
memory_global_dirty_log_stop();
--
1.7.7.6
^ permalink raw reply related [flat|nested] 11+ messages in thread
* [Qemu-devel] [PATCH v17 6/9] Add xbzrle_encode_buffer and xbzrle_decode_buffer functions
2012-07-10 9:37 [Qemu-devel] [PATCH v17 0/9] XBZRLE delta for live migration of large memory app Orit Wasserman
` (4 preceding siblings ...)
2012-07-10 9:37 ` [Qemu-devel] [PATCH v17 5/9] Change ram_save_block to return -1 if there are no more changes Orit Wasserman
@ 2012-07-10 9:37 ` Orit Wasserman
2012-07-10 9:37 ` [Qemu-devel] [PATCH v17 7/9] Add XBZRLE to ram_save_block and ram_save_live Orit Wasserman
` (2 subsequent siblings)
8 siblings, 0 replies; 11+ messages in thread
From: Orit Wasserman @ 2012-07-10 9:37 UTC (permalink / raw)
To: qemu-devel
Cc: peter.maydell, aliguori, quintela, Petter Svard, stefanha,
mdroth, Benoit Hudzia, blauwirbel, Orit Wasserman, chegu_vinod,
avi, Aidan Shribman, pbonzini, eblake
For performance we are encoding long word at a time.
For nzrun we use long-word-at-a-time NULL-detection tricks from strcmp():
using ((lword - 0x0101010101010101) & (~lword) & 0x8080808080808080) test
to find out if any byte in the long word is zero.
Signed-off-by: Benoit Hudzia <benoit.hudzia@sap.com>
Signed-off-by: Petter Svard <petters@cs.umu.se>
Signed-off-by: Aidan Shribman <aidan.shribman@sap.com>
Signed-off-by: Orit Wasserman <owasserm@redhat.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
---
migration.h | 4 ++
savevm.c | 159 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 163 insertions(+), 0 deletions(-)
diff --git a/migration.h b/migration.h
index acc0b94..c46af82 100644
--- a/migration.h
+++ b/migration.h
@@ -100,4 +100,8 @@ void migrate_add_blocker(Error *reason);
*/
void migrate_del_blocker(Error *reason);
+int xbzrle_encode_buffer(uint8_t *old_buf, uint8_t *new_buf, int slen,
+ uint8_t *dst, int dlen);
+int xbzrle_decode_buffer(uint8_t *src, int slen, uint8_t *dst, int dlen);
+
#endif
diff --git a/savevm.c b/savevm.c
index a15c163..261111d 100644
--- a/savevm.c
+++ b/savevm.c
@@ -2385,3 +2385,162 @@ void vmstate_register_ram_global(MemoryRegion *mr)
{
vmstate_register_ram(mr, NULL);
}
+
+/*
+ page = zrun nzrun
+ | zrun nzrun page
+
+ zrun = length
+
+ nzrun = length byte...
+
+ length = uleb128 encoded integer
+ */
+int xbzrle_encode_buffer(uint8_t *old_buf, uint8_t *new_buf, int slen,
+ uint8_t *dst, int dlen)
+{
+ uint32_t zrun_len = 0, nzrun_len = 0;
+ int d = 0, i = 0;
+ long res, xor;
+ uint8_t *nzrun_start = NULL;
+
+ g_assert(!(((uintptr_t)old_buf | (uintptr_t)new_buf | slen) %
+ sizeof(long)));
+
+ while (i < slen) {
+ /* overflow */
+ if (d + 2 > dlen) {
+ return -1;
+ }
+
+ /* not aligned to sizeof(long) */
+ res = (slen - i) % sizeof(long);
+ while (res && old_buf[i] == new_buf[i]) {
+ zrun_len++;
+ i++;
+ res--;
+ }
+
+ /* word at a time for speed */
+ if (!res) {
+ while (i < slen &&
+ (*(long *)(old_buf + i)) == (*(long *)(new_buf + i))) {
+ i += sizeof(long);
+ zrun_len += sizeof(long);
+ }
+
+ /* go over the rest */
+ while (i < slen && old_buf[i] == new_buf[i]) {
+ zrun_len++;
+ i++;
+ }
+ }
+
+ /* buffer unchanged */
+ if (zrun_len == slen) {
+ return 0;
+ }
+
+ /* skip last zero run */
+ if (i == slen) {
+ return d;
+ }
+
+ d += uleb128_encode_small(dst + d, zrun_len);
+
+ zrun_len = 0;
+ nzrun_start = new_buf + i;
+
+ /* overflow */
+ if (d + 2 > dlen) {
+ return -1;
+ }
+ /* not aligned to sizeof(long) */
+ res = (slen - i) % sizeof(long);
+ while (res && old_buf[i] != new_buf[i]) {
+ i++;
+ nzrun_len++;
+ res--;
+ }
+
+ /* word at a time for speed, use of 32-bit long okay */
+ if (!res) {
+ /* truncation to 32-bit long okay */
+ long mask = 0x0101010101010101ULL;
+ while (i < slen) {
+ xor = *(long *)(old_buf + i) ^ *(long *)(new_buf + i);
+ if ((xor - mask) & ~xor & (mask << 7)) {
+ /* found the end of an nzrun within the current long */
+ while (old_buf[i] != new_buf[i]) {
+ nzrun_len++;
+ i++;
+ }
+ break;
+ } else {
+ i += sizeof(long);
+ nzrun_len += sizeof(long);
+ }
+ }
+ }
+
+ d += uleb128_encode_small(dst + d, nzrun_len);
+ /* overflow */
+ if (d + nzrun_len > dlen) {
+ return -1;
+ }
+ memcpy(dst + d, nzrun_start, nzrun_len);
+ d += nzrun_len;
+ nzrun_len = 0;
+ }
+
+ return d;
+}
+
+int xbzrle_decode_buffer(uint8_t *src, int slen, uint8_t *dst, int dlen)
+{
+ int i = 0, d = 0;
+ int ret;
+ uint32_t count = 0;
+
+ while (i < slen) {
+
+ /* zrun */
+ if ((slen - i) < 2) {
+ return -1;
+ }
+
+ ret = uleb128_decode_small(src + i, &count);
+ if (ret < 0 || (i && !count)) {
+ return -1;
+ }
+ i += ret;
+ d += count;
+
+ /* overflow */
+ if (d > dlen) {
+ return -1;
+ }
+
+ /* nzrun */
+ if ((slen - i) < 2) {
+ return -1;
+ }
+
+ ret = uleb128_decode_small(src + i, &count);
+ if (ret < 0 || !count) {
+ return -1;
+ }
+ i += ret;
+
+ /* overflow */
+ if (d + count > dlen || i + count > slen) {
+ return -1;
+ }
+
+ memcpy(dst + d , src + i, count);
+ d += count;
+ i += count;
+ }
+
+ return d;
+}
--
1.7.7.6
^ permalink raw reply related [flat|nested] 11+ messages in thread
* [Qemu-devel] [PATCH v17 7/9] Add XBZRLE to ram_save_block and ram_save_live
2012-07-10 9:37 [Qemu-devel] [PATCH v17 0/9] XBZRLE delta for live migration of large memory app Orit Wasserman
` (5 preceding siblings ...)
2012-07-10 9:37 ` [Qemu-devel] [PATCH v17 6/9] Add xbzrle_encode_buffer and xbzrle_decode_buffer functions Orit Wasserman
@ 2012-07-10 9:37 ` Orit Wasserman
2012-07-10 9:37 ` [Qemu-devel] [PATCH v17 8/9] Add migrate_set_cachesize command Orit Wasserman
2012-07-10 9:37 ` [Qemu-devel] [PATCH v17 9/9] Add XBZRLE statistics Orit Wasserman
8 siblings, 0 replies; 11+ messages in thread
From: Orit Wasserman @ 2012-07-10 9:37 UTC (permalink / raw)
To: qemu-devel
Cc: peter.maydell, aliguori, quintela, Petter Svard, stefanha,
mdroth, Benoit Hudzia, blauwirbel, Orit Wasserman, chegu_vinod,
avi, Aidan Shribman, pbonzini, eblake
In the outgoing migration check to see if the page is cached and
changed than send compressed page by using save_xbrle_page function.
In the incoming migration check to see if RAM_SAVE_FLAG_XBZRLE is set
and decompress the page (by using load_xbrle function).
Signed-off-by: Benoit Hudzia <benoit.hudzia@sap.com>
Signed-off-by: Petter Svard <petters@cs.umu.se>
Signed-off-by: Aidan Shribman <aidan.shribman@sap.com>
Signed-off-by: Orit Wasserman <owasserm@redhat.com>
---
arch_init.c | 187 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++--
migration.c | 24 ++++++++
migration.h | 4 +
3 files changed, 210 insertions(+), 5 deletions(-)
diff --git a/arch_init.c b/arch_init.c
index 91e583f..8bbd6da 100644
--- a/arch_init.c
+++ b/arch_init.c
@@ -43,6 +43,7 @@
#include "hw/smbios.h"
#include "exec-memory.h"
#include "hw/pcspk.h"
+#include "qemu/page_cache.h"
#ifdef DEBUG_ARCH_INIT
#define DPRINTF(fmt, ...) \
@@ -102,6 +103,7 @@ const uint32_t arch_type = QEMU_ARCH;
#define RAM_SAVE_FLAG_PAGE 0x08
#define RAM_SAVE_FLAG_EOS 0x10
#define RAM_SAVE_FLAG_CONTINUE 0x20
+#define RAM_SAVE_FLAG_XBZRLE 0x40
#ifdef __ALTIVEC__
#include <altivec.h>
@@ -169,6 +171,27 @@ static int is_dup_page(uint8_t *page)
return 1;
}
+/* XBZRLE (Xor Based Zero Length Encoding */
+typedef struct XBZRLEHeader {
+ uint16_t xh_len;
+ uint8_t xh_flags;
+} XBZRLEHeader;
+
+/* struct contains XBZRLE cache and a static page
+ used by the compression */
+static struct {
+ /* buffer used for XBZRLE encoding */
+ uint8_t *encoded_buf;
+ /* buffer used for XBZRLE decoding */
+ uint8_t *decoded_buf;
+ /* Cache for XBZRLE */
+ PageCache *cache;
+} XBZRLE = {
+ .encoded_buf = NULL,
+ .decoded_buf = NULL,
+ .cache = NULL,
+};
+
static void save_block_hdr(QEMUFile *f, RAMBlock *block, ram_addr_t offset,
int cont, int flag)
{
@@ -181,15 +204,76 @@ static void save_block_hdr(QEMUFile *f, RAMBlock *block, ram_addr_t offset,
}
+#define ENCODING_FLAG_XBZRLE 0x1
+
+static int save_xbzrle_page(QEMUFile *f, uint8_t *current_data,
+ ram_addr_t current_addr, RAMBlock *block,
+ ram_addr_t offset, int cont, int stage)
+{
+ int encoded_len = 0, bytes_sent = -1, ret = -1;
+ XBZRLEHeader hdr = {
+ .xh_len = 0,
+ .xh_flags = 0,
+ };
+ uint8_t *prev_cached_page;
+
+ /* Stage 1 cache the page and exit.
+ Stage 2 check to see if page is cached, if not cache the page.
+ Stage 3 check if the page is cached and if not exit.
+ */
+ if (stage == 1 || !cache_is_cached(XBZRLE.cache, current_addr)) {
+ if (stage != 3) {
+ cache_insert(XBZRLE.cache, current_addr,
+ g_memdup(current_data, TARGET_PAGE_SIZE));
+ }
+ return -1;
+ }
+
+ prev_cached_page = get_cached_data(XBZRLE.cache, current_addr);
+
+ /* XBZRLE encoding (if there is no overflow) */
+ encoded_len = xbzrle_encode_buffer(prev_cached_page, current_data,
+ TARGET_PAGE_SIZE, XBZRLE.encoded_buf,
+ TARGET_PAGE_SIZE);
+ if (encoded_len == 0) {
+ DPRINTF("Skipping unmodified page\n");
+ return 0;
+ } else if (encoded_len == -1) {
+ DPRINTF("Overflow\n");
+ /* update data in the cache */
+ memcpy(prev_cached_page, current_data, TARGET_PAGE_SIZE);
+ return -1;
+ }
+
+ /* we need to update the data in the cache, in order to get the same data
+ we cached we decode the encoded page on the cached data */
+ ret = xbzrle_decode_buffer(XBZRLE.encoded_buf, encoded_len,
+ prev_cached_page, TARGET_PAGE_SIZE);
+ g_assert(ret != -1);
+
+ hdr.xh_len = encoded_len;
+ hdr.xh_flags |= ENCODING_FLAG_XBZRLE;
+
+ /* Send XBZRLE based compressed page */
+ save_block_hdr(f, block, offset, cont, RAM_SAVE_FLAG_XBZRLE);
+ qemu_put_byte(f, hdr.xh_flags);
+ qemu_put_be16(f, hdr.xh_len);
+ qemu_put_buffer(f, XBZRLE.encoded_buf, encoded_len);
+ bytes_sent = encoded_len + sizeof(hdr);
+
+ return bytes_sent;
+}
+
static RAMBlock *last_block;
static ram_addr_t last_offset;
-static int ram_save_block(QEMUFile *f)
+static int ram_save_block(QEMUFile *f, int stage)
{
RAMBlock *block = last_block;
ram_addr_t offset = last_offset;
int bytes_sent = -1;
MemoryRegion *mr;
+ ram_addr_t current_addr;
if (!block)
block = QLIST_FIRST(&ram_list.blocks);
@@ -210,13 +294,31 @@ static int ram_save_block(QEMUFile *f)
save_block_hdr(f, block, offset, cont, RAM_SAVE_FLAG_COMPRESS);
qemu_put_byte(f, *p);
bytes_sent = 1;
- } else {
+ } else if (migrate_use_xbzrle() && stage != 3) {
+ current_addr = block->offset + offset;
+ /* In stage 1 we only cache the pages before sending them
+ from the cache (uncompressed).
+ We don't use compression for stage 3.
+ */
+ bytes_sent = save_xbzrle_page(f, p, current_addr, block,
+ offset, cont, stage);
+
+ /* send the cached page copy for consistency
+ In stage 3 we send the host page */
+ p = get_cached_data(XBZRLE.cache, current_addr);
+ }
+
+ /* either we didn't send yet (we may have had XBZRLE overflow) */
+ if (bytes_sent == -1) {
save_block_hdr(f, block, offset, cont, RAM_SAVE_FLAG_PAGE);
qemu_put_buffer(f, p, TARGET_PAGE_SIZE);
bytes_sent = TARGET_PAGE_SIZE;
}
- break;
+ /* if page is unmodified, continue to the next */
+ if (bytes_sent != 0) {
+ break;
+ }
}
offset += TARGET_PAGE_SIZE;
@@ -294,6 +396,14 @@ static void sort_ram_list(void)
static void migration_end(void)
{
memory_global_dirty_log_stop();
+
+ if (migrate_use_xbzrle()) {
+ cache_fini(XBZRLE.cache);
+ g_free(XBZRLE.cache);
+ g_free(XBZRLE.encoded_buf);
+ g_free(XBZRLE.decoded_buf);
+ XBZRLE.cache = NULL;
+ }
}
#define MAX_WAIT 50 /* ms, half buffered_file limit */
@@ -320,6 +430,17 @@ int ram_save_live(QEMUFile *f, int stage, void *opaque)
last_offset = 0;
sort_ram_list();
+ if (migrate_use_xbzrle()) {
+ XBZRLE.cache = cache_init(migrate_xbzrle_cache_size() /
+ TARGET_PAGE_SIZE,
+ TARGET_PAGE_SIZE);
+ if (!XBZRLE.cache) {
+ DPRINTF("Error creating cache\n");
+ return -1;
+ }
+ XBZRLE.encoded_buf = g_malloc0(TARGET_PAGE_SIZE);
+ }
+
/* Make sure all dirty bits are set */
QLIST_FOREACH(block, &ram_list.blocks, next) {
for (addr = 0; addr < block->length; addr += TARGET_PAGE_SIZE) {
@@ -348,7 +469,7 @@ int ram_save_live(QEMUFile *f, int stage, void *opaque)
while ((ret = qemu_file_rate_limit(f)) == 0) {
int bytes_sent;
- bytes_sent = ram_save_block(f);
+ bytes_sent = ram_save_block(f, stage);
/* bytes_sent 0 represent unchanged page,
bytes_sent -1 represent no more blocks*/
if (bytes_sent > 0) {
@@ -390,7 +511,7 @@ int ram_save_live(QEMUFile *f, int stage, void *opaque)
int bytes_sent;
/* flush all remaining blocks regardless of rate limiting */
- while ((bytes_sent = ram_save_block(f)) != -1) {
+ while ((bytes_sent = ram_save_block(f, stage)) != -1) {
bytes_transferred += bytes_sent;
}
memory_global_dirty_log_stop();
@@ -410,6 +531,49 @@ int ram_save_live(QEMUFile *f, int stage, void *opaque)
return 0;
}
+static int load_xbzrle(QEMUFile *f, ram_addr_t addr, void *host)
+{
+ int ret, rc = 0;
+ XBZRLEHeader hdr = {
+ .xh_len = 0,
+ .xh_flags = 0,
+ };
+
+ if (!XBZRLE.decoded_buf) {
+ XBZRLE.decoded_buf = g_malloc(TARGET_PAGE_SIZE);
+ }
+
+ /* extract RLE header */
+ hdr.xh_flags = qemu_get_byte(f);
+ hdr.xh_len = qemu_get_be16(f);
+
+ if (!(hdr.xh_flags & ENCODING_FLAG_XBZRLE)) {
+ fprintf(stderr, "Failed to load XBZRLE page - wrong compression!\n");
+ return -1;
+ }
+
+ if (hdr.xh_len > TARGET_PAGE_SIZE) {
+ fprintf(stderr, "Failed to load XBZRLE page - len overflow!\n");
+ return -1;
+ }
+ /* load data and decode */
+ qemu_get_buffer(f, XBZRLE.decoded_buf, hdr.xh_len);
+
+ /* decode RLE */
+ ret = xbzrle_decode_buffer(XBZRLE.decoded_buf, hdr.xh_len, host,
+ TARGET_PAGE_SIZE);
+ if (ret == -1) {
+ fprintf(stderr, "Failed to load XBZRLE page - decode error!\n");
+ rc = -1;
+ } else if (ret > TARGET_PAGE_SIZE) {
+ fprintf(stderr, "Failed to load XBZRLE page - size %d exceeds %d!\n",
+ ret, TARGET_PAGE_SIZE);
+ rc = -1;
+ }
+
+ return rc;
+}
+
static inline void *host_from_stream_offset(QEMUFile *f,
ram_addr_t offset,
int flags)
@@ -523,6 +687,19 @@ int ram_load(QEMUFile *f, void *opaque, int version_id)
}
qemu_get_buffer(f, host, TARGET_PAGE_SIZE);
+ } else if (flags & RAM_SAVE_FLAG_XBZRLE) {
+ if (!migrate_use_xbzrle()) {
+ return -EINVAL;
+ }
+ void *host = host_from_stream_offset(f, addr, flags);
+ if (!host) {
+ return -EINVAL;
+ }
+
+ if (load_xbzrle(f, addr, host) < 0) {
+ ret = -EINVAL;
+ goto done;
+ }
}
error = qemu_file_get_error(f);
if (error) {
diff --git a/migration.c b/migration.c
index fd004d7..1a264a9 100644
--- a/migration.c
+++ b/migration.c
@@ -43,6 +43,9 @@ enum {
#define MAX_THROTTLE (32 << 20) /* Migration speed throttling */
+/* Migration XBZRLE default cache size */
+#define DEFAULT_MIGRATE_CACHE_SIZE (64 * 1024 * 1024)
+
static NotifierList migration_state_notifiers =
NOTIFIER_LIST_INITIALIZER(migration_state_notifiers);
@@ -55,6 +58,7 @@ static MigrationState *migrate_get_current(void)
static MigrationState current_migration = {
.state = MIG_STATE_SETUP,
.bandwidth_limit = MAX_THROTTLE,
+ .xbzrle_cache_size = DEFAULT_MIGRATE_CACHE_SIZE,
};
return ¤t_migration;
@@ -439,6 +443,7 @@ static MigrationState *migrate_init(const MigrationParams *params)
MigrationState *s = migrate_get_current();
int64_t bandwidth_limit = s->bandwidth_limit;
bool enabled_capabilities[MIGRATION_CAPABILITY_MAX];
+ int64_t xbzrle_cache_size = s->xbzrle_cache_size;
memcpy(enabled_capabilities, s->enabled_capabilities,
sizeof(enabled_capabilities));
@@ -448,6 +453,7 @@ static MigrationState *migrate_init(const MigrationParams *params)
s->params = *params;
memcpy(s->enabled_capabilities, enabled_capabilities,
sizeof(enabled_capabilities));
+ s->xbzrle_cache_size = xbzrle_cache_size;
s->state = MIG_STATE_SETUP;
s->total_time = qemu_get_clock_ms(rt_clock);
@@ -546,3 +552,21 @@ void qmp_migrate_set_downtime(double value, Error **errp)
value = MAX(0, MIN(UINT64_MAX, value));
max_downtime = (uint64_t)value;
}
+
+int migrate_use_xbzrle(void)
+{
+ MigrationState *s;
+
+ s = migrate_get_current();
+
+ return s->enabled_capabilities[MIGRATION_CAPABILITY_XBZRLE];
+}
+
+int64_t migrate_xbzrle_cache_size(void)
+{
+ MigrationState *s;
+
+ s = migrate_get_current();
+
+ return s->xbzrle_cache_size;
+}
diff --git a/migration.h b/migration.h
index c46af82..9b61e70 100644
--- a/migration.h
+++ b/migration.h
@@ -40,6 +40,7 @@ struct MigrationState
MigrationParams params;
int64_t total_time;
bool enabled_capabilities[MIGRATION_CAPABILITY_MAX];
+ int64_t xbzrle_cache_size;
};
void process_incoming_migration(QEMUFile *f);
@@ -104,4 +105,7 @@ int xbzrle_encode_buffer(uint8_t *old_buf, uint8_t *new_buf, int slen,
uint8_t *dst, int dlen);
int xbzrle_decode_buffer(uint8_t *src, int slen, uint8_t *dst, int dlen);
+int migrate_use_xbzrle(void);
+int64_t migrate_xbzrle_cache_size(void);
+
#endif
--
1.7.7.6
^ permalink raw reply related [flat|nested] 11+ messages in thread
* [Qemu-devel] [PATCH v17 8/9] Add migrate_set_cachesize command
2012-07-10 9:37 [Qemu-devel] [PATCH v17 0/9] XBZRLE delta for live migration of large memory app Orit Wasserman
` (6 preceding siblings ...)
2012-07-10 9:37 ` [Qemu-devel] [PATCH v17 7/9] Add XBZRLE to ram_save_block and ram_save_live Orit Wasserman
@ 2012-07-10 9:37 ` Orit Wasserman
2012-07-10 9:37 ` [Qemu-devel] [PATCH v17 9/9] Add XBZRLE statistics Orit Wasserman
8 siblings, 0 replies; 11+ messages in thread
From: Orit Wasserman @ 2012-07-10 9:37 UTC (permalink / raw)
To: qemu-devel
Cc: peter.maydell, aliguori, quintela, Petter Svard, stefanha,
mdroth, Benoit Hudzia, blauwirbel, Orit Wasserman, chegu_vinod,
avi, Aidan Shribman, pbonzini, eblake
Change XBZRLE cache size in bytes (the size should be a power of 2, it will be
rounded down to the nearest power of 2).
If XBZRLE cache size is too small there will be many cache miss.
Signed-off-by: Benoit Hudzia <benoit.hudzia@sap.com>
Signed-off-by: Petter Svard <petters@cs.umu.se>
Signed-off-by: Aidan Shribman <aidan.shribman@sap.com>
Signed-off-by: Orit Wasserman <owasserm@redhat.com>
---
arch_init.c | 10 ++++++++++
hmp-commands.hx | 20 ++++++++++++++++++++
hmp.c | 13 +++++++++++++
hmp.h | 1 +
migration.c | 14 ++++++++++++++
migration.h | 2 ++
qapi-schema.json | 16 ++++++++++++++++
qmp-commands.hx | 23 +++++++++++++++++++++++
8 files changed, 99 insertions(+), 0 deletions(-)
diff --git a/arch_init.c b/arch_init.c
index 8bbd6da..be6670c 100644
--- a/arch_init.c
+++ b/arch_init.c
@@ -192,6 +192,16 @@ static struct {
.cache = NULL,
};
+
+int64_t xbzrle_cache_resize(int64_t new_size)
+{
+ if (XBZRLE.cache != NULL) {
+ return cache_resize(XBZRLE.cache, new_size / TARGET_PAGE_SIZE) *
+ TARGET_PAGE_SIZE;
+ }
+ return pow2floor(new_size);
+}
+
static void save_block_hdr(QEMUFile *f, RAMBlock *block, ram_addr_t offset,
int cont, int flag)
{
diff --git a/hmp-commands.hx b/hmp-commands.hx
index 9245bef..052a0a3 100644
--- a/hmp-commands.hx
+++ b/hmp-commands.hx
@@ -829,6 +829,26 @@ STEXI
@item migrate_cancel
@findex migrate_cancel
Cancel the current VM migration.
+
+ETEXI
+
+ {
+ .name = "migrate_set_cachesize",
+ .args_type = "value:o",
+ .params = "value",
+ .help = "set cache size (in bytes) for XBZRLE migrations,"
+ "the cache size will be rounded down to the nearest "
+ "power of 2.\n"
+ "The cache size effects the number of cache misses."
+ "In case of a high cache miss ratio you need to increase"
+ " the cache size",
+ .mhandler.cmd = hmp_migrate_set_cachesize,
+ },
+
+STEXI
+@item migrate_set_cachesize @var{value}
+@findex migrate_set_cachesize
+Set cache size to @var{value} (in bytes) for xbzrle migrations.
ETEXI
{
diff --git a/hmp.c b/hmp.c
index b0440e6..99ad00a 100644
--- a/hmp.c
+++ b/hmp.c
@@ -758,6 +758,19 @@ void hmp_migrate_set_downtime(Monitor *mon, const QDict *qdict)
qmp_migrate_set_downtime(value, NULL);
}
+void hmp_migrate_set_cachesize(Monitor *mon, const QDict *qdict)
+{
+ int64_t value = qdict_get_int(qdict, "value");
+ Error *err = NULL;
+
+ qmp_migrate_set_cache_size(value, &err);
+ if (err) {
+ monitor_printf(mon, "%s\n", error_get_pretty(err));
+ error_free(err);
+ return;
+ }
+}
+
void hmp_migrate_set_speed(Monitor *mon, const QDict *qdict)
{
int64_t value = qdict_get_int(qdict, "value");
diff --git a/hmp.h b/hmp.h
index 09ba198..7c5117d 100644
--- a/hmp.h
+++ b/hmp.h
@@ -53,6 +53,7 @@ void hmp_migrate_cancel(Monitor *mon, const QDict *qdict);
void hmp_migrate_set_downtime(Monitor *mon, const QDict *qdict);
void hmp_migrate_set_speed(Monitor *mon, const QDict *qdict);
void hmp_migrate_set_parameter(Monitor *mon, const QDict *qdict);
+void hmp_migrate_set_cachesize(Monitor *mon, const QDict *qdict);
void hmp_set_password(Monitor *mon, const QDict *qdict);
void hmp_expire_password(Monitor *mon, const QDict *qdict);
void hmp_eject(Monitor *mon, const QDict *qdict);
diff --git a/migration.c b/migration.c
index 1a264a9..d134bf6 100644
--- a/migration.c
+++ b/migration.c
@@ -533,6 +533,20 @@ void qmp_migrate_cancel(Error **errp)
migrate_fd_cancel(migrate_get_current());
}
+void qmp_migrate_set_cache_size(int64_t value, Error **errp)
+{
+ MigrationState *s = migrate_get_current();
+
+ /* Check for truncation */
+ if (value != (size_t)value) {
+ error_set(errp, QERR_INVALID_PARAMETER_VALUE, "cache size",
+ "exceeding address space");
+ return;
+ }
+
+ s->xbzrle_cache_size = xbzrle_cache_resize(value);
+}
+
void qmp_migrate_set_speed(int64_t value, Error **errp)
{
MigrationState *s;
diff --git a/migration.h b/migration.h
index 9b61e70..a73a34a 100644
--- a/migration.h
+++ b/migration.h
@@ -108,4 +108,6 @@ int xbzrle_decode_buffer(uint8_t *src, int slen, uint8_t *dst, int dlen);
int migrate_use_xbzrle(void);
int64_t migrate_xbzrle_cache_size(void);
+int64_t xbzrle_cache_resize(int64_t new_size);
+
#endif
diff --git a/qapi-schema.json b/qapi-schema.json
index a8408fd..a0f0f95 100644
--- a/qapi-schema.json
+++ b/qapi-schema.json
@@ -1390,6 +1390,22 @@
{ 'command': 'migrate_set_speed', 'data': {'value': 'int'} }
##
+# @migrate-set-cache-size
+#
+# Set XBZRLE cache size
+#
+# @value: cache size in bytes
+#
+# The size will be rounded down to the nearest power of 2.
+# The cache size can be modified before and during ongoing migration
+#
+# Returns: nothing on success
+#
+# Since: 1.2
+##
+{ 'command': 'migrate-set-cache-size', 'data': {'value': 'int'} }
+
+##
# @ObjectPropertyInfo:
#
# @name: the name of the property
diff --git a/qmp-commands.hx b/qmp-commands.hx
index 3ee6e00..a3d57ce 100644
--- a/qmp-commands.hx
+++ b/qmp-commands.hx
@@ -520,6 +520,29 @@ Example:
<- { "return": {} }
EQMP
+{
+ .name = "migrate-set-cache-size",
+ .args_type = "value:o",
+ .mhandler.cmd_new = qmp_marshal_input_migrate_set_cache_size,
+ },
+
+SQMP
+migrate-set-cache-size
+---------------------
+
+Set cache size to be used by XBZRLE migration, the cache size will be rounded
+down to the nearest power of 2
+
+Arguments:
+
+- "value": cache size in bytes (json-int)
+
+Example:
+
+-> { "execute": "migrate-set-cache-size", "arguments": { "value": 536870912 } }
+<- { "return": {} }
+
+EQMP
{
.name = "migrate_set_speed",
--
1.7.7.6
^ permalink raw reply related [flat|nested] 11+ messages in thread
* [Qemu-devel] [PATCH v17 9/9] Add XBZRLE statistics
2012-07-10 9:37 [Qemu-devel] [PATCH v17 0/9] XBZRLE delta for live migration of large memory app Orit Wasserman
` (7 preceding siblings ...)
2012-07-10 9:37 ` [Qemu-devel] [PATCH v17 8/9] Add migrate_set_cachesize command Orit Wasserman
@ 2012-07-10 9:37 ` Orit Wasserman
8 siblings, 0 replies; 11+ messages in thread
From: Orit Wasserman @ 2012-07-10 9:37 UTC (permalink / raw)
To: qemu-devel
Cc: peter.maydell, aliguori, quintela, Petter Svard, stefanha,
mdroth, Benoit Hudzia, blauwirbel, Orit Wasserman, chegu_vinod,
avi, Aidan Shribman, pbonzini, eblake
Signed-off-by: Benoit Hudzia <benoit.hudzia@sap.com>
Signed-off-by: Petter Svard <petters@cs.umu.se>
Signed-off-by: Aidan Shribman <aidan.shribman@sap.com>
Signed-off-by: Orit Wasserman <owasserm@redhat.com>
---
arch_init.c | 66 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
hmp.c | 13 ++++++++++
migration.c | 49 ++++++++++++++++++++++++++++++++++++++++
migration.h | 9 +++++++
qapi-schema.json | 37 ++++++++++++++++++++++++++----
qmp-commands.hx | 35 +++++++++++++++++++++++++++-
6 files changed, 203 insertions(+), 6 deletions(-)
diff --git a/arch_init.c b/arch_init.c
index be6670c..aa38801 100644
--- a/arch_init.c
+++ b/arch_init.c
@@ -202,6 +202,64 @@ int64_t xbzrle_cache_resize(int64_t new_size)
return pow2floor(new_size);
}
+/* accounting for migration statistics */
+typedef struct AccountingInfo {
+ uint64_t dup_pages;
+ uint64_t norm_pages;
+ uint64_t xbzrle_bytes;
+ uint64_t xbzrle_pages;
+ uint64_t xbzrle_cache_miss;
+ uint64_t iterations;
+ uint64_t xbzrle_overflows;
+} AccountingInfo;
+
+static AccountingInfo acct_info;
+
+static void acct_clear(void)
+{
+ memset(&acct_info, 0, sizeof(acct_info));
+}
+
+uint64_t dup_mig_bytes_transferred(void)
+{
+ return acct_info.dup_pages * TARGET_PAGE_SIZE;
+}
+
+uint64_t dup_mig_pages_transferred(void)
+{
+ return acct_info.dup_pages;
+}
+
+uint64_t norm_mig_bytes_transferred(void)
+{
+ return acct_info.norm_pages * TARGET_PAGE_SIZE;
+}
+
+uint64_t norm_mig_pages_transferred(void)
+{
+ return acct_info.norm_pages;
+}
+
+uint64_t xbzrle_mig_bytes_transferred(void)
+{
+ return acct_info.xbzrle_bytes;
+}
+
+uint64_t xbzrle_mig_pages_transferred(void)
+{
+ return acct_info.xbzrle_pages;
+}
+
+uint64_t xbzrle_mig_pages_cache_miss(void)
+{
+ return acct_info.xbzrle_cache_miss;
+}
+
+uint64_t xbzrle_mig_pages_overflow(void)
+{
+ return acct_info.xbzrle_overflows;
+}
+
static void save_block_hdr(QEMUFile *f, RAMBlock *block, ram_addr_t offset,
int cont, int flag)
{
@@ -236,6 +294,7 @@ static int save_xbzrle_page(QEMUFile *f, uint8_t *current_data,
cache_insert(XBZRLE.cache, current_addr,
g_memdup(current_data, TARGET_PAGE_SIZE));
}
+ acct_info.xbzrle_cache_miss++;
return -1;
}
@@ -250,6 +309,7 @@ static int save_xbzrle_page(QEMUFile *f, uint8_t *current_data,
return 0;
} else if (encoded_len == -1) {
DPRINTF("Overflow\n");
+ acct_info.xbzrle_overflows++;
/* update data in the cache */
memcpy(prev_cached_page, current_data, TARGET_PAGE_SIZE);
return -1;
@@ -269,7 +329,9 @@ static int save_xbzrle_page(QEMUFile *f, uint8_t *current_data,
qemu_put_byte(f, hdr.xh_flags);
qemu_put_be16(f, hdr.xh_len);
qemu_put_buffer(f, XBZRLE.encoded_buf, encoded_len);
+ acct_info.xbzrle_pages++;
bytes_sent = encoded_len + sizeof(hdr);
+ acct_info.xbzrle_bytes += bytes_sent;
return bytes_sent;
}
@@ -301,6 +363,7 @@ static int ram_save_block(QEMUFile *f, int stage)
p = memory_region_get_ram_ptr(mr) + offset;
if (is_dup_page(p)) {
+ acct_info.dup_pages++;
save_block_hdr(f, block, offset, cont, RAM_SAVE_FLAG_COMPRESS);
qemu_put_byte(f, *p);
bytes_sent = 1;
@@ -323,6 +386,7 @@ static int ram_save_block(QEMUFile *f, int stage)
save_block_hdr(f, block, offset, cont, RAM_SAVE_FLAG_PAGE);
qemu_put_buffer(f, p, TARGET_PAGE_SIZE);
bytes_sent = TARGET_PAGE_SIZE;
+ acct_info.norm_pages++;
}
/* if page is unmodified, continue to the next */
@@ -449,6 +513,7 @@ int ram_save_live(QEMUFile *f, int stage, void *opaque)
return -1;
}
XBZRLE.encoded_buf = g_malloc0(TARGET_PAGE_SIZE);
+ acct_clear();
}
/* Make sure all dirty bits are set */
@@ -484,6 +549,7 @@ int ram_save_live(QEMUFile *f, int stage, void *opaque)
bytes_sent -1 represent no more blocks*/
if (bytes_sent > 0) {
bytes_transferred += bytes_sent;
+ acct_info.iterations++;
} else if (bytes_sent == -1) { /* no more blocks */
break;
}
diff --git a/hmp.c b/hmp.c
index 99ad00a..0d7333b 100644
--- a/hmp.c
+++ b/hmp.c
@@ -168,6 +168,19 @@ void hmp_info_migrate(Monitor *mon)
info->disk->total >> 10);
}
+ if (info->has_cache) {
+ monitor_printf(mon, "cache size: %" PRIu64 " bytes\n",
+ info->cache->cache_size);
+ monitor_printf(mon, "xbzrle transferred: %" PRIu64 " kbytes\n",
+ info->cache->xbzrle_bytes >> 10);
+ monitor_printf(mon, "xbzrle pages: %" PRIu64 " pages\n",
+ info->cache->xbzrle_pages);
+ monitor_printf(mon, "xbzrle cache miss: %" PRIu64 "\n",
+ info->cache->xbzrle_cache_miss);
+ monitor_printf(mon, "xbzrle overflow : %" PRIu64 "\n",
+ info->cache->xbzrle_overflow);
+ }
+
qapi_free_MigrationInfo(info);
}
diff --git a/migration.c b/migration.c
index d134bf6..e11f451 100644
--- a/migration.c
+++ b/migration.c
@@ -137,6 +137,17 @@ MigrationInfo *qmp_query_migrate(Error **errp)
info->capabilities->value->state = s->enabled_capabilities[i];
info->capabilities->next = NULL;
}
+
+ /* display xbzrle cache size */
+ if (migrate_use_xbzrle()) {
+ info->has_cache = true;
+ info->cache = g_malloc0(sizeof(*info->cache));
+ info->cache->cache_size = migrate_xbzrle_cache_size();
+ info->cache->xbzrle_bytes = xbzrle_mig_bytes_transferred();
+ info->cache->xbzrle_pages = xbzrle_mig_pages_transferred();
+ info->cache->xbzrle_cache_miss = xbzrle_mig_pages_cache_miss();
+ info->cache->xbzrle_overflow = xbzrle_mig_pages_overflow();
+ }
break;
case MIG_STATE_ACTIVE:
for (i = 0; i < MIGRATION_CAPABILITY_MAX; i++) {
@@ -161,6 +172,8 @@ MigrationInfo *qmp_query_migrate(Error **errp)
info->ram->total = ram_bytes_total();
info->ram->total_time = qemu_get_clock_ms(rt_clock)
- s->total_time;
+ info->ram->duplicate = dup_mig_pages_transferred();
+ info->ram->normal = norm_mig_pages_transferred();
if (blk_mig_active()) {
info->has_disk = true;
@@ -169,6 +182,16 @@ MigrationInfo *qmp_query_migrate(Error **errp)
info->disk->remaining = blk_mig_bytes_remaining();
info->disk->total = blk_mig_bytes_total();
}
+
+ if (migrate_use_xbzrle()) {
+ info->has_cache = true;
+ info->cache = g_malloc0(sizeof(*info->cache));
+ info->cache->cache_size = migrate_xbzrle_cache_size();
+ info->cache->xbzrle_bytes = xbzrle_mig_bytes_transferred();
+ info->cache->xbzrle_pages = xbzrle_mig_pages_transferred();
+ info->cache->xbzrle_cache_miss = xbzrle_mig_pages_cache_miss();
+ info->cache->xbzrle_overflow = xbzrle_mig_pages_overflow();
+ }
break;
case MIG_STATE_COMPLETED:
for (i = 0; i < MIGRATION_CAPABILITY_MAX; i++) {
@@ -183,6 +206,32 @@ MigrationInfo *qmp_query_migrate(Error **errp)
info->capabilities->next = NULL;
}
+ info->has_ram = true;
+ info->ram = g_malloc0(sizeof(*info->ram));
+ info->ram->transferred = ram_bytes_transferred();
+ info->ram->remaining = ram_bytes_remaining();
+ info->ram->total = ram_bytes_total();
+ info->ram->duplicate = dup_mig_pages_transferred();
+ info->ram->normal = norm_mig_pages_transferred();
+
+ if (blk_mig_active()) {
+ info->has_disk = true;
+ info->disk = g_malloc0(sizeof(*info->disk));
+ info->disk->transferred = blk_mig_bytes_transferred();
+ info->disk->remaining = blk_mig_bytes_remaining();
+ info->disk->total = blk_mig_bytes_total();
+ }
+
+ if (migrate_use_xbzrle()) {
+ info->has_cache = true;
+ info->cache = g_malloc0(sizeof(*info->cache));
+ info->cache->cache_size = migrate_xbzrle_cache_size();
+ info->cache->xbzrle_bytes = xbzrle_mig_bytes_transferred();
+ info->cache->xbzrle_pages = xbzrle_mig_pages_transferred();
+ info->cache->xbzrle_cache_miss = xbzrle_mig_pages_cache_miss();
+ info->cache->xbzrle_overflow = xbzrle_mig_pages_overflow();
+ }
+
info->has_status = true;
info->status = g_strdup("completed");
diff --git a/migration.h b/migration.h
index a73a34a..67f4462 100644
--- a/migration.h
+++ b/migration.h
@@ -84,6 +84,15 @@ uint64_t ram_bytes_remaining(void);
uint64_t ram_bytes_transferred(void);
uint64_t ram_bytes_total(void);
+uint64_t dup_mig_bytes_transferred(void);
+uint64_t dup_mig_pages_transferred(void);
+uint64_t norm_mig_bytes_transferred(void);
+uint64_t norm_mig_pages_transferred(void);
+uint64_t xbzrle_mig_bytes_transferred(void);
+uint64_t xbzrle_mig_pages_transferred(void);
+uint64_t xbzrle_mig_pages_overflow(void);
+uint64_t xbzrle_mig_pages_cache_miss(void);
+
int ram_save_live(QEMUFile *f, int stage, void *opaque);
int ram_load(QEMUFile *f, void *opaque, int version_id);
diff --git a/qapi-schema.json b/qapi-schema.json
index a0f0f95..961810b 100644
--- a/qapi-schema.json
+++ b/qapi-schema.json
@@ -264,11 +264,35 @@
# migration has ended, it returns the total migration
# time. (since 1.2)
#
-# Since: 0.14.0.
+# @duplicate: #optional, number of duplicate pages
+#
+# @normal : #optional, number of normal pages
+#
+# Since: 0.14.0, 'duplicate' and 'normal' since 1.2
##
{ 'type': 'MigrationStats',
'data': {'transferred': 'int', 'remaining': 'int', 'total': 'int' ,
- 'total_time': 'int' } }
+ 'total_time': 'int', '*duplicate': 'int', '*normal': 'int' } }
+##
+# @CacheStats
+#
+# Detailed XBZRLE migration cache statistics
+#
+# @cache_size: XBZRLE cache size
+#
+# @xbzrle_bytes: amount of bytes already transferred to the target VM
+#
+# @xbzrle_pages: amount of pages transferred to the target VM
+#
+# @xbzrle_cache_miss: number of cache miss
+#
+# @xbzrle_overflow: number of overflows
+#
+# Since: 1.2
+##
+{ 'type': 'CacheStats',
+ 'data': {'cache-size': 'int', 'xbzrle-bytes': 'int', 'xbzrle-pages': 'int',
+ 'xbzrle-cache-miss': 'int', 'xbzrle-overflow': 'int' } }
##
# @MigrationInfo
@@ -291,13 +315,16 @@
# @capabilities: #optional a list describing all the migration capabilities
# state
#
-# Since: 0.14.0, 'capabilities' since 1.2
+# @cache: #optional @MigrationStats containing detailed XBZRLE migration
+# statistics
+#
+# Since: 0.14.0, 'capabilities' and 'cache' since 1.2
##
{ 'type': 'MigrationInfo',
'data': {'*status': 'str', '*ram': 'MigrationStats',
'*disk': 'MigrationStats',
- '*capabilities': ['MigrationCapabilityInfo']} }
-
+ '*capabilities': ['MigrationCapabilityInfo'],
+ '*cache': 'CacheStats'} }
##
# @query-migrate
#
diff --git a/qmp-commands.hx b/qmp-commands.hx
index a3d57ce..34d4675 100644
--- a/qmp-commands.hx
+++ b/qmp-commands.hx
@@ -2093,6 +2093,8 @@ The main json-object contains the following:
- "transferred": amount transferred (json-int)
- "remaining": amount remaining (json-int)
- "total": total (json-int)
+ - "duplicate": number of duplicated pages (json-int)
+ - "normal" : number of normal pages transferred (json-int)
- "disk": only present if "status" is "active" and it is a block migration,
it is a json-object with the following disk information (in bytes):
- "transferred": amount transferred (json-int)
@@ -2100,10 +2102,17 @@ The main json-object contains the following:
- "total": total (json-int)
- "capabilities": migration capabilities state
- "xbzrle" : XBZRLE state (json-bool)
+- "cache": only present if "status" and XBZRLE is active.
+ It is a json-object with the following XBZRLE information:
+ - "cache-size": XBZRLE cache size
+ - "xbzrle-bytes": total XBZRLE bytes transferred
+ - "xbzrle-pages": number of XBZRLE compressed pages
+ - "cache-miss": number of cache misses
+ - "overflow": number of XBZRLE overflows
+
Examples:
1. Before the first migration
-
-> { "execute": "query-migrate" }
<- { "return": {
"capabilities" : [ { "capability" : "xbzrle", "state" : false } ]
@@ -2164,6 +2173,30 @@ Examples:
}
}
+6. Migration is being performed and XBZRLE is active:
+
+-> { "execute": "query-migrate" }
+<- {
+ "return":{
+ "status":"active",
+ "capabilities" : [ { "capability": "xbzrle", "state" : true } ],
+ "ram":{
+ "total":1057024,
+ "remaining":1053304,
+ "transferred":3720,
+ "duplicate": 10,
+ "normal" : 3333
+ },
+ "cache":{
+ "cache-size": 1024
+ "xbzrle-transferred":20971520,
+ "xbzrle-pages":2444343,
+ "xbzrle-cache-miss":2244,
+ "xbzrle-overflow":34434
+ }
+ }
+ }
+
EQMP
{
--
1.7.7.6
^ permalink raw reply related [flat|nested] 11+ messages in thread
* [Qemu-devel] [PATCH v17 3/9] Add cache handling functions
2012-07-10 9:37 ` [Qemu-devel] [PATCH v17 3/9] Add cache handling functions Orit Wasserman
@ 2012-07-10 19:16 ` Orit Wasserman
0 siblings, 0 replies; 11+ messages in thread
From: Orit Wasserman @ 2012-07-10 19:16 UTC (permalink / raw)
To: qemu-devel
Cc: peter.maydell, aliguori, quintela, Petter Svard, stefanha,
mdroth, Benoit Hudzia, blauwirbel, Orit Wasserman, chegu_vinod,
avi, Aidan Shribman, pbonzini, eblake
Add LRU page cache mechanism.
The page are accessed by their address.
Signed-off-by: Benoit Hudzia <benoit.hudzia@sap.com>
Signed-off-by: Petter Svard <petters@cs.umu.se>
Signed-off-by: Aidan Shribman <aidan.shribman@sap.com>
Signed-off-by: Orit Wasserman <owasserm@redhat.com>
---
Makefile.objs | 1 +
cutils.c | 9 ++
include/qemu/page_cache.h | 79 ++++++++++++++++
page_cache.c | 216 +++++++++++++++++++++++++++++++++++++++++++++
qemu-common.h | 13 +++
5 files changed, 318 insertions(+), 0 deletions(-)
create mode 100644 include/qemu/page_cache.h
create mode 100644 page_cache.c
diff --git a/Makefile.objs b/Makefile.objs
index 5ebbcfa..e0fb69b 100644
--- a/Makefile.objs
+++ b/Makefile.objs
@@ -77,6 +77,7 @@ common-obj-y += qemu-char.o #aio.o
common-obj-y += block-migration.o iohandler.o
common-obj-y += pflib.o
common-obj-y += bitmap.o bitops.o
+common-obj-y += page_cache.o
common-obj-$(CONFIG_POSIX) += migration-exec.o migration-unix.o migration-fd.o
common-obj-$(CONFIG_WIN32) += version.o
diff --git a/cutils.c b/cutils.c
index e2bc1b8..b0bdd4b 100644
--- a/cutils.c
+++ b/cutils.c
@@ -375,3 +375,12 @@ int qemu_parse_fd(const char *param)
}
return fd;
}
+
+/* round down to the nearest power of 2*/
+int64_t pow2floor(int64_t value)
+{
+ if (!is_power_of_2(value)) {
+ value = 0x8000000000000000ULL >> clz64(value);
+ }
+ return value;
+}
diff --git a/include/qemu/page_cache.h b/include/qemu/page_cache.h
new file mode 100644
index 0000000..3839ac7
--- /dev/null
+++ b/include/qemu/page_cache.h
@@ -0,0 +1,79 @@
+/*
+ * Page cache for QEMU
+ * The cache is base on a hash of the page address
+ *
+ * Copyright 2012 Red Hat, Inc. and/or its affiliates
+ *
+ * Authors:
+ * Orit Wasserman <owasserm@redhat.com>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or later.
+ * See the COPYING file in the top-level directory.
+ *
+ */
+
+#ifndef PAGE_CACHE_H
+#define PAGE_CACHE_H
+
+/* Page cache for storing guest pages */
+typedef struct PageCache PageCache;
+
+/**
+ * cache_init: Initialize the page cache
+ *
+ *
+ * Returns new allocated cache or NULL on error
+ *
+ * @cache pointer to the PageCache struct
+ * @num_pages: cache maximal number of cached pages
+ * @page_size: cache page size
+ */
+PageCache *cache_init(int64_t num_pages, unsigned int page_size);
+
+/**
+ * cache_fini: free all cache resources
+ * @cache pointer to the PageCache struct
+ */
+void cache_fini(PageCache *cache);
+
+/**
+ * cache_is_cached: Checks to see if the page is cached
+ *
+ * Returns %true if page is cached
+ *
+ * @cache pointer to the PageCache struct
+ * @addr: page addr
+ */
+bool cache_is_cached(const PageCache *cache, uint64_t addr);
+
+/**
+ * get_cached_data: Get the data cached for an addr
+ *
+ * Returns pointer to the data cached or NULL if not cached
+ *
+ * @cache pointer to the PageCache struct
+ * @addr: page addr
+ */
+uint8_t *get_cached_data(const PageCache *cache, uint64_t addr);
+
+/**
+ * cache_insert: insert the page into the cache. the previous value will be overwritten
+ *
+ * @cache pointer to the PageCache struct
+ * @addr: page address
+ * @pdata: pointer to the page
+ */
+void cache_insert(PageCache *cache, uint64_t addr, uint8_t *pdata);
+
+/**
+ * cache_resize: resize the page cache. In case of size reduction the extra
+ * pages will be freed
+ *
+ * Returns -1 on error new cache size on success
+ *
+ * @cache pointer to the PageCache struct
+ * @num_pages: new page cache size (in pages)
+ */
+int64_t cache_resize(PageCache *cache, int64_t num_pages);
+
+#endif
diff --git a/page_cache.c b/page_cache.c
new file mode 100644
index 0000000..8110273
--- /dev/null
+++ b/page_cache.c
@@ -0,0 +1,216 @@
+/*
+ * Page cache for QEMU
+ * The cache is base on a hash of the page address
+ *
+ * Copyright 2012 Red Hat, Inc. and/or its affiliates
+ *
+ * Authors:
+ * Orit Wasserman <owasserm@redhat.com>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or later.
+ * See the COPYING file in the top-level directory.
+ *
+ */
+
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <strings.h>
+#include <string.h>
+#include <sys/time.h>
+#include <sys/types.h>
+#include <stdbool.h>
+#include <glib.h>
+#include <strings.h>
+
+#include "qemu-common.h"
+#include "qemu/page_cache.h"
+
+#ifdef DEBUG_CACHE
+#define DPRINTF(fmt, ...) \
+ do { fprintf(stdout, "cache: " fmt, ## __VA_ARGS__); } while (0)
+#else
+#define DPRINTF(fmt, ...) \
+ do { } while (0)
+#endif
+
+typedef struct CacheItem CacheItem;
+
+struct CacheItem {
+ uint64_t it_addr;
+ uint64_t it_age;
+ uint8_t *it_data;
+};
+
+struct PageCache {
+ CacheItem *page_cache;
+ unsigned int page_size;
+ int64_t max_num_items;
+ uint64_t max_item_age;
+ int64_t num_items;
+};
+
+PageCache *cache_init(int64_t num_pages, unsigned int page_size)
+{
+ int64_t i;
+
+ PageCache *cache = g_malloc(sizeof(*cache));
+
+ if (num_pages <= 0) {
+ DPRINTF("invalid number of pages\n");
+ return NULL;
+ }
+
+ /* round down to the nearest power of 2 */
+ if (!is_power_of_2(num_pages)) {
+ num_pages = pow2floor(num_pages);
+ DPRINTF("rounding down to %" PRId64 "\n", num_pages);
+ }
+ cache->page_size = page_size;
+ cache->num_items = 0;
+ cache->max_item_age = 0;
+ cache->max_num_items = num_pages;
+
+ DPRINTF("Setting cache buckets to %" PRId64 "\n", cache->max_num_items);
+
+ cache->page_cache = g_malloc((cache->max_num_items) *
+ sizeof(*cache->page_cache));
+
+ for (i = 0; i < cache->max_num_items; i++) {
+ cache->page_cache[i].it_data = NULL;
+ cache->page_cache[i].it_age = 0;
+ cache->page_cache[i].it_addr = -1;
+ }
+
+ return cache;
+}
+
+void cache_fini(PageCache *cache)
+{
+ int64_t i;
+
+ g_assert(cache);
+ g_assert(cache->page_cache);
+
+ for (i = 0; i < cache->max_num_items; i++) {
+ g_free(cache->page_cache[i].it_data);
+ }
+
+ g_free(cache->page_cache);
+ cache->page_cache = NULL;
+}
+
+static unsigned long cache_get_cache_pos(const PageCache *cache,
+ uint64_t address)
+{
+ unsigned long pos;
+
+ g_assert(cache->max_num_items);
+ pos = (address / cache->page_size) & (cache->max_num_items - 1);
+ return pos;
+}
+
+bool cache_is_cached(const PageCache *cache, uint64_t addr)
+{
+ unsigned long pos;
+
+ g_assert(cache);
+ g_assert(cache->page_cache);
+
+ pos = cache_get_cache_pos(cache, addr);
+
+ return (cache->page_cache[pos].it_addr == addr);
+}
+
+static CacheItem *cache_get_by_addr(const PageCache *cache, uint64_t addr)
+{
+ unsigned long pos;
+
+ g_assert(cache);
+ g_assert(cache->page_cache);
+
+ pos = cache_get_cache_pos(cache, addr);
+
+ return &cache->page_cache[pos];
+}
+
+uint8_t *get_cached_data(const PageCache *cache, uint64_t addr)
+{
+ return cache_get_by_addr(cache, addr)->it_data;
+}
+
+void cache_insert(PageCache *cache, uint64_t addr, uint8_t *pdata)
+{
+
+ CacheItem *it = NULL;
+
+ g_assert(cache);
+ g_assert(cache->page_cache);
+
+ /* actual update of entry */
+ it = cache_get_by_addr(cache, addr);
+
+ if (!it->it_data) {
+ cache->num_items++;
+ }
+
+ it->it_data = pdata;
+ it->it_age = ++cache->max_item_age;
+ it->it_addr = addr;
+}
+
+int64_t cache_resize(PageCache *cache, int64_t new_num_pages)
+{
+ PageCache *new_cache;
+ int64_t i;
+
+ CacheItem *old_it, *new_it;
+
+ g_assert(cache);
+
+ /* cache was not inited */
+ if (cache->page_cache == NULL) {
+ return -1;
+ }
+
+ /* same size */
+ if (pow2floor(new_num_pages) == cache->max_num_items) {
+ return cache->max_num_items;
+ }
+
+ new_cache = cache_init(new_num_pages, cache->page_size);
+ if (!(new_cache)) {
+ DPRINTF("Error creating new cache\n");
+ return -1;
+ }
+
+ /* move all data from old cache */
+ for (i = 0; i < cache->max_num_items; i++) {
+ old_it = &cache->page_cache[i];
+ if (old_it->it_addr != -1) {
+ /* check for collision , if there is, keep the first value */
+ new_it = cache_get_by_addr(new_cache, old_it->it_addr);
+ if (new_it->it_data) {
+ /* keep the oldest page */
+ if (new_it->it_age >= old_it->it_age) {
+ g_free(old_it->it_data);
+ } else {
+ g_free(new_it->it_data);
+ new_it->it_data = old_it->it_data;
+ new_it->it_age = old_it->it_age;
+ new_it->it_addr = old_it->it_addr;
+ }
+ } else {
+ cache_insert(new_cache, old_it->it_addr, old_it->it_data);
+ }
+ }
+ }
+
+ cache->page_cache = new_cache->page_cache;
+ cache->max_num_items = new_cache->max_num_items;
+ cache->num_items = new_cache->num_items;
+
+ g_free(new_cache);
+
+ return cache->max_num_items;
+}
diff --git a/qemu-common.h b/qemu-common.h
index 09676f5..195bab5 100644
--- a/qemu-common.h
+++ b/qemu-common.h
@@ -1,3 +1,4 @@
+
/* Common header file that is included by all of qemu. */
#ifndef QEMU_COMMON_H
#define QEMU_COMMON_H
@@ -411,6 +412,18 @@ static inline uint64_t muldiv64(uint64_t a, uint32_t b, uint32_t c)
/* Round number up to multiple */
#define QEMU_ALIGN_UP(n, m) QEMU_ALIGN_DOWN((n) + (m) - 1, (m))
+static inline bool is_power_of_2(int64_t value)
+{
+ if (!value) {
+ return 0;
+ }
+
+ return !(value & (value - 1));
+}
+
+/* round down to the nearest power of 2*/
+int64_t pow2floor(int64_t value);
+
#include "module.h"
#endif
--
1.7.7.6
^ permalink raw reply related [flat|nested] 11+ messages in thread
end of thread, other threads:[~2012-07-10 19:17 UTC | newest]
Thread overview: 11+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2012-07-10 9:37 [Qemu-devel] [PATCH v17 0/9] XBZRLE delta for live migration of large memory app Orit Wasserman
2012-07-10 9:37 ` [Qemu-devel] [PATCH v17 1/9] Add migration capabilities Orit Wasserman
2012-07-10 9:37 ` [Qemu-devel] [PATCH v17 2/9] Add XBZRLE documentation Orit Wasserman
2012-07-10 9:37 ` [Qemu-devel] [PATCH v17 3/9] Add cache handling functions Orit Wasserman
2012-07-10 19:16 ` Orit Wasserman
2012-07-10 9:37 ` [Qemu-devel] [PATCH v17 4/9] Add uleb encoding/decoding functions Orit Wasserman
2012-07-10 9:37 ` [Qemu-devel] [PATCH v17 5/9] Change ram_save_block to return -1 if there are no more changes Orit Wasserman
2012-07-10 9:37 ` [Qemu-devel] [PATCH v17 6/9] Add xbzrle_encode_buffer and xbzrle_decode_buffer functions Orit Wasserman
2012-07-10 9:37 ` [Qemu-devel] [PATCH v17 7/9] Add XBZRLE to ram_save_block and ram_save_live Orit Wasserman
2012-07-10 9:37 ` [Qemu-devel] [PATCH v17 8/9] Add migrate_set_cachesize command Orit Wasserman
2012-07-10 9:37 ` [Qemu-devel] [PATCH v17 9/9] Add XBZRLE statistics Orit Wasserman
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