migration: move rate limiting to QEMUFile
Rate limiting is now simply a byte counter; client call
qemu_file_rate_limit() manually to determine if they have to exit.
So it is possible and simple to move the functionality to QEMUFile.
This makes the remaining functionality of s->file redundant;
in the next patch we can remove it and write directly to s->migration_file.
Reviewed-by: Orit Wasserman <owasserm@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
diff --git a/docs/migration.txt b/docs/migration.txt
index f3ddd2f..0719a55 100644
--- a/docs/migration.txt
+++ b/docs/migration.txt
@@ -55,10 +55,7 @@
QEMUFile *qemu_fopen_ops(void *opaque,
QEMUFilePutBufferFunc *put_buffer,
QEMUFileGetBufferFunc *get_buffer,
- QEMUFileCloseFunc *close,
- QEMUFileRateLimit *rate_limit,
- QEMUFileSetRateLimit *set_rate_limit,
- QEMUFileGetRateLimit *get_rate_limit);
+ QEMUFileCloseFunc *close);
The functions have the following functionality:
@@ -80,24 +77,9 @@
typedef int (QEMUFileCloseFunc)(void *opaque);
-Called to determine if the file has exceeded its bandwidth allocation. The
-bandwidth capping is a soft limit, not a hard limit.
-
-typedef int (QEMUFileRateLimit)(void *opaque);
-
-Called to change the current bandwidth allocation. This function must return
-the new actual bandwidth. It should be new_rate if everything goes OK, and
-the old rate otherwise.
-
-typedef size_t (QEMUFileSetRateLimit)(void *opaque, size_t new_rate);
-typedef size_t (QEMUFileGetRateLimit)(void *opaque);
-
You can use any internal state that you need using the opaque void *
pointer that is passed to all functions.
-The rate limiting functions are used to limit the bandwidth used by
-QEMU migration.
-
The important functions for us are put_buffer()/get_buffer() that
allow to write/read a buffer into the QEMUFile.
diff --git a/include/migration/qemu-file.h b/include/migration/qemu-file.h
index 25e8461..df81261 100644
--- a/include/migration/qemu-file.h
+++ b/include/migration/qemu-file.h
@@ -51,26 +51,11 @@
*/
typedef int (QEMUFileGetFD)(void *opaque);
-/* Called to determine if the file has exceeded its bandwidth allocation. The
- * bandwidth capping is a soft limit, not a hard limit.
- */
-typedef int (QEMUFileRateLimit)(void *opaque);
-
-/* Called to change the current bandwidth allocation. This function must return
- * the new actual bandwidth. It should be new_rate if everything goes ok, and
- * the old rate otherwise
- */
-typedef int64_t (QEMUFileSetRateLimit)(void *opaque, int64_t new_rate);
-typedef int64_t (QEMUFileGetRateLimit)(void *opaque);
-
typedef struct QEMUFileOps {
QEMUFilePutBufferFunc *put_buffer;
QEMUFileGetBufferFunc *get_buffer;
QEMUFileCloseFunc *close;
QEMUFileGetFD *get_fd;
- QEMUFileRateLimit *rate_limit;
- QEMUFileSetRateLimit *set_rate_limit;
- QEMUFileGetRateLimit *get_rate_limit;
} QEMUFileOps;
QEMUFile *qemu_fopen_ops(void *opaque, const QEMUFileOps *ops);
@@ -109,7 +94,8 @@
uint64_t qemu_get_be64(QEMUFile *f);
int qemu_file_rate_limit(QEMUFile *f);
-int64_t qemu_file_set_rate_limit(QEMUFile *f, int64_t new_rate);
+void qemu_file_reset_rate_limit(QEMUFile *f);
+void qemu_file_set_rate_limit(QEMUFile *f, int64_t new_rate);
int64_t qemu_file_get_rate_limit(QEMUFile *f);
int qemu_file_get_error(QEMUFile *f);
diff --git a/migration.c b/migration.c
index 1f58d77..4b04d50 100644
--- a/migration.c
+++ b/migration.c
@@ -518,7 +518,6 @@
return ret;
}
- s->bytes_xfer += size;
return size;
}
@@ -543,49 +542,6 @@
return qemu_get_fd(s->migration_file);
}
-/*
- * The meaning of the return values is:
- * 0: We can continue sending
- * 1: Time to stop
- * negative: There has been an error
- */
-static int migration_rate_limit(void *opaque)
-{
- MigrationState *s = opaque;
- int ret;
-
- ret = qemu_file_get_error(s->file);
- if (ret) {
- return ret;
- }
-
- if (s->bytes_xfer >= s->xfer_limit) {
- return 1;
- }
-
- return 0;
-}
-
-static int64_t migration_set_rate_limit(void *opaque, int64_t new_rate)
-{
- MigrationState *s = opaque;
- if (qemu_file_get_error(s->file)) {
- goto out;
- }
-
- s->xfer_limit = new_rate;
-
-out:
- return s->xfer_limit;
-}
-
-static int64_t migration_get_rate_limit(void *opaque)
-{
- MigrationState *s = opaque;
-
- return s->xfer_limit;
-}
-
static void *migration_thread(void *opaque)
{
MigrationState *s = opaque;
@@ -646,7 +602,7 @@
s->expected_downtime = s->dirty_bytes_rate / bandwidth;
}
- s->bytes_xfer = 0;
+ qemu_file_reset_rate_limit(s->file);
sleep_time = 0;
initial_time = current_time;
initial_bytes = qemu_ftell(s->file);
@@ -679,9 +635,6 @@
.get_fd = migration_get_fd,
.put_buffer = migration_put_buffer,
.close = migration_close,
- .rate_limit = migration_rate_limit,
- .get_rate_limit = migration_get_rate_limit,
- .set_rate_limit = migration_set_rate_limit,
};
void migrate_fd_connect(MigrationState *s)
@@ -689,10 +642,8 @@
s->state = MIG_STATE_ACTIVE;
trace_migrate_set_state(MIG_STATE_ACTIVE);
- s->bytes_xfer = 0;
/* This is a best 1st approximation. ns to ms */
s->expected_downtime = max_downtime/1000000;
-
s->cleanup_bh = qemu_bh_new(migrate_fd_cleanup, s);
s->file = qemu_fopen_ops(s, &migration_file_ops);
diff --git a/savevm.c b/savevm.c
index 1414f08..147e2d2 100644
--- a/savevm.c
+++ b/savevm.c
@@ -119,6 +119,9 @@
void *opaque;
int is_write;
+ int64_t bytes_xfer;
+ int64_t xfer_limit;
+
int64_t pos; /* start of buffer when writing, end of buffer
when reading */
int buf_index;
@@ -479,7 +482,6 @@
f->opaque = opaque;
f->ops = ops;
f->is_write = 0;
-
return f;
}
@@ -605,6 +607,7 @@
memcpy(f->buf + f->buf_index, buf, l);
f->is_write = 1;
f->buf_index += l;
+ f->bytes_xfer += l;
buf += l;
size -= l;
if (f->buf_index >= IO_BUF_SIZE) {
@@ -725,28 +728,28 @@
int qemu_file_rate_limit(QEMUFile *f)
{
- if (f->ops->rate_limit)
- return f->ops->rate_limit(f->opaque);
-
+ if (qemu_file_get_error(f)) {
+ return 1;
+ }
+ if (f->xfer_limit > 0 && f->bytes_xfer > f->xfer_limit) {
+ return 1;
+ }
return 0;
}
int64_t qemu_file_get_rate_limit(QEMUFile *f)
{
- if (f->ops->get_rate_limit)
- return f->ops->get_rate_limit(f->opaque);
-
- return 0;
+ return f->xfer_limit;
}
-int64_t qemu_file_set_rate_limit(QEMUFile *f, int64_t new_rate)
+void qemu_file_set_rate_limit(QEMUFile *f, int64_t limit)
{
- /* any failed or completed migration keeps its state to allow probing of
- * migration data, but has no associated file anymore */
- if (f && f->ops->set_rate_limit)
- return f->ops->set_rate_limit(f->opaque, new_rate);
+ f->xfer_limit = limit;
+}
- return 0;
+void qemu_file_reset_rate_limit(QEMUFile *f)
+{
+ f->bytes_xfer = 0;
}
void qemu_put_be16(QEMUFile *f, unsigned int v)
