From: Amit Shah <amit.shah@redhat.com>
To: Peter Maydell <peter.maydell@linaro.org>
Cc: Juan Quintela <quintela@redhat.com>,
"Dr. David Alan Gilbert" <dgilbert@redhat.com>,
liang.z.li@intel.com, den@openvz.org,
qemu list <qemu-devel@nongnu.org>,
Amit Shah <amit.shah@redhat.com>
Subject: [Qemu-devel] [PULL 05/13] migration: Fix a potential issue
Date: Fri, 17 Jun 2016 18:36:44 +0530 [thread overview]
Message-ID: <5533b2e9bcd222e37ca6c2ff06e79adf9bf036bf.1466168448.git.amit.shah@redhat.com> (raw)
In-Reply-To: <cover.1466168448.git.amit.shah@redhat.com>
In-Reply-To: <cover.1466168448.git.amit.shah@redhat.com>
From: Liang Li <liang.z.li@intel.com>
At the end of live migration and before vm_start() on the destination
side, we should make sure all the decompression tasks are finished, if
this can not be guaranteed, the VM may get the incorrect memory data,
or the updated memory may be overwritten by the decompression thread.
Add the code to fix this potential issue.
Suggested-by: David Alan Gilbert <dgilbert@redhat.com>
Suggested-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Liang Li <liang.z.li@intel.com>
Message-Id: <1462433579-13691-3-git-send-email-liang.z.li@intel.com>
Signed-off-by: Amit Shah <amit.shah@redhat.com>
---
migration/ram.c | 19 +++++++++++++++++++
1 file changed, 19 insertions(+)
diff --git a/migration/ram.c b/migration/ram.c
index f3fe6c7..5ccc068 100644
--- a/migration/ram.c
+++ b/migration/ram.c
@@ -2223,6 +2223,24 @@ static void *do_data_decompress(void *opaque)
return NULL;
}
+static void wait_for_decompress_done(void)
+{
+ int idx, thread_count;
+
+ if (!migrate_use_compression()) {
+ return;
+ }
+
+ thread_count = migrate_decompress_threads();
+ qemu_mutex_lock(&decomp_done_lock);
+ for (idx = 0; idx < thread_count; idx++) {
+ while (!decomp_param[idx].done) {
+ qemu_cond_wait(&decomp_done_cond, &decomp_done_lock);
+ }
+ }
+ qemu_mutex_unlock(&decomp_done_lock);
+}
+
void migrate_decompress_threads_create(void)
{
int i, thread_count;
@@ -2557,6 +2575,7 @@ static int ram_load(QEMUFile *f, void *opaque, int version_id)
}
}
+ wait_for_decompress_done();
rcu_read_unlock();
DPRINTF("Completed load of VM with exit code %d seq iteration "
"%" PRIu64 "\n", ret, seq_iter);
--
2.7.4
next prev parent reply other threads:[~2016-06-17 13:07 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-06-17 13:06 [Qemu-devel] [PULL 00/13] migration: many fixes Amit Shah
2016-06-17 13:06 ` [Qemu-devel] [PULL 01/13] migration: Don't use *_to_cpup() and cpu_to_*w() Amit Shah
2016-06-17 13:06 ` [Qemu-devel] [PULL 02/13] migration: Trace improvements Amit Shah
2016-06-17 13:06 ` [Qemu-devel] [PULL 03/13] migration: fix inability to save VM after snapshot Amit Shah
2016-06-17 13:06 ` [Qemu-devel] [PULL 04/13] migration: Fix multi-thread compression bug Amit Shah
2016-06-17 13:06 ` Amit Shah [this message]
2016-06-17 13:06 ` [Qemu-devel] [PULL 06/13] migration: remove useless code Amit Shah
2016-06-17 13:06 ` [Qemu-devel] [PULL 07/13] qemu-file: Fix qemu_put_compression_data flaw Amit Shah
2016-06-17 13:06 ` [Qemu-devel] [PULL 08/13] migration: refine ram_save_compressed_page Amit Shah
2016-06-17 13:06 ` [Qemu-devel] [PULL 09/13] migration: protect the quit flag by lock Amit Shah
2016-06-17 13:06 ` [Qemu-devel] [PULL 10/13] migration: refine the compression code Amit Shah
2016-06-17 13:06 ` [Qemu-devel] [PULL 11/13] migration: refine the decompression code Amit Shah
2016-06-17 13:06 ` [Qemu-devel] [PULL 12/13] migration: code clean up Amit Shah
2016-06-17 13:06 ` [Qemu-devel] [PULL 13/13] vmstate-static-checker: fix size mismatch detection in unused fields Amit Shah
2016-06-17 13:58 ` [Qemu-devel] [PULL 00/13] migration: many fixes Peter Maydell
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