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[Qemu-devel] [PATCH v2 2/9] migration: Fix a potential issue
From: |
Liang Li |
Subject: |
[Qemu-devel] [PATCH v2 2/9] migration: Fix a potential issue |
Date: |
Thu, 5 May 2016 15:32:52 +0800 |
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 <address@hidden>
Suggested-by: Juan Quintela <address@hidden>
Signed-off-by: Liang Li <address@hidden>
---
migration/ram.c | 19 +++++++++++++++++++
1 file changed, 19 insertions(+)
diff --git a/migration/ram.c b/migration/ram.c
index 7ab6ab5..8a59a08 100644
--- a/migration/ram.c
+++ b/migration/ram.c
@@ -2220,6 +2220,24 @@ 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;
@@ -2554,6 +2572,7 @@ 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);
--
1.9.1
- [Qemu-devel] [PATCH v2 0/9] live migration bug fix and refine, Liang Li, 2016/05/05
- [Qemu-devel] [PATCH v2 1/9] migration: Fix multi-thread compression bug, Liang Li, 2016/05/05
- [Qemu-devel] [PATCH v2 2/9] migration: Fix a potential issue,
Liang Li <=
- [Qemu-devel] [PATCH v2 3/9] migration: remove useless code, Liang Li, 2016/05/05
- [Qemu-devel] [PATCH v2 6/9] migration: protect the quit flag by lock, Liang Li, 2016/05/05
- [Qemu-devel] [PATCH v2 7/9] migration: refine the compression code, Liang Li, 2016/05/05
- [Qemu-devel] [PATCH v2 4/9] qemu-file: Fix qemu_put_compression_data flaw, Liang Li, 2016/05/05
- [Qemu-devel] [PATCH v2 8/9] migration: refine the decompression code, Liang Li, 2016/05/05
- [Qemu-devel] [PATCH v2 5/9] migration: refine ram_save_compressed_page, Liang Li, 2016/05/05
- [Qemu-devel] [PATCH v2 9/9] migration: code clean up, Liang Li, 2016/05/05
- Re: [Qemu-devel] [PATCH v2 0/9] live migration bug fix and refine, Amit Shah, 2016/05/23