diff options
| author | Peng Tao <tao.peng@linux.alibaba.com> | 2019-06-14 14:35:13 +0800 |
|---|---|---|
| committer | Juan Quintela <quintela@redhat.com> | 2019-07-15 15:39:03 +0200 |
| commit | b17fbbe55cba95ad323b27c2f9f3e22eb6364d4b (patch) | |
| tree | 075859643375b8f0351cca77f9d320000e0ed164 | |
| parent | 002cad6b16ca01d8dc8160038e139b47e5ca557e (diff) | |
migration: allow private destination ram with x-ignore-shared
By removing the share ram check, qemu is able to migrate
to private destination ram when x-ignore-shared capability
is on. Then we can create multiple destination VMs based
on the same source VM.
This changes the x-ignore-shared migration capability to
work similar to Lai's original bypass-shared-memory
work(https://lists.gnu.org/archive/html/qemu-devel/2018-04/msg00003.html)
which enables kata containers (https://katacontainers.io)
to implement the VM templating feature.
An example usage in kata containers(https://katacontainers.io):
1. Start the source VM:
qemu-system-x86 -m 2G \
-object memory-backend-file,id=mem0,size=2G,share=on,mem-path=/tmpfs/template-memory \
-numa node,memdev=mem0
2. Stop the template VM, set migration x-ignore-shared capability,
migrate "exec:cat>/tmpfs/state", quit it
3. Start target VM:
qemu-system-x86 -m 2G \
-object memory-backend-file,id=mem0,size=2G,share=off,mem-path=/tmpfs/template-memory \
-numa node,memdev=mem0 \
-incoming defer
4. connect to target VM qmp, set migration x-ignore-shared capability,
migrate_incoming "exec:cat /tmpfs/state"
5. create more target VMs repeating 3 and 4
Cc: Dr. David Alan Gilbert <dgilbert@redhat.com>
Cc: Yury Kotov <yury-kotov@yandex-team.ru>
Cc: Jiangshan Lai <laijs@hyper.sh>
Cc: Xu Wang <xu@hyper.sh>
Signed-off-by: Peng Tao <tao.peng@linux.alibaba.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Message-Id: <1560494113-1141-1-git-send-email-tao.peng@linux.alibaba.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
| -rw-r--r-- | migration/ram.c | 7 |
1 files changed, 0 insertions, 7 deletions
diff --git a/migration/ram.c b/migration/ram.c index 8a6ad61d3d..8622b4dc49 100644 --- a/migration/ram.c +++ b/migration/ram.c @@ -3426,7 +3426,6 @@ static int ram_save_setup(QEMUFile *f, void *opaque) } if (migrate_ignore_shared()) { qemu_put_be64(f, block->mr->addr); - qemu_put_byte(f, ramblock_is_ignored(block) ? 1 : 0); } } @@ -4393,12 +4392,6 @@ static int ram_load(QEMUFile *f, void *opaque, int version_id) } if (migrate_ignore_shared()) { hwaddr addr = qemu_get_be64(f); - bool ignored = qemu_get_byte(f); - if (ignored != ramblock_is_ignored(block)) { - error_report("RAM block %s should %s be migrated", - id, ignored ? "" : "not"); - ret = -EINVAL; - } if (ramblock_is_ignored(block) && block->mr->addr != addr) { error_report("Mismatched GPAs for block %s " |