Re: [Qemu-devel] [PATCH v2 0/5] Add ignore-external migration capability

[Yury Kotov]

Ping

04.02.2019, 16:27, "Yury Kotov" <address@hidden>:
> Hi,
>
> The series adds a migration capability, which allows to skip shared RAM blocks
> during the migration. It's useful for fast local migration. E.g. to update 
> QEMU
> for the running guests.
>
> Usage example:
> 1. Start source VM:
>    qemu-system-x86 \
>      -m 4G \
>      -object 
> memory-backend-file,id=mem0,size=4G,share=on,mem-path=/dev/shm/mem0 \
>      -numa node,memdev=mem0 \
>      -qmp unix:/tmp/qemu-qmp-1.sock,server,nowait \
>
> 2. Start target VM:
>    qemu-system-x86 \
>      -m 4G \
>      -object 
> memory-backend-file,id=mem0,size=4G,share=on,mem-path=/dev/shm/mem0 \
>      -numa node,memdev=mem0 \
>      -qmp unix:/tmp/qemu-qmp-2.sock,server,nowait \
>      -incoming defer
>
> 3. Enable ignore-external capability on both VMs:
>    { "execute": "migrate-set-capabilities" , "arguments":
>      { "capabilities": [ { "capability": "x-ignore-external", "state": true } 
> ] } }
>
> 4. Start migration.
>
> Another use case I keep in mind is to migrate to file. Usage is very similar.
>
> V1 to V2:
> * Keep migration stream compatibility
> * Reuse the existing code to ignore unwanted RAMBlocks
> * Add capability validation feature
> * ignore-external -> ignore-shared
>
> Regards,
> Yury
>
> Yury Kotov (5):
>   exec: Change RAMBlockIterFunc definition
>   migration: Move qemu_ram_foreach_migratable_block to migration code
>   migration: Introduce ignore-shared capability
>   tests/migration-test: Add a test for ignore-shared capability
>   migration: Add capabilities validation
>
>  exec.c | 38 ++++++-------
>  include/exec/cpu-common.h | 7 +--
>  migration/migration.c | 9 ++++
>  migration/migration.h | 11 +++-
>  migration/postcopy-ram.c | 48 +++++++++--------
>  migration/ram.c | 86 ++++++++++++++++++++++++++----
>  migration/rdma.c | 9 ++--
>  migration/savevm.c | 101 +++++++++++++++++++++++++++++++++++
>  qapi/migration.json | 5 +-
>  stubs/ram-block.c | 15 ++++++
>  tests/migration-test.c | 109 +++++++++++++++++++++++++++++++-------
>  util/vfio-helpers.c | 6 +--
>  12 files changed, 361 insertions(+), 83 deletions(-)
>
> --
> 2.20.1