* Yury Kotov (yury-ko...@yandex-team.ru) wrote:
> 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.
Other than the title of this cover letter being out of date, I think
we're about OK!
Dave
> 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-shared capability on both VMs:
> { "execute": "migrate-set-capabilities" , "arguments":
> { "capabilities": [ { "capability": "x-ignore-shared", "state": true } ]
> } }
>
> 4. Start migration.
>
> Another use case I keep in mind is to migrate to file. Usage is very similar.
>
> V2 to V3:
> * Split "migration: Introduce ignore-shared capability"
> * Serialize the capabilities as strings rather than as indexes
> * Don't allow to enable postcopy and ignore-shared together
> * Skip the test for OSs which don't have /dev/shm
> * Add a check whether shared RAM has been really skipped
>
> 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: Introduce ignore-shared capability
> migration: Add an ability to ignore shared RAM blocks
> 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 | 14 ++++
> migration/migration.h | 5 +-
> migration/postcopy-ram.c | 48 +++++++------
> migration/ram.c | 110 ++++++++++++++++++++++--------
> migration/rdma.c | 9 ++-
> migration/savevm.c | 137 ++++++++++++++++++++++++++++++++++++++
> qapi/migration.json | 5 +-
> stubs/ram-block.c | 15 +++++
> tests/migration-test.c | 131 +++++++++++++++++++++++++++++-------
> util/vfio-helpers.c | 6 +-
> 12 files changed, 420 insertions(+), 105 deletions(-)
>
> --
> 2.20.1
>
--
Dr. David Alan Gilbert / dgilb...@redhat.com / Manchester, UK
