| Message ID | 20190204130958.18904-1-yury-kotov@yandex-team.ru (mailing list archive) |
|---|---|
| Headers | show |
| Series | Add ignore-external migration capability | expand |
Ping 04.02.2019, 16:27, "Yury Kotov" <yury-kotov@yandex-team.ru>: > 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
* Yury Kotov (yury-kotov@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. > > 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. Hi, I've cc'd in Eric, Lai and Peter, all who were asking for something similar last year; can you all confirm this patch does what you need or can work with what you needed to do? Dave > 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 > -- Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK
On Mon, Feb 11, 2019 at 04:03:57PM +0000, Dr. David Alan Gilbert wrote: > * Yury Kotov (yury-kotov@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. > > > > 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. > > Hi, > I've cc'd in Eric, Lai and Peter, all who were asking for something > similar last year; can you all confirm this patch does what you need or > can work with what you needed to do? x-ignore-external is a global setting so affects all memory-backend-file instances. The obvious question is where there is any reasonable/conceivable scenario in which QEMU would have multiple "-object memory-backend-file" intsances and it be neccessary/desirable to migrate some, but skip migrate of others ? Could there ever be a device backend which is using a memory region to communicate with an external process, where you would need to have a new instance for the migration target QEMU, and explicitly not reuse the source QEMU's memory-backend-file storage ? Regards, Daniel
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(-)