mbox series

[v1,0/4] virtio-mem: Support "x-ignore-shared" migration

Message ID 20230620130354.322180-1-david@redhat.com
Headers show
Series virtio-mem: Support "x-ignore-shared" migration | expand

Message

David Hildenbrand June 20, 2023, 1:03 p.m. UTC
Stumbling over "x-ignore-shared" migration support for virtio-mem on
my todo list, I remember talking to Dave G. a while ago about how
ram_block_discard_range() in MAP_PIRVATE file mappings is possibly
harmful when the file is used somewhere else -- for example, with VM
templating in multiple VMs.

This series adds a warning to ram_block_discard_range() in that problematic
case and adds "x-ignore-shared" migration support for virtio-mem, which
is pretty straight-forward. The last patch also documents how VM templating
interacts with virtio-mem.

Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Juan Quintela <quintela@redhat.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Leonardo Bras <leobras@redhat.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: "Philippe Mathieu-Daudé" <philmd@linaro.org>
Cc: Peng Tao <tao.peng@linux.alibaba.com>

David Hildenbrand (4):
  softmmu/physmem: Warn with ram_block_discard_range() on MAP_PRIVATE
    file mapping
  virtio-mem: Skip most of virtio_mem_unplug_all() without plugged
    memory
  migration/ram: Expose ramblock_is_ignored() as
    migrate_ram_is_ignored()
  virtio-mem: Support "x-ignore-shared" migration

 hw/virtio/virtio-mem.c   | 67 ++++++++++++++++++++++++++++------------
 include/migration/misc.h |  1 +
 migration/postcopy-ram.c |  2 +-
 migration/ram.c          | 14 ++++-----
 migration/ram.h          |  3 +-
 softmmu/physmem.c        | 18 +++++++++++
 6 files changed, 76 insertions(+), 29 deletions(-)

Comments

Mario Casquero July 6, 2023, 5:59 a.m. UTC | #1
This series has been tested successfully by QE. Start a VM with a 8G
virtio-mem device and start memtester on it. Enable x-ignore-shared
capability and then do migration. Migration was successful and
virtio-mem can be resized as usual.

Tested-by: Mario Casquero <mcasquer@redhat.com>

BR,
Mario




On Tue, Jun 20, 2023 at 3:05 PM David Hildenbrand <david@redhat.com> wrote:
>
> Stumbling over "x-ignore-shared" migration support for virtio-mem on
> my todo list, I remember talking to Dave G. a while ago about how
> ram_block_discard_range() in MAP_PIRVATE file mappings is possibly
> harmful when the file is used somewhere else -- for example, with VM
> templating in multiple VMs.
>
> This series adds a warning to ram_block_discard_range() in that problematic
> case and adds "x-ignore-shared" migration support for virtio-mem, which
> is pretty straight-forward. The last patch also documents how VM templating
> interacts with virtio-mem.
>
> Cc: "Michael S. Tsirkin" <mst@redhat.com>
> Cc: Juan Quintela <quintela@redhat.com>
> Cc: Peter Xu <peterx@redhat.com>
> Cc: Leonardo Bras <leobras@redhat.com>
> Cc: Paolo Bonzini <pbonzini@redhat.com>
> Cc: "Philippe Mathieu-Daudé" <philmd@linaro.org>
> Cc: Peng Tao <tao.peng@linux.alibaba.com>
>
> David Hildenbrand (4):
>   softmmu/physmem: Warn with ram_block_discard_range() on MAP_PRIVATE
>     file mapping
>   virtio-mem: Skip most of virtio_mem_unplug_all() without plugged
>     memory
>   migration/ram: Expose ramblock_is_ignored() as
>     migrate_ram_is_ignored()
>   virtio-mem: Support "x-ignore-shared" migration
>
>  hw/virtio/virtio-mem.c   | 67 ++++++++++++++++++++++++++++------------
>  include/migration/misc.h |  1 +
>  migration/postcopy-ram.c |  2 +-
>  migration/ram.c          | 14 ++++-----
>  migration/ram.h          |  3 +-
>  softmmu/physmem.c        | 18 +++++++++++
>  6 files changed, 76 insertions(+), 29 deletions(-)
>
> --
> 2.40.1
>
>
David Hildenbrand July 6, 2023, 7:19 a.m. UTC | #2
On 06.07.23 07:59, Mario Casquero wrote:
> This series has been tested successfully by QE. Start a VM with a 8G
> virtio-mem device and start memtester on it. Enable x-ignore-shared
> capability and then do migration. Migration was successful and
> virtio-mem can be resized as usual.
> 
> Tested-by: Mario Casquero <mcasquer@redhat.com>
> 

Thanks a lot Mario!