On 12/12/2012 06:46 AM, Paolo Bonzini wrote: > Signed-off-by: Paolo Bonzini <pbonz...@redhat.com> > --- > blockdev.c | 55 +++++++++++++++++++++++++++++++++++++++++++++++ > blockdev.h | 1 + > hmp-commands.hx | 39 ++++++++++++++++++++++++++++++++++ > hmp.c | 27 +++++++++++++++++++++++ > hmp.h | 2 ++ > qapi-schema.json | 56 ++++++++++++++++++++++++++++++++++++++++++++++++ > qmp-commands.hx | 65 > ++++++++++++++++++++++++++++++++++++++++++++++++++++++++ > 7 files changed, 245 insertions(+) >
A bit light on the commit message. What is the proper sequence of QMP
commands for using this feature in relation to driver-mirror and such?
For example, let's say I want to start a mirror, then shutdown qemu,
then start a new qemu -S; what is the right sequence for when to call
this to re-initialize the dirty bitmap and resume the mirror at the same
point, all prior to issuing 'cont' to the new qemu instance? Once I
know that, then I can fix libvirt to allow disk-copy across qemu
restarts (right now, libvirt limits disk-copy to transient domains,
since those don't have to worry about restarts).
> +If the dirty bitmap is already active, or used by something else (for
> +example @command{drive_mirror}), the granularity argument must be absent
> +or equal to the active granularity. The granularity must be a power-of-two
> +comprised between 4,096 and 67,108,864.
4k to 64M here...
> +++ b/qapi-schema.json
> @@ -3028,3 +3028,59 @@
> # Since: 1.3.0
> ##
> { 'command': 'nbd-server-stop' }
> +
> +##
> +# @blockdev-dirty-enable:
> +#
> +# @granularity: #optional granularity of the dirty bitmap, default is 64K
> +# if the image format doesn't have clusters, 4K if the clusters
> +# are smaller than that, else the cluster size. Must be a
> +# power of 2 between 512 and 64M.
but 512 here. Which is right?
> +#
> +# Returns: Nothing on success
> +#
> +# Since: 1.3
1.4, now
> +##
> +{ 'command': 'blockdev-dirty-enable',
> + 'data': {'device': 'str', 'filename': 'str', '*granularity': 'uint32' } }
> +
> +##
> +# @blockdev-dirty-disable:
> +#
> +# Stop tracking dirty blocks for a block device. Dirty blocks will
> +# be written to an on-disk file, with one bit per block and an arbitrary
> +# granularity.
> +#
> +# If the dirty bitmap is already active, or used by something else (for
> +# example blockdev-drive-mirror), the granularity argument must be absent
You named it 'drive-mirror', not 'blockdev-drive-mirror'.
> +# or equal to the active granularity.
> +#
> +# @device: the name of the device to track dirty blocks of
> +#
> +# @force: #optional true to immediately stop writing to the dirty
> +# bitmap file; false to do so only when the last user of the
> +# dirty bitmap stops using it (default false)
> +#
> +# Returns: Nothing on success
> +#
> +# Since: 1.3
Again, 1.4.
--
Eric Blake eblake redhat com +1-919-301-3266
Libvirt virtualization library http://libvirt.org
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