Re: [Qemu-devel] [PATCH for-3.2 v3 0/3] HMP/snapshot changes - do not use ID anymore

[Kevin Wolf]

Am 07.11.2018 um 14:09 hat Daniel Henrique Barboza geschrieben:
> changes in v3:
> - rebased to v3.1.0-rc0 tag
> - hmp-commands.hx documentation now mentions the change of semantics
> starting version 3.2.
> - previous version link:
> http://lists.nongnu.org/archive/html/qemu-devel/2018-09/msg00629.html
> 
> 
> It is not uncommon to see bugs being opened by testers that attempt to
> create VM snapshots using HMP. It turns out that "0" and "1" are quite
> common snapshot names and they trigger a lot of bugs. I gave an example
> in the commit message of patch 1, but to sum up here: QEMU treats the
> input of savevm/loadvm/delvm sometimes as 'ID', sometimes as 'name'. It
> is documented as such, but this can lead to strange situations.
> 
> Given that it is strange for an API to consider a parameter to be 2 fields
> at the same time, and inadvently treating them as one or the other, and
> that removing the ID field is too drastic, my idea here is to keep the
> ID field for internal control, but do not let the user set it.
> 
> This series simplifies the meaning of savevm/loadvm/delvm to be up to
> par to what the QEMU code (and Libvirt) is already doing: snapshot
> operations using "tag" semantics only, leaving the "id" to be
> automatically calculated by the block drivers and used internally
> only.
> 
> This change of semantics does not affect existing snapshots. What
> changes is that any HMP operations with them will use the
> updated semantics.

Thanks, applied to the block branch.

Kevin