[libvirt] [REPOSTv2 PATCH v3 0/6] Add support for VM Generation ID (vmgenid)

Fri May 25 12:04:00 UTC 2018

On 05/25/2018 07:39 AM, Michal Privoznik wrote:
> On 05/25/2018 01:10 PM, John Ferlan wrote:
>>
>>
>> On 05/25/2018 04:24 AM, Michal Privoznik wrote:
>>> On 05/17/2018 02:42 PM, John Ferlan wrote:
>>>> Second reposting of:
>>>>
>>>> https://www.redhat.com/archives/libvir-list/2018-May/msg00813.html
>>>>
>>>> To update patches with more conflicts for patch 2 (capabilities) and
>>>> patch 6 (news)
>>>>
>>>> Cover from the v3 posting:
>>>>
>>>> v2: https://www.redhat.com/archives/libvir-list/2018-April/msg02234.html
>>>>
>>>> Changes since v2: 
>>>>
>>>>   * Essentially handle comments from code review of original series from
>>>>     comments received for patch 6:
>>>>
>>>>     https://www.redhat.com/archives/libvir-list/2018-April/msg02240.html
>>>>
>>>>     It's a somewhat simplified approach removing the ABI checks and the
>>>>     adjustment to the genid value as part of domain def copy.
>>>>
>>>>   * (NEW) Patch 5 - add a 'genid' domain capability (similar to how Cole
>>>>     added support for vmcoreinfo). Since the apps need a way to determine
>>>>     whether this is enabled, this seems to be the best way.
>>>>
>>>>
>>>> John Ferlan (6):
>>>>   conf: Add VM Generation ID parse/format support
>>>>   qemu: Add VM Generation ID device capability
>>>>   qemu: Alter VM Generation ID for specific startup/launch transitions
>>>>   qemu: Add VM Generation ID to qemu command line
>>>>   domcaps: Add 'genid' to domain capabilities
>>>>   docs: Add news article for VM Generation ID
>>>>
>>>>  docs/formatdomain.html.in                          | 27 +++++++++++
>>>>  docs/formatdomaincaps.html.in                      |  7 ++-
>>>>  docs/news.xml                                      | 13 ++++++
>>>>  docs/schemas/domaincaps.rng                        |  7 +++
>>>>  docs/schemas/domaincommon.rng                      |  8 ++++
>>>>  src/conf/domain_capabilities.c                     |  3 ++
>>>>  src/conf/domain_capabilities.h                     |  1 +
>>>>  src/conf/domain_conf.c                             | 54 ++++++++++++++++++++++
>>>>  src/conf/domain_conf.h                             |  5 ++
>>>>  src/qemu/qemu_capabilities.c                       |  4 ++
>>>>  src/qemu/qemu_capabilities.h                       |  1 +
>>>>  src/qemu/qemu_command.c                            | 24 ++++++++++
>>>>  src/qemu/qemu_driver.c                             | 17 +++++--
>>>>  src/qemu/qemu_process.c                            | 46 +++++++++++++++++-
>>>>  src/qemu/qemu_process.h                            |  1 +
>>>>  tests/domaincapsschemadata/basic.xml               |  1 +
>>>>  tests/domaincapsschemadata/bhyve_basic.x86_64.xml  |  1 +
>>>>  tests/domaincapsschemadata/bhyve_fbuf.x86_64.xml   |  1 +
>>>>  tests/domaincapsschemadata/bhyve_uefi.x86_64.xml   |  1 +
>>>>  tests/domaincapsschemadata/full.xml                |  1 +
>>>>  tests/domaincapsschemadata/libxl-xenfv-usb.xml     |  1 +
>>>>  tests/domaincapsschemadata/libxl-xenfv.xml         |  1 +
>>>>  tests/domaincapsschemadata/libxl-xenpv-usb.xml     |  1 +
>>>>  tests/domaincapsschemadata/libxl-xenpv.xml         |  1 +
>>>>  tests/domaincapsschemadata/qemu_1.7.0.x86_64.xml   |  1 +
>>>>  .../qemu_2.12.0-virt.aarch64.xml                   |  1 +
>>>>  tests/domaincapsschemadata/qemu_2.12.0.ppc64.xml   |  1 +
>>>>  tests/domaincapsschemadata/qemu_2.12.0.s390x.xml   |  1 +
>>>>  tests/domaincapsschemadata/qemu_2.12.0.x86_64.xml  |  1 +
>>>>  .../qemu_2.6.0-virt.aarch64.xml                    |  1 +
>>>>  tests/domaincapsschemadata/qemu_2.6.0.aarch64.xml  |  1 +
>>>>  tests/domaincapsschemadata/qemu_2.6.0.ppc64.xml    |  1 +
>>>>  tests/domaincapsschemadata/qemu_2.6.0.x86_64.xml   |  1 +
>>>>  tests/domaincapsschemadata/qemu_2.7.0.s390x.xml    |  1 +
>>>>  .../domaincapsschemadata/qemu_2.8.0-tcg.x86_64.xml |  1 +
>>>>  tests/domaincapsschemadata/qemu_2.8.0.s390x.xml    |  1 +
>>>>  tests/domaincapsschemadata/qemu_2.8.0.x86_64.xml   |  1 +
>>>>  .../domaincapsschemadata/qemu_2.9.0-q35.x86_64.xml |  1 +
>>>>  .../domaincapsschemadata/qemu_2.9.0-tcg.x86_64.xml |  1 +
>>>>  tests/domaincapsschemadata/qemu_2.9.0.x86_64.xml   |  1 +
>>>>  tests/qemucapabilitiesdata/caps_2.10.0.x86_64.xml  |  1 +
>>>>  tests/qemucapabilitiesdata/caps_2.12.0.x86_64.xml  |  1 +
>>>>  tests/qemucapabilitiesdata/caps_2.9.0.x86_64.xml   |  1 +
>>>>  .../qemuxml2argvdata/genid-auto.x86_64-latest.args | 30 ++++++++++++
>>>>  tests/qemuxml2argvdata/genid-auto.xml              | 32 +++++++++++++
>>>>  tests/qemuxml2argvdata/genid.x86_64-latest.args    | 30 ++++++++++++
>>>>  tests/qemuxml2argvdata/genid.xml                   | 32 +++++++++++++
>>>>  tests/qemuxml2argvtest.c                           |  4 ++
>>>>  tests/qemuxml2xmloutdata/genid-active.xml          | 32 +++++++++++++
>>>>  tests/qemuxml2xmloutdata/genid-auto-active.xml     | 32 +++++++++++++
>>>>  tests/qemuxml2xmloutdata/genid-auto-inactive.xml   | 32 +++++++++++++
>>>>  tests/qemuxml2xmloutdata/genid-inactive.xml        | 32 +++++++++++++
>>>>  tests/qemuxml2xmltest.c                            |  5 +-
>>>>  53 files changed, 500 insertions(+), 7 deletions(-)
>>>>  create mode 100644 tests/qemuxml2argvdata/genid-auto.x86_64-latest.args
>>>>  create mode 100644 tests/qemuxml2argvdata/genid-auto.xml
>>>>  create mode 100644 tests/qemuxml2argvdata/genid.x86_64-latest.args
>>>>  create mode 100644 tests/qemuxml2argvdata/genid.xml
>>>>  create mode 100644 tests/qemuxml2xmloutdata/genid-active.xml
>>>>  create mode 100644 tests/qemuxml2xmloutdata/genid-auto-active.xml
>>>>  create mode 100644 tests/qemuxml2xmloutdata/genid-auto-inactive.xml
>>>>  create mode 100644 tests/qemuxml2xmloutdata/genid-inactive.xml
>>>>
>>>
>>> I like the patches, I do. I'd ACK them but some discussion is needed
>>> first in my opinion.
>>>
>>
>> Discussion about what? Honestly this "version" of the patches has been
>> languishing for the entire month without any review. I know "everyone"
>> is "busy" with their own stuff and facing their own deadlines so I don't
>> expect immediate review, but a whole month without any feedback is a
>> bitter pill to swallow. Now that we reach the end of the month and
>> release time - the design is being called into question. That's fine -
>> although IMO I got review on the original design from the RFC posted in
>> March and the v1 posted in early April. The v2 series posted a couple
>> weeks later gave a lot more important feedback and resulted in the
>> adjustments posted here. So as noted in another response, the v2 review
>> gave the best feedback and is the basis for this simplified approach.
> 
> I meant answers to my questions. Esp. on the capability check and usage
> of flags. If you fix the capability check like I'm suggesting in 4/6 you
> have my ACK for the whole patch set.

Ironically, as part of review of v2 patch 10, I was asked to remove the
check from qemuBuildVMGenIDCommandLine:

https://www.redhat.com/archives/libvir-list/2018-April/msg02253.html

Perhaps it's best to just move it from qemu_process to qemu_command -
that just means passing @qemuCaps into qemuBuildVMGenIDCommandLine and
using it as well as removing @priv from qemuProcessGenID.

It really doesn't matter in qemu_process whether the capability exists,
it was an optimization to put it there rather than an error path in
qemu_command... and with that change GenIDCommandLine now could return
-1 or 0; whereas, without the caps check it was only ever returning 0.

I can repost the entire series if so desired.

Tks -

John

> 
> Also, sorry for leaving these patches so long without any review.
> 
> Michal
> 