[libvirt] [PATCH 0/7] qemu: use domCaps for validation

Cole Robinson crobinso at redhat.com
Tue Aug 6 23:50:02 UTC 2019


On 4/29/19 8:35 AM, Michal Privoznik wrote:
> On 4/5/19 1:37 AM, Cole Robinson wrote:
>> I'm trying to remove some hurdles and pitfalls WRT extending
>> domaincapabilities data. One issue is that it's too easy to add
>> invalid data to it, or let the data become out of date.
>>
>> For example the first two patches of this series add <rng model=X>
>> domcaps reporting. The logic to fill in the domcaps data from qemuCaps
>> is nearly identical to the logic we use to validate rng->model in
>> qemuDomainRNGDefValidate. If just those patches are added, and later
>> a new qemu rng model was introduced, a future patch could easily
>> miss updated domaincapabilities output.
>>
>> This series aims to set up a pattern to prevent these types of issues
>> from sneaking in. A function virDomainCapsDeviceDefValidate is added
>> which will use domcaps data to perform validation against a devicedef.
>> The existing qemu <rng> model validation is moved there. This ensures
>> that any future <rng> model additions, if they want to work in the
>> qemu driver, effectively need to extend domaincapabilities as well.
>> It's also theoretically useful for other drivers too.
>>
>> One issue is that at DomainDefValidate time we don't have domCaps
>> handy, or any cache layer for domCaps assembling. Patch #4 adds
>> a domCapsCache hashtable to the virQEMUCaps class for caching domCaps
>> builds based on the full tuple of emulator+machine+arch+virttype.
>> If qemuCaps need to be regenerated, the domCaps cache is wiped out
>> for us so we don't need to worry about the data being stale, it's
>> tied to the lifetime of a qemuCaps instance.
>>
>> Cole Robinson (7):
>>    conf: domcaps: Report device <rng>
>>    qemu: capabilities: fill in domcaps <rng>
>>    qemu: conf: add virQEMUDriverGetDomainCapabilities
>>    qemu: conf: Cache domCaps in qemuCaps
>>    conf: domcaps: Add virDomainCapsDeviceDefValidate
>>    qemu: domain: Call virDomainCapsDeviceDefValidate
>>    qemu: Move rng model validation to domcaps
>>
>>   docs/formatdomaincaps.html.in                 | 35 ++++++++
>>   docs/schemas/domaincaps.rng                   | 10 +++
>>   src/conf/domain_capabilities.c                | 83 ++++++++++++++++++
>>   src/conf/domain_capabilities.h                | 14 ++++
>>   src/libvirt_private.syms                      |  1 +
>>   src/qemu/qemu_capabilities.c                  | 41 +++++++++
>>   src/qemu/qemu_capabilities.h                  |  1 +
>>   src/qemu/qemu_conf.c                          | 84 +++++++++++++++++++
>>   src/qemu/qemu_conf.h                          |  7 ++
>>   src/qemu/qemu_domain.c                        | 38 +++------
>>   src/qemu/qemu_driver.c                        | 18 +---
>>   .../qemu_1.7.0.x86_64.xml                     |  9 ++
>>   .../qemu_2.12.0-virt.aarch64.xml              | 11 +++
>>   .../qemu_2.12.0.ppc64.xml                     | 11 +++
>>   .../qemu_2.12.0.s390x.xml                     | 11 +++
>>   .../qemu_2.12.0.x86_64.xml                    | 11 +++
>>   .../qemu_2.6.0-virt.aarch64.xml               | 11 +++
>>   .../qemu_2.6.0.aarch64.xml                    | 11 +++
>>   .../domaincapsschemadata/qemu_2.6.0.ppc64.xml | 11 +++
>>   .../qemu_2.6.0.x86_64.xml                     | 11 +++
>>   .../domaincapsschemadata/qemu_2.7.0.s390x.xml | 11 +++
>>   .../qemu_2.8.0-tcg.x86_64.xml                 | 11 +++
>>   .../domaincapsschemadata/qemu_2.8.0.s390x.xml | 11 +++
>>   .../qemu_2.8.0.x86_64.xml                     | 11 +++
>>   .../qemu_2.9.0-q35.x86_64.xml                 | 11 +++
>>   .../qemu_2.9.0-tcg.x86_64.xml                 | 11 +++
>>   .../qemu_2.9.0.x86_64.xml                     | 11 +++
>>   .../domaincapsschemadata/qemu_3.0.0.s390x.xml | 11 +++
>>   .../qemu_4.0.0.x86_64.xml                     | 11 +++
>>   29 files changed, 488 insertions(+), 40 deletions(-)
>>
> 
> ACK if you address Daniel's and mine findings.
> 
> Sorry for delayed review.
> 

So I completely forgot about this series and never even saw the ACKs!

I rebased the patches and they applied cleanly besides the
driver->privileged piece that was already mentioned. So I addressed all
the original review comments, add RB tags for you and Daniel, and pushed
now. So no worries on the review delay :)

Thanks,
Cole




More information about the libvir-list mailing list