Earlier  
Posted Nick Remark
#openstack-nova - 2019-06-20
12:47:03 rdopiera I think that was the idea behind the reported issue in the first place
12:47:13 bauzas remember, before 2.30, it wasn't possible to not force a destination
12:48:03 bauzas it was either possible to either pass a destination and then force to it without checking the scheduler *or* not pass a destination and then the scheduler would be giving you some target
12:48:06 bauzas rdopiera: ^
12:48:15 rdopiera and after 2.67 it's impossible to force it
12:48:22 bauzas correct
12:48:33 rdopiera so there is going to be a change at some point either way
12:48:44 bauzas so, I'd recommend you to not ask for a target with 2.29 and older
12:49:14 bauzas and for 2.30, accept a target by defaulting to not force to it
12:49:39 bauzas that actually depends on what kind of user experience you'd like to provide
12:50:15 bauzas the force flag was just a way to keep the same behaviour for some time
12:51:30 rdopiera personally I don't feel like I have enough knowledge about Nova to decide on user experience, I would rather ask for recommendation from people who designed it
12:52:53 rdopiera you know what, how about I just abandon that patch and close the bug with "current version" explaining that later versions of the api behave as expected?
13:23:21 mriedem o/
13:23:30 sean-k-mooney o/
13:33:10 bauzas rdopiera: whoops, missed your question
13:33:38 efried kashyap: "Book will arrive tomorrow" --Renae (aka wife aka personal shopper)
13:33:41 bauzas rdopiera: I think yeah it's a reasonable approach, as I wouldn't recommend to change an expected behaviour
13:34:04 kashyap efried: Ow, you trusted me. Thank you :-)
13:34:12 bauzas rdopiera: but this is kind of a tribal knowledge, so again it really depends on what the horizon community would like to see
13:34:31 bauzas and when I see community, I obviously mean devs *and* ops
13:34:38 bauzas (or rather users)
13:45:16 mriedem alex_xu: i replied to you here https://review.opendev.org/#/c/610727/ - i'm not sure if i misunderstood your comment
13:49:03 mriedem sean-k-mooney: is https://review.opendev.org/#/c/644881/ ready for re-review? i saw you went from PS33 to PS37 :)
13:51:02 sean-k-mooney it should be. i had to fix the unit tests and then i had to put it to grammerly to fix my spelling in the commit message
13:52:37 sean-k-mooney the changes are not really that big but i think i have adressed everything. ill respin if there are anything else you would like changed.
13:53:03 openstackgerrit Adam Spiers proposed openstack/nova master: Add extra spec parameter and image property for memory encryption https://review.opendev.org/664420
13:53:11 aspiers efried: ^^^ should address all your feedback
13:53:19 efried ack
13:56:07 aspiers rebasing ...
13:56:13 openstackgerrit Adam Spiers proposed openstack/nova master: Pass extra_specs to flavor in vif tests https://review.opendev.org/662556
13:56:13 openstackgerrit Adam Spiers proposed openstack/nova master: Use fake flavor instead of empty dict in test https://review.opendev.org/662555
13:56:14 openstackgerrit Adam Spiers proposed openstack/nova master: Add element to guest config for AMD SEV https://review.opendev.org/636318
13:56:14 openstackgerrit Adam Spiers proposed openstack/nova master: Extract SEV-specific bits on host detection https://review.opendev.org/636334
13:56:15 openstackgerrit Adam Spiers proposed openstack/nova master: Detect that SEV is required and enable iommu for devices https://review.opendev.org/644565
13:56:15 openstackgerrit Adam Spiers proposed openstack/nova master: Allow guest devices to include https://review.opendev.org/644564
13:56:16 openstackgerrit Adam Spiers proposed openstack/nova master: Enable memory locking if SEV is requested https://review.opendev.org/662558
13:56:16 openstackgerrit Adam Spiers proposed openstack/nova master: Use element when SEV is required https://review.opendev.org/662557
14:01:19 aspiers efried: the way bbobrov added the code to ensure virtio devices have IOMMU enabled when SEV is requested, it was inserted within each chunk of device config creation. I'm wondering if it might be better to have a single method which is called after all device config is created if SEV is required, and iterates over each device, enabling IOMMU where required?
14:02:17 aspiers efried: similar to how the tests do it: https://review.opendev.org/#/c/644565/9/nova/tests/unit/virt/libvirt/test_driver.py@2609
14:02:57 efried aspiers: I don't really understand how libvirt works. Kind of relying on folks like kashyap to validate those top patches.
14:03:02 aspiers maybe not, since other code might want to insist on (say) disabling IOMMU for a specific type of device
14:03:36 efried aspiers: IMO if the flavor/image requested encryption and some other piece of code thinks that shouldn't happen, that should be an error.
14:03:39 kashyap On a long call; back in a few, folks
14:03:54 aspiers maybe better to keep each device's IOMMU decision local to the code which creates its config
14:04:11 efried We should never turn off requested encryption based on something discovered internally "later on".
14:04:18 aspiers efried: sure, that's not quite the scenario I mean though
14:04:22 efried okay
14:04:44 aspiers let's say some other extra spec requires a particular storage device to be virtio but have IOMMU disabled
14:04:54 aspiers and there's also an extra spec or image property requiring memory encryption
14:05:32 aspiers these are mutually incompatible since SEV requires IOMMU on all virtio devices
14:05:36 aspiers now ideally, this would be caught earlier on than at instance creation time
14:05:52 aspiers but as a last resort, the chunk of code building the XML for that device should spot the conflict
14:06:33 aspiers whereas if I followed my previous suggestion of moving the "turn IOMMU on for all virtio devices" code to a separate SEV method, it couldn't
14:07:25 aspiers so in summary, maybe the general approach in places like https://review.opendev.org/#/c/644565/9/nova/virt/libvirt/driver.py@1626 is fine
14:07:35 aspiers well
14:07:42 aspiers fine, except for your valid point about explicit turn-off
14:07:46 aspiers which I am still replying to
14:18:38 openstackgerrit Adam Spiers proposed openstack/nova master: Use element when SEV is required https://review.opendev.org/662557
14:18:38 openstackgerrit Adam Spiers proposed openstack/nova master: Detect that SEV is required and enable iommu for devices https://review.opendev.org/644565
14:18:39 openstackgerrit Adam Spiers proposed openstack/nova master: Enable memory locking if SEV is requested https://review.opendev.org/662558
14:22:56 aspiers efried: regarding the need for some kind of master switch: I don't think I can float the MEM_ENCRYPTION_CONTEXT patch to the top - at very least, that's the one which bumps os-resource-classes to 0.4.0 to provide the new class
14:23:43 aspiers efried: if I combined the top three patches, that would be the master switch really, since none of the others change the way guests are created
14:27:55 openstackgerrit Merged openstack/nova master: Log disk transfer stats in live migration monitor. https://review.opendev.org/619395
14:33:04 mriedem melwitt: replied inline on https://review.opendev.org/#/c/633227/
14:33:07 mriedem thanks for thinking through that
14:39:59 kashyap aspiers: Back here for 15 min. So on the approach to enable IOMMU for virtio devices 'if-SEV-is-requested': I need a fresher mind than the pear-shaped one I have now, afraid. Not to mention a chunky block of time. Let's work it out tomm?
14:40:18 aspiers kashyap: sure but it's simpler than you think
14:40:40 aspiers e.g. https://review.opendev.org/#/c/644565/11/nova/virt/libvirt/driver.py@1626
14:40:56 aspiers the only question I'm asking is whether this is the right place to do it
14:40:57 kashyap aspiers: The "single method" thing does make sense to me
14:41:19 aspiers except the single method approach has the issue described above
14:41:31 aspiers (35 mins ago)
14:41:47 kashyap Hm, "maybe not, since other code might want to insist on (say) disabling IOMMU for a specific type of device"
14:42:43 kashyap aspiers: Did you audit what other code will insist disabling IOMMU? Let me quickly check with the RHT virt folks
14:43:02 aspiers kashyap: no, that was a potentially hypothetical future scenario
14:43:04 kashyap As in, for potential gotchas here
14:44:36 kashyap aspiers: So SEV requires IOMMU unconditionally on _all_ virtio devices?
14:46:12 aspiers kashyap: yes, http://specs.openstack.org/openstack/nova-specs/specs/train/approved/amd-sev-libvirt-support.html#proposed-change
14:46:43 kashyap aspiers: So, I looked at the "enable IOMMU at the time of each device configuration" code -- where the check is: *if* bus is 'virtio', then enable IOMMU...
14:53:13 efried aspiers: My problem with "none of the others change the way guests are created" is that as of patch #3: the inventory is being exposed, the flavor/image syntax is being accepted, and the allocation is being created. The only thing that's *not* happening is... the actual feature. That's bad.
14:53:42 aspiers efried: OK. Totally open to suggestions for how to fix that
14:53:44 efried aspiers: You can put the os-traits bump in whatever patch first needs it. That's fine.
14:53:58 stephenfin jangutter, sean-k-mooney, ralonsoh: I've royally confused myself again (every damn time) - either of you care to remind me of the difference between VIF_TYPE_foo and VNIC_TYPE_foo?
14:54:24 efried aspiers: I'm saying that exposing the inventory is a nice master switch, because without it, there's zero expectation of anything else working.
14:54:26 aspiers efried: o-r-c not o-t, but yeah sure, I can split the o-r-c patch in two
14:54:35 stephenfin I think one refers to the backend that handles the VIF, while the other determines how it's actually attached to the instance. Right?
14:54:44 aspiers efried: wfm
14:55:11 efried aspiers: As far as I'm concerned, we can *always* bump ot and orc to latest. (In other projects we've implemented canary tests that will fail as soon as a new release comes through upper-constraints.)
14:55:11 jangutter stephenfin: VNIC_TYPE can in theory be set by the user, where VIF type is behind the scenes.
14:55:25 aspiers efried: yup, makes sense
14:55:43 efried aspiers: So for my money, you could do that in its own patch on the bottom, and not even have to tag it against this blueprint.
14:55:53 jangutter stephenfin: VNIC is an _attribute_ of the VIF.
14:56:43 Sundar sean-k-mooney, mriedem, gibi, johnthetubaguy: There has been further discussion on Line 276 of https://review.opendev.org/#/c/603955/14. That seems to be the sole point to address before this spec is merged. Please take a look. Thanks.
14:57:09 stephenfin jangutter: So in theory any VIF type could use one of the...six VNIC types we provide?
14:57:45 jangutter stephenfin: there are two checks I think. Neutron has to allow it, and Nova has to translate it right from Neutron.
14:58:23 stephenfin Yeah, in theory but not in practice
14:58:35 jangutter stephenfin: there's no easy way to answer the question: "does this cloud support this VNIC type" without trying to spawn an instance.
14:58:56 openstackgerrit Matt Riedemann proposed openstack/os-traits master: Add COMPUTE_SAME_HOST_COLD_MIGRATE trait https://review.opendev.org/666604
14:59:32 jangutter stephenfin: your first NACK might be neutron saying "this combination of driver + vnic type is not valid". But it could go right up to Nova failing to find a free PCI device conforming to the NUMA topology.

Earlier   Later