This patch changes a rare corner case of custom label rules with an
empty set of matchexpressions. The patch removes a special case where an
empty match expression set matched everything and returned all feature
elements for templates to consume. With this patch the match expression
set logically evaluates all expressions in the set and returns all
matches - if there are no expressions there are no matches and no
matched features are returned. However, the overall match result
(determining if "non-template" labels will be created) in this special
case will be "true" as before as none of the zero match expressions
failed.
The former behavior was somewhat illogical and counterintuitive: having
1 to N expressions matched and returned 1 to N features (at most), but,
having 0 expressions always matched everything and returned all
features. This was some leftover proof-of-concept functionality (for
some possible future extensions) that should have been removed before
merging.
Discover "iommu/intel-iommu/version" sysfs attribute for pci devices.
This information is available for custom label rules.
An example custom rule:
- name: "iommu version rule"
labels:
iommu.version_1: "true"
matchFeatures:
- feature: pci.device
matchExpressions:
"iommu/intel-iommu/version": {op: In, value: ["1:0"]}
Add "iommu_group/type" to the list of PCI device attributes that are
discovered. The value is the raw value from sysfs (i.e DMA, DMA-FQ or
identity).
No built-in (automatic) labels are generated based on this, but, the
attribute is available for custom label rules to use. Examples of custom
rules:
- name: "iommu enabled rule"
labels:
iommu.enabled: "true"
matchFeatures:
- feature: pci.device
matchExpressions:
"iommu_group/type": {op: NotIn, value: ["unknown"]}
- name: "iommu passthrough rule"
labels:
iommu.passthrough: "true"
matchFeatures:
- feature: pci.device
matchExpressions:
"iommu_group/type": {op: In, value: ["identity"]}
Add a separate customization guide. Move documentation of the custom and
local sources there. Also, cover the new NodeFeatureRules custom
resource and the new expression-based label rule format.
This patch also simplifies the "Feature labels" page, describing
built-in labels. Reformat the tables describing feature labels.
Make table of contents in the pages cleaner and more readable by
dropping the main heading (H1 level) from TOCs. This was the original
intention with the usage of "no_toc" kramdown magic, which was broken,
however. The kramdown class magic needs to be specified on the line
immediately following the headinds, otherwise it has no effect. We need
to disable MD022 rule of mdlint as it does not understand this magic.
