/sys/class/vvu
| Field | Value |
|---|---|
| Subsystem | unknown from cached sources - no subsystem documentation found (see below); implementation file not in cached tree |
| Config gate | not verifiable from the cached sources (cached tree has no Kconfig or driver files) |
| ABI documentation | none found in tree - recursive search of Documentation/ABI/{stable,testing,obsolete,removed} for “vvu” returns nothing |
| Since | not stated by any cached source |
| Live (5.10.134 host) | class present and empty: live-sys/class-list.txt records vvu 0; /sys/class/vvu verified empty live |
| Ledger ID | SYSC-vvu |
What it represents
A sysfs class directory whose purpose cannot be established from the cached sources. What is verifiable: the 5.10.134 host kernel registers a class named vvu, and it contains no devices on this host (class-list.txt count 0, empty directory live). The name suggests a virtio/vhost-user related transport class, but no cached file states this, so the claim is not made here.
Relationship to the device model
The class is registered early enough to exist with zero devices (like backlight, bsg or iommu on this host), which in the device model means a struct class was registered but no device was ever added to it in this configuration. Whether member directories would be class views of virtio devices, char-device backed, or plain control objects cannot be determined from the cached tree.
Attributes
None verifiable. No ABI file, no Documentation mention, no MAINTAINERS entry, and the live directory is empty - so there is no attribute to cite. This page is deliberately a source-limited stub: it records the existence of the class on the live host and the negative search results, and nothing more.
| Attribute | R/W | Unit/format | Conditional? | Source |
|---|---|---|---|---|
| (none found) | – | – | – | recursive ABI search + live enumeration returned no attributes |
Safety and writes
No documented reads or writes. If the class is device-bearing on other systems, any safety statement would be speculation; on this host there is nothing to read or write beyond the empty directory itself. The safe engineering conclusion is: do not script against /sys/class/vvu without first establishing, on the target kernel, what driver registers it and what files appear when devices bind.
References
- Live enumeration: /sys/class/vvu empty (kernel 5.10.134); live-sys/class-list.txt row
vvu 0 - Negative search results (cached tree):
Documentation/ABI/for “vvu” - no match; MAINTAINERS for “vvu” - no match - Implementation: not in cached tree
- Coverage: ledger