Merge branch 'selftests-net-groundwork-for-ynl-based-tests'

Jakub Kicinski says:

====================
selftests: net: groundwork for YNL-based tests (YNL prep)

v1: https://lore.kernel.org/all/20240402010520.1209517-1-kuba@kernel.org/
====================

Merge the non-controversial YNL adjustment and spec additions.

Link: https://lore.kernel.org/r/20240403023426.1762996-1-kuba@kernel.orgSigned-off-by: Jakub Kicinski <kuba@kernel.org>

Documentation/netlink/specs/ethtool.yaml

@@ -16,6 +16,11 @@ definitions:
     name: stringset
     type: enum
     entries: []
+  -
+    name: header-flags
+    enum-name:
+    type: flags
+    entries: [ compact-bitsets, omit-reply, stats ]
 
 attribute-sets:
   -
@@ -30,6 +35,7 @@ attribute-sets:
       -
         name: flags
         type: u32
+        enum: header-flags
 
   -
     name: bitset-bit

tools/net/ynl/lib/ynl.py

@@ -100,9 +100,10 @@ class Netlink:
 class NlError(Exception):
   def __init__(self, nl_msg):
     self.nl_msg = nl_msg
+    self.error = -nl_msg.error
 
   def __str__(self):
-    return f"Netlink error: {os.strerror(-self.nl_msg.error)}\n{self.nl_msg}"
+    return f"Netlink error: {os.strerror(self.error)}\n{self.nl_msg}"
 
 
 class ConfigError(Exception):