From: Dave Hansen To: dave.hansen@linux.intel.com Subject: Re: [PATCH v9 22/23] coco/tdx-host: Document TDX module update compatibility criteria In-Reply-To: <20260513151045.1420990-23-chao.gao@intel.com> References: <20260513151045.1420990-23-chao.gao@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit [Draft review generated by x86-maintainer-agent applying Dave_Hansen.txt rules to the v9 series. Strip this banner before sending.] ABI documentation that names the failure modes ("device-busy", "firmware-invalid"), explains what userspace can do about each, and ties firmware-invalid to the "tdx_host/version returns -ENXIO" observable, is exactly the RULE 13 + RULE 20 surface we need documented before this lands. One tightening pass: > + "firmware-invalid" may be fatal, causing all TDs and the TDX > + module to be lost and preventing further TDX operations. This > + occurs when reading /sys/devices/faux/tdx_host/version returns > + -ENXIO. Suggest moving the "-ENXIO" observability hint into the version= attribute's Description as well (it's currently only mentioned in the error= attribute's Description, so a user looking at version= alone has no clue that -ENXIO is "the module is dead" rather than "the kernel doesn't have this feature"). See review on 05/23 for the matching code-side comment. Reviewed-by: Dave Hansen [conditional]