linux-kernel - [RFC PATCH 5/5] x86/virt/tdx: Update the kexec section in the TDX documentation

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Message-ID: <2e88fd265c88cb42cef505e89c466c5625f4a5b6.1741778537.git.kai.huang@intel.com>
Date: Thu, 13 Mar 2025 00:34:17 +1300
From: Kai Huang <kai.huang@...el.com>
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Subject: [RFC PATCH 5/5] x86/virt/tdx: Update the kexec section in the TDX documentation

TDX host kernel now supports kexec/kdump.  Update the documentation to
reflect that.

Signed-off-by: Kai Huang <kai.huang@...el.com>
---
 Documentation/arch/x86/tdx.rst | 17 ++++++++++-------
 1 file changed, 10 insertions(+), 7 deletions(-)

diff --git a/Documentation/arch/x86/tdx.rst b/Documentation/arch/x86/tdx.rst
index 719043cd8b46..8874c210e545 100644
--- a/Documentation/arch/x86/tdx.rst
+++ b/Documentation/arch/x86/tdx.rst
@@ -142,13 +142,6 @@ but depends on the BIOS to behave correctly.
 Note TDX works with CPU logical online/offline, thus the kernel still
 allows to offline logical CPU and online it again.
 
-Kexec()
-~~~~~~~
-
-TDX host support currently lacks the ability to handle kexec.  For
-simplicity only one of them can be enabled in the Kconfig.  This will be
-fixed in the future.
-
 Erratum
 ~~~~~~~
 
@@ -171,6 +164,16 @@ If the platform has such erratum, the kernel prints additional message in
 machine check handler to tell user the machine check may be caused by
 kernel bug on TDX private memory.
 
+Kexec
+~~~~~~~
+
+Kexec/kdump works normally when TDX is enabled in the kernel.  One
+limitation is if the old kernel has ever enabled TDX the new kernel won't
+be able to use TDX anymore.
+
+One exception is kexec/kdump are disabled on the platform with the TDX
+"tdx_pw_mce" erratum.  This will be enhanced in the future.
+
 Interaction vs S3 and deeper states
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
-- 
2.48.1