linux-kernel - Re: [PATCH v5 0/5] TDX host: kexec() support

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Message-ID: <29fba60b-b024-417c-86e2-d76a23aa4d6c@intel.com>
Date: Tue, 20 Aug 2024 10:16:10 +1200
From: "Huang, Kai" <kai.huang@...el.com>
To: Sagi Shahar <sagis@...gle.com>
CC: <bp@...en8.de>, <dave.hansen@...el.com>, <hpa@...or.com>,
	<kirill.shutemov@...ux.intel.com>, <linux-kernel@...r.kernel.org>,
	<luto@...nel.org>, <mingo@...hat.com>, <pbonzini@...hat.com>,
	<peterz@...radead.org>, <seanjc@...gle.com>, <tglx@...utronix.de>,
	<thomas.lendacky@....com>, <x86@...nel.org>
Subject: Re: [PATCH v5 0/5] TDX host: kexec() support



On 20/08/2024 9:21 am, Sagi Shahar wrote:
>> Currently kexec() support and TDX host are muturally exclusive in the
>> Kconfig.  This series adds the TDX host kexec support so that they can
>> work together and can be enabled at the same time in the Kconfig.
> 
> I tried testing the kexec functionality and noticed that the TDX module
> fails initialization on the second kernel so you can't actually kexec
> between 2 kernels that enable TDX. Is that the expected behavior? Are
> there future patches to enable that functionality?
> 

Thanks for testing!

Yes this is the expected behaviour.  If the first kernel has enabled 
TDX, then the second kernel will fail to init TDX.  The reason the first 
SEAMCALL to initialize TDX module in the second kernel will fail due to 
module having been initialized.

However if the first kernel has not enabled TDX, the second kernel is 
able to enable it.