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Message-ID: <efe20a00-9a7c-4c03-8fcc-fce265cdbf0e@suse.com>
Date: Wed, 31 Jan 2024 09:31:21 +0200
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Subject: Re: [PATCHv6 00/16] x86/tdx: Add kexec support
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To: Paolo Bonzini <pbonzini@redhat.com>,
 "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>,
 Thomas Gleixner <tglx@linutronix.de>, Ingo Molnar <mingo@redhat.com>,
 Borislav Petkov <bp@alien8.de>, Dave Hansen <dave.hansen@linux.intel.com>,
 x86@kernel.org
Cc: "Rafael J. Wysocki" <rafael@kernel.org>,
 Peter Zijlstra <peterz@infradead.org>,
 Adrian Hunter <adrian.hunter@intel.com>,
 Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>,
 Elena Reshetova <elena.reshetova@intel.com>,
 Jun Nakajima <jun.nakajima@intel.com>,
 Rick Edgecombe <rick.p.edgecombe@intel.com>,
 Tom Lendacky <thomas.lendacky@amd.com>, "Kalra, Ashish"
 <ashish.kalra@amd.com>, Sean Christopherson <seanjc@google.com>,
 "Huang, Kai" <kai.huang@intel.com>, Baoquan He <bhe@redhat.com>,
 kexec@lists.infradead.org, linux-coco@lists.linux.dev,
 linux-kernel@vger.kernel.org
References: <20240124125557.493675-1-kirill.shutemov@linux.intel.com>
 <3f44458f-2b4a-4464-a3df-cb791298dafc@redhat.com>
From: Nikolay Borisov <nik.borisov@suse.com>
In-Reply-To: <3f44458f-2b4a-4464-a3df-cb791298dafc@redhat.com>
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On 30.01.24 г. 15:43 ч., Paolo Bonzini wrote:
> On 1/24/24 13:55, Kirill A. Shutemov wrote:
>> The patchset adds bits and pieces to get kexec (and crashkernel) work on
>> TDX guest.
>>
>> The last patch implements CPU offlining according to the approved ACPI
>> spec change poposal[1]. It unlocks kexec with all CPUs visible in the 
>> target
>> kernel. It requires BIOS-side enabling. If it missing we fallback to 
>> booting
>> 2nd kernel with single CPU.
>>
>> Please review. I would be glad for any feedback.
> 
> Hi Kirill,
> 
> I have a very basic question: is there a reason why this series does not 
> revert commit cb8eb06d50fc, "x86/virt/tdx: Disable TDX host support when 
> kexec is enabled"?

While on the topic, Paolo do you think it's  better to have a runtime 
disable of kexec rather than at compile time:

[RFC PATCH] x86/virt/tdx: Disable KEXEC in the presence of TDX

20240118160118.1899299-1-nik.borisov@suse.com

I'm trying to get traction for this patch.


> 
> Thanks,
> 
> Paolo
> 
>