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Date: Wed, 19 Feb 2025 09:32:31 +0200
From: Mike Rapoport <rppt@kernel.org>
To: RuiRui Yang <ruyang@redhat.com>
Cc: linux-kernel@vger.kernel.org, Alexander Graf <graf@amazon.com>,
	Andrew Morton <akpm@linux-foundation.org>,
	Andy Lutomirski <luto@kernel.org>,
	Anthony Yznaga <anthony.yznaga@oracle.com>,
	Arnd Bergmann <arnd@arndb.de>, Ashish Kalra <ashish.kalra@amd.com>,
	Benjamin Herrenschmidt <benh@kernel.crashing.org>,
	Borislav Petkov <bp@alien8.de>,
	Catalin Marinas <catalin.marinas@arm.com>,
	Dave Hansen <dave.hansen@linux.intel.com>,
	David Woodhouse <dwmw2@infradead.org>,
	Eric Biederman <ebiederm@xmission.com>,
	Ingo Molnar <mingo@redhat.com>, James Gowans <jgowans@amazon.com>,
	Jonathan Corbet <corbet@lwn.net>,
	Krzysztof Kozlowski <krzk@kernel.org>,
	Mark Rutland <mark.rutland@arm.com>,
	Paolo Bonzini <pbonzini@redhat.com>,
	Pasha Tatashin <pasha.tatashin@soleen.com>,
	"H. Peter Anvin" <hpa@zytor.com>,
	Peter Zijlstra <peterz@infradead.org>,
	Pratyush Yadav <ptyadav@amazon.de>,
	Rob Herring <robh+dt@kernel.org>, Rob Herring <robh@kernel.org>,
	Saravana Kannan <saravanak@google.com>,
	Stanislav Kinsburskii <skinsburskii@linux.microsoft.com>,
	Steven Rostedt <rostedt@goodmis.org>,
	Thomas Gleixner <tglx@linutronix.de>,
	Tom Lendacky <thomas.lendacky@amd.com>,
	Usama Arif <usama.arif@bytedance.com>,
	Will Deacon <will@kernel.org>, devicetree@vger.kernel.org,
	kexec@lists.infradead.org, linux-arm-kernel@lists.infradead.org,
	linux-doc@vger.kernel.org, linux-mm@kvack.org, x86@kernel.org
Subject: Re: [PATCH v4 00/14] kexec: introduce Kexec HandOver (KHO)
Message-ID: <Z7WJD6eBLuIRnLwk@kernel.org>
References: <20250206132754.2596694-1-rppt@kernel.org>
 <CALu+AoRMQyRDFS_4L0KQkmrFT_S+yk=uZ-Mqt86JQYKKnj-5Ug@mail.gmail.com>
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On Mon, Feb 17, 2025 at 11:19:45AM +0800, RuiRui Yang wrote:
> On Thu, 6 Feb 2025 at 21:34, Mike Rapoport <rppt@kernel.org> wrote:
> > == Limitations ==
> >
> > Currently KHO is only implemented for file based kexec. The kernel
> > interfaces in the patch set are already in place to support user space
> > kexec as well, but it is still not implemented it yet inside kexec tools.
> >
> 
> What architecture exactly does this KHO work fine?   Device Tree
> should be ok on arm*, x86 and power*, but how about s390?

KHO does not use device tree as the boot protocol, it uses FDT as a data
structure and adds architecture specific bits to the boot structures to
point to that data, very similar to how IMA_KEXEC works.

Currently KHO is implemented on arm64 and x86, but there is no fundamental
reason why it wouldn't work on any architecture that supports kexec.
 
> Thanks
> Dae
> 

-- 
Sincerely yours,
Mike.