From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 1A1121465A1 for ; Fri, 1 Aug 2025 03:02:49 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.133.124 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1754017371; cv=none; b=MZz4LGNIEM6lge4EJ3HexSW03u62R6Wn+QRJzkfHq8aYej0EHcWIEVGQj/wT9/9pv+HcJa+Qoqu4kSWw3VVTSmgScet3n7tE8SY2+UBnhYMiEkhAr6FLBdUB9MWly1Yp5nJrKbwdiHWc2I2lnwCeN+voRQk964IQQNWTkRI8MsQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1754017371; c=relaxed/simple; bh=p20Xxl+itiPTVTN9K/Rj5u1N4M+6Q1+WogOfcN8095M=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=PJi94PQk+SQjhKC17OHqJmSaACf1092UtjW/7H+UMmWmTiJfjc4+RyfPjizgibP0jbbRGxFM8ooi5zOrEMwtXHODxGB3ftGhnEywSG3rd7sJMG/uAfd/8RgZx+s0p5vCgQT1kVNurNl+T2MSbKeDvFSMJuG5FgquYxkH2ee9KOg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=YGXnGqJm; arc=none smtp.client-ip=170.10.133.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="YGXnGqJm" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1754017369; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=NlRwIOX39loAW8Ndc7IEtOq9p1vayc9rGBUA9qXU/0w=; b=YGXnGqJm9xBbw/SALAnQo7w4S06W8Q0jv1nGvvi5Re7p9dTH8qC6LHoBY5qkFTWlaKBX8W 1AbFW+4VJQRfhAKEahcM7vZ/BSh2zWi7dEyK/Oy1rMWN+95T/BXmN/RKtnLVlsZQAJIRqW MwDKJCZnPS8LdCe8le8uxeFQfl/B+Fg= Received: from mx-prod-mc-08.mail-002.prod.us-west-2.aws.redhat.com (ec2-35-165-154-97.us-west-2.compute.amazonaws.com [35.165.154.97]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-644-ATep_vWVM4mb-Cfc0HRovQ-1; Thu, 31 Jul 2025 23:02:42 -0400 X-MC-Unique: ATep_vWVM4mb-Cfc0HRovQ-1 X-Mimecast-MFC-AGG-ID: ATep_vWVM4mb-Cfc0HRovQ_1754017360 Received: from mx-prod-int-01.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-01.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.4]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-08.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 1D9DA1800374; Fri, 1 Aug 2025 03:02:40 +0000 (UTC) Received: from localhost (unknown [10.72.112.183]) by mx-prod-int-01.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id AD09D3000199; Fri, 1 Aug 2025 03:02:36 +0000 (UTC) Date: Fri, 1 Aug 2025 11:02:32 +0800 From: Baoquan He To: Brian Mak Cc: Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , "H. Peter Anvin" , Andrew Morton , Rob Herring , Saravana Kannan , x86@kernel.org, kexec@lists.infradead.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH RESEND] x86/kexec: Carry forward the boot DTB on kexec Message-ID: References: <20250729182142.4875-1-makb@juniper.net> Precedence: bulk X-Mailing-List: devicetree@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20250729182142.4875-1-makb@juniper.net> X-Scanned-By: MIMEDefang 3.4.1 on 10.30.177.4 On 07/29/25 at 11:21am, Brian Mak wrote: > The kexec_file_load syscall on x86 currently does not support passing > a device tree blob to the new kernel. > > To add support for this, we copy the behavior of ARM64 and PowerPC and > copy the current boot's device tree blob for use in the new kernel. We > do this on x86 by passing the device tree blob as a setup_data entry in > accordance with the x86 boot protocol. I see how, but no why. Why do we need to add DTB for x86?