From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail.zytor.com (terminus.zytor.com [198.137.202.136]) (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 C71A113D25F; Mon, 3 Jun 2024 23:47:36 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.137.202.136 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1717458458; cv=none; b=rbY7A4uBLJdWJOwZgWUns1kCVblq83oYpyhGfbuhjjreK0BWVg/relnz0blER7nCOo5VcuO60rfggZBf+0F+S9PMq/kGhKiPSzjxqLZDFxb47WuaMWAXjVN2Fq0ZjaspYisQsp09g+KkmMHHzFrGLoWEhxArl8gBgHyy97OL38g= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1717458458; c=relaxed/simple; bh=kSZeBvRXuEwaL+IlHMDX4WGJNsrJcRdd9a4wOhfLKfY=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=Mn6t3e+4u6cATNJyZcJgWEL6l4x+CTQ6eyF4jSpLV9Wg62C6hWhC5+SoigDNxvYYBtJcFJsqzYtiBoyh6vtaogrv2J1VfPImVjVBFQCFpNJu+uIiw92VO9o2oE4ssbMR7UKm6HJtnBDwaPjCGBeZ43lgsozNRUD6kQHk5B6BgDE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=zytor.com; spf=pass smtp.mailfrom=zytor.com; dkim=pass (2048-bit key) header.d=zytor.com header.i=@zytor.com header.b=FBToC2O4; arc=none smtp.client-ip=198.137.202.136 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=zytor.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=zytor.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=zytor.com header.i=@zytor.com header.b="FBToC2O4" Received: from [IPV6:2607:fb90:3707:40b:a32e:4449:b3a:891d] ([IPv6:2607:fb90:3707:40b:a32e:4449:b3a:891d]) (authenticated bits=0) by mail.zytor.com (8.17.2/8.17.1) with ESMTPSA id 453MhgU5475578 (version=TLSv1.3 cipher=TLS_AES_128_GCM_SHA256 bits=128 verify=NO); Mon, 3 Jun 2024 15:43:42 -0700 DKIM-Filter: OpenDKIM Filter v2.11.0 mail.zytor.com 453MhgU5475578 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=zytor.com; s=2024051501; t=1717454626; bh=wuD6WLaEWhP4n3Qasi9wvzUCa2upP1PV62NIREW0BKw=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=FBToC2O4KGQk197cIv7t84JmESw/VZTY3yCo3LqaSIXdLNAqfkAdoAN+wohABjwpV GG8YdHXGo0U45ht4clybrH6eJ/AiZIL2nz1YNbWGmte1xbtzL3wkn7penFxvDyij1J w1sPlUp39rOPmBXa3KDRfbxxVxioSumuNPHXOXJoU60YnM/WXbT8vWyCloinAqoZ+E lAArupSy4TdrTTju+IaHtBBQsQHt8qzCikfK/2TAoD86qTyqGlwTzhL4m2ipVvPsk+ mp0olUR+8EO4Z6RjUV5pc3lZiwOYm3IvGz1v+NNFEsPXVh1CpFmDZisWBu3BX+ytNL s7upucbc1rdrQ== Message-ID: <2b661d91-badc-4c90-9a9a-fe82635cf514@zytor.com> Date: Mon, 3 Jun 2024 15:43:41 -0700 Precedence: bulk X-Mailing-List: linux-hyperv@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCHv11 05/19] x86/relocate_kernel: Use named labels for less confusion To: Nikolay Borisov , "Kirill A. Shutemov" , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , x86@kernel.org Cc: "Rafael J. Wysocki" , Peter Zijlstra , Adrian Hunter , Kuppuswamy Sathyanarayanan , Elena Reshetova , Jun Nakajima , Rick Edgecombe , Tom Lendacky , "Kalra, Ashish" , Sean Christopherson , "Huang, Kai" , Ard Biesheuvel , Baoquan He , "K. Y. Srinivasan" , Haiyang Zhang , kexec@lists.infradead.org, linux-hyperv@vger.kernel.org, linux-acpi@vger.kernel.org, linux-coco@lists.linux.dev, linux-kernel@vger.kernel.org References: <20240528095522.509667-1-kirill.shutemov@linux.intel.com> <20240528095522.509667-6-kirill.shutemov@linux.intel.com> <1e1d1aea-7346-4022-9f5f-402d171adfda@suse.com> Content-Language: en-US From: "H. Peter Anvin" In-Reply-To: <1e1d1aea-7346-4022-9f5f-402d171adfda@suse.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit On 5/29/24 03:47, Nikolay Borisov wrote: >> >> diff --git a/arch/x86/kernel/relocate_kernel_64.S >> b/arch/x86/kernel/relocate_kernel_64.S >> index 56cab1bb25f5..085eef5c3904 100644 >> --- a/arch/x86/kernel/relocate_kernel_64.S >> +++ b/arch/x86/kernel/relocate_kernel_64.S >> @@ -148,9 +148,10 @@ SYM_CODE_START_LOCAL_NOALIGN(identity_mapped) >>        */ >>       movl    $X86_CR4_PAE, %eax >>       testq    $X86_CR4_LA57, %r13 >> -    jz    1f >> +    jz    .Lno_la57 >>       orl    $X86_CR4_LA57, %eax >> -1: >> +.Lno_la57: >> + >>       movq    %rax, %cr4 >>       jmp 1f > Sorry if this is a duplicate; something strange happened with my email. If you are cleaning up this code anyway... this whole piece of code can be simplified to: and $(X86_CR4_PAE | X86_CR4_LA57), %r13d mov %r13, %cr4 The PAE bit in %r13 is guaranteed to be set, and %r13 is dead after this. -hpa