From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 512C6C83003 for ; Wed, 29 Apr 2020 13:26:42 +0000 (UTC) Received: from lists.xenproject.org (lists.xenproject.org [192.237.175.120]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 2DA752087E for ; Wed, 29 Apr 2020 13:26:42 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 2DA752087E Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=suse.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=xen-devel-bounces@lists.xenproject.org Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1jTmjQ-0008EJ-Dq; Wed, 29 Apr 2020 13:26:32 +0000 Received: from all-amaz-eas1.inumbo.com ([34.197.232.57] helo=us1-amaz-eas2.inumbo.com) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1jTmjP-0008EE-Q4 for xen-devel@lists.xenproject.org; Wed, 29 Apr 2020 13:26:31 +0000 X-Inumbo-ID: 0993a872-8a1d-11ea-9949-12813bfff9fa Received: from mx2.suse.de (unknown [195.135.220.15]) by us1-amaz-eas2.inumbo.com (Halon) with ESMTPS id 0993a872-8a1d-11ea-9949-12813bfff9fa; Wed, 29 Apr 2020 13:26:31 +0000 (UTC) X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx2.suse.de (Postfix) with ESMTP id DFD55AF86; Wed, 29 Apr 2020 13:26:28 +0000 (UTC) Subject: Re: [PATCH] x86/S3: Drop {save,restore}_rest_processor_state() completely To: Andrew Cooper References: <20200429110903.15418-1-andrew.cooper3@citrix.com> <42c1a2ec-51a1-7b03-aea5-f8ffe80d6928@suse.com> <52bdc00f-7778-bd06-14e1-d5c6086466d3@citrix.com> From: Jan Beulich Message-ID: <8cfa1ae3-24ef-5885-d758-ccb188e4e4e2@suse.com> Date: Wed, 29 Apr 2020 15:25:15 +0200 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:68.0) Gecko/20100101 Thunderbird/68.7.0 MIME-Version: 1.0 In-Reply-To: <52bdc00f-7778-bd06-14e1-d5c6086466d3@citrix.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit X-BeenThere: xen-devel@lists.xenproject.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Cc: Xen-devel , Wei Liu , Roger Pau Monne Errors-To: xen-devel-bounces@lists.xenproject.org Sender: "Xen-devel" On 29.04.2020 13:32, Andrew Cooper wrote: > On 29/04/2020 12:16, Jan Beulich wrote: >> On 29.04.2020 13:09, Andrew Cooper wrote: >>> --- a/xen/arch/x86/boot/trampoline.S >>> +++ b/xen/arch/x86/boot/trampoline.S >>> @@ -91,6 +91,11 @@ trampoline_protmode_entry: >>> and %edi,%edx >>> wrmsr >>> 1: >>> + /* Set up PAT before enabling paging. */ >>> + mov $XEN_MSR_PAT & 0xffffffff, %eax >>> + mov $XEN_MSR_PAT >> 32, %edx >>> + mov $MSR_IA32_CR_PAT, %ecx >>> + wrmsr >> Doesn't this also eliminate the need for cpu_init() doing this? >> If you agree with that one also dropped >> Reviewed-by: Jan Beulich > > That doesn't cover the BSP on either the legacy or EFI paths. The legacy path, afaict, uses it: .Lskip_realmode: /* EBX == 0 indicates we are the BP (Boot Processor). */ xor %ebx,%ebx /* Jump to the common bootstrap entry point. */ jmp trampoline_protmode_entry The xen.efi entry path really should have the change you make mirrored anyway. Jan