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 Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 28FF9C4332F for ; Mon, 19 Dec 2022 20:08:50 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id A46F88E0003; Mon, 19 Dec 2022 15:08:49 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 9F6A18E0001; Mon, 19 Dec 2022 15:08:49 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 8E7088E0003; Mon, 19 Dec 2022 15:08:49 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0010.hostedemail.com [216.40.44.10]) by kanga.kvack.org (Postfix) with ESMTP id 7C6B18E0001 for ; Mon, 19 Dec 2022 15:08:49 -0500 (EST) Received: from smtpin28.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay03.hostedemail.com (Postfix) with ESMTP id 5CF04A05D5 for ; Mon, 19 Dec 2022 20:08:49 +0000 (UTC) X-FDA: 80260143978.28.A2A03E4 Received: from mail.skyhub.de (mail.skyhub.de [5.9.137.197]) by imf18.hostedemail.com (Postfix) with ESMTP id 4EB621C0016 for ; Mon, 19 Dec 2022 20:08:42 +0000 (UTC) Authentication-Results: imf18.hostedemail.com; dkim=temperror ("DNS error when getting key") header.d=alien8.de header.s=dkim header.b=CPfVndn+; spf=temperror (imf18.hostedemail.com: error in processing during lookup of bp@alien8.de: DNS error) smtp.mailfrom=bp@alien8.de; dmarc=temperror reason="SPF/DKIM temp error" header.from=alien8.de (policy=temperror) ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1671480527; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=lrxhiTTF/whrwIYbK5JLyaQ/VG3LtXMAICiu0E+hLIM=; b=iUK5cKIegbg0gD746giv9vobERRxOIHtmryukWNGCXg2pbc1vrJU9+Sg7I/Rs2V7aFl+cY fem4Dj5smKSR8wILlCM6x5Q9ijYHky2scO1Sv2uPzowNN/XtZg8bDqi/45rm9IdOLQtrMI 97qG5TJ+GctLooXV7S942X2ubkZV4UI= ARC-Authentication-Results: i=1; imf18.hostedemail.com; dkim=temperror ("DNS error when getting key") header.d=alien8.de header.s=dkim header.b=CPfVndn+; spf=temperror (imf18.hostedemail.com: error in processing during lookup of bp@alien8.de: DNS error) smtp.mailfrom=bp@alien8.de; dmarc=temperror reason="SPF/DKIM temp error" header.from=alien8.de (policy=temperror) ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1671480527; a=rsa-sha256; cv=none; b=ToeJf/ngXYpN4zC/NNTODOusdvXRyulEgYjMdc9BaxIpkonRHlUrXt7Qwsev1rNO6cNr82 j9lzGgUFtEcfAp4gAYgNJtJkkHplt2/vHWgeZJQ5xT0oLKYqkMp20uLyprjjba55UA9JU1 edk66Sj6jJQjGXlfxmLu+hIYy7AlqZo= Received: from zn.tnic (p5de8e9fe.dip0.t-ipconnect.de [93.232.233.254]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.skyhub.de (SuperMail on ZX Spectrum 128k) with ESMTPSA id 803F81EC06BB; Mon, 19 Dec 2022 21:08:36 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=alien8.de; s=dkim; t=1671480516; 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: content-transfer-encoding:in-reply-to:in-reply-to: references:references; bh=lrxhiTTF/whrwIYbK5JLyaQ/VG3LtXMAICiu0E+hLIM=; b=CPfVndn+VkW6ZTjP2XUvlPrNlTglu5FlJdPvPusIvXkI+AKI73wrD/UnBGU+ZFq9G9BDBX 1YNpBXsM6I/noQiW3niuawwNR7ZLs0XqfnUxMgMGzXliFX1+Jr8KiQJ2FfC20aOgOhl9gd vH/ng88yULsTbeLMMEWrlt3tMWlBIzc= Date: Mon, 19 Dec 2022 21:08:31 +0100 From: Borislav Petkov To: Michael Roth Cc: Ashish Kalra , x86@kernel.org, linux-kernel@vger.kernel.org, kvm@vger.kernel.org, linux-coco@lists.linux.dev, linux-mm@kvack.org, linux-crypto@vger.kernel.org, tglx@linutronix.de, mingo@redhat.com, jroedel@suse.de, thomas.lendacky@amd.com, hpa@zytor.com, ardb@kernel.org, pbonzini@redhat.com, seanjc@google.com, vkuznets@redhat.com, jmattson@google.com, luto@kernel.org, dave.hansen@linux.intel.com, slp@redhat.com, pgonda@google.com, peterz@infradead.org, srinivas.pandruvada@linux.intel.com, rientjes@google.com, dovmurik@linux.ibm.com, tobin@ibm.com, vbabka@suse.cz, kirill@shutemov.name, ak@linux.intel.com, tony.luck@intel.com, marcorr@google.com, sathyanarayanan.kuppuswamy@linux.intel.com, alpergun@google.com, dgilbert@redhat.com, jarkko@kernel.org Subject: Re: [PATCH Part2 v6 07/49] x86/sev: Invalid pages from direct map when adding it to RMP table Message-ID: References: <243778c282cd55a554af9c11d2ecd3ff9ea6820f.1655761627.git.ashish.kalra@amd.com> <20221219150026.bltiyk72pmdc2ic3@amd.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20221219150026.bltiyk72pmdc2ic3@amd.com> X-Rspamd-Server: rspam05 X-Rspamd-Queue-Id: 4EB621C0016 X-Stat-Signature: 7764ngmykyyfzjuz6gtsknuq3emjwet7 X-Rspam-User: X-HE-Tag: 1671480522-676735 X-HE-Meta: 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 c4YoEP67 EUnRoKTfNNYPsODAWg1ONUaTD1gvsE3ZjF6x7vrcbUuIDBCGbhGUO7i9V6bRZdq8ZAAy4bH6qDGqh6zGpKeUHJx9jk19I0bXmWXX6zvnCYYTjAVs= X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Mon, Dec 19, 2022 at 09:00:26AM -0600, Michael Roth wrote: > We implemented this approach for v7, but it causes a fairly significant > performance regression, particularly for the case for npages > 1 which > this change was meant to optimize. > > I still need to dig in a big but I'm guessing it's related to flushing > behavior. Well, AFAICT, change_page_attr_set_clr() flushes once at the end. Don't you need to flush when you modify the direct map? > It would however be nice to have a set_direct_map_default_noflush() > variant that accepted a 'npages' argument, since it would be more > performant here and also would potentially allow for restoring the 2M > direct mapping in some cases. Will look into this more for v8. set_pages_direct_map_default_noflush() I guess. Although the name is a mouthful so I wouldn't mind having those shortened. In any case, as long as that helper is properly defined and documented, I don't mind. Thx. -- Regards/Gruss, Boris. https://people.kernel.org/tglx/notes-about-netiquette