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=-5.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS 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 D4130C07E95 for ; Tue, 20 Jul 2021 11:50:42 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 7A42B6113B for ; Tue, 20 Jul 2021 11:50:42 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 7A42B6113B Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=suse.de Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 27BB36B007B; Tue, 20 Jul 2021 07:50:43 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 22C566B00BD; Tue, 20 Jul 2021 07:50:43 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 0A53D8D0001; Tue, 20 Jul 2021 07:50:43 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0235.hostedemail.com [216.40.44.235]) by kanga.kvack.org (Postfix) with ESMTP id DD2696B007B for ; Tue, 20 Jul 2021 07:50:42 -0400 (EDT) Received: from smtpin13.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay03.hostedemail.com (Postfix) with ESMTP id 588CB8248047 for ; Tue, 20 Jul 2021 11:50:41 +0000 (UTC) X-FDA: 78382799082.13.13D58BF Received: from smtp-out2.suse.de (smtp-out2.suse.de [195.135.220.29]) by imf04.hostedemail.com (Postfix) with ESMTP id DD5EB50000A4 for ; Tue, 20 Jul 2021 11:50:40 +0000 (UTC) Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by smtp-out2.suse.de (Postfix) with ESMTPS id 835B0202D3; Tue, 20 Jul 2021 11:50:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_rsa; t=1626781839; h=from:from:reply-to: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=z2Cng5i3OUjv4oE3o0Cxd2ysYKFVEJhz28Z9hUv0Cgg=; b=dv5NLBcMhqkVq5L+OZWbu6xPfU7Pnhsn0ERp2q+7IMppmivU/Klww1o9yjo0CsPg7vATlD /IkCCBchP+LNtpjjUTNm7UK6f0Qt5KKHbpb258k8DKEJMzKehSBp+5LeaDEM5M8Jdh4Rtn ufUF4mqeqBb7INbD3C/xZ4adDqWXwL0= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_ed25519; t=1626781839; h=from:from:reply-to: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=z2Cng5i3OUjv4oE3o0Cxd2ysYKFVEJhz28Z9hUv0Cgg=; b=XwwLO0FmO3fYr+vtcsQgJeX6JpOh+brfu9TgeNuu9I0CWPkBTabrfPyA9K7L0V7x1Ur0ST WQoJPK+37VlKyWBA== Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by imap2.suse-dmz.suse.de (Postfix) with ESMTPS id B425513D6B; Tue, 20 Jul 2021 11:50:38 +0000 (UTC) Received: from dovecot-director2.suse.de ([192.168.254.65]) by imap2.suse-dmz.suse.de with ESMTPSA id JpiTKY649mCEWAAAMHmgww (envelope-from ); Tue, 20 Jul 2021 11:50:38 +0000 Date: Tue, 20 Jul 2021 13:50:37 +0200 From: Joerg Roedel To: "Dr. David Alan Gilbert" Cc: Andi Kleen , David Rientjes , Borislav Petkov , Andy Lutomirski , Sean Christopherson , Andrew Morton , Vlastimil Babka , "Kirill A. Shutemov" , Brijesh Singh , Tom Lendacky , Jon Grimm , Thomas Gleixner , Peter Zijlstra , Paolo Bonzini , Ingo Molnar , "Kaplan, David" , Varad Gautam , Dario Faggioli , x86@kernel.org, linux-mm@kvack.org, linux-coco@lists.linux.dev Subject: Re: Runtime Memory Validation in Intel-TDX and AMD-SNP Message-ID: References: <4e33d22e-330f-c5ba-bc15-08a3298598c5@linux.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Authentication-Results: imf04.hostedemail.com; dkim=pass header.d=suse.de header.s=susede2_rsa header.b=dv5NLBcM; dkim=pass header.d=suse.de header.s=susede2_ed25519 header.b=XwwLO0Fm; spf=pass (imf04.hostedemail.com: domain of jroedel@suse.de designates 195.135.220.29 as permitted sender) smtp.mailfrom=jroedel@suse.de; dmarc=none X-Rspamd-Server: rspam02 X-Stat-Signature: 184oz3zaxughi58xr1dw658qxyrktsas X-Rspamd-Queue-Id: DD5EB50000A4 X-HE-Tag: 1626781840-351106 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 Tue, Jul 20, 2021 at 10:34:01AM +0100, Dr. David Alan Gilbert wrote: > Does the bitmap need to be page granulairty or can we work > on bigger chunks? I think page granularity is needed, because some regions shared with the HV are only one page in size (the GHCBs in SEV-ES for example). But in general it is worth to discuss whether validating memory in bigger chunks than a page is beneficial wrt. to allocation latency vs. required HV round-trips for validation. Regards, Joerg