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 lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 2EF55C433EF for ; Wed, 13 Apr 2022 13:37:53 +0000 (UTC) Received: from localhost ([::1]:57774 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1nedBv-0006P5-0T for qemu-devel@archiver.kernel.org; Wed, 13 Apr 2022 09:37:51 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:55074) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1nedAc-0005iP-Kr for qemu-devel@nongnu.org; Wed, 13 Apr 2022 09:36:30 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]:50718) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1nedAZ-0002ld-6G for qemu-devel@nongnu.org; Wed, 13 Apr 2022 09:36:29 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1649856985; 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:content-transfer-encoding; bh=EhyWe/cai3Ei0JTtT0j3378X3H+cKoa5Jq1NmD8GUUM=; b=RmCFDYAChgdj+67HURH4I5TiJZh0yMu0dHkuuDY1s6iVzO5zQY7a694u3AQXLqHn3r2Zb/ +DA+MfGEFuaqhoq56y9sphpvv9AG5hjID02JdLVWXmSZLwwrqG/Xa6L1XF5Us86C0W2J4z esP/AMzcdgKf8jxYT6U3AbOCSpPbN2I= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-658-AdPL8sEdO0yq8d7oHkQ7wg-1; Wed, 13 Apr 2022 09:36:24 -0400 X-MC-Unique: AdPL8sEdO0yq8d7oHkQ7wg-1 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.rdu2.redhat.com [10.11.54.8]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id B69171014A63; Wed, 13 Apr 2022 13:36:23 +0000 (UTC) Received: from [10.22.8.161] (unknown [10.22.8.161]) by smtp.corp.redhat.com (Postfix) with ESMTP id 5B53FC28109; Wed, 13 Apr 2022 13:36:23 +0000 (UTC) Message-ID: Date: Wed, 13 Apr 2022 09:36:23 -0400 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.7.0 Content-Language: en-US From: Cole Robinson Subject: adding 'official' way to dump SEV VMSA To: "kvm@vger.kernel.org" Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-Scanned-By: MIMEDefang 2.85 on 10.11.54.8 Received-SPF: pass client-ip=170.10.133.124; envelope-from=crobinso@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -28 X-Spam_score: -2.9 X-Spam_bar: -- X-Spam_report: (-2.9 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.082, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_LOW=-0.7, RCVD_IN_MSPIKE_H5=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, T_SCC_BODY_TEXT_LINE=-0.01 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Tom Lendacky , "Daniel P. Berrange" , qemu-devel , "Dr. David Alan Gilbert" , Dov Murik , Paolo Bonzini , "Singh, Brijesh" Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" Hi all, SEV-ES and SEV-SNP attestation require a copy of the initial VMSA to validate the launch measurement. For developers dipping their toe into SEV-* work, the easiest way to get sample VMSA data for their machine is to grab it from a running VM. There's two techniques I've seen for that: patch some printing into kernel __sev_launch_update_vmsa, or use systemtap like danpb's script here: https://gitlab.com/berrange/libvirt/-/blob/lgtm/scripts/sev-vmsa.stp Seems like this could be friendlier though. I'd like to work on this if others agree. Some ideas I've seen mentioned in passing: - debugfs entry in /sys/kernel/debug/kvm/.../vcpuX/ - new KVM ioctl - something with tracepoints - some kind of dump in dmesg that doesn't require a patch Thoughts? Thanks, Cole