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=-15.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=ham 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 E2F98C2BB9A for ; Thu, 17 Dec 2020 11:40:46 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B9A7E238A0 for ; Thu, 17 Dec 2020 11:40:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727784AbgLQLkj (ORCPT ); Thu, 17 Dec 2020 06:40:39 -0500 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:60281 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726840AbgLQLki (ORCPT ); Thu, 17 Dec 2020 06:40:38 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1608205152; 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: in-reply-to:in-reply-to:references:references; bh=MgOj6EuRPRhgc87E1eKvG+ZcwKY4KgeCGuqpCKprihs=; b=hkCyy7VLVQrMcFW8YIq1R6+3YqSx35B9guwNkDODbH6VlF+laTUPt9pRwNe7y/arZGaLoI /yXrQm1NzIXgvSYr75wcWzwGszsSO81n1ocpjJJPbZqBjuRaMk1eeEmGMSripW8Tt8oiwD 3tguQDzgQBdQUZ/2rE6V1M/uAqfNluQ= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-445-KUnFFOc5NUOpCTQHrf2Jbw-1; Thu, 17 Dec 2020 06:39:10 -0500 X-MC-Unique: KUnFFOc5NUOpCTQHrf2Jbw-1 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.phx2.redhat.com [10.5.11.15]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 4CB4A59; Thu, 17 Dec 2020 11:39:08 +0000 (UTC) Received: from gondolin (ovpn-113-176.ams2.redhat.com [10.36.113.176]) by smtp.corp.redhat.com (Postfix) with ESMTP id A1E4F2C314; Thu, 17 Dec 2020 11:38:57 +0000 (UTC) Date: Thu, 17 Dec 2020 12:38:42 +0100 From: Cornelia Huck To: David Gibson Cc: pair@us.ibm.com, pbonzini@redhat.com, frankja@linux.ibm.com, brijesh.singh@amd.com, dgilbert@redhat.com, qemu-devel@nongnu.org, Eduardo Habkost , qemu-ppc@nongnu.org, rth@twiddle.net, thuth@redhat.com, berrange@redhat.com, mdroth@linux.vnet.ibm.com, Marcelo Tosatti , "Michael S. Tsirkin" , Marcel Apfelbaum , david@redhat.com, Richard Henderson , borntraeger@de.ibm.com, kvm@vger.kernel.org, qemu-s390x@nongnu.org, pasic@linux.ibm.com Subject: Re: [for-6.0 v5 11/13] spapr: PEF: prevent migration Message-ID: <20201217123842.51063918.cohuck@redhat.com> In-Reply-To: <20201217054736.GH310465@yekko.fritz.box> References: <20201204054415.579042-1-david@gibson.dropbear.id.au> <20201204054415.579042-12-david@gibson.dropbear.id.au> <20201214182240.2abd85eb.cohuck@redhat.com> <20201217054736.GH310465@yekko.fritz.box> Organization: Red Hat GmbH MIME-Version: 1.0 Content-Type: multipart/signed; boundary="Sig_/ukk4S5nSA=gXo.pxm5suYdZ"; protocol="application/pgp-signature"; micalg=pgp-sha256 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.15 Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org --Sig_/ukk4S5nSA=gXo.pxm5suYdZ Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: quoted-printable On Thu, 17 Dec 2020 16:47:36 +1100 David Gibson wrote: > On Mon, Dec 14, 2020 at 06:22:40PM +0100, Cornelia Huck wrote: > > On Fri, 4 Dec 2020 16:44:13 +1100 > > David Gibson wrote: > > =20 > > > We haven't yet implemented the fairly involved handshaking that will = be > > > needed to migrate PEF protected guests. For now, just use a migration > > > blocker so we get a meaningful error if someone attempts this (this i= s the > > > same approach used by AMD SEV). > > >=20 > > > Signed-off-by: David Gibson > > > Reviewed-by: Dr. David Alan Gilbert > > > --- > > > hw/ppc/pef.c | 9 +++++++++ > > > 1 file changed, 9 insertions(+) > > >=20 > > > diff --git a/hw/ppc/pef.c b/hw/ppc/pef.c > > > index 3ae3059cfe..edc3e744ba 100644 > > > --- a/hw/ppc/pef.c > > > +++ b/hw/ppc/pef.c > > > @@ -38,7 +38,11 @@ struct PefGuestState { > > > }; > > > =20 > > > #ifdef CONFIG_KVM > > > +static Error *pef_mig_blocker; > > > + > > > static int kvmppc_svm_init(Error **errp) =20 > >=20 > > This looks weird? =20 >=20 > Oops. Not sure how that made it past even my rudimentary compile > testing. >=20 > > > + > > > +int kvmppc_svm_init(SecurableGuestMemory *sgm, Error **errp) > > > { > > > if (!kvm_check_extension(kvm_state, KVM_CAP_PPC_SECURABLE_GUEST)= ) { > > > error_setg(errp, > > > @@ -54,6 +58,11 @@ static int kvmppc_svm_init(Error **errp) > > > } > > > } > > > =20 > > > + /* add migration blocker */ > > > + error_setg(&pef_mig_blocker, "PEF: Migration is not implemented"= ); > > > + /* NB: This can fail if --only-migratable is used */ > > > + migrate_add_blocker(pef_mig_blocker, &error_fatal); =20 > >=20 > > Just so that I understand: is PEF something that is enabled by the host > > (and the guest is either secured or doesn't start), or is it using a > > model like s390x PV where the guest initiates the transition into > > secured mode? =20 >=20 > Like s390x PV it's initiated by the guest. >=20 > > Asking because s390x adds the migration blocker only when the > > transition is actually happening (i.e. guests that do not transition > > into secure mode remain migratable.) This has the side effect that you > > might be able to start a machine with --only-migratable that > > transitions into a non-migratable machine via a guest action, if I'm > > not mistaken. Without the new object, I don't see a way to block with > > --only-migratable; with it, we should be able to do that. Not sure what > > the desirable behaviour is here. =20 >=20 > Hm, I'm not sure what the best option is here either. If we agree on anything, it should be as consistent across architectures as possible :) If we want to add the migration blocker to s390x even before the guest transitions, it needs to be tied to the new object; if we'd make it dependent on the cpu feature bit, we'd block migration of all machines on hardware with SE and a recent kernel. Is there a convenient point in time when PEF guests transition where QEMU can add a blocker? >=20 > > =20 > > > + > > > return 0; > > > } > > > =20 > > =20 >=20 --Sig_/ukk4S5nSA=gXo.pxm5suYdZ Content-Type: application/pgp-signature Content-Description: OpenPGP digital signature -----BEGIN PGP SIGNATURE----- iQIyBAEBCAAdFiEEw9DWbcNiT/aowBjO3s9rk8bwL68FAl/bQ0IACgkQ3s9rk8bw L6+AFA/4tEcBhNhYOgLqWDrIgP/QxylFpcbIrcxUr5u3yx5AdGqesDKqSgOiMcQX zNhP4JKbdrIPrgvWiGkknQnbXPy0Z4Ge1OUJ3eGMz+h3/L8cD7Kq51WMwTXK+NUB hySnI3x7LbNUhAkTFr3jN7OC2GTn+x/c/tSx6kAOGJHWLgN0Mk6cdKvgEHwTRm/I EW7GCEkpvQKS1ePdYaRHEjNtqFvP45PRg5Li/0hMEuQPkCGE1Wp0MV6kneQ8Z0cw eY1e6BjBblCJV9ZInWKstJSQGDityJ6ln0xlmF/bhQrmGszs0Jyka/wPyVZdEb73 ypgU51dP6JDU9scKJSNNy/+oOpTDRHw50FrrS7NxF/AXd65QlOkRAveWtc+fWO4b FH0XlxnAsDLrae8AcGSUtQZzXXebtVtqXQKjV+CtIrR0uEObCLgPRozEQ7bLVqzZ AwzIOWRFHww/ILvnBxqK76HYfZW3Lc/goTPrpFctwiUvxzPuPau//H6ZgKwhDN+E QspwFSgRS1hw/PqM/837nlAJcJJsW/9kZpXVeJt4vjyNJxvpysn8pJq/7QGCuolW A1GvRARCQY/i+chjjobrrkGbN0n6Rro+2V/Mv2HAGR3CUo0uqRsd7nlhb+WHCLBI wUk8dOlzAsBFNlGBywqOQTxPd9JRoPz7gJGyx6YiNCGS5P96Xg== =07GC -----END PGP SIGNATURE----- --Sig_/ukk4S5nSA=gXo.pxm5suYdZ--