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 lists1p.gnu.org (lists1p.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 3B943C44539 for ; Wed, 22 Jul 2026 13:05:17 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists1p.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1wmWcy-0002LK-56; Wed, 22 Jul 2026 09:04:48 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists1p.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1wmWcs-0002G2-O3 for qemu-devel@nongnu.org; Wed, 22 Jul 2026 09:04:43 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.129.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1wmWcp-0005sP-Fg for qemu-devel@nongnu.org; Wed, 22 Jul 2026 09:04:42 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1784725478; h=from:from:reply-to: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: in-reply-to:in-reply-to:references:references; bh=/gDylmEcv0VIKUXdb/4kLIAKCNnbiAzPEvpCFp0zwgA=; b=PnsbnEwCG3mVFXxoLY6aKjObVrlyUalCHgQXdZtNAn+fVcQjabmRau+9JSAJNWG3h3Wrgb MfZ58JoyCvh8snISWY5xpwYQeiZUQ95ex0Z9izke1BeeiML2SAedIpl4fS/kimjl4MUMZB YbeLb5LVujIAf/k/bgD4qeAFYjs7sCg= Received: from mx-prod-mc-08.mail-002.prod.us-west-2.aws.redhat.com (ec2-35-165-154-97.us-west-2.compute.amazonaws.com [35.165.154.97]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-473-CjZxZXv_PlW_2fYs0Zu8sw-1; Wed, 22 Jul 2026 09:04:34 -0400 X-MC-Unique: CjZxZXv_PlW_2fYs0Zu8sw-1 X-Mimecast-MFC-AGG-ID: CjZxZXv_PlW_2fYs0Zu8sw_1784725473 Received: from mx-prod-int-01.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-01.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.4]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-08.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 53E3018002DE; Wed, 22 Jul 2026 13:04:33 +0000 (UTC) Received: from redhat.com (unknown [10.44.49.82]) by mx-prod-int-01.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 8671930040BE; Wed, 22 Jul 2026 13:04:30 +0000 (UTC) Date: Wed, 22 Jul 2026 14:04:27 +0100 From: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= To: =?utf-8?Q?C=C3=A9dric?= Le Goater Cc: qemu-devel@nongnu.org, Thomas Huth , Pierrick Bouvier , devel@lists.libvirt.org, =?utf-8?Q?Marc-Andr=C3=A9?= Lureau , Paolo Bonzini , Philippe =?utf-8?Q?Mathieu-Daud=C3=A9?= Subject: Re: [PATCH for 11.1] crypto: deprecate the AF_ALG crypto backend Message-ID: References: <20260722115701.716516-1-berrange@redhat.com> <7421bba8-74d2-4e8f-ad4c-a4c06df1a385@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <7421bba8-74d2-4e8f-ad4c-a4c06df1a385@redhat.com> User-Agent: Mutt/2.4.0 (2026-06-19) X-Scanned-By: MIMEDefang 3.4.1 on 10.30.177.4 Received-SPF: permerror client-ip=170.10.129.124; envelope-from=berrange@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.001, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H2=-0.01, SPF_HELO_PASS=-0.001, T_SPF_PERMERROR=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: qemu development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Reply-To: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org On Wed, Jul 22, 2026 at 03:03:16PM +0200, Cédric Le Goater wrote: > On 7/22/26 13:57, Daniel P. Berrangé via Devel wrote: > > Linux 7.1 has deprecated the AF_ALG crypto backend: > > > > https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=a67afb1884ba815079bd43d5c998e155e03b08b6 > > > > And has documented it to be always slower than userspace crypto: > > > > https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=5624ea54f3ba5c83d2e5503411a31a8be0278c1e > > > > as a result of dropping support for zero-copy and hardware > > accelerators: > > > > https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=7524070f26d8d347c26787dc297fb844baa26abf > > https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=ffdd2bc378953b525aca61902534e753f1f8e734 > > > > The main use case for the AF_ALG impl was to improve the performance > > of virtio-crypto with the cryptodev-backend-builtin driver. In > > practice this did not matter since 'cryptodev-backend-lkcf' can do > > offload to the kernel via the keyctl syscall, and 'cryptodev-vhost-user' > > can offload to an external process which can optionally integrate with > > hardware accelerators without kernel assistance. > > > > The AF_ALG backend has no user visible configuration options at runtime, > > it is unconditionally tried with any use of the cipher APIs. So it does > > not strictly have to go through the deprecation process, however, it is > > left available initially in case there was an unexpected use case that > > relies on it which may be faster with old kernels before the above Linux > > commits. > > > > Suggested-by: Thomas Huth > > Signed-off-by: Daniel P. Berrangé > > --- > > docs/about/deprecated.rst | 21 +++++++++++++++++++++ > > meson.build | 6 ++++++ > > 2 files changed, 27 insertions(+) > > > > diff --git a/docs/about/deprecated.rst b/docs/about/deprecated.rst > > index 0c656a968f..54b2662752 100644 > > --- a/docs/about/deprecated.rst > > +++ b/docs/about/deprecated.rst > > @@ -416,6 +416,27 @@ ABI is long-obsolete. We are therefore deprecating both OABI support > > and NWFPE emulation, and they will be removed in a future QEMU > > release. > > +Build features > > +-------------- > > + > > +Crypto AF_ALG backend > > +--------------------- > > > Crypto AF_ALG backend (since 11.1) > '''''''''''''''''''''''''''''''''' > > ? Oppps, yes, of course it needs a version :-) > > With that, > > Reviewed-by: Cédric Le Goater > With regards, Daniel -- |: https://berrange.com ~~ https://hachyderm.io/@berrange :| |: https://libvirt.org ~~ https://entangle-photo.org :| |: https://pixelfed.art/berrange ~~ https://fstop138.berrange.com :|