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 28F6FC27C53 for ; Wed, 12 Jun 2024 08:30:53 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1sHJNJ-0000sK-QR; Wed, 12 Jun 2024 04:30:33 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1sHJNI-0000s9-OD for qemu-devel@nongnu.org; Wed, 12 Jun 2024 04:30:32 -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 1sHJNG-0001SA-Sm for qemu-devel@nongnu.org; Wed, 12 Jun 2024 04:30:32 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1718181028; 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=5J4zs9cJmmGO99W/I3dfSsAXt52SURVOm8dXnZpoitc=; b=K855uRH1EAWkW24U+5JB/FlYX0HY0ROXpGCgGaeHkM2vKXcd7ONdCb6dQQrGiv1KBy2Unn 4wtkwgcWGP9WMpB4nn+ibCyVaWiRSxO5Sc6XOfdV+ycAnP55HRIkowzseHcAdfq+1X455u krLkdzDTy40MmAb0Oe+EzIcGuCbuGh4= Received: from mx-prod-mc-03.mail-002.prod.us-west-2.aws.redhat.com (ec2-54-186-198-63.us-west-2.compute.amazonaws.com [54.186.198.63]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-543-u-i3Bp7PPA6ez7I0URP8AQ-1; Wed, 12 Jun 2024 04:30:25 -0400 X-MC-Unique: u-i3Bp7PPA6ez7I0URP8AQ-1 Received: from mx-prod-int-04.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-04.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.40]) (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-03.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 55F2919560B2; Wed, 12 Jun 2024 08:30:24 +0000 (UTC) Received: from blackfin.pond.sub.org (unknown [10.39.192.93]) by mx-prod-int-04.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id D392D19560AE; Wed, 12 Jun 2024 08:30:23 +0000 (UTC) Received: by blackfin.pond.sub.org (Postfix, from userid 1000) id B0F1A21E6757; Wed, 12 Jun 2024 10:30:21 +0200 (CEST) From: Markus Armbruster To: Gerd Hoffmann Cc: qemu-devel@nongnu.org, Paolo Bonzini , Eduardo Habkost , Eric Blake , Daniel P. =?utf-8?Q?Berrang=C3=A9?= Subject: Re: [PATCH v3 4/4] qdev: add device policy [RfC] In-Reply-To: <20240606143010.1318226-5-kraxel@redhat.com> (Gerd Hoffmann's message of "Thu, 6 Jun 2024 16:30:10 +0200") References: <20240606143010.1318226-1-kraxel@redhat.com> <20240606143010.1318226-5-kraxel@redhat.com> Date: Wed, 12 Jun 2024 10:30:21 +0200 Message-ID: <87le3aftr6.fsf@pond.sub.org> User-Agent: Gnus/5.13 (Gnus v5.13) MIME-Version: 1.0 Content-Type: text/plain X-Scanned-By: MIMEDefang 3.0 on 10.30.177.40 Received-SPF: pass client-ip=170.10.129.124; envelope-from=armbru@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: 11 X-Spam_score: 1.1 X-Spam_bar: + X-Spam_report: (1.1 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.141, 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_H4=0.001, RCVD_IN_MSPIKE_WL=0.001, RCVD_IN_SBL_CSS=3.335, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, T_SCC_BODY_TEXT_LINE=-0.01 autolearn=no 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: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Gerd Hoffmann writes: > Add policies for devices which are deprecated or not secure. > There are three options: allow, warn and deny. > > It's implemented for devices only. Devices will probably be the main > user of this. Also object_new() can't fail as of today so it's a bit > hard to implement policy checking at object level, especially the 'deny' > part of it. > > TODO: add a command line option to actually set these policies. > > Comments are welcome. > > Signed-off-by: Gerd Hoffmann > --- > hw/core/qdev.c | 60 +++++++++++++++++++++++++++++++++++++++++++++++++- > 1 file changed, 59 insertions(+), 1 deletion(-) > > diff --git a/hw/core/qdev.c b/hw/core/qdev.c > index f3a996f57dee..0c4e5cec743c 100644 > --- a/hw/core/qdev.c > +++ b/hw/core/qdev.c > @@ -43,6 +43,15 @@ > static bool qdev_hot_added = false; > bool qdev_hot_removed = false; > > +enum qdev_policy { > + QDEV_ALLOW = 0, > + QDEV_WARN = 1, > + QDEV_DENY = 2, > +}; > + > +static enum qdev_policy qdev_deprecated_policy; > +static enum qdev_policy qdev_not_secure_policy; > + > const VMStateDescription *qdev_get_vmsd(DeviceState *dev) > { > DeviceClass *dc = DEVICE_GET_CLASS(dev); > @@ -144,6 +153,43 @@ bool qdev_set_parent_bus(DeviceState *dev, BusState *bus, Error **errp) > return true; > } > > +static bool qdev_class_check(const char *name, ObjectClass *oc) > +{ > + bool allow = true; > + > + if (oc->deprecated) { > + switch (qdev_deprecated_policy) { > + case QDEV_WARN: > + warn_report("device \"%s\" is deprecated", name); > + break; > + case QDEV_DENY: > + error_report("device \"%s\" is deprecated", name); > + allow = false; > + break; > + default: > + /* nothing */ > + break; > + } > + } > + > + if (oc->not_secure) { > + switch (qdev_not_secure_policy) { > + case QDEV_WARN: > + warn_report("device \"%s\" is not secure", name); > + break; > + case QDEV_DENY: > + error_report("device \"%s\" is not secure", name); > + allow = false; > + break; > + default: > + /* nothing */ > + break; > + } > + } > + > + return allow; > +} > + > DeviceState *qdev_new(const char *name) > { > ObjectClass *oc = object_class_by_name(name); > @@ -162,14 +208,26 @@ DeviceState *qdev_new(const char *name) > error_report("unknown type '%s'", name); > abort(); > } > + > + if (!qdev_class_check(name, oc)) { Anti-pattern: use of error_report() from within a function that returns an error via Error **errp argument. One such call chain: QMP core -> qmp_device_add() -> qdev_device_add() -> qdev_device_add_from_qdict() -> qdev_new(). Your error message goes to stderr, which is wrong. > + exit(1); Worse, QMP command device_add can now kill the guest instantly. You need to lift the check up the call chains some. > + } > + > return DEVICE(object_new(name)); > } > > DeviceState *qdev_try_new(const char *name) > { > - if (!module_object_class_by_name(name)) { > + ObjectClass *oc = module_object_class_by_name(name); > + > + if (!oc) { > return NULL; > } > + > + if (!qdev_class_check(name, oc)) { > + return NULL; > + } > + > return DEVICE(object_new(name)); > }