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 6FF1DD2124C for ; Thu, 17 Oct 2024 08:45:08 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1t1M7Y-0007gf-D7; Thu, 17 Oct 2024 04:44:36 -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 1t1M7W-0007gG-7p for qemu-devel@nongnu.org; Thu, 17 Oct 2024 04:44:34 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1t1M7U-0000i0-Lh for qemu-devel@nongnu.org; Thu, 17 Oct 2024 04:44:34 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1729154670; 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:in-reply-to:in-reply-to: references:references; bh=/22rKZZSTb7ZDnh1sARGvgQPTpvPfyxJ70xl01LBoKg=; b=Njcd/TS4E2fMEWzrYbCLLf6HwpN26GiMnUjMyK2QnY6vXgZ+8zcGf7PPJDZcO0Esj+Uruk h4rDyBaHKVnef8IiyP0buYeKu0l08SuUPQSNOGJg/QBQMxggHLfUh9Eeb6f1uPRmPVD/3g 9LMnfIraeDd3rkQOeYXXqO8oAJpNrLE= Received: from mx-prod-mc-04.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-558-FcCUpfHuPnu7RBF8-r_yiA-1; Thu, 17 Oct 2024 04:44:29 -0400 X-MC-Unique: FcCUpfHuPnu7RBF8-r_yiA-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-04.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 22AC31955DD2 for ; Thu, 17 Oct 2024 08:44:28 +0000 (UTC) Received: from redhat.com (unknown [10.42.28.94]) by mx-prod-int-04.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 2934519560AD; Thu, 17 Oct 2024 08:44:25 +0000 (UTC) Date: Thu, 17 Oct 2024 09:44:22 +0100 From: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= To: Albert Esteve Cc: qemu-devel@nongnu.org, dbassey@redhat.com, Stefano Garzarella , "Michael S. Tsirkin" Subject: Re: [PATCH] vhost-user: fix shared object return values Message-ID: References: <20241016090606.2358056-1-aesteve@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20241016090606.2358056-1-aesteve@redhat.com> User-Agent: Mutt/2.2.12 (2023-09-09) X-Scanned-By: MIMEDefang 3.0 on 10.30.177.40 Received-SPF: pass client-ip=170.10.133.124; envelope-from=berrange@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: 12 X-Spam_score: 1.2 X-Spam_bar: + X-Spam_report: (1.2 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.038, 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_H3=0.001, RCVD_IN_MSPIKE_WL=0.001, RCVD_IN_SBL_CSS=3.335, RCVD_IN_VALIDITY_RPBL_BLOCKED=0.001, RCVD_IN_VALIDITY_SAFE_BLOCKED=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 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: , 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, Oct 16, 2024 at 11:06:06AM +0200, Albert Esteve wrote: > VHOST_USER_BACKEND_SHARED_OBJECT_ADD and > VHOST_USER_BACKEND_SHARED_OBJECT_REMOVE state > in the spec that they return 0 for successful > operations, non-zero otherwise. However, > implementation relies on the return types > of the virtio-dmabuf library, with opposite > semantics (true if everything is correct, > false otherwise). Therefore, current implementaion > violates the specification. > > Revert the logic so that the implementation > of the vhost-user handling methods matches > the specification. > > Fixes: 043e127a126bb3ceb5fc753deee27d261fd0c5ce > Fixes: 160947666276c5b7f6bca4d746bcac2966635d79 > Signed-off-by: Albert Esteve > --- > hw/virtio/vhost-user.c | 8 ++++---- > 1 file changed, 4 insertions(+), 4 deletions(-) > > diff --git a/hw/virtio/vhost-user.c b/hw/virtio/vhost-user.c > index 00561daa06..90917352a4 100644 > --- a/hw/virtio/vhost-user.c > +++ b/hw/virtio/vhost-user.c > @@ -1607,7 +1607,7 @@ vhost_user_backend_handle_shared_object_add(struct vhost_dev *dev, > QemuUUID uuid; > > memcpy(uuid.data, object->uuid, sizeof(object->uuid)); > - return virtio_add_vhost_device(&uuid, dev); > + return !virtio_add_vhost_device(&uuid, dev); > } This virtio_add_vhost_device() method returns a bool, but this vhost_user_backend_handle_shared_object_add() method returns an int, but fills that int with an inverted bool value. The caller then assigns the return value to an int, but then interprets the int as a bool, and assigns that bool result to an u64. This call chain is madness :-( Change vhost_user_backend_handle_shared_object_add to return a bool to reduce the madness IMHO. > > static int > @@ -1623,16 +1623,16 @@ vhost_user_backend_handle_shared_object_remove(struct vhost_dev *dev, > struct vhost_dev *owner = virtio_lookup_vhost_device(&uuid); > if (dev != owner) { > /* Not allowed to remove non-owned entries */ > - return 0; > + return -EPERM; > } > break; > } > default: > /* Not allowed to remove non-owned entries */ > - return 0; > + return -EPERM; > } > > - return virtio_remove_resource(&uuid); > + return !virtio_remove_resource(&uuid); > } These return values are inconsistent. In some places you're returning a negative errno, but in this last place you're returning true or false, by calling virtio_remove_resource which is a 'bool' method & inverting it. On top of this inconsistency, it has all the same madness mentioneed above. With regards, Daniel -- |: https://berrange.com -o- https://www.flickr.com/photos/dberrange :| |: https://libvirt.org -o- https://fstop138.berrange.com :| |: https://entangle-photo.org -o- https://www.instagram.com/dberrange :|