From nobody Mon Feb 9 10:48:22 2026 Delivered-To: importer@patchew.org Authentication-Results: mx.zohomail.com; dkim=pass; spf=pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; dmarc=pass(p=none dis=none) header.from=redhat.com ARC-Seal: i=1; a=rsa-sha256; t=1658140558; cv=none; d=zohomail.com; s=zohoarc; b=DpO+9W2at03SxI61r67kY+4LX4RoBfJL42KRRX8u9p9rwImk64v/cpENBySU0398rvl2eQ+ktOANsV6V5J4psSm+uSg8+JuzJx2NvITCc85Rw/rguB00Y0PMWrvrGYdR6OMgHlGyagsCduV85Nkw7H5YvCTTgvsroM7qlTyn5So= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=zohomail.com; s=zohoarc; t=1658140558; h=Content-Type:Content-Transfer-Encoding:Cc:Date:From:In-Reply-To:List-Subscribe:List-Post:List-Id:List-Archive:List-Help:List-Unsubscribe:MIME-Version:Message-ID:References:Sender:Subject:To; bh=3nkoou4Oxj4dhaj1rNXqI5e5LTCePj0MM4Qd4yCljRo=; b=O52iFGT5n1yTi/ncb1rnCV4OHBOK2isAnI+mFJo+7I1+BJlafBqKigKFe+BBs41RhZwGUtIufSZJ0c9p81s50i3bLrTzmAsShGKb1LM8X8wiH8z3StoAPvUpNUoAJoQeHOT1HxaFDtF85ZitBpDoU1XaBRaEemM1WmdXshbgGWk= ARC-Authentication-Results: i=1; mx.zohomail.com; dkim=pass; spf=pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; dmarc=pass header.from= (p=none dis=none) Return-Path: Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) by mx.zohomail.com with SMTPS id 1658140558400191.60034490707335; Mon, 18 Jul 2022 03:35:58 -0700 (PDT) Received: from localhost ([::1]:34284 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1oDO6X-0000x1-Cu for importer@patchew.org; Mon, 18 Jul 2022 06:35:57 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:54672) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1oDO1I-0000P8-VO for qemu-devel@nongnu.org; Mon, 18 Jul 2022 06:30:33 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]:26921) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1oDO1G-0001Ul-7p for qemu-devel@nongnu.org; Mon, 18 Jul 2022 06:30:31 -0400 Received: from mimecast-mx02.redhat.com (mx3-rdu2.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-608-iaa9i98mNBKtdbCxQkRIhQ-1; Mon, 18 Jul 2022 06:30:25 -0400 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.rdu2.redhat.com [10.11.54.6]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id DC72E3C0D187; Mon, 18 Jul 2022 10:30:24 +0000 (UTC) Received: from eperezma.remote.csb (unknown [10.39.192.86]) by smtp.corp.redhat.com (Postfix) with ESMTP id A20912166B26; Mon, 18 Jul 2022 10:30:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1658140229; 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: in-reply-to:in-reply-to:references:references; bh=3nkoou4Oxj4dhaj1rNXqI5e5LTCePj0MM4Qd4yCljRo=; b=alIQfcqR71HmKVLwxi2U1QKkeCx4RIXCLOOUHXD3ID70mcpxn1o6H2+N4eNbzGgpOy1/bR M88mMsCGMLM2PU/Wp/yAVyXFpazUMdL5SezCu69EAAwCwLGqUQttaurj1vHWt9SPRIwvnn 3Vyh5YxymmpS/i1njgKN8mKrxguUkfA= X-MC-Unique: iaa9i98mNBKtdbCxQkRIhQ-1 From: =?UTF-8?q?Eugenio=20P=C3=A9rez?= To: qemu-devel@nongnu.org Cc: Cindy Lu , Gautam Dawar , Cornelia Huck , Laurent Vivier , Paolo Bonzini , "Gonglei (Arei)" , Zhu Lingshan , Stefan Hajnoczi , Liuxiangdong , Jason Wang , Stefano Garzarella , Eli Cohen , Harpreet Singh Anand , "Michael S. Tsirkin" , Eric Blake , Markus Armbruster , Parav Pandit Subject: [PATCH v4 06/19] vhost: Check for queue full at vhost_svq_add Date: Mon, 18 Jul 2022 12:29:36 +0200 Message-Id: <20220718102949.2868267-7-eperezma@redhat.com> In-Reply-To: <20220718102949.2868267-1-eperezma@redhat.com> References: <20220718102949.2868267-1-eperezma@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable X-Scanned-By: MIMEDefang 2.78 on 10.11.54.6 Received-SPF: pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) client-ip=209.51.188.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Received-SPF: pass client-ip=170.10.133.124; envelope-from=eperezma@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -21 X-Spam_score: -2.2 X-Spam_bar: -- X-Spam_report: (-2.2 / 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_NONE=-0.0001, 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: , Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" X-ZohoMail-DKIM: pass (identity @redhat.com) X-ZM-MESSAGEID: 1658140559164100001 The series need to expose vhost_svq_add with full functionality, including checking for full queue. Signed-off-by: Eugenio P=C3=A9rez --- hw/virtio/vhost-shadow-virtqueue.c | 59 +++++++++++++++++------------- 1 file changed, 33 insertions(+), 26 deletions(-) diff --git a/hw/virtio/vhost-shadow-virtqueue.c b/hw/virtio/vhost-shadow-vi= rtqueue.c index e5a4a62daa..aee9891a67 100644 --- a/hw/virtio/vhost-shadow-virtqueue.c +++ b/hw/virtio/vhost-shadow-virtqueue.c @@ -233,21 +233,29 @@ static void vhost_svq_kick(VhostShadowVirtqueue *svq) * Add an element to a SVQ. * * The caller must check that there is enough slots for the new element. It - * takes ownership of the element: In case of failure, it is free and the = SVQ - * is considered broken. + * takes ownership of the element: In case of failure not ENOSPC, it is fr= ee. + * + * Return -EINVAL if element is invalid, -ENOSPC if dev queue is full */ -static bool vhost_svq_add(VhostShadowVirtqueue *svq, VirtQueueElement *ele= m) +static int vhost_svq_add(VhostShadowVirtqueue *svq, VirtQueueElement *elem) { unsigned qemu_head; - bool ok =3D vhost_svq_add_split(svq, elem, &qemu_head); + unsigned ndescs =3D elem->in_num + elem->out_num; + bool ok; + + if (unlikely(ndescs > vhost_svq_available_slots(svq))) { + return -ENOSPC; + } + + ok =3D vhost_svq_add_split(svq, elem, &qemu_head); if (unlikely(!ok)) { g_free(elem); - return false; + return -EINVAL; } =20 svq->ring_id_maps[qemu_head] =3D elem; vhost_svq_kick(svq); - return true; + return 0; } =20 /** @@ -274,7 +282,7 @@ static void vhost_handle_guest_kick(VhostShadowVirtqueu= e *svq) =20 while (true) { VirtQueueElement *elem; - bool ok; + int r; =20 if (svq->next_guest_avail_elem) { elem =3D g_steal_pointer(&svq->next_guest_avail_elem); @@ -286,25 +294,24 @@ static void vhost_handle_guest_kick(VhostShadowVirtqu= eue *svq) break; } =20 - if (elem->out_num + elem->in_num > vhost_svq_available_slots(s= vq)) { - /* - * This condition is possible since a contiguous buffer in= GPA - * does not imply a contiguous buffer in qemu's VA - * scatter-gather segments. If that happens, the buffer ex= posed - * to the device needs to be a chain of descriptors at this - * moment. - * - * SVQ cannot hold more available buffers if we are here: - * queue the current guest descriptor and ignore further k= icks - * until some elements are used. - */ - svq->next_guest_avail_elem =3D elem; - return; - } - - ok =3D vhost_svq_add(svq, elem); - if (unlikely(!ok)) { - /* VQ is broken, just return and ignore any other kicks */ + r =3D vhost_svq_add(svq, elem); + if (unlikely(r !=3D 0)) { + if (r =3D=3D -ENOSPC) { + /* + * This condition is possible since a contiguous buffe= r in + * GPA does not imply a contiguous buffer in qemu's VA + * scatter-gather segments. If that happens, the buffer + * exposed to the device needs to be a chain of descri= ptors + * at this moment. + * + * SVQ cannot hold more available buffers if we are he= re: + * queue the current guest descriptor and ignore kicks + * until some elements are used. + */ + svq->next_guest_avail_elem =3D elem; + } + + /* VQ is full or broken, just return and ignore kicks */ return; } } --=20 2.31.1