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dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:38662 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1kDgNW-0007pJ-2Y for qemu-devel@archiver.kernel.org; Wed, 02 Sep 2020 23:57:38 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:35300) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1kDgMu-0007OL-P5 for qemu-devel@nongnu.org; Wed, 02 Sep 2020 23:57:00 -0400 Received: from us-smtp-delivery-124.mimecast.com ([63.128.21.124]:30293) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA1:256) (Exim 4.90_1) (envelope-from ) id 1kDgMt-0002Nr-0U for qemu-devel@nongnu.org; Wed, 02 Sep 2020 23:57:00 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1599105418; 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=5/JG5XyDsHqWumfAnTXInft4dB6pdMmLiaHw7ZBejpY=; b=Jmfmbme7qFnWNLrTNBLOd5IGqy365aESeskkG1CZ0zQzKMjSz6Jdk209Jcs96kVVphGkML IzLYjDRdqk5EkU2a3u7iZpVWqsvC/1MD/i1ECm/XcoVm1uHmNObWDYK7VaTCpfe+CUVzaV H+iV337fPbeFRikN2ywwGP07WIrWCfQ= 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-462-S8TNl2GyMlOFlQEjCEcoSQ-1; Wed, 02 Sep 2020 23:56:43 -0400 X-MC-Unique: S8TNl2GyMlOFlQEjCEcoSQ-1 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 7C65B10051AE; Thu, 3 Sep 2020 03:56:42 +0000 (UTC) Received: from [10.72.13.109] (ovpn-13-109.pek2.redhat.com [10.72.13.109]) by smtp.corp.redhat.com (Postfix) with ESMTP id 847027049D; Thu, 3 Sep 2020 03:56:31 +0000 (UTC) Subject: Re: [PATCH 1/2] net: forbid the reentrant RX To: Alexander Bulekov References: <20200722085747.6514-1-jasowang@redhat.com> <0fd8eb52-6410-1bbd-2462-598c6fcebeb9@redhat.com> <20200902155614.aubuw5ygll35p3vp@mozz.bu.edu> From: Jason Wang Message-ID: <9a6be1f3-84dd-d710-1a18-50e7972c30a2@redhat.com> Date: Thu, 3 Sep 2020 11:56:27 +0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.10.0 MIME-Version: 1.0 In-Reply-To: <20200902155614.aubuw5ygll35p3vp@mozz.bu.edu> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.11 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=jasowang@redhat.com X-Mimecast-Spam-Score: 0.002 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit Content-Language: en-US Received-SPF: pass client-ip=63.128.21.124; envelope-from=jasowang@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-detected-operating-system: by eggs.gnu.org: First seen = 2020/09/02 23:55:14 X-ACL-Warn: Detected OS = Linux 2.2.x-3.x [generic] [fuzzy] X-Spam_score_int: -23 X-Spam_score: -2.4 X-Spam_bar: -- X-Spam_report: (-2.4 / 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, NICE_REPLY_A=-0.324, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H5=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: dmitry.fleytman@gmail.com, mst@redhat.com, liq3ea@gmail.com, liq3ea@163.com, qemu-devel@nongnu.org, Michael Tokarev , stefanha@redhat.com, pbonzini@redhat.com Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On 2020/9/2 下午11:56, Alexander Bulekov wrote: > On 200728 1200, Jason Wang wrote: >> On 2020/7/22 下午4:57, Jason Wang wrote: >>> The memory API allows DMA into NIC's MMIO area. This means the NIC's >>> RX routine must be reentrant. Instead of auditing all the NIC, we can >>> simply detect the reentrancy and return early. The queue->delivering >>> is set and cleared by qemu_net_queue_deliver() for other queue helpers >>> to know whether the delivering in on going (NIC's receive is being >>> called). We can check it and return early in qemu_net_queue_flush() to >>> forbid reentrant RX. >>> >>> Signed-off-by: Jason Wang >>> --- >>> net/queue.c | 3 +++ >>> 1 file changed, 3 insertions(+) >>> >>> diff --git a/net/queue.c b/net/queue.c >>> index 0164727e39..19e32c80fd 100644 >>> --- a/net/queue.c >>> +++ b/net/queue.c >>> @@ -250,6 +250,9 @@ void qemu_net_queue_purge(NetQueue *queue, NetClientState *from) >>> bool qemu_net_queue_flush(NetQueue *queue) >>> { >>> + if (queue->delivering) >>> + return false; >>> + >>> while (!QTAILQ_EMPTY(&queue->packets)) { >>> NetPacket *packet; >>> int ret; >> >> Queued for rc2. >> >> Thanks >> > Hi Jason, > I don't think this ever made it in. Are there any remaining problems? > Thanks > -Alex Hi Alex: It should have been merged: https://git.qemu.org/?p=qemu.git;a=commit;h=22dc8663d9fc7baa22100544c600b6285a63c7a3 Thanks >