From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wi0-f180.google.com (mail-wi0-f180.google.com [209.85.212.180]) by dpdk.org (Postfix) with ESMTP id B596B5694 for ; Wed, 13 May 2015 12:47:15 +0200 (CEST) Received: by wicmx19 with SMTP id mx19so7502461wic.0 for ; Wed, 13 May 2015 03:47:14 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:from:to:cc:subject:date:message-id:organization :user-agent:in-reply-to:references:mime-version :content-transfer-encoding:content-type; bh=xEC58IK/ovDvk/UGb2fYvzUrQPwIBQfYHD7BG2JGpVw=; b=iYAFJkGu9DK4xhNXn/04Ux+BY7qdnyhGtLlkbpg5SDWY+/4LJCBspdh8MAGqLdx6oG FdYYazswHy02XiFe3yVjSg/nG8/KD3N1hWSKV9lRJaFiAVdX6N4Oje4AWvizo1AZwZSB uvsU9Cbp6VefztA/xkayIrJWl83glln9VZ6Fvs7dwIV+zj8eCW4z87eQWfBLFr+5/IlB JQNqgnLrr4rh9rSuXOEMPx7JwnWLE3wIMsCJcVyDL7lK5uGV5qlWq+wEN9uYuRtB210U 4CshUP6TT0IcqbuDIY+3+pur/b4mMZWosGMgJeISwSSvEL4K3a9Ei0b0qX/awmwQ45bf jR4Q== X-Gm-Message-State: ALoCoQnCwVwnkzRYIGILacM4vaxOPnw2j6W1JOyygVh2Gm1pYunSTlfVYJOmH9QY3ONOCZNStAaw X-Received: by 10.180.39.147 with SMTP id p19mr38039948wik.15.1431514034434; Wed, 13 May 2015 03:47:14 -0700 (PDT) Received: from xps13.localnet (136-92-190-109.dsl.ovh.fr. [109.190.92.136]) by mx.google.com with ESMTPSA id g14sm32283927wjs.47.2015.05.13.03.47.12 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 13 May 2015 03:47:13 -0700 (PDT) From: Thomas Monjalon To: Huawei Xie Date: Wed, 13 May 2015 12:46:30 +0200 Message-ID: <1907109.z7RyHoHxuq@xps13> Organization: 6WIND User-Agent: KMail/4.14.7 (Linux/4.0.1-1-ARCH; KDE/4.14.7; x86_64; ; ) In-Reply-To: <1430305884-9139-1-git-send-email-huawei.xie@intel.com> References: <1429720392-25345-1-git-send-email-huawei.xie@intel.com> <1430305884-9139-1-git-send-email-huawei.xie@intel.com> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="us-ascii" Cc: dev@dpdk.org, mst@redhat.com Subject: Re: [dpdk-dev] [PATCH v2] vhost: flush used->idx update before reading avail->flags X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: patches and discussions about DPDK List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 13 May 2015 10:47:15 -0000 2015-04-29 19:11, Huawei Xie: > update of used->idx and read of avail->flags could be reordered. > memory fence should be used to ensure the order, otherwise guest could see a stale used->idx value after it toggles the interrupt suppression flag. > After guest sets the interrupt suppression flag, it will check if there is more buffer to process through used->idx. If it sees a stale value, it will exit the processing while host willn't send interrupt to guest. > > Signed-off-by: Huawei Xie Applied with following title, thanks vhost: fix virtio freeze due to missed interrupt