From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Burakov, Anatoly" Subject: Re: [PATCH] vfio: don't needlessly setup devices in secondary process Date: Fri, 23 Nov 2018 09:12:51 +0000 Message-ID: <902e9ebc-e658-fd41-55ce-8ba9e3a72728@intel.com> References: <20181121184132.34039-1-dariusz.stojaczyk@intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit To: Darek Stojaczyk , dev@dpdk.org Return-path: Received: from mga09.intel.com (mga09.intel.com [134.134.136.24]) by dpdk.org (Postfix) with ESMTP id 682191B4FF for ; Fri, 23 Nov 2018 10:12:54 +0100 (CET) In-Reply-To: <20181121184132.34039-1-dariusz.stojaczyk@intel.com> Content-Language: en-US List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dev-bounces@dpdk.org Sender: "dev" On 21-Nov-18 6:41 PM, Darek Stojaczyk wrote: > Setting up a device that wasn't setup in the primary > process will possibly break the primary process. That's > because the IPC message to retrieve the group fd in the > primary will also *open* that group if it wasn't opened > before. Even though the secondary process closes that fd > soon after as a part of its error handling path, the > primary process leaks it. > > What's worse, opening that fd on the primary will > increment the process-local counter of opened groups. > If it was 0 before, then the group will never be added > to the vfio container, nor dpdk memory will be ever > mapped. > > This patch moves the proper error checks earlier in the > code to fuly prevent setting up devices in secondary > processes that weren't setup in the primary process. > > Fixes: 2f4adfad0a69 ("vfio: add multiprocess support") > Cc: anatoly.burakov@intel.com > > Signed-off-by: Darek Stojaczyk > --- Acked-by: Anatoly Burakov -- Thanks, Anatoly