From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wi0-f169.google.com (mail-wi0-f169.google.com [209.85.212.169]) by dpdk.org (Postfix) with ESMTP id AB7C17E23 for ; Thu, 1 Oct 2015 17:19:36 +0200 (CEST) Received: by wicgb1 with SMTP id gb1so34761898wic.1 for ; Thu, 01 Oct 2015 08:19:36 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:subject:to:references:cc:from:message-id:date :user-agent:mime-version:in-reply-to:content-type :content-transfer-encoding; bh=/t+rWR55eOal/19mvgck+a5brnr8517gpe8aRjrbtTI=; b=XMji3J8dQDJMHQ1wDP59tXDyieR8ak5/Aw5rfcKbF6d4jJAGxSoU18FchH1SmQrT1m EfpFOxAplUyHpJ1RKPuigQR/KNo9fbZnKVP5oBe42IYJRhxduiUVqHJOQP9dWqRcPoD2 WqumfXGnN3hXG1eZ9tqTDnoFz+DAymIsHQr/NUi4m/HPYXldCu0RM/uZak5ODmm3KiYM xs2fyD4l6eIdd3cwPWahFrNmmyB4BV2ZFrbCZaFStzcamThnTrffKTnKQaxY6W95T4zL LILOZBx2ute2+E7aANmjJMnZbkXRZPHnNPx/VClFf52aE2qZEPr7a51eF0S2W1zFLVne EGsg== X-Gm-Message-State: ALoCoQmxUwjg25nZsqcLw8MwqF0hG6BmAaEoLeKS95rMSGnMkbCLmiulaXaK5qtmgKqYOamx/EZ5 X-Received: by 10.180.210.163 with SMTP id mv3mr3866599wic.40.1443712776502; Thu, 01 Oct 2015 08:19:36 -0700 (PDT) Received: from avi.cloudius ([37.142.229.250]) by smtp.googlemail.com with ESMTPSA id bh5sm6616480wjb.42.2015.10.01.08.19.34 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 01 Oct 2015 08:19:35 -0700 (PDT) To: "Michael S. Tsirkin" References: <20151001120027-mutt-send-email-mst@redhat.com> <560CFB66.5050904@scylladb.com> <20151001124211-mutt-send-email-mst@redhat.com> <560D0413.5080401@scylladb.com> <20151001131754-mutt-send-email-mst@redhat.com> <560D0FE2.7010905@scylladb.com> <20151001135054-mutt-send-email-mst@redhat.com> <560D1705.30300@scylladb.com> <20151001142640-mutt-send-email-mst@redhat.com> <560D19C3.4060206@scylladb.com> <20151001151154.GA24549@redhat.com> From: Avi Kivity Message-ID: <560D4F05.5040105@scylladb.com> Date: Thu, 1 Oct 2015 18:19:33 +0300 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.2.0 MIME-Version: 1.0 In-Reply-To: <20151001151154.GA24549@redhat.com> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Cc: "dev@dpdk.org" Subject: Re: [dpdk-dev] Having troubles binding an SR-IOV VF to uio_pci_generic on Amazon instance 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: Thu, 01 Oct 2015 15:19:36 -0000 On 10/01/2015 06:11 PM, Michael S. Tsirkin wrote: > On Thu, Oct 01, 2015 at 02:32:19PM +0300, Avi Kivity wrote: >>> We already agreed this kernel >>> is going to be tainted, and unsupportable. >> Yes. So your only motivation in rejecting the patch is to get the author to >> write the ring translation patch and port it to all relevant drivers >> instead? > Not only that. > > To make sure users are aware they are doing insecure > things when using software poking at device BARs in sysfs. I don't think you need to worry about that. People who program DMA are aware of the damage is can cause. If you want to be extra sure, have uio taint the kernel when bus mastering is enabled. > To avoid giving virtualization a bad name for security. There is no security issue here. Those VMs run a single application, and cannot attack the host or other VMs. > To get people to work on safe, maintainable solutions. That's a great goal but I don't think it can be achieved without sacrificing performance, which is the only reason for dpdk's existence. If safe and maintainable were the only requirements, people would not bypass the kernel. The only thing you are really achieving by blocking this is causing pain.