Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
Message-ID: <651476f1-ccae-0ba1-4778-1a63f34aa65d@redhat.com>
Date:   Wed, 30 Aug 2023 13:27:18 +0200
MIME-Version: 1.0
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101
 Thunderbird/102.13.0
Content-Language: en-US
To:     "Michael S. Tsirkin" <mst@redhat.com>
Cc:     Jakub Kicinski <kuba@kernel.org>, xieyongji@bytedance.com,
        jasowang@redhat.com, david.marchand@redhat.com, lulu@redhat.com,
        linux-kernel@vger.kernel.org,
        virtualization@lists.linux-foundation.org, netdev@vger.kernel.org,
        xuanzhuo@linux.alibaba.com, eperezma@redhat.com
References: <20230705100430.61927-1-maxime.coquelin@redhat.com>
 <20230810150347-mutt-send-email-mst@kernel.org>
 <20230810142949.074c9430@kernel.org>
 <20230810174021-mutt-send-email-mst@kernel.org>
 <20230810150054.7baf34b7@kernel.org>
 <ad2b2f93-3598-cffc-0f0d-fe20b2444011@redhat.com>
 <20230829130430-mutt-send-email-mst@kernel.org>
From:   Maxime Coquelin <maxime.coquelin@redhat.com>
Subject: Re: [PATCH v3 0/3] vduse: add support for networking devices
In-Reply-To: <20230829130430-mutt-send-email-mst@kernel.org>
Content-Type: text/plain; charset=UTF-8; format=flowed
Content-Transfer-Encoding: 7bit
Precedence: bulk


On 8/29/23 19:05, Michael S. Tsirkin wrote:
> On Tue, Aug 29, 2023 at 03:34:06PM +0200, Maxime Coquelin wrote:
>>
>>
>> On 8/11/23 00:00, Jakub Kicinski wrote:
>>> On Thu, 10 Aug 2023 17:42:11 -0400 Michael S. Tsirkin wrote:
>>>>> Directly into the stack? I thought VDUSE is vDPA in user space,
>>>>> meaning to get to the kernel the packet has to first go thru
>>>>> a virtio-net instance.
>>>>
>>>> yes. is that a sufficient filter in your opinion?
>>>
>>> Yes, the ability to create the device feels stronger than CAP_NET_RAW,
>>> and a bit tangential to CAP_NET_ADMIN. But I don't have much practical
>>> experience with virt so no strong opinion, perhaps it does make sense
>>> for someone's deployment? Dunno..
>>>
>>
>> I'm not sure CAP_NET_ADMIN should be required for creating the VDUSE
>> devices, as the device could be attached to vhost-vDPA and so not
>> visible to the Kernel networking stack.
>>
>> However, CAP_NET_ADMIN should be required to attach the VDUSE device to
>> virtio-vdpa/virtio-net.
>>
>> Does that make sense?
>>
>> Maxime
> 
> OK. How are we going to enforce it?

Actually, it seems already enforced for all VDPA devices types.
Indeed, the VDPA_CMD_DEV_NEW Netlink command used to add the device to
the VDPA bus has the GENL_ADMIN_PERM flag set, and so require
CAT_NET_ADMIN.

> Also, we need a way for selinux to enable/disable some of these things
> but not others.

Ok, I can do it in a patch on top.
Do you have a pointer where it is done for Virtio Block devices?

Maxime