netdev - Re: [RFC v3 03/11] vdpa: Remove the restriction that only supports virtio-net devices

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Message-ID: <20210201110521.o3m6temcw3nmkiea@steredhat>
Date:   Mon, 1 Feb 2021 12:05:21 +0100
From:   Stefano Garzarella <sgarzare@...hat.com>
To:     Yongji Xie <xieyongji@...edance.com>
Cc:     Jason Wang <jasowang@...hat.com>,
        "Michael S. Tsirkin" <mst@...hat.com>,
        Stefan Hajnoczi <stefanha@...hat.com>,
        Parav Pandit <parav@...dia.com>, Bob Liu <bob.liu@...cle.com>,
        Christoph Hellwig <hch@...radead.org>,
        Randy Dunlap <rdunlap@...radead.org>,
        Matthew Wilcox <willy@...radead.org>, viro@...iv.linux.org.uk,
        Jens Axboe <axboe@...nel.dk>, bcrl@...ck.org,
        Jonathan Corbet <corbet@....net>,
        virtualization@...ts.linux-foundation.org, netdev@...r.kernel.org,
        kvm@...r.kernel.org, linux-aio@...ck.org,
        linux-fsdevel@...r.kernel.org
Subject: Re: [RFC v3 03/11] vdpa: Remove the restriction that only supports
 virtio-net devices

On Sat, Jan 30, 2021 at 07:33:08PM +0800, Yongji Xie wrote:
>On Fri, Jan 29, 2021 at 11:04 PM Stefano Garzarella <sgarzare@...hat.com> wrote:
>>
>> On Thu, Jan 28, 2021 at 11:11:49AM +0800, Jason Wang wrote:
>> >
>> >On 2021/1/27 下午4:57, Stefano Garzarella wrote:
>> >>On Wed, Jan 27, 2021 at 11:33:03AM +0800, Jason Wang wrote:
>> >>>
>> >>>On 2021/1/20 下午7:08, Stefano Garzarella wrote:
>> >>>>On Wed, Jan 20, 2021 at 11:46:38AM +0800, Jason Wang wrote:
>> >>>>>
>> >>>>>On 2021/1/19 下午12:59, Xie Yongji wrote:
>> >>>>>>With VDUSE, we should be able to support all kinds of virtio devices.
>> >>>>>>
>> >>>>>>Signed-off-by: Xie Yongji <xieyongji@...edance.com>
>> >>>>>>---
>> >>>>>> drivers/vhost/vdpa.c | 29 +++--------------------------
>> >>>>>> 1 file changed, 3 insertions(+), 26 deletions(-)
>> >>>>>>
>> >>>>>>diff --git a/drivers/vhost/vdpa.c b/drivers/vhost/vdpa.c
>> >>>>>>index 29ed4173f04e..448be7875b6d 100644
>> >>>>>>--- a/drivers/vhost/vdpa.c
>> >>>>>>+++ b/drivers/vhost/vdpa.c
>> >>>>>>@@ -22,6 +22,7 @@
>> >>>>>> #include <linux/nospec.h>
>> >>>>>> #include <linux/vhost.h>
>> >>>>>> #include <linux/virtio_net.h>
>> >>>>>>+#include <linux/virtio_blk.h>
>> >>>>>> #include "vhost.h"
>> >>>>>>@@ -185,26 +186,6 @@ static long
>> >>>>>>vhost_vdpa_set_status(struct vhost_vdpa *v, u8 __user
>> >>>>>>*statusp)
>> >>>>>>     return 0;
>> >>>>>> }
>> >>>>>>-static int vhost_vdpa_config_validate(struct vhost_vdpa *v,
>> >>>>>>-                      struct vhost_vdpa_config *c)
>> >>>>>>-{
>> >>>>>>-    long size = 0;
>> >>>>>>-
>> >>>>>>-    switch (v->virtio_id) {
>> >>>>>>-    case VIRTIO_ID_NET:
>> >>>>>>-        size = sizeof(struct virtio_net_config);
>> >>>>>>-        break;
>> >>>>>>-    }
>> >>>>>>-
>> >>>>>>-    if (c->len == 0)
>> >>>>>>-        return -EINVAL;
>> >>>>>>-
>> >>>>>>-    if (c->len > size - c->off)
>> >>>>>>-        return -E2BIG;
>> >>>>>>-
>> >>>>>>-    return 0;
>> >>>>>>-}
>> >>>>>
>> >>>>>
>> >>>>>I think we should use a separate patch for this.
>> >>>>
>> >>>>For the vdpa-blk simulator I had the same issues and I'm adding
>> >>>>a .get_config_size() callback to vdpa devices.
>> >>>>
>> >>>>Do you think make sense or is better to remove this check in
>> >>>>vhost/vdpa, delegating the boundaries checks to
>> >>>>get_config/set_config callbacks.
>> >>>
>> >>>
>> >>>A question here. How much value could we gain from
>> >>>get_config_size() consider we can let vDPA parent to validate the
>> >>>length in its get_config().
>> >>>
>> >>
>> >>I agree, most of the implementations already validate the length,
>> >>the only gain is an error returned since get_config() is void, but
>> >>eventually we can add a return value to it.
>> >
>> >
>> >Right, one problem here is that. For the virito path, its get_config()
>> >returns void. So we can not propagate error to virtio drivers. But it
>> >might not be a big issue since we trust kernel virtio driver.
>> >
>> >So I think it makes sense to change the return value in the vdpa config ops.
>>
>> Thanks for your feedback!
>>
>> @Xie do you plan to do this?
>>
>> Otherwise I can do in my vdpa-blk-sim series, where for now I used this
>> patch as is.
>>
>
>Hi Stefano, please do in your vdpa-blk-sim series. I have no plan for 
>it now.

Okay, I'll do it.

Thanks,
Stefano