Date:   Tue, 30 Nov 2021 18:21:58 -0500
From:   "Michael S. Tsirkin" <mst@redhat.com>
To:     "Wang, Wei W" <wei.w.wang@intel.com>
Cc:     Stefano Garzarella <sgarzare@redhat.com>,
        "stefanha@redhat.com" <stefanha@redhat.com>,
        "davem@davemloft.net" <davem@davemloft.net>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        "virtualization@lists.linux-foundation.org" 
        <virtualization@lists.linux-foundation.org>,
        "netdev@vger.kernel.org" <netdev@vger.kernel.org>
Subject: Re: [PATCH v2] virtio/vsock: fix the transport to work with
 VMADDR_CID_ANY
Message-ID: <20211130181948-mutt-send-email-mst@kernel.org>
References: <20211126011823.1760-1-wei.w.wang@intel.com>
 <20211126085341.wiab2frkcbmkg4ca@steredhat>
 <2853d4c373aa4cf0961a256622014eed@intel.com>
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In-Reply-To: <2853d4c373aa4cf0961a256622014eed@intel.com>
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On Tue, Nov 30, 2021 at 01:34:20AM +0000, Wang, Wei W wrote:
> Hi Michael,
> 
> Do you plan to merge this patch through your tree?
> If not, I'll resend to have it applied to the net tree.
> 
> Thanks,
> Wei


Sure, I'll merge it. Thanks!

> On Friday, November 26, 2021 4:54 PM, Stefano Garzarella wrote:
> > On Thu, Nov 25, 2021 at 08:18:23PM -0500, Wei Wang wrote:
> > >The VMADDR_CID_ANY flag used by a socket means that the socket isn't
> > >bound to any specific CID. For example, a host vsock server may want to
> > >be bound with VMADDR_CID_ANY, so that a guest vsock client can connect
> > >to the host server with CID=VMADDR_CID_HOST (i.e. 2), and meanwhile, a
> > >host vsock client can connect to the same local server with
> > >CID=VMADDR_CID_LOCAL (i.e. 1).
> > >
> > >The current implementation sets the destination socket's svm_cid to a
> > >fixed CID value after the first client's connection, which isn't an
> > >expected operation. For example, if the guest client first connects to
> > >the host server, the server's svm_cid gets set to VMADDR_CID_HOST, then
> > >other host clients won't be able to connect to the server anymore.
> > >
> > >Reproduce steps:
> > >1. Run the host server:
> > >   socat VSOCK-LISTEN:1234,fork -
> > >2. Run a guest client to connect to the host server:
> > >   socat - VSOCK-CONNECT:2:1234
> > >3. Run a host client to connect to the host server:
> > >   socat - VSOCK-CONNECT:1:1234
> > >
> > >Without this patch, step 3. above fails to connect, and socat complains
> > >"socat[1720] E connect(5, AF=40 cid:1 port:1234, 16): Connection reset
> > >by peer".
> > >With this patch, the above works well.
> > >
> > >Fixes: c0cfa2d8a788 ("vsock: add multi-transports support")
> > >Signed-off-by: Wei Wang <wei.w.wang@intel.com>
> > >---
> > > net/vmw_vsock/virtio_transport_common.c | 3 ++-
> > > 1 file changed, 2 insertions(+), 1 deletion(-)
> > 
> > Usually fixes for net/vmw_vsock/* are applied through the net tree
> > (netdev@vger.kernel.org) that seems not CCed. Please
> > use ./scripts/get_maintainer.pl next time.
> > 
> > Maybe this one can be queued by Michael, let's wait a bit, otherwise please
> > resend CCing netdev and using "net" tag.
> > 
> > Anyway the patch LGTM:
> > 
> > Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>