Re: [PATCH net-next 5/6] vsock: use local transport when it is loaded

From: Stefano Garzarella <sgarzare@redhat.com>
To: Stefan Hajnoczi <stefanha@gmail.com>
Cc: netdev@vger.kernel.org,
	virtualization@lists.linux-foundation.org,
	Dexuan Cui <decui@microsoft.com>,
	Stefan Hajnoczi <stefanha@redhat.com>,
	linux-kernel@vger.kernel.org, kvm@vger.kernel.org,
	"David S. Miller" <davem@davemloft.net>,
	Jorgen Hansen <jhansen@vmware.com>
Subject: Re: [PATCH net-next 5/6] vsock: use local transport when it is loaded
Date: Thu, 21 Nov 2019 11:01:56 +0100	[thread overview]
Message-ID: <20191121100156.v4ehwmstlhujrviv@steredhat> (raw)
In-Reply-To: <20191121094614.GC439743@stefanha-x1.localdomain>

On Thu, Nov 21, 2019 at 09:46:14AM +0000, Stefan Hajnoczi wrote:
> On Tue, Nov 19, 2019 at 12:01:20PM +0100, Stefano Garzarella wrote:
> > @@ -420,9 +436,10 @@ int vsock_assign_transport(struct vsock_sock *vsk, struct vsock_sock *psk)
> >  		new_transport = transport_dgram;
> >  		break;
> >  	case SOCK_STREAM:
> > -		if (remote_cid <= VMADDR_CID_HOST ||
> > -		    (transport_g2h &&
> > -		     remote_cid == transport_g2h->get_local_cid()))
> > +		if (vsock_use_local_transport(remote_cid))
> > +			new_transport = transport_local;
> > +		else if (remote_cid == VMADDR_CID_HOST ||
> > +			 remote_cid == VMADDR_CID_HYPERVISOR)
> >  			new_transport = transport_g2h;
> >  		else
> >  			new_transport = transport_h2g;
> 
> We used to send VMADDR_CID_RESERVED to the host.  Now we send
> VMADDR_CID_RESERVED (LOCAL) to the guest when there is no
> transport_local loaded?
> 
> If this is correct, is there a justification for this change?  It seems
> safest to retain existing behavior.

You're right, I'll revert this change in v2.

Thanks,
Stefano