From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Michael S. Tsirkin" Subject: Re: [PATCH 2/2] tcm_vhost: Initialize vq->last_used_idx when set endpoint Date: Wed, 27 Mar 2013 23:45:59 +0200 Message-ID: <20130327214559.GB10678@redhat.com> References: <1363920748-32139-1-git-send-email-asias@redhat.com> <1363920748-32139-3-git-send-email-asias@redhat.com> <20130325111611.GD9221@redhat.com> <1364416155.17698.3.camel@haakon2.linux-iscsi.org> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Content-Disposition: inline In-Reply-To: <1364416155.17698.3.camel@haakon2.linux-iscsi.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: virtualization-bounces@lists.linux-foundation.org Errors-To: virtualization-bounces@lists.linux-foundation.org To: "Nicholas A. Bellinger" Cc: kvm@vger.kernel.org, virtualization@lists.linux-foundation.org, target-devel@vger.kernel.org, Stefan Hajnoczi , Paolo Bonzini List-Id: virtualization@lists.linuxfoundation.org On Wed, Mar 27, 2013 at 01:29:15PM -0700, Nicholas A. Bellinger wrote: > On Mon, 2013-03-25 at 13:16 +0200, Michael S. Tsirkin wrote: > > On Fri, Mar 22, 2013 at 10:52:28AM +0800, Asias He wrote: > > > This patch fixes guest hang when booting seabios and guest. > > > > > > [ 0.576238] scsi0 : Virtio SCSI HBA > > > [ 0.616754] virtio_scsi virtio1: request:id 0 is not a head! > > > > > > vq->last_used_idx is initialized only when /dev/vhost-scsi is > > > opened or closed. > > > > > > vhost_scsi_open -> vhost_dev_init() -> vhost_vq_reset() > > > vhost_scsi_release() -> vhost_dev_cleanup -> vhost_vq_reset() > > > > > > So, when guest talks to tcm_vhost after seabios does, vq->last_used_idx > > > still contains the old valule for seabios. This confuses guest. > > > > > > Fix this by calling vhost_init_used() to init vq->last_used_idx when > > > we set endpoint. > > > > > > Signed-off-by: Asias He > > > > Good catch, thanks. > > > > Acked-by: Michael S. Tsirkin > > > > Nicholas can you pick this one up for 3.9 please? > > > > Just a heads up that this needs PATCH 1/2 as vhost_init_used() expects > vq->private_data to already have been set.. > > Can you take a another look at the first patch as a v3.9 item..? Both > are required in order for Asias's seabios changes to work. > > Thanks, > > --nab > Both me and Asias agreed it's not 3.9 material. Asias, can you please rework 2/2 to avoid dependency on 1/2? Should be trivial enough ... > > > drivers/vhost/tcm_vhost.c | 1 + > > > 1 file changed, 1 insertion(+) > > > > > > diff --git a/drivers/vhost/tcm_vhost.c b/drivers/vhost/tcm_vhost.c > > > index 099feef..0524267 100644 > > > --- a/drivers/vhost/tcm_vhost.c > > > +++ b/drivers/vhost/tcm_vhost.c > > > @@ -848,6 +848,7 @@ static int vhost_scsi_set_endpoint( > > > /* Flushing the vhost_work acts as synchronize_rcu */ > > > mutex_lock(&vq->mutex); > > > rcu_assign_pointer(vq->private_data, vs); > > > + vhost_init_used(vq); > > > mutex_unlock(&vq->mutex); > > > } > > > ret = 0; > > > -- > > > 1.8.1.4 > > -- > > To unsubscribe from this list: send the line "unsubscribe target-devel" in > > the body of a message to majordomo@vger.kernel.org > > More majordomo info at http://vger.kernel.org/majordomo-info.html >