[PATCH v8 06/13] vdpa/ifc: add block device SW live-migration

[Pei, Andy]

Hi Chenbo,

Thanks for your reply, I will fix them in next version.

> -----Original Message-----
> From: Xia, Chenbo <chenbo.xia at intel.com>
> Sent: Monday, May 23, 2022 1:25 PM
> To: Pei, Andy <andy.pei at intel.com>; dev at dpdk.org
> Cc: maxime.coquelin at redhat.com; Cao, Gang <gang.cao at intel.com>; Liu,
> Changpeng <changpeng.liu at intel.com>; Xu, Rosen <rosen.xu at intel.com>;
> Xiao, QimaiX <qimaix.xiao at intel.com>
> Subject: RE: [PATCH v8 06/13] vdpa/ifc: add block device SW live-migration
> 
> > -----Original Message-----
> > From: Pei, Andy <andy.pei at intel.com>
> > Sent: Wednesday, May 18, 2022 8:14 PM
> > To: dev at dpdk.org
> > Cc: Xia, Chenbo <chenbo.xia at intel.com>; maxime.coquelin at redhat.com;
> > Cao, Gang <gang.cao at intel.com>; Liu, Changpeng
> > <changpeng.liu at intel.com>; Xu, Rosen <rosen.xu at intel.com>; Xiao,
> > QimaiX <qimaix.xiao at intel.com>
> > Subject: [PATCH v8 06/13] vdpa/ifc: add block device SW live-migration
> >
> > Add SW live-migration support to block device.
> > For block device, it is critical that no packet should be dropped. So
> > when virtio blk device is pause, make sure hardware last_avail_idx and
> 
> paused
> 
> > last_used_idx are the same. This indicates all requests have recieved
> > acks, and no inflight IO.
> 
> received
> 
> With above fixed:
> 
> Reviewed-by: Chenbo Xia <chenbo.xia at intel.com>
> 
> >
> > Signed-off-by: Andy Pei <andy.pei at intel.com>
> > ---
> >  drivers/vdpa/ifc/base/ifcvf.h |  1 +
> >  drivers/vdpa/ifc/ifcvf_vdpa.c | 42
> > ++++++++++++++++++++++++++++++++++++++----
> >  2 files changed, 39 insertions(+), 4 deletions(-)
> >
> > diff --git a/drivers/vdpa/ifc/base/ifcvf.h
> > b/drivers/vdpa/ifc/base/ifcvf.h index 244de46..4fb1736 100644
> > --- a/drivers/vdpa/ifc/base/ifcvf.h
> > +++ b/drivers/vdpa/ifc/base/ifcvf.h
> > @@ -65,6 +65,7 @@
> >  #define IFCVF_MEDIATED_VRING		0x200000000000
> >
> >  #define IFCVF_32_BIT_MASK		0xffffffff
> > +#define IFCVF_16_BIT_MASK		0xffff
> >
> >
> >  #ifndef VHOST_USER_PROTOCOL_F_CONFIG
> > diff --git a/drivers/vdpa/ifc/ifcvf_vdpa.c
> > b/drivers/vdpa/ifc/ifcvf_vdpa.c index 509a1ed..3e78c7d 100644
> > --- a/drivers/vdpa/ifc/ifcvf_vdpa.c
> > +++ b/drivers/vdpa/ifc/ifcvf_vdpa.c
> > @@ -316,8 +316,34 @@ struct rte_vdpa_dev_info {
> >  	uint64_t features = 0;
> >  	uint64_t log_base = 0, log_size = 0;
> >  	uint64_t len;
> > +	u32 ring_state = 0;
> >
> >  	vid = internal->vid;
> > +
> > +	/* to make sure no packet is lost for blk device
> > +	 * do not stop until last_avail_idx == last_used_idx
> > +	 */
> > +	if (internal->hw.device_type == IFCVF_BLK) {
> > +		for (i = 0; i < hw->nr_vring; i++) {
> > +			do {
> > +				if (hw->lm_cfg != NULL)
> > +					ring_state = *(u32 *)(hw->lm_cfg +
> > +
> 	IFCVF_LM_RING_STATE_OFFSET +
> > +						i * IFCVF_LM_CFG_SIZE);
> > +				hw->vring[i].last_avail_idx =
> > +					(u16)(ring_state &
> IFCVF_16_BIT_MASK);
> > +				hw->vring[i].last_used_idx =
> > +					(u16)(ring_state >> 16);
> > +				if (hw->vring[i].last_avail_idx !=
> > +					hw->vring[i].last_used_idx) {
> > +					ifcvf_notify_queue(hw, i);
> > +					usleep(10);
> > +				}
> > +			} while (hw->vring[i].last_avail_idx !=
> > +				hw->vring[i].last_used_idx);
> > +		}
> > +	}
> > +
> >  	ifcvf_stop_hw(hw);
> >
> >  	for (i = 0; i < hw->nr_vring; i++)
> > @@ -641,8 +667,10 @@ struct rte_vdpa_dev_info {
> >  		}
> >  		hw->vring[i].avail = gpa;
> >
> > -		/* Direct I/O for Tx queue, relay for Rx queue */
> > -		if (i & 1) {
> > +		/* NET: Direct I/O for Tx queue, relay for Rx queue
> > +		 * BLK: relay every queue
> > +		 */
> > +		if ((internal->hw.device_type == IFCVF_NET) && (i & 1)) {
> >  			gpa = hva_to_gpa(vid, (uint64_t)(uintptr_t)vq.used);
> >  			if (gpa == 0) {
> >  				DRV_LOG(ERR, "Fail to get GPA for used
> ring."); @@ -692,8 +720,12
> > @@ struct rte_vdpa_dev_info {
> >
> >  	for (i = 0; i < hw->nr_vring; i++) {
> >  		/* synchronize remaining new used entries if any */
> > -		if ((i & 1) == 0)
> > +		if (internal->hw.device_type == IFCVF_NET) {
> > +			if ((i & 1) == 0)
> > +				update_used_ring(internal, i);
> > +		} else if (internal->hw.device_type == IFCVF_BLK) {
> >  			update_used_ring(internal, i);
> > +		}
> >
> >  		rte_vhost_get_vhost_vring(vid, i, &vq);
> >  		len = IFCVF_USED_RING_LEN(vq.size); @@ -755,7 +787,9
> @@ struct
> > rte_vdpa_dev_info {
> >  		}
> >  	}
> >
> > -	for (qid = 0; qid < q_num; qid += 2) {
> > +	for (qid = 0; qid < q_num; qid += 1) {
> > +		if ((internal->hw.device_type == IFCVF_NET) && (qid & 1))
> > +			continue;
> >  		ev.events = EPOLLIN | EPOLLPRI;
> >  		/* leave a flag to mark it's for interrupt */
> >  		ev.data.u64 = 1 | qid << 1 |
> > --
> > 1.8.3.1