RE: [PATCH v2 3/8] vdpa/ifc: set max queues according to HW spec

["Pei, Andy" <andy.pei@intel.com>]

Hi Chenbo,

Thanks for your reply.
My reply is inline.

> -----Original Message-----
> From: Xia, Chenbo <chenbo.xia@intel.com>
> Sent: Friday, September 9, 2022 1:56 PM
> To: Pei, Andy <andy.pei@intel.com>; dev@dpdk.org
> Cc: Xu, Rosen <rosen.xu@intel.com>; Huang, Wei <wei.huang@intel.com>; Cao,
> Gang <gang.cao@intel.com>; maxime.coquelin@redhat.com
> Subject: RE: [PATCH v2 3/8] vdpa/ifc: set max queues according to HW spec
> 
> > -----Original Message-----
> > From: Pei, Andy <andy.pei@intel.com>
> > Sent: Thursday, September 8, 2022 1:54 PM
> > To: dev@dpdk.org
> > Cc: Xia, Chenbo <chenbo.xia@intel.com>; Xu, Rosen
> > <rosen.xu@intel.com>; Huang, Wei <wei.huang@intel.com>; Cao, Gang
> > <gang.cao@intel.com>; maxime.coquelin@redhat.com; Huang Wei
> > <wei_huang@intel.com>
> > Subject: [PATCH v2 3/8] vdpa/ifc: set max queues according to HW spec
> 
> vdpa/ifc: set max queues based on virtio spec
> 
OK

> >
> > Set max_queues according to virtio HW spec.
> > For virtio BLK device, set max_queues to the value of "num_queues".
> > "num_queues" is element of struct virtio_blk_config.
> 
> Both virtio-net/blk should be described.
> 
OK
> >
> > Signed-off-by: Andy Pei <andy.pei@intel.com>
> > Signed-off-by: Huang Wei <wei_huang@intel.com>
> 
> Email is wrong, please fix all in next version
> 
OK

> > ---
> >  drivers/vdpa/ifc/base/ifcvf.h |  2 +-  drivers/vdpa/ifc/ifcvf_vdpa.c
> > | 21 ++++++++++++++++++++-
> >  2 files changed, 21 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/vdpa/ifc/base/ifcvf.h
> > b/drivers/vdpa/ifc/base/ifcvf.h index ad505f1..c17bf2a 100644
> > --- a/drivers/vdpa/ifc/base/ifcvf.h
> > +++ b/drivers/vdpa/ifc/base/ifcvf.h
> > @@ -21,7 +21,7 @@
> >  #define IFCVF_NET_DEVICE_ID                 0x0001
> >  #define IFCVF_BLK_DEVICE_ID                 0x0002
> >
> > -#define IFCVF_MAX_QUEUES		1
> > +#define IFCVF_MAX_QUEUES		32
> >
> >  #ifndef VIRTIO_F_IOMMU_PLATFORM
> >  #define VIRTIO_F_IOMMU_PLATFORM		33
> > diff --git a/drivers/vdpa/ifc/ifcvf_vdpa.c
> > b/drivers/vdpa/ifc/ifcvf_vdpa.c index 2d165c0..2b42850 100644
> > --- a/drivers/vdpa/ifc/ifcvf_vdpa.c
> > +++ b/drivers/vdpa/ifc/ifcvf_vdpa.c
> > @@ -26,6 +26,18 @@
> >
> >  #include "base/ifcvf.h"
> >
> > +/*
> > + * RTE_MAX() and RTE_MIN() cannot be used since braced-group within
> > + * expression allowed only inside a function, but MAX() is used as
> > + * a number of elements in array.
> > + */
> > +#ifndef MAX
> > +#define MAX(v1, v2)	((v1) > (v2) ? (v1) : (v2))
> > +#endif
> > +#ifndef MIN
> > +#define MIN(v1, v2)	((v1) < (v2) ? (v1) : (v2))
> > +#endif
> 
> Above ifndef is not needed?
> 
> Seems MAX is not used, so remove it
> 
OK
> > +
> >  RTE_LOG_REGISTER(ifcvf_vdpa_logtype, pmd.vdpa.ifcvf, NOTICE);
> > #define DRV_LOG(level, fmt, args...) \
> >  	rte_log(RTE_LOG_ ## level, ifcvf_vdpa_logtype, \ @@ -1512,6 +1524,7
> > @@ struct rte_vdpa_dev_info dev_info[] = {
> >  	uint64_t capacity = 0;
> >  	uint8_t *byte;
> >  	uint32_t i;
> > +	uint16_t queue_pairs;
> >
> >  	if (rte_eal_process_type() != RTE_PROC_PRIMARY)
> >  		return 0;
> > @@ -1559,7 +1572,6 @@ struct rte_vdpa_dev_info dev_info[] = {
> >  	}
> >
> >  	internal->configured = 0;
> > -	internal->max_queues = IFCVF_MAX_QUEUES;
> >  	features = ifcvf_get_features(&internal->hw);
> >
> >  	device_id = ifcvf_pci_get_device_type(pci_dev);
> > @@ -1570,6 +1582,10 @@ struct rte_vdpa_dev_info dev_info[] = {
> >
> >  	if (device_id == VIRTIO_ID_NET) {
> >  		internal->hw.device_type = IFCVF_NET;
> > +		queue_pairs = (internal->hw.common_cfg->num_queues - 1) / 2;
> 
> Please note this logic assumes CTRL_VQ is always there, if for the read hardware,
> that is the case, then it's fine. You can decide yourself to check CTRL_VQ feature
> is there or not.
> 
I will keep the code as it is now, and add some comments to explain ifc driver assumes CTRL_VQ is always there.
> Thanks,
> Chenbo
> 
> > +		DRV_LOG(INFO, "%s support %u queue pairs", pci_dev->name,
> > +			queue_pairs);
> > +		internal->max_queues = MIN(IFCVF_MAX_QUEUES,
> queue_pairs);
> >  		internal->features = features &
> >  					~(1ULL <<
> VIRTIO_F_IOMMU_PLATFORM);
> >  		internal->features |= dev_info[IFCVF_NET].features; @@ -
> 1609,6
> > +1625,9 @@ struct rte_vdpa_dev_info dev_info[] = {
> >  			internal->hw.blk_cfg->geometry.sectors);
> >  		DRV_LOG(DEBUG, "num_queues: 0x%08x",
> >  			internal->hw.blk_cfg->num_queues);
> > +
> > +		internal->max_queues = MIN(IFCVF_MAX_QUEUES,
> > +			internal->hw.blk_cfg->num_queues);
> >  	}
> >
> >  	list->internal = internal;
> > --
> > 1.8.3.1