[dpdk-dev] [EXT] Re: [PATCH v6 2/4] lib/kni: add PCI related information

Vamsi Krishna Attunuru vattunuru at marvell.com
Thu Jun 27 11:43:59 CEST 2019




________________________________
From: Stephen Hemminger <stephen at networkplumber.org>
Sent: Wednesday, June 26, 2019 8:28 PM
To: Vamsi Krishna Attunuru
Cc: dev at dpdk.org; ferruh.yigit at intel.com; olivier.matz at 6wind.com; arybchenko at solarflare.com
Subject: Re: [EXT] Re: [dpdk-dev] [PATCH v6 2/4] lib/kni: add PCI related information

On Wed, 26 Jun 2019 03:48:12 +0000
Vamsi Krishna Attunuru <vattunuru at marvell.com> wrote:

> ________________________________
> From: Stephen Hemminger <stephen at networkplumber.org>
> Sent: Tuesday, June 25, 2019 11:11 PM
> To: Vamsi Krishna Attunuru
> Cc: dev at dpdk.org; ferruh.yigit at intel.com; olivier.matz at 6wind.com; arybchenko at solarflare.com
> Subject: [EXT] Re: [dpdk-dev] [PATCH v6 2/4] lib/kni: add PCI related information
>
> External Email
>
> ----------------------------------------------------------------------
> On Tue, 25 Jun 2019 09:26:58 +0530
> <vattunuru at marvell.com> wrote:
>
> > From: Vamsi Attunuru <vattunuru at marvell.com>
> >
> > PCI related information is needed in KNI kernel module,
> > since it requires iommu domain info for address
> > translations(using iommu_iova_to_phys() call) when
> > KNI runs in IOVA = VA mode.
> >
> > Signed-off-by: Vamsi Attunuru <vattunuru at marvell.com>
> > ---
> >  lib/librte_eal/linux/eal/include/rte_kni_common.h | 7 +++++++
> >  lib/librte_kni/rte_kni.c                          | 5 +++++
> >  2 files changed, 12 insertions(+)
> >
> > diff --git a/lib/librte_eal/linux/eal/include/rte_kni_common.h b/lib/librte_eal/linux/eal/include/rte_kni_common.h
> > index 91a1c14..5db5a13 100644
> > --- a/lib/librte_eal/linux/eal/include/rte_kni_common.h
> > +++ b/lib/librte_eal/linux/eal/include/rte_kni_common.h
> > @@ -111,6 +111,13 @@ struct rte_kni_device_info {
> >        void * mbuf_va;
> >        phys_addr_t mbuf_phys;
> >
> > +     /* PCI info */
> > +     uint16_t vendor_id;           /**< Vendor ID or PCI_ANY_ID. */
> > +     uint16_t device_id;           /**< Device ID or PCI_ANY_ID. */
> > +     uint8_t bus;                  /**< Device bus */
> > +     uint8_t devid;                /**< Device ID */
> > +     uint8_t function;             /**< Device function. */
> > +
> >        uint16_t group_id;            /**< Group ID */
> >        uint32_t core_id;             /**< core ID to bind for kernel thread */
> >
> > diff --git a/lib/librte_kni/rte_kni.c b/lib/librte_kni/rte_kni.c
> > index e29d0cc..99c4bf5 100644
> > --- a/lib/librte_kni/rte_kni.c
> > +++ b/lib/librte_kni/rte_kni.c
> > @@ -242,6 +242,11 @@ rte_kni_alloc(struct rte_mempool *pktmbuf_pool,
> >                kni->ops.port_id = UINT16_MAX;
> >
> >        memset(&dev_info, 0, sizeof(dev_info));
> > +     dev_info.bus = conf->addr.bus;
> > +     dev_info.devid = conf->addr.devid;
> > +     dev_info.function = conf->addr.function;
> > +     dev_info.vendor_id = conf->id.vendor_id;
> > +     dev_info.device_id = conf->id.device_id;
> >        dev_info.core_id = conf->core_id;
> >        dev_info.force_bind = conf->force_bind;
> >        dev_info.group_id = conf->group_id;
>
>
> NAK
>
> Why is PCI info part of KNI. KNI can be used with non-PCI devices now
>
> Kernel KNI module needs device info(PCI in this case) to figure out iommu domain details to work with IOVA=VA mode and the struct rte_kni_device_info only carries KNI device info to the kernel module, if not here, where do you suggest me to put this info.

The kernel KNI driver works as is with netvsc PMD (which is vmbus).
Your code may break that. If needs to work for both.

Vamsi >  I do not think this changes would break any existing functionality, as it can still operate in PA mode if any PMD or application requires so, same for netvsc as well right. Please correct me if am missing any assumptions here.


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