From mboxrd@z Thu Jan  1 00:00:00 1970
From: Srikanth Akula <srikanth044@gmail.com>
Subject: Re: Hotplug
Date: Wed, 7 Oct 2015 14:16:12 -0700
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To: Stephen Hemminger <stephen@networkplumber.org>
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Thank you for the inputs .

I was able to solve the problem of device notification from my control
plane.

I would like to know if we have any way to know if the PCI device is
already attached before we try to attach it ( if the device is already
attached pci probe will result an error ) .
But i want to know before hand to verify if the device is already attached
or not .

I came with small API which can be used to check if the pci device is
already bound to any driver .

+int
+rte_eal_pci_is_attached(const char *devargs)
+{
+        struct rte_pci_device *dev = NULL;
+        struct rte_pci_addr addr;
+        memset(&addr,0,sizeof(struct rte_pci_addr));
+
+        if (eal_parse_pci_DomBDF(devargs, &addr) == 0)
+          {
+            TAILQ_FOREACH(dev, &pci_device_list, next) {
+            if (!rte_eal_compare_pci_addr(&dev->addr, &addr))
+              {
+                if (dev->driver)
+                  {
+                    /*pci_dump_one_device(stdout,dev);*/
+                    RTE_LOG(WARNING, EAL, "Requested device " PCI_PRI_FMT
+                      " cannot be used\n", dev->addr.domain, dev->addr.bus,
+                    dev->addr.devid, dev->addr.function);
+                   return -1;
+                 }
+              }
+           }
+         }
+   return 0;
+}
+

Could you please let me know if it is good to have such APIs

Regards,
_Srikanth_


On Mon, Sep 28, 2015 at 9:44 PM, Stephen Hemminger <
stephen@networkplumber.org> wrote:

> On Mon, 28 Sep 2015 21:12:50 -0700
> Srikanth Akula <srikanth044@gmail.com> wrote:
>
> > Hello ,
> >
> > I am trying to write an application based on DPDK port hotplug feature .
> My
> > requirement is to get an event when a new PCI devices gets added to the
> > system on the go.
> >
> > Do we have any in-built mechanism in DPDK (UIO/e1000/vfio drivers ) that
> i
> > can use to get notifications when a new device gets added . I know the
> > alternatives such as inotify etc .
> >
> > But i am more interested to get equivalent support in dpdk drivers .
> >
> > Please let me know .
> >
> > Srikanth
>
> Implementing hotplug requires integration with the OS more than any
> additional
> DPDK support. What the Brocade vRouter does is leverage the existing Linux
> udev infrastructure to send a message to the router application which then
> initializes and sets up the new hardware. Most of the DPDK changes are
> upstream
> already and involve being able to dynamically add ports on the fly.
>
>