Re: [dpdk-dev] [PATCH] tools/dpdk_nic_bind: Fix can't bind virtio-pci issue

["Ouyang, Changchun" <changchun.ouyang@intel.com>]

Hi,

> -----Original Message-----
> From: Richardson, Bruce
> Sent: Tuesday, March 3, 2015 7:44 PM
> To: Ouyang, Changchun
> Cc: dev@dpdk.org; Cao, Waterman
> Subject: Re: [PATCH] tools/dpdk_nic_bind: Fix can't bind virtio-pci issue
> 
> On Thu, Feb 26, 2015 at 12:57:49PM +0800, Ouyang Changchun wrote:
> First off, I think the title needs to be changed. How about something like:
> "dpdk_nic_bind: don't exit if an unused module is missing"
> 
> > In virtio test, on guest
> > 1. Bind virtio port to igb_uio driver; 2. Remove igb_uio module; 3.
> > Bind virtio port to virtio-pci driver, it fails and reports:
> >    "Error - no supported modules are loaded"
> >
> > The tool should check the to-be-bound driver flag, if it is dpdk
> > driver(igb_uio, vfio etc), and the corresponding module is not loaded,
> > then exit, otherwise, just report a warning, and continue to bind the non-
> dpdk driver(like virtio-pci) to dev.
> 
> This is a good description of the problem. Once you change the title, I think
> an initial sentence is needed here by way of intro - such as:
> "The dpdk_nic_bind script will not allow ports to be bound or unbound if
> none of the kernel modules supported by DPDK is loaded. This patch relaxes
> this restriction by checking if a DPDK module is actually requested. The
> example below illustrates this problem:"
> 

Will update this description in v2.
Thanks

> >
> > Signed-off-by: Changchun Ouyang <changchun.ouyang@intel.com>
> > ---
> >  tools/dpdk_nic_bind.py | 7 +++++--
> >  1 file changed, 5 insertions(+), 2 deletions(-)
> >
> > diff --git a/tools/dpdk_nic_bind.py b/tools/dpdk_nic_bind.py index
> > 2483056..8523f82 100755
> > --- a/tools/dpdk_nic_bind.py
> > +++ b/tools/dpdk_nic_bind.py
> > @@ -175,8 +175,11 @@ def check_modules():
> >
> >      # check if we have at least one loaded module
> >      if True not in [mod["Found"] for mod in mods] and b_flag is not None:
> > -        print "Error - no supported modules are loaded"
> > -        sys.exit(1)
> > +        if b_flag in dpdk_drivers:
> > +            print "Error - no supported modules(DPDK driver) are loaded"
> > +            sys.exit(1)
> > +        else:
> > +            print "Warning - no supported modules(DPDK driver) are loaded"
> >
> >      # change DPDK driver list to only contain drivers that are loaded
> >      dpdk_drivers = [mod["Name"] for mod in mods if mod["Found"]]
> > --
> > 1.8.4.2
> >
> This is a worthwhile change. However, I think it could be made better:
> * If we try to bind a device to ixgbe, and ixgbe is not loaded, we get no error
> from the script
> * If igb_uio is loaded and we try to bind a device to vfio which is not loaded
> again we get no error from the script.
> 
> If would be nice if instead of this checking explicitly for DPDK modules, we
> just check if the module to be bound is present and give an error if not.
>
 
For all these cases, they could be detected in function bind_one,
If any module exactly required can't be found/opened,  it will go to except branch and raise a error message like:
Error: bind failed ..... Cannot open.....

Thanks
Changchun