Re: [PATCH] pci/sriov: Add an option to probe VFs or not before enabling SR-IOV

From	Gavin Shan <gwshan@linux.vnet.ibm.com>
Newsgroups	linux.kernel
Subject	Re: [PATCH] pci/sriov: Add an option to probe VFs or not before enabling SR-IOV
Date	2017-03-22 00:50 +0100
Message-ID	<tnBHj-216-1@gated-at.bofh.it> (permalink)
References	(4 earlier) <tnkQ9-7nw-1@gated-at.bofh.it> <tnljb-7NQ-1@gated-at.bofh.it> <tnoh4-1nw-15@gated-at.bofh.it> <tnt73-4zY-13@gated-at.bofh.it> <tnt73-4zY-17@gated-at.bofh.it>
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On Tue, Mar 21, 2017 at 02:34:46PM +0000, Eli Cohen wrote:
>> If we want to talk about the ABI, I would suggest drawing from existing ABIs.  We already have
>> drivers_autoprobe as part of the standard sysfs ABI, so if we want a binary switch, then 
>>sriov_drivers_autoprobe might be a logical choice.  If you're concerned about this mythical overhead of > binding to one driver then another, then why not draw from the driver_override interface to allow the 
>> user to specify the driver to bind to, perhaps sriov_driver_override.  Then if the user wants to bind all 
>> the devices to vfio-pci, they can do so easily.  I still fail to see that probing some fixed number of the VFs 
>> and leaving the rest unprobed has any practical value and I imagine bugs coming in because users are 
>> confused why some of their VFs behave differently than others.  Thanks,
>
>I agree with Alex - the interface should better be binary - either probe VFs or not. The rest can be done with binding/unbinding VFs as necessary. The main goal is to refrain from automatically initializing virtual functions at the hypervisor if they were initially instantiated to assign then to guests.
>

It's fairly reasonable. Thanks for confirm. I'll review v2.

Thanks,
Gavin

Thread

[PATCH] pci/sriov: Add an option to probe VFs or not before enabling SR-IOV bodong@mellanox.com - 2017-03-20 16:30 +0100
  Re: [PATCH] pci/sriov: Add an option to probe VFs or not before  enabling SR-IOV Gavin Shan <gwshan@linux.vnet.ibm.com> - 2017-03-21 00:10 +0100
    Re: [PATCH] pci/sriov: Add an option to probe VFs or not before  enabling SR-IOV Gavin Shan <gwshan@linux.vnet.ibm.com> - 2017-03-21 01:50 +0100
    Re: [PATCH] pci/sriov: Add an option to probe VFs or not before  enabling SR-IOV Alex Williamson <alex.williamson@redhat.com> - 2017-03-21 06:10 +0100
      Re: [PATCH] pci/sriov: Add an option to probe VFs or not before  enabling SR-IOV Gavin Shan <gwshan@linux.vnet.ibm.com> - 2017-03-21 06:50 +0100
        Re: [PATCH] pci/sriov: Add an option to probe VFs or not before  enabling SR-IOV Alex Williamson <alex.williamson@redhat.com> - 2017-03-21 07:20 +0100
          Re: [PATCH] pci/sriov: Add an option to probe VFs or not before  enabling SR-IOV Gavin Shan <gwshan@linux.vnet.ibm.com> - 2017-03-21 10:30 +0100
            RE: [PATCH] pci/sriov: Add an option to probe VFs or not before  enabling SR-IOV Eli Cohen <eli@mellanox.com> - 2017-03-21 15:40 +0100
              Re: [PATCH] pci/sriov: Add an option to probe VFs or not before  enabling SR-IOV Gavin Shan <gwshan@linux.vnet.ibm.com> - 2017-03-22 00:50 +0100
            Re: [PATCH] pci/sriov: Add an option to probe VFs or not before  enabling SR-IOV Alex Williamson <alex.williamson@redhat.com> - 2017-03-21 15:40 +0100
              Re: [PATCH] pci/sriov: Add an option to probe VFs or not before  enabling SR-IOV Gavin Shan <gwshan@linux.vnet.ibm.com> - 2017-03-22 00:50 +0100

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