From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wg0-f46.google.com ([74.125.82.46]:58836 "EHLO mail-wg0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753221AbaLGSmr (ORCPT ); Sun, 7 Dec 2014 13:42:47 -0500 Received: by mail-wg0-f46.google.com with SMTP id x13so2100185wgg.19 for ; Sun, 07 Dec 2014 10:42:46 -0800 (PST) From: Eli Cohen Date: Sun, 7 Dec 2014 20:42:43 +0200 To: Yuval Mintz Cc: Eli Cohen , "bhelgaas@google.com" , David Miller , linux-pci , netdev , "ogerlitz@mellanox.com" , "yevgenyp@mellanox.com" , Donald Dutile Subject: Re: [PATCH RFC] pci: Control whether VFs are probed on pci_enable_sriov Message-ID: <20141207184242.GA24790@mtldesk30> References: <1417957693-24979-1-git-send-email-eli@mellanox.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: Sender: linux-pci-owner@vger.kernel.org List-ID: On Sun, Dec 07, 2014 at 05:05:06PM +0000, Yuval Mintz wrote: > > >This can save host side resource usage by VF instances which would be > >eventually probed to VMs. > > >Use a parameter to pci_enable_sriov to control that policy, and modify > >all current callers such that they retain the same functionality. > > What's the end-game here? How eventually would this be controlled? You can probe any VF at the hypervisor through sysfs files (bind/unbind). You can also pass them through to a VM. Nothing changes. > > >Use a one shot flag on struct pci_device which is cleared after the > >first probe is ignored so subsequent attempts go through. > > Does a one-shot flag suffice? E.g., consider assigning a VF to VM and > than shutting down the VM. Assuming this feature is disabled, > the VF didn't appear on the hypervisor prior to the assignment but > will appear after its shutdown. Sorry, I don't follow you here. Please clarify. To be clear, the functionality proposed here is really one shot. It just prevents calling probe once; besides that nothing changes.