From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S941215AbcIVVJ3 convert rfc822-to-8bit (ORCPT ); Thu, 22 Sep 2016 17:09:29 -0400 Received: from userp1040.oracle.com ([156.151.31.81]:39319 "EHLO userp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750868AbcIVVJ1 (ORCPT ); Thu, 22 Sep 2016 17:09:27 -0400 Subject: Re: [PATCH v3 3/3] xen/pciback: support driver_override To: Juergen Gross , linux-kernel@vger.kernel.org, xen-devel@lists.xenproject.org References: <1474533941-6976-1-git-send-email-jgross@suse.com> <1474533941-6976-4-git-send-email-jgross@suse.com> Cc: david.vrabel@citrix.com From: Boris Ostrovsky Message-ID: <7c429c09-944c-481e-aa2d-2ee59bc4a649@oracle.com> Date: Thu, 22 Sep 2016 17:10:55 -0400 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.3.0 MIME-Version: 1.0 In-Reply-To: <1474533941-6976-4-git-send-email-jgross@suse.com> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 8BIT X-Source-IP: userv0021.oracle.com [156.151.31.71] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 09/22/2016 04:45 AM, Juergen Gross wrote: > Support the driver_override scheme introduced with commit 782a985d7af2 > ("PCI: Introduce new device binding path using pci_dev.driver_override") > > As pcistub_probe() is called for all devices (it has to check for a > match based on the slot address rather than device type) it has to > check for driver_override set to "pciback" itself. > > Up to now for assigning a pci device to pciback you need something like: > > echo 0000:07:10.0 > /sys/bus/pci/devices/0000\:07\:10.0/driver/unbind > echo 0000:07:10.0 > /sys/bus/pci/drivers/pciback/new_slot > echo 0000:07:10.0 > /sys/bus/pci/drivers_probe > > while with the patch you can use the same mechanism as for similar > drivers like pci-stub and vfio-pci: > > echo pciback > /sys/bus/pci/devices/0000\:07\:10.0/driver_override > echo 0000:07:10.0 > /sys/bus/pci/devices/0000\:07\:10.0/driver/unbind > echo 0000:07:10.0 > /sys/bus/pci/drivers_probe > > So e.g. libvirt doesn't need special handling for pciback. > > Signed-off-by: Juergen Gross > --- > V3: Move override check up in order not to miss the PCI_HEADER_TYPE > check. > Add an assigned device to the slot list. > > V2: Removed now unused label > --- > drivers/xen/xen-pciback/pci_stub.c | 36 +++++++++++++++++++++++++++++------- > 1 file changed, 29 insertions(+), 7 deletions(-) > > diff --git a/drivers/xen/xen-pciback/pci_stub.c b/drivers/xen/xen-pciback/pci_stub.c > index 0179333..6331a95 100644 > --- a/drivers/xen/xen-pciback/pci_stub.c > +++ b/drivers/xen/xen-pciback/pci_stub.c > @@ -25,6 +25,8 @@ > #include "conf_space.h" > #include "conf_space_quirks.h" > > +#define PCISTUB_DRIVER_NAME "pciback" > + > static char *pci_devs_to_hide; > wait_queue_head_t xen_pcibk_aer_wait_queue; > /*Add sem for sync AER handling and xen_pcibk remove/reconfigue ops, > @@ -508,15 +510,18 @@ static void pcistub_device_id_add_list(struct pcistub_device_id *new, > kfree(new); > } > > -static int pcistub_seize(struct pci_dev *dev) > +static int pcistub_seize(struct pci_dev *dev, > + struct pcistub_device_id *pci_dev_id) > { > struct pcistub_device *psdev; > unsigned long flags; > int err = 0; > > psdev = pcistub_device_alloc(dev); > - if (!psdev) > + if (!psdev) { > + kfree(pci_dev_id); Here too --- I'd rather have it freed by whoever allocated it (i.e. the caller). In fact I think you can allocate this here and instead of passing pci_dev_id pointer pass a flag of some sort. -boris > return -ENOMEM; > + } > > spin_lock_irqsave(&pcistub_devices_lock, flags); > > @@ -537,8 +542,12 @@ static int pcistub_seize(struct pci_dev *dev) > > spin_unlock_irqrestore(&pcistub_devices_lock, flags); > > - if (err) > + if (err) { > + kfree(pci_dev_id); > pcistub_device_put(psdev); > + } else if (pci_dev_id) > + pcistub_device_id_add_list(pci_dev_id, pci_domain_nr(dev->bus), > + dev->bus->number, dev->devfn); > > return err; > } > @@ -547,11 +556,16 @@ static int pcistub_seize(struct pci_dev *dev) > * other functions that take the sysfs lock. */ > static int pcistub_probe(struct pci_dev *dev, const struct pci_device_id *id) > { > - int err = 0; > + int err = 0, match; > + struct pcistub_device_id *pci_dev_id = NULL; > > dev_dbg(&dev->dev, "probing...\n"); > > - if (pcistub_match(dev)) { > + match = pcistub_match(dev); > + > + if ((dev->driver_override && > + !strcmp(dev->driver_override, PCISTUB_DRIVER_NAME)) || > + match) { > > if (dev->hdr_type != PCI_HEADER_TYPE_NORMAL > && dev->hdr_type != PCI_HEADER_TYPE_BRIDGE) { > @@ -562,8 +576,16 @@ static int pcistub_probe(struct pci_dev *dev, const struct pci_device_id *id) > goto out; > } > > + if (!match) { > + pci_dev_id = kmalloc(sizeof(*pci_dev_id), GFP_ATOMIC); > + if (!pci_dev_id) { > + err = -ENOMEM; > + goto out; > + } > + } > + > dev_info(&dev->dev, "seizing device\n"); > - err = pcistub_seize(dev); > + err = pcistub_seize(dev, pci_dev_id); > } else > /* Didn't find the device */ > err = -ENODEV; > @@ -975,7 +997,7 @@ static const struct pci_error_handlers xen_pcibk_error_handler = { > static struct pci_driver xen_pcibk_pci_driver = { > /* The name should be xen_pciback, but until the tools are updated > * we will keep it as pciback. */ > - .name = "pciback", > + .name = PCISTUB_DRIVER_NAME, > .id_table = pcistub_ids, > .probe = pcistub_probe, > .remove = pcistub_remove,