From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755386AbeDCK5o (ORCPT ); Tue, 3 Apr 2018 06:57:44 -0400 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:53462 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1754869AbeDCK5n (ORCPT ); Tue, 3 Apr 2018 06:57:43 -0400 Date: Tue, 3 Apr 2018 12:57:37 +0200 From: Cornelia Huck To: Tony Krowiak Cc: linux-s390@vger.kernel.org, linux-kernel@vger.kernel.org, kvm@vger.kernel.org, freude@de.ibm.com, schwidefsky@de.ibm.com, heiko.carstens@de.ibm.com, borntraeger@de.ibm.com, kwankhede@nvidia.com, bjsdjshi@linux.vnet.ibm.com, pbonzini@redhat.com, alex.williamson@redhat.com, pmorel@linux.vnet.ibm.com, alifm@linux.vnet.ibm.com, mjrosato@linux.vnet.ibm.com, jjherne@linux.vnet.ibm.com, thuth@redhat.com, pasic@linux.vnet.ibm.com, berrange@redhat.com, fiuczy@linux.vnet.ibm.com, buendgen@de.ibm.com Subject: Re: [PATCH v3 05/14] s390: vfio-ap: base implementation of VFIO AP device driver Message-ID: <20180403125737.15cb55fb.cohuck@redhat.com> In-Reply-To: <1521051954-25715-6-git-send-email-akrowiak@linux.vnet.ibm.com> References: <1521051954-25715-1-git-send-email-akrowiak@linux.vnet.ibm.com> <1521051954-25715-6-git-send-email-akrowiak@linux.vnet.ibm.com> Organization: Red Hat GmbH MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 14 Mar 2018 14:25:45 -0400 Tony Krowiak wrote: > Introduces a new AP device driver. This device driver > is built on the VFIO mediated device framework. The framework > provides sysfs interfaces that facilitate passthrough > access by guests to devices installed on the linux host. > > The VFIO AP device driver will serve two purposes: > > 1. Provide the interfaces to reserve AP devices for exclusive > use by KVM guests. This is accomplished by unbinding the > devices to be reserved for guest usage from the default AP > device driver and binding them to the VFIO AP device driver. > > 2. Implements the functions, callbacks and sysfs attribute > interfaces required to create one or more VFIO mediated > devices each of which will be used to configure the AP > matrix for a guest and serve as a file descriptor > for facilitating communication between QEMU and the > VFIO AP device driver. > > When the VFIO AP device driver is initialized: > > * It registers with the AP bus for control of type 10 (CEX4 > and newer) AP queue devices. The probe and remove callbacks > will be provided to support the binding/unbinding of > AP queue devices to/from the VFIO AP device driver. > > * Creates a /sys/devices/vfio-ap/matrix device to hold > the APQNs of the AP devices bound to the VFIO > AP device driver and serves as the parent of the > mediated devices created for each guest. > > Signed-off-by: Tony Krowiak > --- > MAINTAINERS | 2 + > arch/s390/Kconfig | 11 +++ > drivers/s390/crypto/Makefile | 4 + > drivers/s390/crypto/vfio_ap_drv.c | 135 +++++++++++++++++++++++++++++++++ > drivers/s390/crypto/vfio_ap_private.h | 22 ++++++ > include/uapi/linux/vfio.h | 2 + > 6 files changed, 176 insertions(+), 0 deletions(-) > create mode 100644 drivers/s390/crypto/vfio_ap_drv.c > create mode 100644 drivers/s390/crypto/vfio_ap_private.h > > diff --git a/drivers/s390/crypto/vfio_ap_drv.c b/drivers/s390/crypto/vfio_ap_drv.c > new file mode 100644 > index 0000000..459e595 > --- /dev/null > +++ b/drivers/s390/crypto/vfio_ap_drv.c > @@ -0,0 +1,135 @@ > +/* > + * VFIO based AP device driver > + * > + * Copyright IBM Corp. 2017 Update to 2018? > + * > + * Author(s): Tony Krowiak > + */ > + > +#include > +#include > +#include > + > +#include "vfio_ap_private.h" > + > +#define VFIO_AP_ROOT_NAME "vfio_ap" > +#define VFIO_AP_DEV_TYPE_NAME "ap_matrix" > +#define VFIO_AP_DEV_NAME "matrix" > + > +MODULE_AUTHOR("IBM Corporation"); > +MODULE_DESCRIPTION("VFIO AP device driver, Copyright IBM Corp. 2017"); > +MODULE_LICENSE("GPL v2"); > + > +static struct device *vfio_ap_root_device; > + > +static struct ap_driver vfio_ap_drv; > + > +static struct ap_matrix *ap_matrix; > + > +static struct device_type vfio_ap_dev_type = { > + .name = VFIO_AP_DEV_TYPE_NAME, > +}; > + > +/* Only type 10 adapters (CEX4 and later) are supported > + * by the AP matrix device driver > + */ > +static struct ap_device_id ap_queue_ids[] = { > + { .dev_type = AP_DEVICE_TYPE_CEX4, > + .match_flags = AP_DEVICE_ID_MATCH_QUEUE_TYPE }, > + { .dev_type = AP_DEVICE_TYPE_CEX5, > + .match_flags = AP_DEVICE_ID_MATCH_QUEUE_TYPE }, > + { .dev_type = AP_DEVICE_TYPE_CEX6, > + .match_flags = AP_DEVICE_ID_MATCH_QUEUE_TYPE }, > + { /* end of sibling */ }, > +}; > + > +MODULE_DEVICE_TABLE(vfio_ap, ap_queue_ids); > + > +static int vfio_ap_queue_dev_probe(struct ap_device *apdev) > +{ > + return 0; > +} > + > +static void vfio_ap_matrix_dev_release(struct device *dev) > +{ > + struct ap_matrix *ap_matrix = dev_get_drvdata(dev); > + > + kfree(ap_matrix); > +} > + > +static int vfio_ap_matrix_dev_create(void) > +{ > + int ret; > + > + vfio_ap_root_device = root_device_register(VFIO_AP_ROOT_NAME); > + > + ret = IS_ERR(vfio_ap_root_device); > + if (ret) { Minor nit: I'd contract that to if (IS_ERR(vfio_ap_root_device)) { (you're writing ret in any case) > + ret = PTR_ERR(vfio_ap_root_device); > + goto done; > + } > + > + ap_matrix = kzalloc(sizeof(*ap_matrix), GFP_KERNEL); > + if (!ap_matrix) { > + ret = -ENOMEM; > + goto matrix_alloc_err; > + } > + > + ap_matrix->device.type = &vfio_ap_dev_type; > + dev_set_name(&ap_matrix->device, "%s", VFIO_AP_DEV_NAME); > + ap_matrix->device.parent = vfio_ap_root_device; > + ap_matrix->device.release = vfio_ap_matrix_dev_release; > + ap_matrix->device.driver = &vfio_ap_drv.driver; > + > + ret = device_register(&ap_matrix->device); > + if (ret) > + goto matrix_reg_err; > + > + goto done; > + > +matrix_reg_err: > + put_device(&ap_matrix->device); > + kfree(ap_matrix); The kfree() is wrong: If you called device_register for the embedded struct device, this needs to be handled via the ->release callback exclusively (IOW, the put_device() is enough and the kfree needs to go). > + > +matrix_alloc_err: > + root_device_unregister(vfio_ap_root_device); > + > +done: > + return ret; > +}