From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S966119AbcKOJeB (ORCPT ); Tue, 15 Nov 2016 04:34:01 -0500 Received: from mga01.intel.com ([192.55.52.88]:35757 "EHLO mga01.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S941376AbcKOJd6 (ORCPT ); Tue, 15 Nov 2016 04:33:58 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.31,641,1473145200"; d="scan'208";a="1068642097" Message-ID: <582AD5A1.5050006@intel.com> Date: Tue, 15 Nov 2016 17:30:09 +0800 From: Jike Song User-Agent: Mozilla/5.0 (X11; Linux i686 on x86_64; rv:17.0) Gecko/20130801 Thunderbird/17.0.8 MIME-Version: 1.0 To: Kirti Wankhede CC: alex.williamson@redhat.com, pbonzini@redhat.com, kraxel@redhat.com, cjia@nvidia.com, qemu-devel@nongnu.org, kvm@vger.kernel.org, kevin.tian@intel.com, bjsdjshi@linux.vnet.ibm.com, linux-kernel@vger.kernel.org Subject: Re: [PATCH v12 12/22] vfio: Add notifier callback to parent's ops structure of mdev References: <1479138156-28905-1-git-send-email-kwankhede@nvidia.com> <1479138156-28905-13-git-send-email-kwankhede@nvidia.com> <582AAF16.5080906@intel.com> <9f612340-efd5-5f9c-60a2-08c176b0e509@nvidia.com> In-Reply-To: <9f612340-efd5-5f9c-60a2-08c176b0e509@nvidia.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 11/15/2016 04:11 PM, Kirti Wankhede wrote: > > > On 11/15/2016 12:15 PM, Jike Song wrote: >> On 11/14/2016 11:42 PM, Kirti Wankhede wrote: >>> Add a notifier calback to parent's ops structure of mdev device so that per >>> device notifer for vfio module is registered through vfio_mdev module. >>> >>> Signed-off-by: Kirti Wankhede >>> Signed-off-by: Neo Jia >>> Change-Id: Iafa6f1721aecdd6e50eb93b153b5621e6d29b637 >>> --- >>> drivers/vfio/mdev/vfio_mdev.c | 19 +++++++++++++++++++ >>> include/linux/mdev.h | 9 +++++++++ >>> 2 files changed, 28 insertions(+) >>> >>> diff --git a/drivers/vfio/mdev/vfio_mdev.c b/drivers/vfio/mdev/vfio_mdev.c >>> index ffc36758cb84..1694b1635607 100644 >>> --- a/drivers/vfio/mdev/vfio_mdev.c >>> +++ b/drivers/vfio/mdev/vfio_mdev.c >>> @@ -24,6 +24,15 @@ >>> #define DRIVER_AUTHOR "NVIDIA Corporation" >>> #define DRIVER_DESC "VFIO based driver for Mediated device" >>> >>> +static int vfio_mdev_notifier(struct notifier_block *nb, unsigned long action, >>> + void *data) >>> +{ >>> + struct mdev_device *mdev = container_of(nb, struct mdev_device, nb); >>> + struct parent_device *parent = mdev->parent; >>> + >>> + return parent->ops->notifier(mdev, action, data); >>> +} >>> + >>> static int vfio_mdev_open(void *device_data) >>> { >>> struct mdev_device *mdev = device_data; >>> @@ -40,6 +49,11 @@ static int vfio_mdev_open(void *device_data) >>> if (ret) >>> module_put(THIS_MODULE); >>> >>> + if (likely(parent->ops->notifier)) { >>> + mdev->nb.notifier_call = vfio_mdev_notifier; >>> + if (vfio_register_notifier(&mdev->dev, &mdev->nb)) >>> + pr_err("Failed to register notifier for mdev\n"); >>> + } >> >> Hi Kirti, >> >> Could you please move the notifier registration before parent->ops->open()? >> as you might know, I'm extending your vfio_register_notifier to also include >> the attaching/detaching events of vfio_group and kvm. Basically if vfio_group >> not attached to any kvm instance, the parent->ops->open() should return -ENODEV >> to indicate the failure, but to know whether kvm is available in open(), the >> notifier registration should be earlier. >> > > Ok. That seem fine to me. > Thanks - and I guess it's also good to move unregister after ->release(), so that a sequence of register-open-release-unregister guaranteed :) -- Thanks, Jike From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:49015) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1c6a7x-0007Mp-Ix for qemu-devel@nongnu.org; Tue, 15 Nov 2016 04:34:06 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1c6a7t-0007Yt-2D for qemu-devel@nongnu.org; Tue, 15 Nov 2016 04:34:05 -0500 Received: from mga05.intel.com ([192.55.52.43]:29346) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1c6a7s-0007WB-Pq for qemu-devel@nongnu.org; Tue, 15 Nov 2016 04:34:01 -0500 Message-ID: <582AD5A1.5050006@intel.com> Date: Tue, 15 Nov 2016 17:30:09 +0800 From: Jike Song MIME-Version: 1.0 References: <1479138156-28905-1-git-send-email-kwankhede@nvidia.com> <1479138156-28905-13-git-send-email-kwankhede@nvidia.com> <582AAF16.5080906@intel.com> <9f612340-efd5-5f9c-60a2-08c176b0e509@nvidia.com> In-Reply-To: <9f612340-efd5-5f9c-60a2-08c176b0e509@nvidia.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH v12 12/22] vfio: Add notifier callback to parent's ops structure of mdev List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Kirti Wankhede Cc: alex.williamson@redhat.com, pbonzini@redhat.com, kraxel@redhat.com, cjia@nvidia.com, qemu-devel@nongnu.org, kvm@vger.kernel.org, kevin.tian@intel.com, bjsdjshi@linux.vnet.ibm.com, linux-kernel@vger.kernel.org On 11/15/2016 04:11 PM, Kirti Wankhede wrote: > > > On 11/15/2016 12:15 PM, Jike Song wrote: >> On 11/14/2016 11:42 PM, Kirti Wankhede wrote: >>> Add a notifier calback to parent's ops structure of mdev device so that per >>> device notifer for vfio module is registered through vfio_mdev module. >>> >>> Signed-off-by: Kirti Wankhede >>> Signed-off-by: Neo Jia >>> Change-Id: Iafa6f1721aecdd6e50eb93b153b5621e6d29b637 >>> --- >>> drivers/vfio/mdev/vfio_mdev.c | 19 +++++++++++++++++++ >>> include/linux/mdev.h | 9 +++++++++ >>> 2 files changed, 28 insertions(+) >>> >>> diff --git a/drivers/vfio/mdev/vfio_mdev.c b/drivers/vfio/mdev/vfio_mdev.c >>> index ffc36758cb84..1694b1635607 100644 >>> --- a/drivers/vfio/mdev/vfio_mdev.c >>> +++ b/drivers/vfio/mdev/vfio_mdev.c >>> @@ -24,6 +24,15 @@ >>> #define DRIVER_AUTHOR "NVIDIA Corporation" >>> #define DRIVER_DESC "VFIO based driver for Mediated device" >>> >>> +static int vfio_mdev_notifier(struct notifier_block *nb, unsigned long action, >>> + void *data) >>> +{ >>> + struct mdev_device *mdev = container_of(nb, struct mdev_device, nb); >>> + struct parent_device *parent = mdev->parent; >>> + >>> + return parent->ops->notifier(mdev, action, data); >>> +} >>> + >>> static int vfio_mdev_open(void *device_data) >>> { >>> struct mdev_device *mdev = device_data; >>> @@ -40,6 +49,11 @@ static int vfio_mdev_open(void *device_data) >>> if (ret) >>> module_put(THIS_MODULE); >>> >>> + if (likely(parent->ops->notifier)) { >>> + mdev->nb.notifier_call = vfio_mdev_notifier; >>> + if (vfio_register_notifier(&mdev->dev, &mdev->nb)) >>> + pr_err("Failed to register notifier for mdev\n"); >>> + } >> >> Hi Kirti, >> >> Could you please move the notifier registration before parent->ops->open()? >> as you might know, I'm extending your vfio_register_notifier to also include >> the attaching/detaching events of vfio_group and kvm. Basically if vfio_group >> not attached to any kvm instance, the parent->ops->open() should return -ENODEV >> to indicate the failure, but to know whether kvm is available in open(), the >> notifier registration should be earlier. >> > > Ok. That seem fine to me. > Thanks - and I guess it's also good to move unregister after ->release(), so that a sequence of register-open-release-unregister guaranteed :) -- Thanks, Jike