From: Jike Song <jike.song@intel.com>
To: Alex Williamson <alex.williamson@redhat.com>
Cc: Kirti Wankhede <kwankhede@nvidia.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 v10 01/19] vfio: Mediated device Core driver
Date: Tue, 01 Nov 2016 13:28:57 +0800 [thread overview]
Message-ID: <58182819.2050109@intel.com> (raw)
In-Reply-To: <20161031214453.49da775c@t450s.home>
On 11/01/2016 11:44 AM, Alex Williamson wrote:
> On Tue, 01 Nov 2016 11:08:15 +0800
> Jike Song <jike.song@intel.com> wrote:
>> On 10/27/2016 05:29 AM, Kirti Wankhede wrote:
>>> +static int mdev_attach_iommu(struct mdev_device *mdev)
>>> +{
>>> + int ret;
>>> + struct iommu_group *group;
>>> +
>>> + group = iommu_group_alloc();
>>> + if (IS_ERR(group))
>>> + return PTR_ERR(group);
>>
>> Maybe I overthought, but where the iommu_group is released? On successful
>> return you already have a ref, I didn't find an iommu_group_put after that.
> ...
>>> +
>>> + ret = iommu_group_add_device(group, &mdev->dev);
>>> + if (ret)
>>> + goto attach_fail;
>>> +
>>> + dev_info(&mdev->dev, "MDEV: group_id = %d\n",
>>> + iommu_group_id(group));
>>> +attach_fail:
>>> + iommu_group_put(group);
>>> + return ret;
>>> +}
>>> +
>>> +static void mdev_detach_iommu(struct mdev_device *mdev)
>>> +{
>>> + iommu_group_remove_device(&mdev->dev);
>
> Here. Adding a device to the group takes a group reference so we can
> 'put' the group to release the reference from the alloc as soon as a
> device is added. When we remove the device, that reference is removed
> and this should result in a release of the group if all other
> references are balanced. Thanks,
Now I understand, thanks :)
--
Thanks,
Jike
next prev parent reply other threads:[~2016-11-01 5:32 UTC|newest]
Thread overview: 56+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-10-26 21:29 [PATCH v10 00/19] Add Mediated device support Kirti Wankhede
2016-10-26 21:29 ` [PATCH v10 01/19] vfio: Mediated device Core driver Kirti Wankhede
2016-10-29 4:30 ` Jike Song
2016-10-29 10:06 ` Kirti Wankhede
2016-10-29 18:11 ` Jike Song
2016-11-02 7:59 ` Kirti Wankhede
2016-11-02 10:31 ` [Qemu-devel] " Jike Song
2016-11-01 3:08 ` Jike Song
2016-11-01 3:44 ` Alex Williamson
2016-11-01 5:28 ` Jike Song [this message]
2016-10-26 21:29 ` [PATCH v10 02/19] vfio: VFIO based driver for Mediated devices Kirti Wankhede
2016-11-02 10:39 ` Jike Song
2016-10-26 21:29 ` [PATCH v10 03/19] vfio: Rearrange functions to get vfio_group from dev Kirti Wankhede
2016-11-02 10:41 ` Jike Song
2016-10-26 21:29 ` [PATCH v10 04/19] vfio: Common function to increment container_users Kirti Wankhede
2016-11-02 11:34 ` Jike Song
2016-10-26 21:29 ` [PATCH v10 05/19] vfio iommu: Added pin and unpin callback functions to vfio_iommu_driver_ops Kirti Wankhede
2016-11-01 8:07 ` Jike Song
2016-10-26 21:29 ` [PATCH v10 06/19] vfio iommu type1: Update arguments of vfio_lock_acct Kirti Wankhede
2016-10-26 21:29 ` [PATCH v10 07/19] vfio iommu type1: Update argument of vaddr_get_pfn() Kirti Wankhede
2016-10-27 12:11 ` Jike Song
2016-10-27 12:24 ` Kirti Wankhede
2016-10-28 6:01 ` Jike Song
2016-11-02 8:06 ` Kirti Wankhede
2016-10-26 21:29 ` [PATCH v10 08/19] vfio iommu type1: Add find_iommu_group() function Kirti Wankhede
2016-11-02 14:13 ` Jike Song
2016-10-26 21:29 ` [PATCH v10 09/19] vfio iommu type1: Add support for mediated devices Kirti Wankhede
2016-10-27 23:01 ` Alex Williamson
2016-11-02 13:29 ` Jike Song
2016-10-26 21:29 ` [PATCH v10 10/19] vfio iommu: Add blocking notifier to notify DMA_UNMAP Kirti Wankhede
2016-10-28 7:33 ` Jike Song
2016-10-28 12:38 ` Kirti Wankhede
2016-10-28 12:40 ` Alex Williamson
2016-10-28 20:02 ` Kirti Wankhede
2016-10-28 20:33 ` Alex Williamson
2016-10-29 10:37 ` Kirti Wankhede
2016-10-29 14:03 ` Alex Williamson
[not found] ` <20161101034558.GA7186@bjsdjshi@linux.vnet.ibm.com>
2016-11-01 7:47 ` Kirti Wankhede
2016-10-31 3:50 ` Jike Song
2016-10-31 5:59 ` Kirti Wankhede
2016-10-31 6:05 ` Jike Song
2016-10-26 21:29 ` [PATCH v10 11/19] vfio: Introduce common function to add capabilities Kirti Wankhede
2016-10-26 21:29 ` [PATCH v10 12/19] vfio_pci: Update vfio_pci to use vfio_info_add_capability() Kirti Wankhede
2016-10-26 21:29 ` [PATCH v10 13/19] vfio: Introduce vfio_set_irqs_validate_and_prepare() Kirti Wankhede
2016-10-26 21:29 ` [PATCH v10 14/19] vfio_pci: Updated to use vfio_set_irqs_validate_and_prepare() Kirti Wankhede
2016-10-26 21:29 ` [PATCH v10 15/19] vfio_platform: " Kirti Wankhede
2016-10-26 21:29 ` [PATCH v10 16/19] vfio: Define device_api strings Kirti Wankhede
2016-10-26 21:29 ` [PATCH v10 17/19] docs: Add Documentation for Mediated devices Kirti Wankhede
2016-10-26 21:29 ` [PATCH v10 18/19] docs: Sysfs ABI for mediated device framework Kirti Wankhede
2016-10-31 7:19 ` Jike Song
2016-11-02 7:55 ` Kirti Wankhede
2016-10-26 21:29 ` [PATCH v10 19/19] docs: Sample driver to demonstrate how to use Mediated " Kirti Wankhede
2016-10-27 14:29 ` Jonathan Corbet
2016-11-01 8:32 ` [PATCH v10 00/19] Add Mediated device support Jike Song
2016-11-01 15:24 ` Gerd Hoffmann
2016-11-02 1:01 ` [Qemu-devel] " Jike Song
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