From: Alex Williamson <alex.williamson@redhat.com>
To: Kirti Wankhede <kwankhede@nvidia.com>
Cc: Alexey Kardashevskiy <aik@ozlabs.ru>, <pbonzini@redhat.com>,
<kraxel@redhat.com>, <cjia@nvidia.com>, <jike.song@intel.com>,
<kvm@vger.kernel.org>, <linux-kernel@vger.kernel.org>,
<kevin.tian@intel.com>, <qemu-devel@nongnu.org>,
<bjsdjshi@linux.vnet.ibm.com>
Subject: Re: [Qemu-devel] [PATCH v9 04/12] vfio iommu: Add support for mediated devices
Date: Thu, 27 Oct 2016 08:30:10 -0600 [thread overview]
Message-ID: <20161027083010.2d31e50e@t450s.home> (raw)
In-Reply-To: <bdf75609-f2f4-c56f-1c57-01a2989bc40d@nvidia.com>
On Thu, 27 Oct 2016 18:01:51 +0530
Kirti Wankhede <kwankhede@nvidia.com> wrote:
> On 10/27/2016 12:50 PM, Alexey Kardashevskiy wrote:
> > On 18/10/16 08:22, Kirti Wankhede wrote:
> >> VFIO IOMMU drivers are designed for the devices which are IOMMU capable.
> >> Mediated device only uses IOMMU APIs, the underlying hardware can be
> >> managed by an IOMMU domain.
> >>
> >> Aim of this change is:
> >> - To use most of the code of TYPE1 IOMMU driver for mediated devices
> >> - To support direct assigned device and mediated device in single module
> >>
> >> Added two new callback functions to struct vfio_iommu_driver_ops. Backend
> >> IOMMU module that supports pining and unpinning pages for mdev devices
> >> should provide these functions.
> >> Added APIs for pining and unpining pages to VFIO module. These calls back
> >> into backend iommu module to actually pin and unpin pages.
> >>
> >> This change adds pin and unpin support for mediated device to TYPE1 IOMMU
> >> backend module. More details:
> >> - When iommu_group of mediated devices is attached, task structure is
> >> cached which is used later to pin pages and page accounting.
> >
> >
> > For SPAPR TCE IOMMU driver, I ended up caching mm_struct with
> > atomic_inc(&container->mm->mm_count) (patches are on the way) instead of
> > using @current or task as the process might be gone while VFIO container is
> > still alive and @mm might be needed to do proper cleanup; this might not be
> > an issue with this patchset now but still you seem to only use @mm from
> > task_struct.
> >
>
> Consider the example of QEMU process which creates VFIO container, QEMU
> in its teardown path would release the container. How could container be
> alive when process is gone?
If QEMU is sent a SIGKILL, does the process still exist? We must be
able to perform cleanup regardless of the state, or existence, of the
task that created it. Thanks,
Alex
next prev parent reply other threads:[~2016-10-27 14:30 UTC|newest]
Thread overview: 73+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-10-17 21:22 [PATCH v9 00/12] Add Mediated device support Kirti Wankhede
2016-10-17 21:22 ` [PATCH v9 01/12] vfio: Mediated device Core driver Kirti Wankhede
2016-10-18 23:16 ` Alex Williamson
2016-10-19 19:16 ` Kirti Wankhede
2016-10-19 22:20 ` Alex Williamson
2016-10-20 7:23 ` Jike Song
2016-10-20 17:12 ` Alex Williamson
2016-10-21 2:41 ` Jike Song
2016-10-27 5:56 ` Jike Song
2016-10-26 6:52 ` Tian, Kevin
2016-10-26 14:58 ` Kirti Wankhede
2016-10-17 21:22 ` [PATCH v9 02/12] vfio: VFIO based driver for Mediated devices Kirti Wankhede
2016-10-26 6:57 ` Tian, Kevin
2016-10-26 15:01 ` Kirti Wankhede
2016-10-17 21:22 ` [PATCH v9 03/12] vfio: Rearrange functions to get vfio_group from dev Kirti Wankhede
2016-10-19 17:26 ` Alex Williamson
2016-10-17 21:22 ` [PATCH v9 04/12] vfio iommu: Add support for mediated devices Kirti Wankhede
2016-10-19 21:02 ` Alex Williamson
2016-10-20 20:17 ` Kirti Wankhede
2016-10-24 2:32 ` Alex Williamson
2016-10-26 7:19 ` Tian, Kevin
2016-10-26 15:06 ` Kirti Wankhede
2016-10-26 7:53 ` Tian, Kevin
2016-10-26 15:16 ` Alex Williamson
2016-10-26 7:54 ` Tian, Kevin
2016-10-26 15:19 ` Alex Williamson
2016-10-21 7:49 ` Jike Song
2016-10-21 14:36 ` Alex Williamson
2016-10-24 10:35 ` Kirti Wankhede
2016-10-27 7:20 ` [Qemu-devel] " Alexey Kardashevskiy
2016-10-27 12:31 ` Kirti Wankhede
2016-10-27 14:30 ` Alex Williamson [this message]
2016-10-27 15:59 ` Kirti Wankhede
2016-10-28 2:18 ` Alexey Kardashevskiy
2016-11-01 14:01 ` Kirti Wankhede
2016-11-02 1:24 ` Alexey Kardashevskiy
2016-11-02 3:29 ` Kirti Wankhede
2016-11-02 4:09 ` Alexey Kardashevskiy
2016-11-02 12:21 ` Jike Song
2016-11-02 12:41 ` Kirti Wankhede
2016-11-02 13:00 ` Jike Song
2016-11-02 13:18 ` Kirti Wankhede
2016-11-02 13:35 ` Jike Song
2016-11-03 4:29 ` Alexey Kardashevskiy
2016-10-17 21:22 ` [PATCH v9 05/12] vfio: Introduce common function to add capabilities Kirti Wankhede
2016-10-20 19:24 ` Alex Williamson
2016-10-24 21:27 ` Kirti Wankhede
2016-10-24 21:39 ` Alex Williamson
2016-10-17 21:22 ` [PATCH v9 06/12] vfio_pci: Update vfio_pci to use vfio_info_add_capability() Kirti Wankhede
2016-10-20 19:24 ` Alex Williamson
2016-10-24 21:22 ` Kirti Wankhede
2016-10-24 21:37 ` Alex Williamson
2016-10-17 21:22 ` [PATCH v9 07/12] vfio: Introduce vfio_set_irqs_validate_and_prepare() Kirti Wankhede
2016-10-17 21:22 ` [PATCH v9 08/12] vfio_pci: Updated to use vfio_set_irqs_validate_and_prepare() Kirti Wankhede
2016-10-17 21:22 ` [PATCH v9 09/12] vfio_platform: " Kirti Wankhede
2016-10-17 21:22 ` [PATCH v9 10/12] vfio: Add function to get device_api string from vfio_device_info.flags Kirti Wankhede
2016-10-20 19:34 ` Alex Williamson
2016-10-20 20:29 ` Kirti Wankhede
2016-10-20 21:05 ` Alex Williamson
2016-10-20 21:14 ` Kirti Wankhede
2016-10-20 21:22 ` Alex Williamson
2016-10-21 3:00 ` Kirti Wankhede
2016-10-21 3:20 ` Alex Williamson
2016-10-17 21:22 ` [PATCH v9 11/12] docs: Add Documentation for Mediated devices Kirti Wankhede
2016-10-25 16:17 ` Alex Williamson
2016-10-17 21:22 ` [PATCH v9 12/12] docs: Sample driver to demonstrate how to use Mediated device framework Kirti Wankhede
[not found] ` <20161018025411.GA22572@bjsdjshi@linux.vnet.ibm.com>
2016-10-18 17:17 ` Alex Williamson
2016-10-19 19:19 ` Kirti Wankhede
2016-10-17 21:41 ` [PATCH v9 00/12] Add Mediated device support Alex Williamson
2016-10-24 7:07 ` Jike Song
2016-12-05 17:44 ` Gerd Hoffmann
2016-12-06 2:24 ` Jike Song
2016-12-07 14:40 ` Gerd Hoffmann
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20161027083010.2d31e50e@t450s.home \
--to=alex.williamson@redhat.com \
--cc=aik@ozlabs.ru \
--cc=bjsdjshi@linux.vnet.ibm.com \
--cc=cjia@nvidia.com \
--cc=jike.song@intel.com \
--cc=kevin.tian@intel.com \
--cc=kraxel@redhat.com \
--cc=kvm@vger.kernel.org \
--cc=kwankhede@nvidia.com \
--cc=linux-kernel@vger.kernel.org \
--cc=pbonzini@redhat.com \
--cc=qemu-devel@nongnu.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox
Powered by JetHome