From: Steven Sistare <steven.sistare@oracle.com>
To: Alex Williamson <alex.williamson@redhat.com>
Cc: Cornelia Huck <cohuck@redhat.com>,
Kirti Wankhede <kwankhede@nvidia.com>,
kvm@vger.kernel.org
Subject: Re: [PATCH V1 0/5] vfio virtual address update
Date: Tue, 12 Jan 2021 16:52:04 -0500 [thread overview]
Message-ID: <7cc773c7-1072-1fda-6f7e-e5410e53e4fc@oracle.com> (raw)
In-Reply-To: <1609861013-129801-1-git-send-email-steven.sistare@oracle.com>
On 1/5/2021 10:36 AM, Steve Sistare wrote:
> Add interfaces that allow the underlying memory object of an iova range
> to be mapped to a new virtual address in the host process:
>
> - VFIO_DMA_UNMAP_FLAG_SUSPEND for VFIO_IOMMU_UNMAP_DMA
> - VFIO_DMA_MAP_FLAG_RESUME flag for VFIO_IOMMU_MAP_DMA
> - VFIO_SUSPEND extension for VFIO_CHECK_EXTENSION
>
> The suspend interface blocks vfio translation of host virtual addresses in
> a range, but DMA to already-mapped pages continues. The resume interface
> records the new base VA and resumes translation. The implementation
> supports iommu type1 and mediated devices.
>
> This functionality is necessary for live update, in which a host process
> such as qemu exec's an updated version of itself, while preserving its
> guest and vfio devices. The process suspends vfio VA translation, exec's
> its new self, mmap's the memory object(s) underlying vfio object, and
> resumes VA translation. For a working example that uses these new
> interfaces, see the QEMU patch series "[PATCH V2] Live Update".
>
> Patch 1 modifies the iova rbtree to allow iteration over ranges with gaps,
> without deleting each entry. This is required by patch 4.
> Patch 2 adds an option to unmap all ranges, which simplifies userland code.
> Patch 3 adds an interface to detect if an iommu_group has a valid container,
> which patch 5 uses to release a blocked thread if a container is closed.
> Patch 4 implements the new ioctl's.
> Patch 5 adds blocking to complete the implementation .
>
> Steve Sistare (5):
> vfio: maintain dma_list order
> vfio: option to unmap all
> vfio: detect closed container
> vfio: VA suspend interface
> vfio: block during VA suspend
>
> drivers/vfio/vfio.c | 12 ++++
> drivers/vfio/vfio_iommu_type1.c | 122 ++++++++++++++++++++++++++++++++++------
> include/linux/vfio.h | 1 +
> include/uapi/linux/vfio.h | 19 ++++++-
> 4 files changed, 135 insertions(+), 19 deletions(-)
>
Hi Alex,
I can send a patch V2 for review if you weigh in on the following:
* preferred interface for unmap-all (patch 2)
* name of the suspend and resume flags (patch 4)
* is vfio_iommu_contained() acceptable, or is a new backend interface needed? (patch 5)
- Steve
prev parent reply other threads:[~2021-01-12 21:53 UTC|newest]
Thread overview: 35+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-01-05 15:36 [PATCH V1 0/5] vfio virtual address update Steve Sistare
2021-01-05 15:36 ` [PATCH V1 1/5] vfio: maintain dma_list order Steve Sistare
2021-01-05 18:48 ` kernel test robot
2021-01-06 0:02 ` Alex Williamson
2021-01-06 14:50 ` Steven Sistare
2021-01-05 15:36 ` [PATCH V1 2/5] vfio: option to unmap all Steve Sistare
2021-01-08 19:35 ` Alex Williamson
2021-01-11 21:09 ` Steven Sistare
2021-01-13 19:41 ` Alex Williamson
2021-01-05 15:36 ` [PATCH V1 3/5] vfio: detect closed container Steve Sistare
2021-01-08 19:39 ` Alex Williamson
2021-01-11 21:12 ` Steven Sistare
2021-01-13 19:26 ` Alex Williamson
2021-01-13 19:44 ` Steven Sistare
2021-01-13 19:44 ` Alex Williamson
2021-01-05 15:36 ` [PATCH V1 4/5] vfio: VA suspend interface Steve Sistare
2021-01-08 21:15 ` Alex Williamson
2021-01-11 21:15 ` Steven Sistare
2021-01-12 15:47 ` Jason Zeng
2021-01-12 22:09 ` Alex Williamson
2021-01-13 4:37 ` Jason Zeng
2021-01-12 22:47 ` Alex Williamson
2021-01-13 4:10 ` Alex Williamson
2021-01-13 18:02 ` Steven Sistare
2021-01-13 18:34 ` Alex Williamson
2021-01-13 18:01 ` Steven Sistare
2021-01-19 20:11 ` Steven Sistare
2021-01-05 15:36 ` [PATCH V1 5/5] vfio: block during VA suspend Steve Sistare
2021-01-05 18:08 ` kernel test robot
2021-01-05 20:03 ` kernel test robot
2021-01-07 15:17 ` Steven Sistare
2021-01-05 20:03 ` [RFC PATCH] vfio: vfio_vaddr_valid() can be static kernel test robot
2021-01-08 21:32 ` [PATCH V1 5/5] vfio: block during VA suspend Alex Williamson
2021-01-11 21:16 ` Steven Sistare
2021-01-12 21:52 ` Steven Sistare [this message]
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