From: Jason Gunthorpe <jgg@nvidia.com>
To: Peter Xu <peterx@redhat.com>
Cc: Alex Williamson <alex.williamson@redhat.com>, <cohuck@redhat.com>,
<kvm@vger.kernel.org>, <linux-kernel@vger.kernel.org>
Subject: Re: [RFC PATCH 10/10] vfio/type1: Register device notifier
Date: Thu, 25 Feb 2021 14:19:45 -0400 [thread overview]
Message-ID: <20210225181945.GT4247@nvidia.com> (raw)
In-Reply-To: <20210225175457.GD250483@xz-x1>
On Thu, Feb 25, 2021 at 12:54:57PM -0500, Peter Xu wrote:
> I can't say I fully understand the whole rational behind 5cbf3264bc71, but that
> commit still sounds reasonable to me, since I don't see why VFIO cannot do
> VFIO_IOMMU_MAP_DMA upon another memory range that's neither anonymous memory
> nor vfio mapped MMIO range.
It is not so much it can't, more that it doesn't and doesn't need to.
> In those cases, vm_pgoff namespace defined by vfio may not be true
> anymore, iiuc.
Since this series is proposing linking the VMA to an address_space all
the vm_pgoffs must be in the same namespace
> Or does it mean that we don't want to allow VFIO dma to those unknown memory
> backends, for some reason?
Correct. VFIO can map into the IOMMU PFNs it can get a reference
to. pin_user_pages() works for the majority, special VFIO VMAs cover
the rest, and everthing else must be blocked for security.
Jason
next prev parent reply other threads:[~2021-02-25 18:20 UTC|newest]
Thread overview: 36+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-02-22 16:50 [RFC PATCH 00/10] vfio: Device memory DMA mapping improvements Alex Williamson
2021-02-22 16:50 ` [RFC PATCH 01/10] vfio: Create vfio_fs_type with inode per device Alex Williamson
2021-02-26 5:38 ` Christoph Hellwig
2021-02-26 13:15 ` Jason Gunthorpe
2021-02-22 16:50 ` [RFC PATCH 02/10] vfio: Update vfio_add_group_dev() API Alex Williamson
2021-02-22 17:01 ` Jason Gunthorpe
2021-02-22 16:50 ` [RFC PATCH 03/10] vfio: Export unmap_mapping_range() wrapper Alex Williamson
2021-02-22 16:51 ` [RFC PATCH 04/10] vfio/pci: Use vfio_device_unmap_mapping_range() Alex Williamson
2021-02-22 17:22 ` Jason Gunthorpe
2021-02-24 21:55 ` Alex Williamson
2021-02-25 0:57 ` Jason Gunthorpe
2021-02-22 16:51 ` [RFC PATCH 05/10] vfio: Create a vfio_device from vma lookup Alex Williamson
2021-02-22 17:29 ` Jason Gunthorpe
2021-02-24 21:55 ` Alex Williamson
2021-02-25 0:06 ` Jason Gunthorpe
2021-02-25 22:21 ` Alex Williamson
2021-02-25 23:49 ` Jason Gunthorpe
2021-03-04 21:37 ` Alex Williamson
2021-03-04 23:16 ` Jason Gunthorpe
2021-03-05 0:07 ` Alex Williamson
2021-03-05 0:36 ` Jason Gunthorpe
2021-02-22 16:51 ` [RFC PATCH 06/10] vfio: Add a device notifier interface Alex Williamson
2021-02-22 16:51 ` [RFC PATCH 07/10] vfio/pci: Notify on device release Alex Williamson
2021-02-22 16:52 ` [RFC PATCH 08/10] vfio/type1: Refactor pfn_list clearing Alex Williamson
2021-02-22 16:52 ` [RFC PATCH 09/10] vfio/type1: Pass iommu and dma objects through to vaddr_get_pfn Alex Williamson
2021-02-22 16:52 ` [RFC PATCH 10/10] vfio/type1: Register device notifier Alex Williamson
2021-02-22 17:55 ` Jason Gunthorpe
2021-02-24 21:55 ` Alex Williamson
2021-02-25 0:22 ` Jason Gunthorpe
2021-02-25 17:54 ` Peter Xu
2021-02-25 18:19 ` Jason Gunthorpe [this message]
2021-02-25 19:06 ` Peter Xu
2021-02-25 19:17 ` Jason Gunthorpe
2021-02-25 19:54 ` Peter Xu
2021-02-26 5:47 ` Christoph Hellwig
2021-02-22 18:00 ` [RFC PATCH 00/10] vfio: Device memory DMA mapping improvements Jason Gunthorpe
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