From: Alex Williamson <alex.williamson@redhat.com>
To: Shenming Lu <lushenming@huawei.com>
Cc: Cornelia Huck <cohuck@redhat.com>, Will Deacon <will@kernel.org>,
Robin Murphy <robin.murphy@arm.com>,
Joerg Roedel <joro@8bytes.org>,
Jean-Philippe Brucker <jean-philippe@linaro.org>,
Eric Auger <eric.auger@redhat.com>, <kvm@vger.kernel.org>,
<linux-kernel@vger.kernel.org>,
<linux-arm-kernel@lists.infradead.org>,
<iommu@lists.linux-foundation.org>, <linux-api@vger.kernel.org>,
Kevin Tian <kevin.tian@intel.com>,
Lu Baolu <baolu.lu@linux.intel.com>, <yi.l.liu@intel.com>,
Christoph Hellwig <hch@infradead.org>,
Jonathan Cameron <Jonathan.Cameron@huawei.com>,
Barry Song <song.bao.hua@hisilicon.com>,
<wanghaibin.wang@huawei.com>, <yuzenghui@huawei.com>
Subject: Re: [RFC PATCH v3 7/8] vfio/type1: Add selective DMA faulting support
Date: Tue, 18 May 2021 12:58:13 -0600 [thread overview]
Message-ID: <20210518125813.7b8a78f1.alex.williamson@redhat.com> (raw)
In-Reply-To: <20210409034420.1799-8-lushenming@huawei.com>
On Fri, 9 Apr 2021 11:44:19 +0800
Shenming Lu <lushenming@huawei.com> wrote:
> Some devices only allow selective DMA faulting. Similar to the selective
> dirty page tracking, the vendor driver can call vfio_pin_pages() to
> indicate the non-faultable scope, we add a new struct vfio_range to
> record it, then when the IOPF handler receives any page request out
> of the scope, we can directly return with an invalid response.
Seems like this highlights a deficiency in the design, that the user
can't specify mappings as iopf enabled or disabled. Also, if the
vendor driver has pinned pages within the range, shouldn't that prevent
them from faulting in the first place? Why do we need yet more
tracking structures? Pages pinned by the vendor driver need to count
against the user's locked memory limits regardless of iopf. Thanks,
Alex
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next prev parent reply other threads:[~2021-05-18 19:01 UTC|newest]
Thread overview: 40+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-04-09 3:44 [RFC PATCH v3 0/8] Add IOPF support for VFIO passthrough Shenming Lu
2021-04-09 3:44 ` [RFC PATCH v3 1/8] iommu: Evolve the device fault reporting framework Shenming Lu
2021-05-18 18:58 ` Alex Williamson
2021-05-21 6:37 ` Shenming Lu
2021-04-09 3:44 ` [RFC PATCH v3 2/8] vfio/type1: Add a page fault handler Shenming Lu
2021-05-18 18:58 ` Alex Williamson
2021-05-21 6:38 ` Shenming Lu
2021-05-24 22:11 ` Alex Williamson
2021-05-27 11:16 ` Shenming Lu
2021-04-09 3:44 ` [RFC PATCH v3 3/8] vfio/type1: Add an MMU notifier to avoid pinning Shenming Lu
2021-05-18 18:58 ` Alex Williamson
2021-05-21 6:37 ` Shenming Lu
2021-04-09 3:44 ` [RFC PATCH v3 4/8] vfio/type1: Pre-map more pages than requested in the IOPF handling Shenming Lu
2021-05-18 18:58 ` Alex Williamson
2021-05-21 6:37 ` Shenming Lu
2021-04-09 3:44 ` [RFC PATCH v3 5/8] vfio/type1: VFIO_IOMMU_ENABLE_IOPF Shenming Lu
2021-05-18 18:58 ` Alex Williamson
2021-05-21 6:38 ` Shenming Lu
2021-05-24 22:11 ` Alex Williamson
2021-05-27 11:15 ` Shenming Lu
2021-04-09 3:44 ` [RFC PATCH v3 6/8] vfio/type1: No need to statically pin and map if IOPF enabled Shenming Lu
2021-05-18 18:58 ` Alex Williamson
2021-05-21 6:39 ` Shenming Lu
2021-04-09 3:44 ` [RFC PATCH v3 7/8] vfio/type1: Add selective DMA faulting support Shenming Lu
2021-05-18 18:58 ` Alex Williamson [this message]
2021-05-21 6:39 ` Shenming Lu
2021-04-09 3:44 ` [RFC PATCH v3 8/8] vfio: Add nested IOPF support Shenming Lu
2021-05-18 18:58 ` Alex Williamson
2021-05-21 7:59 ` Shenming Lu
2021-05-24 13:11 ` Shenming Lu
2021-05-24 22:11 ` Alex Williamson
2021-05-27 11:03 ` Shenming Lu
2021-05-27 11:18 ` Lu Baolu
2021-06-01 4:36 ` Shenming Lu
2021-04-26 1:41 ` [RFC PATCH v3 0/8] Add IOPF support for VFIO passthrough Shenming Lu
2021-05-11 11:30 ` Shenming Lu
2021-05-18 18:57 ` Alex Williamson
2021-05-21 6:37 ` Shenming Lu
2021-05-24 22:11 ` Alex Williamson
2021-05-27 11:25 ` Shenming Lu
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