From: joro@8bytes.org (Joerg Roedel)
To: linux-arm-kernel@lists.infradead.org
Subject: [RFC v2 8/8] iommu/arm-smmu: implement add_reserved_regions callback
Date: Fri, 11 Nov 2016 17:22:11 +0100 [thread overview]
Message-ID: <20161111162211.GU2078@8bytes.org> (raw)
In-Reply-To: <79da09b8-ac1e-cebf-5393-7d67f002b3e3@redhat.com>
Hi Eric,
On Fri, Nov 11, 2016 at 04:47:01PM +0100, Auger Eric wrote:
> Effectively in passthrough use case, the userspace defines the address
> space layout and maps guest RAM PA=IOVA to PAs (using
> VFIO_IOMMU_MAP_DMA). But this address space does not comprise the MSI
> IOVAs. Userspace does not care about MSI IOMMU mapping. So the MSI IOVA
> region must be allocated by either the VFIO driver or the IOMMU driver I
> think. Who else could initialize the IOVA allocator domain?
So I think we need a way to tell userspace about the reserved regions
(per iommu-group) so that userspace knows where it can not map anything,
and VFIO can enforce that. But the right struct here is not an
iova-allocator rb-tree, a ordered linked list should be sufficient.
Joerg
next prev parent reply other threads:[~2016-11-11 16:22 UTC|newest]
Thread overview: 30+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-11-04 11:23 [RFC v2 0/8] KVM PCIe/MSI passthrough on ARM/ARM64 - Alt II Eric Auger
[not found] ` <1478258646-3117-5-git-send-email-eric.auger@redhat.com>
2016-11-04 14:00 ` [RFC v2 4/8] iommu: Add a list of iommu_reserved_region in iommu_domain Robin Murphy
2016-11-10 11:22 ` Auger Eric
2016-11-10 11:54 ` Robin Murphy
2016-11-10 12:14 ` Auger Eric
2016-11-10 12:48 ` Robin Murphy
2016-11-10 15:37 ` Joerg Roedel
2016-11-10 15:42 ` Auger Eric
[not found] ` <1478258646-3117-9-git-send-email-eric.auger@redhat.com>
2016-11-04 14:16 ` [RFC v2 8/8] iommu/arm-smmu: implement add_reserved_regions callback Robin Murphy
2016-11-10 15:46 ` Joerg Roedel
2016-11-10 15:57 ` Auger Eric
2016-11-10 16:13 ` Joerg Roedel
2016-11-10 18:00 ` Auger Eric
2016-11-11 11:42 ` Joerg Roedel
2016-11-11 15:47 ` Auger Eric
2016-11-11 16:22 ` Joerg Roedel [this message]
2016-11-11 16:45 ` Auger Eric
2016-11-14 15:31 ` Joerg Roedel
2016-11-14 16:08 ` Auger Eric
2016-11-14 16:20 ` Joerg Roedel
2016-11-14 16:57 ` Auger Eric
2016-11-10 16:07 ` Robin Murphy
2016-11-10 16:16 ` Joerg Roedel
2016-11-11 14:34 ` Robin Murphy
2016-11-11 15:03 ` Joerg Roedel
[not found] ` <1478258646-3117-3-git-send-email-eric.auger@redhat.com>
2016-11-10 15:22 ` [RFC v2 2/8] iommu/iova: fix __alloc_and_insert_iova_range Joerg Roedel
2016-11-10 15:41 ` Auger Eric
[not found] ` <1478258646-3117-4-git-send-email-eric.auger@redhat.com>
2016-11-14 12:36 ` [RFC v2 3/8] iommu/dma: Allow MSI-only cookies Robin Murphy
2016-11-14 23:23 ` Auger Eric
2016-11-15 14:52 ` Robin Murphy
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