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: Mon, 14 Nov 2016 16:31:50 +0100 [thread overview]
Message-ID: <20161114153149.GY2078@8bytes.org> (raw)
In-Reply-To: <634ac375-3507-6926-164f-e67f7c798c98@redhat.com>
Hi Eric,
On Fri, Nov 11, 2016 at 05:45:19PM +0100, Auger Eric wrote:
> On 11/11/2016 17:22, Joerg Roedel wrote:
> > 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,
> Current plan is to expose that info through an iommu-group sysfs
> attribute, as you and Robin advised.
Great.
> > and VFIO can enforce that. But the right struct here is not an
> > iova-allocator rb-tree, a ordered linked list should be sufficient.
> I plan a linked list to store the reserved regions (P2P regions, MSI
> region, ...). get_dma_regions is called with a list local to a function
> for that. Might be needed to move that list head in the iommu_group to
> avoid calling the get_dm_regions again in the attribute show function?
You can re-use the get_dm_regions() call-back available in the iommu-ops
already. Just rename it and add a flag to it which tells the iommu-core
whether that region needs to be mapped or not.
> But to allocate the IOVAs within the MSI reserved region, I understand
> you don't want us to use the iova.c allocator, is that correct? We need
> an allocator though, even a very basic one based on bitmap or whatever.
> There potentially have several different physical MSI frame pages to map.
I don't get this, what do you need and address-allocator for?
Joerg
next prev parent reply other threads:[~2016-11-14 15:31 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] ` <1478258646-3117-9-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
2016-11-11 16:45 ` Auger Eric
2016-11-14 15:31 ` Joerg Roedel [this message]
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] ` <1478258646-3117-5-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] ` <1478258646-3117-4-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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