From: Joerg Roedel <joro@8bytes.org>
To: Don Dutile <ddutile@redhat.com>
Cc: Greg KH <gregkh@suse.de>, Ohad Ben-Cohen <ohad@wizery.com>,
kvm@vger.kernel.org, linux-kernel@vger.kernel.org,
iommu@lists.linux-foundation.org,
David Brown <davidb@codeaurora.org>,
David Woodhouse <dwmw2@infradead.org>
Subject: Re: [PATCH 02/10] Driver core: Add iommu_ops to bus_type
Date: Thu, 8 Sep 2011 10:58:42 +0200 [thread overview]
Message-ID: <20110908085842.GD31674@8bytes.org> (raw)
In-Reply-To: <4E67D5F7.6070103@redhat.com>
On Wed, Sep 07, 2011 at 04:37:11PM -0400, Don Dutile wrote:
> On 09/07/2011 03:44 PM, Greg KH wrote:
>> Why are you pushing this down into the driver core? What other busses
>> becides PCI use/need this?
>>
>> If you can have a different IOMMU driver on the same bus, then wouldn't
>> this be a per-device thing instead of a per-bus thing?
>>
> And given the dma api takes a struct device *, it'd be more efficient
> to be tied into the device structure.
More efficient in what way? Currently no dma-api implementation uses the
iommu-api directly. It is planned to change that, of course. But the
dma-api implementation will use the iommu_map/iommu_unmap functions which
get an iommu_domain parameter and no device structure. Thats why the
domain structure keeps an iommu_ops pointer too.
> Device structure would get iommu ops set by parent(bus);
> if a bus (segment) doesn't provide a unique/different/layered IOMMU
> then the parent bus, it inherits the parent's iommu-ops.
> setting the iommu-ops in the root bus struct, seeds the iommu-ops
> for the (PCI) tree.
>
> For intel & amd IOMMUs, in early pci (bios,root?) init, you would
> seed the pci root busses with appropriate IOMMU support (based on
> dmar/drhd & ivrs/ivhd data structures, respectively), and
> then modify the PCI code to do the inheritence (PPB code inherits
> unless specific device driver for a given PPB vid-did loads a
> different iommu-ops for that segment/branch).
>
> This would enable different types of IOMMUs for different devices
> (or PCI segments, or branches of PCI trees) that are designed for
> different tasks -- simple IOMMUs for legacy devices; complicated, io-page-faulting
> IOMMUs for plug-in, high-end devices on virtualizing servers for PCI (SRIOV) endpoints.
This only works for pci, but the iommu-api is not pci-only.
> and as Greg indicates, is only relevant to PCI.
We already have non-pci iommu drivers implementing the iommu-api. So
this is certainly relevant outside pci too.
Joerg
next prev parent reply other threads:[~2011-09-08 8:58 UTC|newest]
Thread overview: 39+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-09-07 15:41 [PATCH 0/10] IOMMU: Make iommu_ops per-bus_type Joerg Roedel
2011-09-07 15:41 ` [PATCH 01/10] iommu/core: Define iommu_ops and register_iommu only with CONFIG_IOMMU_API Joerg Roedel
2011-09-07 15:41 ` [PATCH 02/10] Driver core: Add iommu_ops to bus_type Joerg Roedel
2011-09-07 18:47 ` Greg KH
2011-09-07 19:19 ` Joerg Roedel
2011-09-07 19:44 ` Greg KH
2011-09-07 20:37 ` Don Dutile
2011-09-08 8:58 ` Joerg Roedel [this message]
2011-09-08 8:41 ` Joerg Roedel
2011-09-12 11:40 ` Sethi Varun-B16395
2011-09-13 14:54 ` Roedel, Joerg
2011-09-13 14:58 ` Greg KH
2011-09-13 15:15 ` Roedel, Joerg
2011-09-13 15:38 ` Roedel, Joerg
2011-09-13 16:21 ` Greg KH
2011-09-14 12:46 ` Roedel, Joerg
2011-09-12 12:08 ` Sethi Varun-B16395
2011-09-12 12:35 ` Roedel, Joerg
2011-09-15 12:45 ` Sethi Varun-B16395
2011-09-15 13:13 ` Roedel, Joerg
2011-09-07 15:41 ` [PATCH 03/10] iommu/core: Add bus_type parameter to iommu_domain_alloc Joerg Roedel
2011-09-12 11:50 ` Sethi Varun-B16395
2011-09-12 12:37 ` Roedel, Joerg
2011-09-07 15:41 ` [PATCH 04/10] iommu/core: Convert iommu_found to iommu_present Joerg Roedel
2011-09-07 15:41 ` [PATCH 05/10] iommu/core: Use bus->iommu_ops in the iommu-api Joerg Roedel
2011-09-07 15:41 ` [PATCH 06/10] iommu/amd: Use bus_set_iommu instead of register_iommu Joerg Roedel
2011-09-07 15:41 ` [PATCH 07/10] iommu/vt-d: " Joerg Roedel
2011-09-07 15:41 ` [PATCH 08/10] iommu/omap: " Joerg Roedel
2011-09-07 15:41 ` [PATCH 09/10] iommu/msm: " Joerg Roedel
2011-09-07 15:41 ` [PATCH 10/10] iommu/core: Remove global iommu_ops and register_iommu Joerg Roedel
2011-09-07 18:48 ` [PATCH 0/10] IOMMU: Make iommu_ops per-bus_type Greg KH
2011-09-07 19:29 ` Joerg Roedel
-- strict thread matches above, loose matches on Subject: below --
2011-09-22 16:14 [PATCH 0/10 v2] " Joerg Roedel
2011-09-22 16:14 ` [PATCH 02/10] Driver core: Add iommu_ops to bus_type Joerg Roedel
2011-09-22 20:11 ` Greg KH
2011-09-23 15:19 ` Roedel, Joerg
2011-09-23 15:45 [PATCH 0/10 v3] IOMMU: Make iommu_ops per-bus_type Joerg Roedel
2011-09-23 15:45 ` [PATCH 02/10] Driver core: Add iommu_ops to bus_type Joerg Roedel
2011-09-29 20:05 ` Greg KH
2011-09-30 6:24 ` Joerg Roedel
2011-09-30 13:58 ` Greg KH
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20110908085842.GD31674@8bytes.org \
--to=joro@8bytes.org \
--cc=davidb@codeaurora.org \
--cc=ddutile@redhat.com \
--cc=dwmw2@infradead.org \
--cc=gregkh@suse.de \
--cc=iommu@lists.linux-foundation.org \
--cc=kvm@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=ohad@wizery.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.