From: "Tian, Kevin" <kevin.tian@intel.com>
To: Stefano Stabellini <sstabellini@kernel.org>,
"Edgar E. Iglesias" <edgar.iglesias@gmail.com>
Cc: "Lan, Tianyu" <tianyu.lan@intel.com>,
"yang.zhang.wz@gmail.com" <yang.zhang.wz@gmail.com>,
"xuquan8@huawei.com" <xuquan8@huawei.com>,
"xen-devel@lists.xensource.com" <xen-devel@lists.xensource.com>,
Jan Beulich <JBeulich@suse.com>,
Andrew Cooper <andrew.cooper3@citrix.com>,
"ian.jackson@eu.citrix.com" <ian.jackson@eu.citrix.com>,
Julien Grall <julien.grall@arm.com>,
"Nakajima, Jun" <jun.nakajima@intel.com>,
"anthony.perard@citrix.com" <anthony.perard@citrix.com>,
Roger Pau Monne <roger.pau@citrix.com>
Subject: Re: Xen virtual IOMMU high level design doc
Date: Thu, 24 Nov 2016 02:00:21 +0000 [thread overview]
Message-ID: <AADFC41AFE54684AB9EE6CBC0274A5D18E03F9A3@SHSMSX101.ccr.corp.intel.com> (raw)
In-Reply-To: <alpine.DEB.2.10.1611231059390.21858@sstabellini-ThinkPad-X260>
> From: Stefano Stabellini [mailto:sstabellini@kernel.org]
> Sent: Thursday, November 24, 2016 3:09 AM
>
> On Wed, 23 Nov 2016, Edgar E. Iglesias wrote:
> > On Wed, Aug 17, 2016 at 08:05:51PM +0800, Lan, Tianyu wrote:
> > > Hi All:
> > > The following is our Xen vIOMMU high level design for detail
> > > discussion. Please have a look. Very appreciate for your comments.
> > > This design doesn't cover changes when root port is moved to hypervisor.
> > > We may design it later.
> >
> > Hi,
> >
> > I have a few questions.
> >
> > If I understand correctly, you'll be emulating an Intel IOMMU in Xen.
> > So guests will essentially create intel iommu style page-tables.
> >
> > If we were to use this on Xen/ARM, we would likely be modelling an ARM
> > SMMU as a vIOMMU. Since Xen on ARM does not use QEMU for emulation, the
> > hypervisor OPs for QEMUs xen dummy IOMMU queries would not really be used.
> > Do I understand this correctly?
>
> I think they could be called from the toolstack. This is why I was
> saying in the other thread that the hypercalls should be general enough
> that QEMU is not the only caller.
>
> For PVH and ARM guests, the toolstack should be able to setup the vIOMMU
> on behalf of the guest without QEMU intervention.
>
>
> > Has a platform agnostic PV-IOMMU been considered to support 2-stage
> > translation (i.e VFIO in the guest)? Perhaps that would hurt map/unmap
> > performance too much?
>
> That's an interesting idea. I don't know if that's feasible, but if it
> is not, then we need to be able to specify the PV-IOMMU type in the
> hypercalls, so that you would get Intel IOMMU on x86 and SMMU on ARM.
>
>
Not considered yet. PV is always possible as we've done for other I/O
devices. Ideally it could be designed being more efficient than full
emulation of vendor specific IOMMU, but also means requirement of
maintaining a new guest IOMMU driver and limitation of supporting
only newer version guest OSes. It's a tradeoff... at least not compelling
now (may consider when we see a real need in the future).
Thanks
Kevin
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next prev parent reply other threads:[~2016-11-24 2:00 UTC|newest]
Thread overview: 86+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-05-26 8:29 Discussion about virtual iommu support for Xen guest Lan Tianyu
2016-05-26 8:42 ` Dong, Eddie
2016-05-27 2:26 ` Lan Tianyu
2016-05-27 8:11 ` Tian, Kevin
2016-05-26 11:35 ` Andrew Cooper
2016-05-27 8:19 ` Lan Tianyu
2016-06-02 15:03 ` Lan, Tianyu
2016-06-02 18:58 ` Andrew Cooper
2016-06-03 11:01 ` Current PVH/HVMlite work and planning (was :Re: Discussion about virtual iommu support for Xen guest) Roger Pau Monne
2016-06-03 11:21 ` Tian, Kevin
2016-06-03 11:52 ` Roger Pau Monne
2016-06-03 12:11 ` Tian, Kevin
2016-06-03 16:56 ` Stefano Stabellini
2016-06-07 5:48 ` Tian, Kevin
2016-06-03 11:17 ` Discussion about virtual iommu support for Xen guest Tian, Kevin
2016-06-03 13:09 ` Lan, Tianyu
2016-06-03 14:00 ` Andrew Cooper
2016-06-03 13:51 ` Andrew Cooper
2016-06-03 14:31 ` Jan Beulich
2016-06-03 17:14 ` Stefano Stabellini
2016-06-07 5:14 ` Tian, Kevin
2016-06-07 7:26 ` Jan Beulich
2016-06-07 10:07 ` Stefano Stabellini
2016-06-08 8:11 ` Tian, Kevin
2016-06-26 13:42 ` Lan, Tianyu
2016-06-29 3:04 ` Tian, Kevin
2016-07-05 13:37 ` Lan, Tianyu
2016-07-05 13:57 ` Jan Beulich
2016-07-05 14:19 ` Lan, Tianyu
2016-08-17 12:05 ` Xen virtual IOMMU high level design doc Lan, Tianyu
2016-08-17 12:42 ` Paul Durrant
2016-08-18 2:57 ` Lan, Tianyu
2016-08-25 11:11 ` Jan Beulich
2016-08-31 8:39 ` Lan Tianyu
2016-08-31 12:02 ` Jan Beulich
2016-09-01 1:26 ` Tian, Kevin
2016-09-01 2:35 ` Lan Tianyu
2016-09-15 14:22 ` Lan, Tianyu
2016-10-05 18:36 ` Konrad Rzeszutek Wilk
2016-10-11 1:52 ` Lan Tianyu
2016-11-23 18:19 ` Edgar E. Iglesias
2016-11-23 19:09 ` Stefano Stabellini
2016-11-24 2:00 ` Tian, Kevin [this message]
2016-11-24 4:09 ` Edgar E. Iglesias
2016-11-24 6:49 ` Lan Tianyu
2016-11-24 13:37 ` Edgar E. Iglesias
2016-11-25 2:01 ` Xuquan (Quan Xu)
2016-11-25 5:53 ` Lan, Tianyu
2016-10-18 14:14 ` Xen virtual IOMMU high level design doc V2 Lan Tianyu
2016-10-18 19:17 ` Andrew Cooper
2016-10-20 9:53 ` Tian, Kevin
2016-10-20 18:10 ` Andrew Cooper
2016-10-20 14:17 ` Lan Tianyu
2016-10-20 20:36 ` Andrew Cooper
2016-10-22 7:32 ` Lan, Tianyu
2016-10-26 9:39 ` Jan Beulich
2016-10-26 15:03 ` Lan, Tianyu
2016-11-03 15:41 ` Lan, Tianyu
2016-10-28 15:36 ` Lan Tianyu
2016-10-18 20:26 ` Konrad Rzeszutek Wilk
2016-10-20 10:11 ` Tian, Kevin
2016-10-20 14:56 ` Lan, Tianyu
2016-10-26 9:36 ` Jan Beulich
2016-10-26 14:53 ` Lan, Tianyu
2016-11-17 15:36 ` Xen virtual IOMMU high level design doc V3 Lan Tianyu
2016-11-18 19:43 ` Julien Grall
2016-11-21 2:21 ` Lan, Tianyu
2016-11-21 13:17 ` Julien Grall
2016-11-21 18:24 ` Stefano Stabellini
2016-11-21 7:05 ` Tian, Kevin
2016-11-23 1:36 ` Lan Tianyu
2016-11-21 13:41 ` Andrew Cooper
2016-11-22 6:02 ` Tian, Kevin
2016-11-22 8:32 ` Lan Tianyu
2016-11-22 10:24 ` Jan Beulich
2016-11-24 2:34 ` Lan Tianyu
2016-06-03 19:51 ` Is: 'basic pci bridge and root device support. 'Was:Re: Discussion about virtual iommu support for Xen guest Konrad Rzeszutek Wilk
2016-06-06 9:55 ` Jan Beulich
2016-06-06 17:25 ` Konrad Rzeszutek Wilk
2016-08-02 15:15 ` Lan, Tianyu
2016-05-27 8:35 ` Tian, Kevin
2016-05-27 8:46 ` Paul Durrant
2016-05-27 9:39 ` Tian, Kevin
2016-05-31 9:43 ` George Dunlap
2016-05-27 2:26 ` Yang Zhang
2016-05-27 8:13 ` Tian, Kevin
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