From: Ian Campbell <ian.campbell@citrix.com>
To: "Edgar E. Iglesias" <edgar.iglesias@gmail.com>
Cc: julien.grall@citrix.com, tim@xen.org, edgar.iglesias@xilinx.com,
stefano.stabellini@citrix.com, xen-devel@lists.xen.org
Subject: Re: [PATCH v4 0/3] Set SMMU s2 input-size based on p2m tables
Date: Wed, 6 May 2015 10:39:51 +0100 [thread overview]
Message-ID: <1430905191.2660.184.camel@citrix.com> (raw)
In-Reply-To: <20150506091729.GA13061@toto>
On Wed, 2015-05-06 at 19:17 +1000, Edgar E. Iglesias wrote:
> > Right, it seems like we may eventually need to introduce the possibility
> > of not sharing the p2m depending on the circumstances as is done on x86.
>
> Yes. How would that work in practice? I guess some of the guests memory space
> would not be DMA:able? or would we allow some kind of dynamic mapping
> driven from the guest?
For domU with passthrough enabled there would be a limitation on the
maximum usable IPA I suppose.
For dom0 it's a bit trickier, but I think the answer is basically that
on systems with insufficiently large SMMU support and peripherals or RAM
above the SMMU's limit we wouldn't be able to take advantage of the SMMU
protections and would be stuck with e.g. 1:1 mode. If it was only RAM
and not peripherals up high then perhaps we could trade off use of SMMU
vs dom0 RAM size.
Ian
next prev parent reply other threads:[~2015-05-06 9:39 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-05-01 1:40 [PATCH v4 0/3] Set SMMU s2 input-size based on p2m tables Edgar E. Iglesias
2015-05-01 1:40 ` [PATCH v4 1/3] xen/arm: Re-order iommu_setup to after setup_virt_paging Edgar E. Iglesias
2015-05-05 13:18 ` Ian Campbell
2015-05-01 1:40 ` [PATCH v4 2/3] xen/arm: Add p2m_ipa_bits Edgar E. Iglesias
2015-05-05 13:23 ` Ian Campbell
2015-05-06 4:28 ` Edgar E. Iglesias
2015-05-01 1:40 ` [PATCH v4 3/3] xen/iommu: arm: Use p2m_ipa_bits as stage2 input size Edgar E. Iglesias
2015-05-01 10:22 ` Julien Grall
2015-05-05 13:24 ` Ian Campbell
2015-05-05 13:48 ` Julien Grall
2015-05-05 13:59 ` Ian Campbell
2015-05-05 14:30 ` Julien Grall
2015-05-06 5:32 ` Edgar E. Iglesias
2015-05-05 13:17 ` [PATCH v4 0/3] Set SMMU s2 input-size based on p2m tables Ian Campbell
2015-05-05 13:45 ` Julien Grall
2015-05-06 3:26 ` Edgar E. Iglesias
2015-05-06 8:54 ` Ian Campbell
2015-05-06 9:17 ` Edgar E. Iglesias
2015-05-06 9:39 ` Ian Campbell [this message]
2015-05-06 11:06 ` Julien Grall
2015-05-06 11:50 ` Ian Campbell
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=1430905191.2660.184.camel@citrix.com \
--to=ian.campbell@citrix.com \
--cc=edgar.iglesias@gmail.com \
--cc=edgar.iglesias@xilinx.com \
--cc=julien.grall@citrix.com \
--cc=stefano.stabellini@citrix.com \
--cc=tim@xen.org \
--cc=xen-devel@lists.xen.org \
/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.