From: Joerg Roedel <joro@8bytes.org>
To: Huang Adrian <adrianhuang0701@gmail.com>
Cc: iommu@lists.linux-foundation.org, Adrian Huang <ahuang12@lenovo.com>
Subject: Re: [PATCH 1/1] iommu/amd: Fix the overwritten exclusion range with multiple IVMDs
Date: Tue, 12 Nov 2019 17:05:39 +0100 [thread overview]
Message-ID: <20191112160539.GA3884@8bytes.org> (raw)
In-Reply-To: <CAHKZfL2Zoj-585mHti3_ZAgUNs0s43T=fxGZYt9cKfhQMnUd3w@mail.gmail.com>
On Tue, Nov 12, 2019 at 05:32:31PM +0800, Huang Adrian wrote:
> > On Mon, Nov 11, 2019 at 11:22 PM Joerg Roedel <joro@8bytes.org> wrote:
> > So there are a couple of options here:
> >
> > 1) Bail out and disable the IOMMU as the BIOS screwed up
> >
> > 2) Treat per-device exclusion ranges just as r/w unity-mapped
> > regions.
> >
> >
> > I think option 2) is the best fix here.
>
> Yes. This is what this patch does (The first exclusion region still
> uses the exclusion range while the remaining exclusion regions are
> modified to be r/w unity-mapped regions when detecting multiple
> exclusion regions) .
Yeah, but I think it is better to just stop using the exclusion-range
feature of the hardware (because it meand BIOSes are correct) and just
treat every exclusion range (also the first one) as an r/w unity range.
> But, I'm guessing you're talking about that BIOS has to define r/w
> unity-mapped regions instead of the per-device exclusions (Fix from
> BIOS, not prevent the failure from kernel). Right?
That would be best, but I fear this is too much to wish for.
Regards,
Joerg
_______________________________________________
iommu mailing list
iommu@lists.linux-foundation.org
https://lists.linuxfoundation.org/mailman/listinfo/iommu
next prev parent reply other threads:[~2019-11-12 16:05 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-11-04 5:58 [PATCH 1/1] iommu/amd: Fix the overwritten exclusion range with multiple IVMDs Adrian Huang
2019-11-11 15:22 ` Joerg Roedel
2019-11-12 9:32 ` Huang Adrian
2019-11-12 16:05 ` Joerg Roedel [this message]
2019-11-13 1:05 ` Huang Adrian
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=20191112160539.GA3884@8bytes.org \
--to=joro@8bytes.org \
--cc=adrianhuang0701@gmail.com \
--cc=ahuang12@lenovo.com \
--cc=iommu@lists.linux-foundation.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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).