From: Joerg Roedel <joro@8bytes.org>
To: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Cc: linux-kernel@vger.kernel.org, iommu@lists.linux-foundation.org,
Jon.Grimm@amd.com, brijesh.singh@amd.com
Subject: Re: [PATCH v2 0/3] amd : iommu : Initial IOMMU support for SNP
Date: Thu, 24 Sep 2020 12:52:00 +0200 [thread overview]
Message-ID: <20200924105200.GP27174@8bytes.org> (raw)
In-Reply-To: <20200923121347.25365-1-suravee.suthikulpanit@amd.com>
On Wed, Sep 23, 2020 at 12:13:44PM +0000, Suravee Suthikulpanit wrote:
> Suravee Suthikulpanit (3):
> iommu: amd: Use 4K page for completion wait write-back semaphore
> iommu: amd: Add support for RMP_PAGE_FAULT and RMP_HW_ERR
> iommu: amd: Re-purpose Exclusion range registers to support SNP CWWB
Applied, thanks. I am slightly concerned about the re-purposing of the
exclusion-range registers based on a feature bit being set. This makes
the hardware incompatible to older IOMMU drivers which do not check the
FEATURE_SNP bit.
It will probably work in this case, as the firmware on systems with
IOMMU-SNP support will not declare exclusion ranges at all and
exclusion-ranges in the IOMMU hardware have been a bad idea since
forever, but it would have been nicer if hardware actually
provided a bit to enable this behavior.
Regards,
Joerg
prev parent reply other threads:[~2020-09-24 10:52 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-09-23 12:13 [PATCH v2 0/3] amd : iommu : Initial IOMMU support for SNP Suravee Suthikulpanit
2020-09-23 12:13 ` [PATCH v2 1/3] iommu: amd: Use 4K page for completion wait write-back semaphore Suravee Suthikulpanit
2020-09-23 12:13 ` [PATCH v2 2/3] iommu: amd: Add support for RMP_PAGE_FAULT and RMP_HW_ERR Suravee Suthikulpanit
2020-09-23 12:13 ` [PATCH v2 3/3] iommu: amd: Re-purpose Exclusion range registers to support SNP CWWB Suravee Suthikulpanit
2020-09-24 10:52 ` Joerg Roedel [this message]
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=20200924105200.GP27174@8bytes.org \
--to=joro@8bytes.org \
--cc=Jon.Grimm@amd.com \
--cc=brijesh.singh@amd.com \
--cc=iommu@lists.linux-foundation.org \
--cc=linux-kernel@vger.kernel.org \
--cc=suravee.suthikulpanit@amd.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 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).