All of lore.kernel.org
 help / color / mirror / Atom feed
From: Jason Gunthorpe via iommu <iommu@lists.linux-foundation.org>
To: Lu Baolu <baolu.lu@linux.intel.com>
Cc: Kevin Tian <kevin.tian@intel.com>,
	iommu@lists.linux-foundation.org, linux-kernel@vger.kernel.org,
	Alex Williamson <alex.williamson@redhat.com>,
	Jacob jun Pan <jacob.jun.pan@intel.com>
Subject: Re: [PATCH 2/5] iommu/vt-d: Set SNP bit only in second-level page table entries
Date: Mon, 2 May 2022 10:05:46 -0300	[thread overview]
Message-ID: <20220502130546.GI8364@nvidia.com> (raw)
In-Reply-To: <20220501112434.874236-3-baolu.lu@linux.intel.com>

On Sun, May 01, 2022 at 07:24:31PM +0800, Lu Baolu wrote:
> The SNP bit is only valid for second-level PTEs. Setting this bit in the
> first-level PTEs has no functional impact because the Intel IOMMU always
> ignores the same bit in first-level PTEs. Anyway, let's check the page
> table type before setting SNP bit in PTEs to make the code more readable.

Shouldn't this be tested before setting force_snooping and not during
every map?

Jason
_______________________________________________
iommu mailing list
iommu@lists.linux-foundation.org
https://lists.linuxfoundation.org/mailman/listinfo/iommu

WARNING: multiple messages have this Message-ID (diff)
From: Jason Gunthorpe <jgg@nvidia.com>
To: Lu Baolu <baolu.lu@linux.intel.com>
Cc: Joerg Roedel <joro@8bytes.org>,
	Alex Williamson <alex.williamson@redhat.com>,
	Kevin Tian <kevin.tian@intel.com>,
	Jacob jun Pan <jacob.jun.pan@intel.com>,
	Liu Yi L <yi.l.liu@intel.com>,
	iommu@lists.linux-foundation.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH 2/5] iommu/vt-d: Set SNP bit only in second-level page table entries
Date: Mon, 2 May 2022 10:05:46 -0300	[thread overview]
Message-ID: <20220502130546.GI8364@nvidia.com> (raw)
In-Reply-To: <20220501112434.874236-3-baolu.lu@linux.intel.com>

On Sun, May 01, 2022 at 07:24:31PM +0800, Lu Baolu wrote:
> The SNP bit is only valid for second-level PTEs. Setting this bit in the
> first-level PTEs has no functional impact because the Intel IOMMU always
> ignores the same bit in first-level PTEs. Anyway, let's check the page
> table type before setting SNP bit in PTEs to make the code more readable.

Shouldn't this be tested before setting force_snooping and not during
every map?

Jason

  reply	other threads:[~2022-05-02 13:05 UTC|newest]

Thread overview: 40+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-05-01 11:24 [PATCH 0/5] iommu/vt-d: Force snooping improvement Lu Baolu
2022-05-01 11:24 ` Lu Baolu
2022-05-01 11:24 ` [PATCH 1/5] iommu/vt-d: Block force-snoop domain attaching if no SC support Lu Baolu
2022-05-01 11:24   ` Lu Baolu
2022-05-02 13:04   ` Jason Gunthorpe via iommu
2022-05-02 13:04     ` Jason Gunthorpe
2022-05-01 11:24 ` [PATCH 2/5] iommu/vt-d: Set SNP bit only in second-level page table entries Lu Baolu
2022-05-01 11:24   ` Lu Baolu
2022-05-02 13:05   ` Jason Gunthorpe via iommu [this message]
2022-05-02 13:05     ` Jason Gunthorpe
2022-05-04  7:25     ` Baolu Lu
2022-05-04  7:25       ` Baolu Lu
2022-05-04 13:31       ` Jason Gunthorpe via iommu
2022-05-04 13:31         ` Jason Gunthorpe
2022-05-04 14:37         ` Baolu Lu
2022-05-04 14:37           ` Baolu Lu
2022-05-01 11:24 ` [PATCH 3/5] iommu/vt-d: Check domain force_snooping against attached devices Lu Baolu
2022-05-01 11:24   ` Lu Baolu
2022-05-02 13:17   ` Jason Gunthorpe via iommu
2022-05-02 13:17     ` Jason Gunthorpe
2022-05-04  7:58     ` Baolu Lu
2022-05-04  7:58       ` Baolu Lu
2022-05-02 21:31   ` Jacob Pan
2022-05-02 21:31     ` Jacob Pan
2022-05-04  8:06     ` Baolu Lu
2022-05-04  8:06       ` Baolu Lu
2022-05-01 11:24 ` [PATCH 4/5] iommu/vt-d: Remove domain_update_iommu_snooping() Lu Baolu
2022-05-01 11:24   ` Lu Baolu
2022-05-02 13:19   ` Jason Gunthorpe via iommu
2022-05-02 13:19     ` Jason Gunthorpe
2022-05-02 21:36   ` Jacob Pan
2022-05-02 21:36     ` Jacob Pan
2022-05-04  8:47     ` Baolu Lu
2022-05-04  8:47       ` Baolu Lu
2022-05-01 11:24 ` [PATCH 5/5] iommu/vt-d: Remove hard coding PGSNP bit in PASID entries Lu Baolu
2022-05-01 11:24   ` Lu Baolu
2022-05-02 13:19   ` Jason Gunthorpe via iommu
2022-05-02 13:19     ` Jason Gunthorpe
2022-05-04  8:49     ` Baolu Lu
2022-05-04  8:49       ` Baolu Lu

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=20220502130546.GI8364@nvidia.com \
    --to=iommu@lists.linux-foundation.org \
    --cc=alex.williamson@redhat.com \
    --cc=baolu.lu@linux.intel.com \
    --cc=jacob.jun.pan@intel.com \
    --cc=jgg@nvidia.com \
    --cc=kevin.tian@intel.com \
    --cc=linux-kernel@vger.kernel.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.