linux-coco.lists.linux.dev archive mirror
 help / color / mirror / Atom feed
From: Andi Kleen <ak@linux.intel.com>
To: Guorui Yu <GuoRui.Yu@linux.alibaba.com>,
	linux-kernel@vger.kernel.org, iommu@lists.linux-foundation.org,
	konrad.wilk@oracle.com, linux-coco@lists.linux.dev
Cc: robin.murphy@arm.com
Subject: Re: [PATCH 2/4] swiotlb: Add a new cc-swiotlb implementation for Confidential VMs
Date: Tue, 31 Jan 2023 09:16:11 -0800	[thread overview]
Message-ID: <ee5d8c26-a453-678c-be48-d586271573d6@linux.intel.com> (raw)
In-Reply-To: <ccc21265-07aa-cd82-f679-4fee9c51df47@linux.alibaba.com>

 >No, this cannot guarantee we always have sufficient TLB caches, so we 
can also have a "No memory for cc-swiotlb buffer" warning.

It's not just a warning, it will be IO errors, right?

>
> But I want to emphasize that in this case, the current implementation 
> is no worse than the legacy implementation. Moreover, dynamic TLB 
> allocation is more suitable for situations where more disks/network 
> devices will be hotplugged, in which case you cannot pre-set a 
> reasonable value.

That's a reasonable stand point, but have to emphasize that is 
"probabilistic" in all the descriptions and comments.

I assume you did some stress testing (E.g. all cores submitting at full 
bandwidth) to validate that it works for you?

-Andi



  reply	other threads:[~2023-01-31 17:16 UTC|newest]

Thread overview: 19+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-01-28  8:32 [RFC] swiotlb: Add a new cc-swiotlb implementation for Confidential VMs GuoRui.Yu
2023-01-28  8:32 ` [PATCH 1/4] swiotlb: Split common code from swiotlb.{c,h} GuoRui.Yu
2023-01-28  8:32 ` [PATCH 2/4] swiotlb: Add a new cc-swiotlb implementation for Confidential VMs GuoRui.Yu
2023-01-28 12:03   ` kernel test robot
2023-01-28 16:41   ` Randy Dunlap
2023-01-29  1:54     ` Guorui Yu
2023-01-29 16:58   ` Andi Kleen
2023-01-30  2:25     ` Guorui Yu
2023-01-30  6:46       ` Andi Kleen
2023-01-30 13:45         ` Guorui Yu
2023-01-31 17:16           ` Andi Kleen [this message]
2023-02-01  2:08             ` Guorui Yu
2023-01-28  8:32 ` [PATCH 3/4] swiotlb: Add tracepoint swiotlb_unbounced GuoRui.Yu
2023-01-28  8:32 ` [PATCH 4/4] cc-swiotlb: Allow set swiotlb watermark from cmdline GuoRui.Yu
2023-01-28 20:19   ` kernel test robot
2023-01-28  9:03 ` [RFC] swiotlb: Add a new cc-swiotlb implementation for Confidential VMs Guorui Yu
2023-01-30  6:54   ` Christoph Hellwig
2023-01-30 13:03 ` Robin Murphy
2023-01-30 14:37   ` Guorui Yu

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=ee5d8c26-a453-678c-be48-d586271573d6@linux.intel.com \
    --to=ak@linux.intel.com \
    --cc=GuoRui.Yu@linux.alibaba.com \
    --cc=iommu@lists.linux-foundation.org \
    --cc=konrad.wilk@oracle.com \
    --cc=linux-coco@lists.linux.dev \
    --cc=linux-kernel@vger.kernel.org \
    --cc=robin.murphy@arm.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).