From: Sean Christopherson <seanjc@google.com>
To: Peng Hao <flyingpenghao@gmail.com>
Cc: pbonzini@redhat.com, kvm@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] kvm: x86: Adjust the location of pkru_mask of kvm_mmu to reduce memory
Date: Mon, 28 Feb 2022 16:10:36 +0000 [thread overview]
Message-ID: <Yhzz/N4+3vNh7AQn@google.com> (raw)
In-Reply-To: <20220228030749.88353-1-flyingpeng@tencent.com>
On Mon, Feb 28, 2022, Peng Hao wrote:
> From: Peng Hao <flyingpeng@tencent.com>
>
> Adjust the field pkru_mask to the back of direct_map to make up 8-byte
> alignment.This reduces the size of kvm_mmu by 8 bytes.
I'd prefer we just burn the extra 8 bytes, at least for now. 'prku' and 'permissions'
are related fields, IMO splitting them to save 24 bytes per vCPU isn't a good tradeoff.
And in the not-too-distant future, all of the 1-byte fields will hopefully go
away, at which point were "wasting" 4 bytes no matter where 'pkru' is defined. 'ept_ad'
can be dropped immediately, I'll send a patch for that. We should be able to drop
'root_level', 'shadow_root_level', and 'direct_map' once Paolo's clean up of the role
stuff lands.
next prev parent reply other threads:[~2022-02-28 16:10 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-02-28 3:07 [PATCH] kvm: x86: Adjust the location of pkru_mask of kvm_mmu to reduce memory Peng Hao
2022-02-28 16:10 ` Sean Christopherson [this message]
2022-04-08 16:46 ` Paolo Bonzini
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=Yhzz/N4+3vNh7AQn@google.com \
--to=seanjc@google.com \
--cc=flyingpenghao@gmail.com \
--cc=kvm@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=pbonzini@redhat.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