linux-kernel - Re: [RFC, PATCH 00/12] TDX: Enable Dynamic PAMT

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <e1e2eddf-7706-4e5f-8e4a-ef2dc331e873@intel.com>
Date: Thu, 15 May 2025 08:03:28 -0700
From: Dave Hansen <dave.hansen@...el.com>
To: "Kirill A. Shutemov" <kirill.shutemov@...ux.intel.com>,
 Sean Christopherson <seanjc@...gle.com>
Cc: pbonzini@...hat.com, rick.p.edgecombe@...el.com,
 isaku.yamahata@...el.com, kai.huang@...el.com, yan.y.zhao@...el.com,
 tglx@...utronix.de, mingo@...hat.com, bp@...en8.de,
 dave.hansen@...ux.intel.com, kvm@...r.kernel.org, x86@...nel.org,
 linux-coco@...ts.linux.dev, linux-kernel@...r.kernel.org
Subject: Re: [RFC, PATCH 00/12] TDX: Enable Dynamic PAMT

On 5/15/25 07:22, Kirill A. Shutemov wrote:
> VMM is responsible for allocating and freeing PAMT_4K. There's a pair of
> new SEAMCALLs for it: TDH.PHYMEM.PAMT.ADD and TDH.PHYMEM.PAMT.REMOVE. They
> add/remove PAMT memory in form of page pair. There's no requirement for
> these pages to be contiguous.

BTW, that second sentence is a little goofy. Is it talking about
ADD/REMOVE being a matched pair? Or that there needs to be 8k of
metadata storage provided to each ADD/REMOVE call?

One thing I've noticed in writing changelogs and so forth is that
repetition can hurt understanding if the concepts aren't the same. Like
saying there is a "pair" of calls and a "pair" of pages when the fact
that both are pairs is a coincidence rather than an intentional and
important part of the design.