From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pl1-f202.google.com (mail-pl1-f202.google.com [209.85.214.202]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 543B91A0BE0 for ; Tue, 7 Jul 2026 00:25:18 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.214.202 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1783383919; cv=none; b=eNbcJQPR5/UpMZssQTzl/xwgzqBd1zf6Wy77iMyEI8KNgRSkJwN4h6DC1jMB0yXhgg0ooGtCi6qUEePspDW0MbVdJac+PIXcL6Rolz6mWRjitJEYsGxr+3uLYn4TszovL0kmV9P4V/mJv28yENZQAeGvDO4xvqVW1KjpEHog+2A= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1783383919; c=relaxed/simple; bh=7x/R57qudJvKK/D5Vz7Hi1BoiQPVT6Eb3LFhPmwn7/k=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=BIPt4Zu7/87xI7jNdMgYZ4gd7IvTkALYMrWtZE9MQ2hTYHoAQyIRFtXvnhuoplkS0GbWSQAm0T5K5EnbZJ49NPdCfeH+1gX5fcpknKMbd1N2Dtia4Mu6yPzu7n9zLaBScEktLpGU3qWxSxY7Y1LOh5X4me0/GMppUn0oXnSqSIM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=flex--seanjc.bounces.google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=DzHARPTF; arc=none smtp.client-ip=209.85.214.202 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=flex--seanjc.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="DzHARPTF" Received: by mail-pl1-f202.google.com with SMTP id d9443c01a7336-2cc640dfde3so32587325ad.1 for ; Mon, 06 Jul 2026 17:25:18 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20251104; t=1783383918; x=1783988718; darn=lists.linux.dev; h=content-type:cc:to:from:subject:message-id:references:mime-version :in-reply-to:date:from:to:cc:subject:date:message-id:reply-to :content-type; bh=Y2tUu5e71+Sget3gJMSknqgMwie3pm4NkHG0E3M9coA=; b=DzHARPTFc9yWiqR/GuPyARhQ/RAAhJ5tBqHboJi+R3jAqIwfO4EmnfGQpP+WEyK2hl 8RMiSxENJ/L3DasiPo8WRN9lMTLKtAxI4Yew468Q6ap6emWV73dHe/Q5QFlVW7py+a/T 4MhKHBK7e5dqy1JhJUsCOD39jM+WUEe5zlEiPB+pGLQ21jgvMTTqN1jNlR4e7vNQGWVh QxSoEEfYVFyXSbU72Gv3J7c7RlbRl6Rw9wx1NwejMGiEAMgjkwPvhczSWlEo+8uUKmL+ VwTJeSwqCv0WFBjsuyPRy27C3MdHaTMv2gYIhv+ha2jtkDo+20oRBRNtYPzO4txmsWNd /QXw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1783383918; x=1783988718; h=content-type:cc:to:from:subject:message-id:references:mime-version :in-reply-to:date:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to:content-type; bh=Y2tUu5e71+Sget3gJMSknqgMwie3pm4NkHG0E3M9coA=; b=JTX31oOGHovmn2rv+L0B1B3xcBUTzDxU0HwevSKPjddBg2JUykhY2IvunKx7JbQRcz Owx/64qbZ5FiiqvHkKuUQhhcCKxpHnX1i/afZlN/Sn4znZCrJ6vl+Tn9irIkVtDzI82q w0ARlsCqwrxlqSjCP43ol7YlKLpdpNQs3yZFI4+5LMFkeEeaZrviScV1LDC8lTI0r7Lt wuZFzdMeKpbfndUw2XRqctXfkdbjHQObnkH3t9D3UroYz3nvRHDjb+n1Ls9gJaIdUiay GljxxlQIyMllKBELauCsRh5rlqL2Dpk4yCV/jEFCB8383m7QWm5w/uOumXqHeM9BaIOn s8SQ== X-Forwarded-Encrypted: i=1; AHgh+RrT54qSfY7ZM4/68LT9MXis7/UiNpRNDsjSPHf29I7eUijH93UM4ULU4DZ8t1uAizMOSov3xKoMAOtT@lists.linux.dev X-Gm-Message-State: AOJu0Yx2V31TK1gPIJSJ+3t3jVWgg0zL+3A/cfl/VXaI2oiTfs5kq8PN WOg2PnzWo84S3CXvTcLKbmfoNnSEniL/dUNEvCY3R+wq7vhvWzEnZDF5fiN82o/O5IUyLGgMzmF NPOgtPg== X-Received: from plq4.prod.google.com ([2002:a17:903:2f84:b0:2cc:73ae:7d4c]) (user=seanjc job=prod-delivery.src-stubby-dispatcher) by 2002:a17:902:ce01:b0:2ca:52ce:6f91 with SMTP id d9443c01a7336-2ccbf056a99mr33058945ad.27.1783383917478; Mon, 06 Jul 2026 17:25:17 -0700 (PDT) Date: Mon, 6 Jul 2026 17:25:16 -0700 In-Reply-To: Precedence: bulk X-Mailing-List: linux-coco@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20260526023515.288829-1-rick.p.edgecombe@intel.com> <20260526023515.288829-8-rick.p.edgecombe@intel.com> Message-ID: Subject: Re: [PATCH v6 07/11] KVM: TDX: Allocate PAMT memory for TD and vCPU control structures From: Sean Christopherson To: Rick P Edgecombe Cc: "kvm@vger.kernel.org" , "linux-coco@lists.linux.dev" , Kai Huang , Dave Hansen , Yan Y Zhao , "kirill.shutemov@linux.intel.com" , "kas@kernel.org" , "linux-kernel@vger.kernel.org" , "mingo@redhat.com" , "pbonzini@redhat.com" , "nik.borisov@suse.com" , "linux-doc@vger.kernel.org" , "hpa@zytor.com" , "tglx@kernel.org" , Vishal Annapurve , "bp@alien8.de" , Chao Gao , "x86@kernel.org" Content-Type: text/plain; charset="us-ascii" On Mon, Jul 06, 2026, Rick P Edgecombe wrote: > On Mon, 2026-07-06 at 16:47 -0700, Sean Christopherson wrote: > > On Mon, May 25, 2026, Rick Edgecombe wrote: > > > From: "Kirill A. Shutemov" > > > > > > Use control page helpers for allocating and freeing TD control structures, > > > such these operations can work for Dynamic PAMT. > > > > > > The TDX module tracks some state for each page of physical memory that it > > > might use. It calls this state the PAMT. It includes separate state for > > > each page size a physical page could be utilized at within the TDX module > > > (1GB, 2MB, 4KB). In Dynamic PAMT, only the 4KB page size state is > > > allocated dynamically. So the kernel must install PAMT backing for each 4KB > > > page before gifting it to the TDX module, and tear it down after the page > > > is reclaimed. > > > > > > TD-scoped control pages (TDR, TDCS) and vCPU-scoped control pages (TDVPR, > > > TDCX) are all handed to the TDX module at 4KB page size and are therefore > > > subject to this requirement. Replace the raw alloc_page()/__free_page() > > > calls for these pages with tdx_alloc/free_control_page(). > > > > > > Switching between special Dynamic PAMT operations or normal page > > > alloc/free operations is handled internally in > > > tdx_alloc/free_control_page(). So don't check for Dynamic PAMT around these > > > calls. Just call them unconditionally. Similarly, drop the NULL checks > > > before freeing, as tdx_free_control_page() handles NULL internally. > > > > > > No functional change intended when Dynamic PAMT is not in use. > > > > > > Assisted-by: GitHub Copilot:claude-opus-4-6 Claude:claude-opus-4-7 > > > > Exactly what assistance was given, and when? I certainly didn't use any of these > > tools, and given that Claude Opus 4.6 was released after I posted the v5 RFC, I > > doubt Kirill did either. > > On this patch specifically, lots of "review this patch" type experiments IIRC. > Probably mostly around the log. > > > > > And in my strong opinion, even if AI tooling was used to rebase the patches, I > > don't think that level of "assistance" should be presented this way. E.g. I would > > rather a more informal: > > > > [ Rick: enhance log, rebase with help from AI tooling] > > > > Because unless I'm missing something, claiming that AI was used to write the patch > > is misleading and disingenuous. > > Yea, I was just trying to follow the policy. It seems things are swinging the > other way now. This works. FWIW, my read of the official policy, even before any change in direction, is that it only applies to using AI to write code. It's not like we given any credit in the patch itself when changes are made in response to code review from human.