From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id EEE2443637D; Wed, 27 May 2026 15:33:23 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779896004; cv=none; b=LVsPBKMIDlEuht3kcgmQ/Tx56GgFUiobP7OQDJh0kKw6aMiPcVoEQ9XHdMic1s81qkDUgDsA5m2hNJubu85ZC9o5JieiJ1x6m4EnAVu7to1ucaIsK/zxILd/4Mrh5aoT1cPtMB6Ql44wBEWrjUtTQSPoAoVSyUBuJrHyJmyQllU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779896004; c=relaxed/simple; bh=bLcxXHk+CcALqz/zzbA0F0Yybtdc+uNVe0wHT/tY7BQ=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=N1a/hydnCoKRyLnAl1BHz9CUIfCRCIgnd8ghQUFF6uPb2B0zGATp5CFXW4DUH6IkCGtljG+rPugxK0n4iYwXht52lOtlC4BhwGsS2Ym6OxIKVnbkbreUy1FdzlAIpWLk1B3DrFfmnqr5Tu0cC4H90OVT7wM1/QTJhjKum+Qvzv0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=ZugAWKNo; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="ZugAWKNo" Received: by smtp.kernel.org (Postfix) with ESMTPS id C532EC2BCFB; Wed, 27 May 2026 15:33:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1779896002; bh=bLcxXHk+CcALqz/zzbA0F0Yybtdc+uNVe0wHT/tY7BQ=; h=From:Date:Subject:References:In-Reply-To:To:Cc:Reply-To:From; b=ZugAWKNou/3hhdk3/0CuslHwBG12FxSCoiQDLoZeTluxV075OF9MTYMvYc/B3dwQE pYt4TldcdTo+0VF7VMlW8lw9NewWgyAdIWMbeWvIm80t/noX6uKVj8+YHOClMxaDVo SI9Lkr34NYgh7xriAcRUxu/oNZDa6C/QUyWV/aizcmrWJh0YRhl3JQXDarb/ZgIFxK lN8OjLatlFAtuSoxeVfB037tOrc4k+2l4CHZHZ13eO0wl6Db/kaaZEXq3ztR0j5H8K zTFb9qQNeo1OydUTwLbFBUwUiAR2+ZYGsaBbOMbsyntsioUdV3Ua50kmUrprl1JrM7 +H6gFaV3R5SOg== Received: from aws-us-west-2-korg-lkml-1.web.codeaurora.org (localhost.localdomain [127.0.0.1]) by smtp.lore.kernel.org (Postfix) with ESMTP id BCF9BCD4F54; Wed, 27 May 2026 15:33:22 +0000 (UTC) From: Ackerley Tng via B4 Relay Date: Wed, 27 May 2026 08:33:18 -0700 Subject: [PATCH RFC 06/12] Documentation: KVM: Have actual headings for exceptions Precedence: bulk X-Mailing-List: linux-doc@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Message-Id: <20260527-kvm-locking-docs-v1-6-4fe8b602ff47@google.com> References: <20260527-kvm-locking-docs-v1-0-4fe8b602ff47@google.com> In-Reply-To: <20260527-kvm-locking-docs-v1-0-4fe8b602ff47@google.com> To: Paolo Bonzini , Jonathan Corbet , Shuah Khan , Tianrui Zhao , Bibo Mao , Huacai Chen , WANG Xuerui , Sean Christopherson , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , Fuad Tabba , vannapurve@google.com, x86@kernel.org, "H. Peter Anvin" Cc: kvm@vger.kernel.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, loongarch@lists.linux.dev, Ackerley Tng X-Mailer: b4 0.14.3 X-Developer-Signature: v=1; a=ed25519-sha256; t=1779896001; l=1576; i=ackerleytng@google.com; s=20260225; h=from:subject:message-id; bh=omLCISL/Cs1+39lE29MDupCtm4WwTzGw7vDPKSySNYo=; b=hprWgud3QVI1IKRiPLGBIYGbG2occ7We7PsN9/HJiCR/0rZEaqlqEP39d5vxdyx0Gpkil7MJV OZNw5t9xeHOAhY9qTRJPjQQyqfcQdggNLhA0ARfSxEm8DrBNtkxx0PE X-Developer-Key: i=ackerleytng@google.com; a=ed25519; pk=sAZDYXdm6Iz8FHitpHeFlCMXwabodTm7p8/3/8xUxuU= X-Endpoint-Received: by B4 Relay for ackerleytng@google.com/20260225 with auth_id=649 X-Original-From: Ackerley Tng Reply-To: ackerleytng@google.com From: Ackerley Tng Exceptions documented are described but without headings, making it hard to identify where each exception description ended. Use actual headings at a lower level than that of the heading used for Exception to improve readability. Signed-off-by: Ackerley Tng --- Documentation/virt/kvm/locking.rst | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/Documentation/virt/kvm/locking.rst b/Documentation/virt/kvm/locking.rst index 5161636cec481..fc4537a7659a9 100644 --- a/Documentation/virt/kvm/locking.rst +++ b/Documentation/virt/kvm/locking.rst @@ -65,7 +65,8 @@ The general rule in KVM is that any modification to shadow page tables (and their entries (SPTEs)) must be protected by ``kvm->mmu_lock``, with the exceptions described below. -Fast page fault: +2.1. Fast page fault +^^^^^^^^^^^^^^^^^^^^ Fast page fault is the fast path which fixes the guest page fault out of the mmu-lock on x86. Currently, the page fault can be fast in one of the @@ -217,7 +218,8 @@ Since the spte is "volatile" if it can be updated out of mmu-lock, we always atomically update the spte and the race caused by fast page fault can be avoided. See the comments in spte_needs_atomic_update() and mmu_spte_update(). -Lockless Access Tracking: +2.2 Lockless Access Tracking +^^^^^^^^^^^^^^^^^^^^^^^^^^^^ This is used for Intel CPUs that are using EPT but do not support the EPT A/D bits. In this case, PTEs are tagged as A/D disabled (using ignored bits), and -- 2.54.0.823.g6e5bcc1fc9-goog