From nobody Thu Apr 2 10:57:43 2026 Received: from outbound.baidu.com (jpmx.baidu.com [119.63.196.201]) by smtp.subspace.kernel.org (Postfix) with SMTP id 9DB3A26ED35; Mon, 30 Mar 2026 03:09:13 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=119.63.196.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774840162; cv=none; b=I4zNIAP3DUB34vx1t6VNE2CbVLuWxAzdGwcVLlsPPJlpb6cstgklR7hWpDC9LnAmoRCxo6V+w8saNHZRs+Q5K8M+yNczaShLxm74uL3gu5GXBnEZ22uZ+S0YG1xObHKzcXHaakCWUHTp54d0HkQ3vv4wa/TNOz5d9+k6RppseyI= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774840162; c=relaxed/simple; bh=4LvOygNpK8r2wOycZQH+/HOfjcETQ2mAGUh+7YUmwpA=; h=From:To:Subject:Date:Message-ID:References:In-Reply-To: Content-Type:MIME-Version; b=FGvmPv447xpLkAYdwSUFx5wYmnZYHZpPb9CB+M3hIXAahdtH0Wjb2S8WZxRCEmsnKQWSQkSvQHCe+INm24CHwXSpoNDhd3mzoKV0jaF5Xgs+ZwCLWhcxlwRtN0JnS2yTlwLbutXH4QybWTqpvfI9jZ7i8pZ+L4TyLQt9o9eDPSI= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=baidu.com; spf=pass smtp.mailfrom=baidu.com; dkim=pass (2048-bit key) header.d=baidu.com header.i=@baidu.com header.b=QYOA/yCF; arc=none smtp.client-ip=119.63.196.201 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=baidu.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=baidu.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=baidu.com header.i=@baidu.com header.b="QYOA/yCF" X-MD-Sfrom: lirongqing@baidu.com X-MD-SrcIP: 172.31.50.45 From: "Li,Rongqing(ACG CCN)" To: Randy Dunlap , Jonathan Corbet , Shuah Khan , Andrew Morton , Borislav Petkov , Peter Zijlstra , Feng Tang , Pawan Gupta , Dapeng Mi , Kees Cook , Marco Elver , "Paul E . McKenney" , Askar Safin , "Bjorn Helgaas" , Sohil Mehta , "linux-doc@vger.kernel.org" , "linux-kernel@vger.kernel.org" Subject: =?utf-8?B?562U5aSNOiBb5aSW6YOo6YKu5Lu2XSBSZTogW1BBVENIXSBkb2NzOiBrZXJu?= =?utf-8?B?ZWwtcGFyYW1ldGVyczogZml4IGFyY2hpdGVjdHVyZSBhbGlnbm1lbnQgZm9y?= =?utf-8?Q?_pt,_nopt,_and_nobypass?= Thread-Topic: =?utf-8?B?W+WklumDqOmCruS7tl0gUmU6IFtQQVRDSF0gZG9jczoga2VybmVsLXBhcmFt?= =?utf-8?B?ZXRlcnM6IGZpeCBhcmNoaXRlY3R1cmUgYWxpZ25tZW50IGZvciBwdCwgbm9w?= =?utf-8?Q?t,_and_nobypass?= Thread-Index: AQHcvPTDWTTbIwKqpUejx9Xe/DuiO7XAdU2AgAX0LIA= Date: Mon, 30 Mar 2026 03:08:58 +0000 Message-ID: <16386e7715284b22b5f72e7106ed5619@baidu.com> References: <20260326074658.1899-1-lirongqing@baidu.com> In-Reply-To: Accept-Language: zh-CN, en-US Content-Language: zh-CN X-MS-Has-Attach: X-MS-TNEF-Correlator: Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=baidu.com; s=selector1; t=1774840145; bh=4LvOygNpK8r2wOycZQH+/HOfjcETQ2mAGUh+7YUmwpA=; h=From:To:Subject:Date:Message-ID:Content-Type; b=QYOA/yCFZb+yGBTWH0UjEwkau/Qb1jkN+EYiOUcydEUn6d1GMDYi6ylOnERL2qGQ0 tERkzaGYkP9A5UqGXJfxS9K8GHrYJTqbAFG+ByDqP0+V0az1qs2TKSQWvCh+RSaRX/ 9TSHxwNtzT/atkObF9v8Hg1R0mmgmt1EkfMgcy/l5RwP0iJiRijp9WL7Ldp2yr5w57 RNc1uvS8Io+8tvqKOoxJesq6BLdnmDnPi8POcbMw/TNJr9qGsIaUsfPw3vQ//+gWWz +zDDUOTlS6rLLbF56BvP6J/67tLEjlyevF1+KZyuKYXqch48jiu2YQPR2/C3JiFvDr myF2Kfz+Q7cQw== > -----=E9=82=AE=E4=BB=B6=E5=8E=9F=E4=BB=B6----- > =E5=8F=91=E4=BB=B6=E4=BA=BA: Randy Dunlap > =E5=8F=91=E9=80=81=E6=97=B6=E9=97=B4: 2026=E5=B9=B43=E6=9C=8827=E6=97=A5 = 0:08 > =E6=94=B6=E4=BB=B6=E4=BA=BA: Li,Rongqing(ACG CCN) ;= Jonathan Corbet > ; Shuah Khan ; Andrew Morton > ; Borislav Petkov ; Peter Zijlst= ra > ; Feng Tang ; Pawan > Gupta ; Dapeng Mi > ; Kees Cook ; Marco Elver > ; Paul E . McKenney ; Askar Safin > ; Bjorn Helgaas ; Sohil Mehta > ; linux-doc@vger.kernel.org; > linux-kernel@vger.kernel.org > =E4=B8=BB=E9=A2=98: [=E5=A4=96=E9=83=A8=E9=82=AE=E4=BB=B6] Re: [PATCH] do= cs: kernel-parameters: fix architecture > alignment for pt, nopt, and nobypass >=20 > Hi, >=20 > On 3/26/26 12:46 AM, lirongqing wrote: > > From: Li RongQing > > > > Commit ab0e7f20768a ("Documentation: Merge x86-specific boot options > > doc into kernel-parameters.txt") introduced a formatting regression > > where architecture tags were placed on separate lines with broken > indentation. > > This caused the 'nopt' [X86] parameter to appear as if it belonged to > > the [PPC/POWERNV] section. > > > > Fix the formatting by placing the architecture tags on the same line > > as their respective parameters ('pt', 'nopt', and 'nobypass') and > > restoring proper indentation. > > > > Fixes: ab0e7f20768a ("Documentation: Merge x86-specific boot options > > doc into kernel-parameters.txt") > > Signed-off-by: Li RongQing > > --- > > Documentation/admin-guide/kernel-parameters.txt | 9 +++------ > > 1 file changed, 3 insertions(+), 6 deletions(-) > > > > diff --git a/Documentation/admin-guide/kernel-parameters.txt > > b/Documentation/admin-guide/kernel-parameters.txt > > index 03a5506..dc1c5bd 100644 > > --- a/Documentation/admin-guide/kernel-parameters.txt > > +++ b/Documentation/admin-guide/kernel-parameters.txt > > @@ -2615,12 +2615,9 @@ Kernel parameters > > Intel machines). This can be used to prevent the usage > > of an available hardware IOMMU. > > > > - [X86] > > - pt > > - [X86] > > - nopt > > - [PPC/POWERNV] > > - nobypass > > + pt [X86] > > + nopt [X86] > > + nobypass [PPC/POWERNV] > > Disable IOMMU bypass, using IOMMU for PCI devices. > > > > [X86] >=20 > This looks good as far as it goes, but there are still some problems IMO. >=20 > These are all iommu=3D options, but iommu says that it's for [X86,EARLY]. > No PPC/POWERNV mentioned there. I think [PPC/POWERNV] should not be added to the main iommu=3D header. Sinc= e that header is already tagged as [X86, EARLY], adding PowerPC there would= imply all subsequent options are cross-platform. Instead, it is cleaner to= keep the main header as X86-specific and explicitly tag the individual nob= ypass option for [PPC/POWERNV]. This avoids the need to redundantly label e= very other X86-only option (like pt or nopt) within the section. >=20 > Then immediately following nobypass, there is this: > [X86] > AMD Gart HW IOMMU-specific options: >=20 > which is also in questionable format. The [X86] isn't needed at all IMO, = or if it's > desirable, those 2 lines should be on one line. >=20 You are right , [X86] isn't needed , How about to remove the [X86], like be= low=20 Documentation/kernel-parameters: fix architecture alignment for pt, nop= t, and nobypass Commit ab0e7f20768a ("Documentation: Merge x86-specific boot options doc into kernel-parameters.txt") introduced a formatting regression where architecture tags were placed on separate lines with broken indentation. This caused the 'nopt' [X86] parameter to appear as if it belonged to the [PPC/POWERNV] section. Furthermore, since the main 'iommu=3D' parameter heading already specif= ies it is for [X86, EARLY], the subsequent standalone [X86] tags for 'pt', 'nopt', and the AMD GART options are redundant and clutter the documentation. Clean up the formatting by removing these redundant tags and properly attributing the 'nobypass' option to [PPC/POWERNV]. Fixes: ab0e7f20768a ("Documentation: Merge x86-specific boot options do= c into kernel-parameters.txt") Signed-off-by: Li RongQing diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentatio= n/admin-guide/kernel-parameters.txt index 03a5506..5253c23 100644 Acked-by: Randy Dunlap --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -2615,15 +2615,11 @@ Kernel parameters Intel machines). This can be used to prevent the us= age of an available hardware IOMMU. - [X86] pt - [X86] nopt - [PPC/POWERNV] - nobypass + nobypass [PPC/POWERNV] Disable IOMMU bypass, using IOMMU for PCI devices. - [X86] AMD Gart HW IOMMU-specific options: [Li,Rongqing]=20 > Anyway, for this patch: > Acked-by: Randy Dunlap >=20 > Thanks. >=20 > -- > ~Randy