From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from ms.lwn.net (ms.lwn.net [45.79.88.28]) (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 DED7036493C; Mon, 1 Jun 2026 18:58:07 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=45.79.88.28 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780340288; cv=none; b=bySbDER8kyCYB/v5cwTbZWTZYlIzxzBi4I+KIZg44Wv/AXLzZufQe/7HhuB/eDF9KkNvcxfJeZzE8SojXHbJMEShIhCnAVzNn/ICaLs2BQQoMSe+HLVGEL4RNj2VyXAW+vAelvmu8+kGqqo/oOPpeS63uXsIxrogbHpy0jihgYw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780340288; c=relaxed/simple; bh=++xLtCDf89nPJ/s5TrtIhgz0rWYhWvRTLVztIWEprUM=; h=From:To:Cc:Subject:In-Reply-To:References:Date:Message-ID: MIME-Version:Content-Type; b=HfFYz0ctVIBiE0NXVfXR7aBr1j4byo70zEYo9/RZbF2K2ZE9Pp7jB4sKOTg3ORK4neCzul2isXqJZnGgvj6inLD/ppGwcXSdwNMeVyM9442Mvo42c5i9gE9/jBPUjuadVPwbWJZwrRVyRVhwUSsIdS4hx7cz7/jTE4+dJgT0TBE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=lwn.net; spf=pass smtp.mailfrom=lwn.net; dkim=pass (2048-bit key) header.d=lwn.net header.i=@lwn.net header.b=X+UiVRB6; arc=none smtp.client-ip=45.79.88.28 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=lwn.net Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=lwn.net Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=lwn.net header.i=@lwn.net header.b="X+UiVRB6" DKIM-Filter: OpenDKIM Filter v2.11.0 ms.lwn.net 2A5A540E49 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=lwn.net; s=20201203; t=1780340287; bh=++xLtCDf89nPJ/s5TrtIhgz0rWYhWvRTLVztIWEprUM=; h=From:To:Cc:Subject:In-Reply-To:References:Date:From; b=X+UiVRB6tY+zXvmCd3R9imOzcLcIVpfzZ3NcUC34+5hOxMnzhD0fG3itlqoAFCbFR QzrAowMcASFO4opS2fG8RQgeUODPJQnZCd5jTvRew8XmUFHTtwKPzzi85OcI0xxBe5 ynlF3tQRVIEJFHZjEedHhfhYsUmJ4FvdzzKN+UaAKYCwMr2eQmkRTsbRlRCzNkFWRI nyooOGln6L1+wyAONHgXBVoyHDpmIRutG7tNcu62ostJ2AmwVe4RZ6SUaWgEZsbn34 vZOuR0Pz1bnrZiW5oJFggG0KHJ2a9dAw/5o/skVISC2N2/uh7Tfzk/mFnCnVNyww0D kSuDvYvzz/pGA== Received: from localhost (unknown [IPv6:2601:280:4600:27b:67c:16ff:fe81:5f9b]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange ECDHE (prime256v1) server-signature ECDSA (prime256v1) server-digest SHA256) (No client certificate requested) by ms.lwn.net (Postfix) with ESMTPSA id 2A5A540E49; Mon, 1 Jun 2026 18:58:07 +0000 (UTC) From: Jonathan Corbet To: Randy Dunlap , linux-kernel@vger.kernel.org Cc: Randy Dunlap , Shuah Khan , linux-doc@vger.kernel.org, Joerg Roedel , Will Deacon , Robin Murphy , iommu@lists.linux.dev, Borislav Petkov Subject: Re: [PATCH] iommu: Documentation: rearrange, update kernel-parameters In-Reply-To: <20260528054611.1524937-1-rdunlap@infradead.org> References: <20260528054611.1524937-1-rdunlap@infradead.org> Date: Mon, 01 Jun 2026 12:58:06 -0600 Message-ID: <8733z69jgh.fsf@trenco.lwn.net> Precedence: bulk X-Mailing-List: linux-doc@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain Randy Dunlap writes: > Add text for some undescribed iommu= parameters (merge, nomerge, > biomerge, panic, nopanic, pt, nopt). Add "usedac" and its description. > Add that iommu=pt is equivalent to iommu.passthrough=1 > and that iommu=nopt is equivalent to iommu.passthrough=0. > > Move the PPC/POWERNV heading & its option "nobypass" to a separate > area since the current "iommu=" applies only to X86 (according to > its heading). > > Unindent the AMD GART IOMMU options heading to make it stand out. > Also add its kconfig symbol name to be explicit about what these > options apply to. > > Make sure that the IOMMU options that are listed under AMD Gart > HW IOMMU-specific options are only for that product; i.e., add "force" > there and move "merge", "nomerge", and "panic" to the general IOMMU > options area. Applied, thanks. jon