From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 284494F5E0; Wed, 20 May 2026 17:59:52 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779299993; cv=none; b=ShhX+jEnHSVjI2emx5i6E0oBbXUHs5wYeG6tGkNCLGLzLSBQ2irrp4Fjx1Um3hpDtCiz4WJ1ajmy4qdLPu5JTKP84Y7nG/mqKkrOr0vXeDv7WS8VJ7Jx1dSyPWBzdlpMp1CXmU5MOngYMhUG/mKDLkU39fKfB2s8MEM6/wc0V20= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779299993; c=relaxed/simple; bh=39iA4Cx/6UzsSSKiLgur6AgH/3hpHfljb4ldfLlRJdk=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=ZrSONmQRg4/lky+R57vL3jQs0jtdxHrv9RNY611q3ZdDo1JG57BArujwq2aPP/T2RiWPGou3IKnrT0+I0yga+1Ufk168GcV5W+2IuGhMxsTT6CVH5NW0upRwTI+ookkCdBj3h/QEkkVRUVFBsPiaD2LyMQ99nEUIL0WkFAswczA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=PYmeyzQl; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="PYmeyzQl" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 8EA4B1F000E9; Wed, 20 May 2026 17:59:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1779299992; bh=Mi9a/8wwx9a3t2iCVxjQnWXcg1IptZPb8EZORVZdGUk=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=PYmeyzQlBNsXpjF3cJXo9xHBzBhWwuxfaceJ8MxmjVeML5ni/mSXKd0mhtnVl4rJo Gpmrr5Aknb0wdPnfH0/Tf0VJ0DzMo/4+zrnI7v5yeJIIYsswjYUdZiEMunT9dj2q4B 9yQ8ORS6QTe0VVV1JN8pPinWUcd3PZK6zNKPrwr4= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, =?UTF-8?q?Naval=20Alcal=C3=A1?= , Lu Baolu , Joerg Roedel Subject: [PATCH 6.18 937/957] iommu/vt-d: Disable DMAR for Intel Q35 IGFX Date: Wed, 20 May 2026 18:23:40 +0200 Message-ID: <20260520162154.917894442@linuxfoundation.org> X-Mailer: git-send-email 2.54.0 In-Reply-To: <20260520162134.554764788@linuxfoundation.org> References: <20260520162134.554764788@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 6.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Naval Alcalá commit 2cda2e10dc8343ae01eae9e999a876b7e7d37861 upstream. Intel Q35 integrated graphics (8086:29b2) exhibits broken DMAR behaviour similar to other G4x/GM45 devices for which DMAR is already disabled via quirks. When DMAR is enabled, the system may hard lock up during boot or early device initialization, requiring a reset. Add the missing PCI ID to the existing quirk list to disable DMAR for this device. Fixes: 1f76249cc3be ("iommu/vt-d: Declare Broadwell igfx dmar support snafu") Cc: stable@vger.kernel.org Closes: https://bugzilla.kernel.org/show_bug.cgi?id=201185 Closes: https://bugzilla.kernel.org/show_bug.cgi?id=216064 Signed-off-by: Naval Alcalá Link: https://lore.kernel.org/r/20260410161622.13549-1-ari@naval.cat Signed-off-by: Lu Baolu Signed-off-by: Joerg Roedel Signed-off-by: Greg Kroah-Hartman --- drivers/iommu/intel/iommu.c | 3 +++ 1 file changed, 3 insertions(+) --- a/drivers/iommu/intel/iommu.c +++ b/drivers/iommu/intel/iommu.c @@ -4517,6 +4517,9 @@ static void quirk_iommu_igfx(struct pci_ disable_igfx_iommu = 1; } +/* Q35 integrated gfx dmar support is totally busted. */ +DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x29b2, quirk_iommu_igfx); + /* G4x/GM45 integrated gfx dmar support is totally busted. */ DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x2a40, quirk_iommu_igfx); DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x2e00, quirk_iommu_igfx);