From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pf1-f201.google.com (mail-pf1-f201.google.com [209.85.210.201]) (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 E2CC6381AF2 for ; Mon, 25 May 2026 18:44:00 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.210.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779734642; cv=none; b=oJY65qXl5T60Lo5tIp2J4kVPKs97A8MwgmsH1nqGhG+EHlbLzt8Aqny7uXuzQO/JoMV7ok90QukbA6eqRu5N4nwFMwHBrsSeKW/HcTd13Rl+3CzZcruf9VbamZzW1P2AWgJNxMwKi3KUHIE/9IY4CPPQXR45G2WU1OZbiwKlRtw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779734642; c=relaxed/simple; bh=TRq4A6KO1VvQ7IbUE+TwHmgzXSdtsRpTby/bdfBdlU0=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=Yfkf11TXdCk8j4s3HzpmFreW6EIFVo5jHh/VPHzfBqAvPWumFuUOYbgn8PokPpKBVhHT5Tr89vI6FZPwfswDUuMmYr5Nl6OlOJBbR3So8JgCtuu/xjqvSyNC96ve1+hU+ewcp9f3ZO6iTLXbx9Vy/nnTVwOdp/l0+arLja/juqg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=flex--praan.bounces.google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=Jsaprtku; arc=none smtp.client-ip=209.85.210.201 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--praan.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="Jsaprtku" Received: by mail-pf1-f201.google.com with SMTP id d2e1a72fcca58-82fa2165c3eso6171468b3a.0 for ; Mon, 25 May 2026 11:44:00 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20251104; t=1779734640; x=1780339440; darn=vger.kernel.org; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=hrjCHBiuBsjUFngiV4EYGqc8MUFFnHs0ozhKw+gXIDU=; b=JsaprtkugXxfgVQskp0i/hKRR0V9U/CvndKCTg6Mau/zx9ro731wLA1MHu8QPPjjBR U18ieYDLYLoKoXw0BOAWbGGu4Q8YqIYvDU4D0/HLYFq0oOUHarGd9jEjKIgzdh1dIyXv UrP5iY9vB9z9SMmGTeLP3DdbLKGXhEXlBdWMHREPoLch0+a/QW5UWoHWSLbDBaWzbj42 5OyQDeUDUN4EOr3UxE0BHCNLktpykqAEgmetdLHxfo06xsLz0XVRG4ym3HozPQWduUyH msu6ts/pA/WM34kihVNsSG0BTvqKbsIWorWQW3P7J2jEbQ+qKag4VcDqU/7PSLM6i0g6 xRWg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1779734640; x=1780339440; h=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; bh=hrjCHBiuBsjUFngiV4EYGqc8MUFFnHs0ozhKw+gXIDU=; b=ZCR9rLZqGm+waqBdCYG1Bgz5KMX58oB7uxTDK46fHG8hJ4w+/wa0aNbQcUSBcA5Sci 9xWswlU6h6yvqi8/PD5x39ME1LE6dwBo9dC2cpfBaPRNjtFBifhGXiHD+VwbLHoYS8nE SbLKBPeTIW9y3ojgF2iFMG2FFqXyNBU7oTBpPB3LlIaDVz5p+5RbEHm0zvzpxfRE5BFr 3S6l6AZExw7b6zuG4KvqdjccjEjZH3HSpWSc2hQACVky3trTf/PXARgohMJU5Y5AHkea ZxZGqp4vFhSoVLz2xHWyILaavsCKFz4AzKoqxqIfAx6MjTAcxCwAwMk2cfFyzH9/fnaU unYA== X-Forwarded-Encrypted: i=1; AFNElJ/mgMkZ/sMWZhP6t25KkEodkGbvu8vJTkI1Ma+xWFBl0DwrFtXOio0FMTEwBVpjLNNPDUDQvi7cw49lwjA=@vger.kernel.org X-Gm-Message-State: AOJu0YzFsU+1BjWJoxPP4r5a0YtDqq9SakX95gyMIEF38CLvASKFa6gd 8meg4YuVjBp46S17sOu9EnfyhS3xKPHwDKGkisMG273W3BK1AEYH/ezXepgSNJTyHHiqiss5C6G XSw== X-Received: from pfbb5.prod.google.com ([2002:a05:6a00:ac85:b0:835:3df8:d72]) (user=praan job=prod-delivery.src-stubby-dispatcher) by 2002:a05:6a00:421a:b0:838:af72:fb44 with SMTP id d2e1a72fcca58-8415f0f16ddmr15589020b3a.2.1779734640045; Mon, 25 May 2026 11:44:00 -0700 (PDT) Date: Mon, 25 May 2026 18:43:46 +0000 In-Reply-To: <20260525184347.4059549-1-praan@google.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20260525184347.4059549-1-praan@google.com> X-Mailer: git-send-email 2.54.0.746.g67dd491aae-goog Message-ID: <20260525184347.4059549-5-praan@google.com> Subject: [PATCH v4 4/5] iommu/vt-d: Fail probe on ATS configuration failure From: Pranjal Shrivastava To: iommu@lists.linux.dev, linux-pci@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Cc: Joerg Roedel , Will Deacon , Bjorn Helgaas , David Woodhouse , Lu Baolu , Robin Murphy , Suravee Suthikulpanit , Jason Gunthorpe , Nicolin Chen , David Matlack , Samiullah Khawaja , Daniel Mentz , Pasha Tatashin , Mostafa Saleh , Pranjal Shrivastava Content-Type: text/plain; charset="UTF-8" Update the Intel VT-d driver to handle ATS configuration and enablement more strictly. Specifically, update the device probe to fail if pci_prepare_ats() returns an error. This ensures that any ATS-capable master reaching the attach phase is guaranteed to have a valid config. Additionally, update iommu_enable_pci_ats() to WARN() if pci_enable_ats fails. Since earlier checks in the probe phase preclude config-related failures, any failure during hardware enablement is considered a kernel bug. Signed-off-by: Pranjal Shrivastava --- drivers/iommu/intel/iommu.c | 15 ++++++++++++--- 1 file changed, 12 insertions(+), 3 deletions(-) diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c index 4d0e65bc131d..22308e4911e1 100644 --- a/drivers/iommu/intel/iommu.c +++ b/drivers/iommu/intel/iommu.c @@ -873,8 +873,14 @@ static void iommu_enable_pci_ats(struct device_domain_info *info) if (!pci_ats_page_aligned(pdev)) return; - if (!pci_enable_ats(pdev, VTD_PAGE_SHIFT)) - info->ats_enabled = 1; + /* + * pci_enable_ats() should not fail here because earlier checks + * have already verified support and configuration. + */ + if (WARN_ON(pci_enable_ats(pdev, VTD_PAGE_SHIFT))) + return; + + info->ats_enabled = 1; } static void iommu_disable_pci_ats(struct device_domain_info *info) @@ -3288,7 +3294,10 @@ static struct iommu_device *intel_iommu_probe_device(struct device *dev) dev_iommu_priv_set(dev, info); if (pdev && pci_ats_supported(pdev)) { - pci_prepare_ats(pdev, VTD_PAGE_SHIFT); + ret = pci_prepare_ats(pdev, VTD_PAGE_SHIFT); + if (ret) + goto free; + ret = device_rbtree_insert(iommu, info); if (ret) goto free; -- 2.54.0.746.g67dd491aae-goog