From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0F22AC433F5 for ; Wed, 10 Nov 2021 12:04:27 +0000 (UTC) Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id C71B0611ED for ; Wed, 10 Nov 2021 12:04:26 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org C71B0611ED Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.intel.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=lists.freedesktop.org Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id B37DC6E03D; Wed, 10 Nov 2021 12:04:20 +0000 (UTC) Received: from mga17.intel.com (mga17.intel.com [192.55.52.151]) by gabe.freedesktop.org (Postfix) with ESMTPS id 3FC246E02E; Wed, 10 Nov 2021 12:04:19 +0000 (UTC) X-IronPort-AV: E=McAfee;i="6200,9189,10163"; a="213383885" X-IronPort-AV: E=Sophos;i="5.87,223,1631602800"; d="scan'208";a="213383885" Received: from orsmga008.jf.intel.com ([10.7.209.65]) by fmsmga107.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 10 Nov 2021 04:04:18 -0800 X-IronPort-AV: E=Sophos;i="5.87,223,1631602800"; d="scan'208";a="503939072" Received: from blu2-mobl3.ccr.corp.intel.com (HELO [10.254.212.217]) ([10.254.212.217]) by orsmga008-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 10 Nov 2021 04:04:16 -0800 Message-ID: <7b2e1427-69cf-8f5d-0c15-73c4e602953d@linux.intel.com> Date: Wed, 10 Nov 2021 20:04:14 +0800 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:91.0) Gecko/20100101 Thunderbird/91.3.0 Content-Language: en-US To: Tvrtko Ursulin , Intel-gfx@lists.freedesktop.org References: <20211109121759.170915-1-tvrtko.ursulin@linux.intel.com> <6e8c55a7-45b6-57ab-35f7-d522401efccb@linux.intel.com> <4d1a0ab9-e0d8-2ed9-1fc4-9ffaf2f19bef@linux.intel.com> From: Lu Baolu In-Reply-To: <4d1a0ab9-e0d8-2ed9-1fc4-9ffaf2f19bef@linux.intel.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Subject: Re: [Intel-gfx] [PATCH] drm/i915: Use per device iommu check X-BeenThere: intel-gfx@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Intel graphics driver community testing & development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: dri-devel@lists.freedesktop.org, baolu.lu@linux.intel.com Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" On 2021/11/10 17:30, Tvrtko Ursulin wrote: > > On 10/11/2021 07:12, Lu Baolu wrote: >> Hi Tvrtko, >> >> On 2021/11/9 20:17, Tvrtko Ursulin wrote: >>> From: Tvrtko Ursulin >>> >>> On igfx + dgfx setups, it appears that intel_iommu=igfx_off option only >>> disables the igfx iommu. Stop relying on global intel_iommu_gfx_mapped >>> and probe presence of iommu domain per device to accurately reflect its >>> status. >>> >>> Signed-off-by: Tvrtko Ursulin >>> Cc: Lu Baolu >>> --- >>> Baolu, is my understanding here correct? Maybe I am confused by both >>> intel_iommu_gfx_mapped and dmar_map_gfx being globals in the intel_iommu >>> driver. But it certainly appears the setup can assign some iommu ops >>> (and >>> assign the discrete i915 to iommu group) when those two are set to off. >> >> diff --git a/drivers/gpu/drm/i915/i915_drv.h >> b/drivers/gpu/drm/i915/i915_drv.h >> index e967cd08f23e..9fb38a54f1fe 100644 >> --- a/drivers/gpu/drm/i915/i915_drv.h >> +++ b/drivers/gpu/drm/i915/i915_drv.h >> @@ -1763,26 +1763,27 @@ static inline bool run_as_guest(void) >>   #define HAS_D12_PLANE_MINIMIZATION(dev_priv) >> (IS_ROCKETLAKE(dev_priv) || \ >>                             IS_ALDERLAKE_S(dev_priv)) >> >> -static inline bool intel_vtd_active(void) >> +static inline bool intel_vtd_active(struct drm_i915_private *i915) >>   { >> -#ifdef CONFIG_INTEL_IOMMU >> -    if (intel_iommu_gfx_mapped) >> +    if (iommu_get_domain_for_dev(i915->drm.dev)) >>           return true; >> -#endif >> >>       /* Running as a guest, we assume the host is enforcing VT'd */ >>       return run_as_guest(); >>   } >> >> Have you verified this change? I am afraid that >> iommu_get_domain_for_dev() always gets a valid iommu domain even >> intel_iommu_gfx_mapped == 0. > > Yes it seems to work as is: > > default: > > # grep -i iommu /sys/kernel/debug/dri/*/i915_capabilities > /sys/kernel/debug/dri/0/i915_capabilities:iommu: enabled > /sys/kernel/debug/dri/1/i915_capabilities:iommu: enabled > > intel_iommu=igfx_off: > > # grep -i iommu /sys/kernel/debug/dri/*/i915_capabilities > /sys/kernel/debug/dri/0/i915_capabilities:iommu: disabled > /sys/kernel/debug/dri/1/i915_capabilities:iommu: enabled > > On my system dri device 0 is integrated graphics and 1 is discrete. The drm device 0 has a dedicated iommu. When the user request igfx not mapped, the VT-d implementation will turn it off to save power. But for shared iommu, you definitely will get it enabled. Best regards, baolu