From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mgamail.intel.com (mgamail.intel.com [192.198.163.19]) (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 D0D2F26AD0 for ; Thu, 31 Oct 2024 03:43:05 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=192.198.163.19 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1730346189; cv=none; b=VyyMGnip8QAQTQpEpwEaJDGyApc7NItg6uGTZA1d4plIDbYR8dHF2RXqfHDOmAweM1btBWS3Vyn/IhEoiZiSOoSV96Xl1rt7V90akSQhybXwtoiQ9HBOpHq6fOeZLiaRI3ImS+83qJRAOA3+P5Q6Fin9FFqX/5tUJ+hpGPpa0zs= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1730346189; c=relaxed/simple; bh=9NF32TNj4ZYmr4oveqUOvSWtxMqVol++8yROTpzjYA4=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=cAMnCo+plYRgi2wM+uAR69Z3SD6EXE8mIy+MQpTkpNGsKf3Wn8e98bVTrnmKsDFBcT+xw6L0nTfMdDxFH/ezUjpM5TARfvwPixTsSRp028co/d8sNdfC76ZtDgT2a/UdzWoZtQpq4hrJys5iExS7XDxX+SKTrWp09fkPLik0b74= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.intel.com; spf=none smtp.mailfrom=linux.intel.com; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b=WS3UNF9W; arc=none smtp.client-ip=192.198.163.19 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.intel.com Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=linux.intel.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="WS3UNF9W" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1730346186; x=1761882186; h=message-id:date:mime-version:subject:to:cc:references: from:in-reply-to:content-transfer-encoding; bh=9NF32TNj4ZYmr4oveqUOvSWtxMqVol++8yROTpzjYA4=; b=WS3UNF9WzCQbN7NWdK9WzIx4Jw9d14Hj7HkGTlCed0N6DcONSHE/3Lc2 d3v3kwNu3wt2WKlVuAAsW8S4mj657HygyCHROIX6TJOFI3dWtz6jma5r7 VfzY3THG8B5GjO3xHacJFet0lbeM5CC8Bkc06+AMPC3ISd4HlQ+lx9wYO ClVFbCIv+eAkGgMzaD8hRbmMasJw6XflQvpY8682RXmW/akQeb2v2f+3A sw9xSqH8fKbqq29LoOk0vV/NPQ0M3CihSwRl7UBgsSTenlKvrSZrXeula CYS4Ylvr3OGuZmBo+GYTkvGFQShc4J7lTREdSPvVsnYqbTnSdJm8P7QP3 Q==; X-CSE-ConnectionGUID: 2ny14P+gSxiysRndAfHb+w== X-CSE-MsgGUID: l+JJdeX0STm9tp2hNntjIg== X-IronPort-AV: E=McAfee;i="6700,10204,11241"; a="29514045" X-IronPort-AV: E=Sophos;i="6.11,246,1725346800"; d="scan'208";a="29514045" Received: from fmviesa007.fm.intel.com ([10.60.135.147]) by fmvoesa113.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 30 Oct 2024 20:43:05 -0700 X-CSE-ConnectionGUID: daw9IZ7ITHaqHf9TrL7mbw== X-CSE-MsgGUID: g9mamfELTcG7K2r/u1X2/w== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.11,246,1725346800"; d="scan'208";a="82159153" Received: from allen-sbox.sh.intel.com (HELO [10.239.159.30]) ([10.239.159.30]) by fmviesa007-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 30 Oct 2024 20:43:03 -0700 Message-ID: Date: Thu, 31 Oct 2024 11:42:24 +0800 Precedence: bulk X-Mailing-List: iommu@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v4 2/5] iommu/vt-d: Remove the pasid present check in prq_event_thread To: Joel Granados Cc: Yi Liu , David Woodhouse , Joerg Roedel , Will Deacon , Robin Murphy , Jason Gunthorpe , Kevin Tian , Klaus Jensen , linux-kernel@vger.kernel.org, iommu@lists.linux.dev, Klaus Jensen References: <20241015-jag-iopfv8-v4-0-b696ca89ba29@kernel.org> <20241015-jag-iopfv8-v4-2-b696ca89ba29@kernel.org> <90c772ce-6d2d-4a1d-bfec-5a7813be43e4@intel.com> Content-Language: en-US From: Baolu Lu In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 10/30/24 22:28, Joel Granados wrote: >> /* >> diff --git a/drivers/iommu/intel/svm.c b/drivers/iommu/intel/svm.c >> index 078d1e32a24e..ff88f31053d1 100644 >> --- a/drivers/iommu/intel/svm.c >> +++ b/drivers/iommu/intel/svm.c >> @@ -304,9 +304,6 @@ void intel_drain_pasid_prq(struct device *dev, u32 >> pasid) >> int qdep; >> >> info = dev_iommu_priv_get(dev); >> - if (WARN_ON(!info || !dev_is_pci(dev))) >> - return; > Did you mean to take out both checks?: > 1. The info pointer check > 2. the dev_is_pci check > > I can understand the dev_is_pci check, but we should definitely take > action if info is NULL. Right? WARN_ON(!info) is duplicate as far as I can see. Accessing info->pri_enable when info is NULL will cause a null pointer dereference warning. This appears irrelevant to this patch though. > >> - >> if (!info->pri_enabled) >> return; >> >> Generally, intel_drain_pasid_prq() should be called if >> >> - a translation is removed from a pasid entry; and > This is the path that is already mentiond > >> - PRI on this device is enabled. > And this path is: > -> intel_iommu_enable_iopf > -> context_flip_pri > -> intel_context_flush_present > -> qi_flush_pasid_cache > > Right? Sorry that I didn't make it clear. It should be "PRI on this device was enabled", a.k.a. info->pri_enabled is true. I didn't meant to say in the PRI enabling path. -- baolu