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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id F1C3EC3DA4A for ; Fri, 9 Aug 2024 15:07:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Transfer-Encoding: Content-Type:In-Reply-To:From:References:Cc:To:Subject:MIME-Version:Date: Message-ID:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=PUuE/GwyZfkoR3+e/tg25U8w+OAqV3TWSOUS8yorwRo=; b=h9StDhx7idE6rvvNHUYRMi1L1L wkBTpJULwBRXOYHfB2XvEKKJ7/xsBIZ2o/i+DXgyrbgK1pt1k56aTmqocVNtu8pQoP7+gmpTsAltc 4rb1HV32hBlVdO59gUwkh/pk2wGdavhYTwSggT7tbJj2Gx1tLl+04roSbc+vMJoIz2w0b8VDgeFCe xCVCaF7X+/56MAsIYEXy4liQEMiG+RHrVx3Zw6BxtWfRu1uRGu6kHgPMQ2/WcKFEwUjx1UY1nkI/6 3dMU5UyAV7ad3IsaJdq1YtCCS8/BoILxn2SBVdGQAgacliWdB7h96PZmsxExPNGbymcP9zuUbndT1 hCbuxClw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.97.1 #2 (Red Hat Linux)) id 1scRCu-0000000BeBE-3l1V; Fri, 09 Aug 2024 15:07:08 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.97.1 #2 (Red Hat Linux)) id 1scRCK-0000000Be89-2OyJ for linux-arm-kernel@lists.infradead.org; Fri, 09 Aug 2024 15:06:34 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id A36B013D5; Fri, 9 Aug 2024 08:06:53 -0700 (PDT) Received: from [10.57.46.232] (unknown [10.57.46.232]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id BAB073F71E; Fri, 9 Aug 2024 08:06:23 -0700 (PDT) Message-ID: Date: Fri, 9 Aug 2024 16:06:22 +0100 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH 6/8] iommu/arm-smmu-v3: Implement IOMMU_HWPT_ALLOC_NEST_PARENT To: Jason Gunthorpe , acpica-devel@lists.linux.dev, Alex Williamson , Hanjun Guo , iommu@lists.linux.dev, Joerg Roedel , Kevin Tian , kvm@vger.kernel.org, Len Brown , linux-acpi@vger.kernel.org, linux-arm-kernel@lists.infradead.org, Lorenzo Pieralisi , "Rafael J. Wysocki" , Robert Moore , Sudeep Holla , Will Deacon Cc: Eric Auger , Jean-Philippe Brucker , Moritz Fischer , Michael Shavit , Nicolin Chen , patches@lists.linux.dev, Shameerali Kolothum Thodi References: <6-v1-54e734311a7f+14f72-smmuv3_nesting_jgg@nvidia.com> From: Robin Murphy Content-Language: en-GB In-Reply-To: <6-v1-54e734311a7f+14f72-smmuv3_nesting_jgg@nvidia.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20240809_080632_689197_ADDA945D X-CRM114-Status: GOOD ( 16.84 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On 2024-08-07 12:41 am, Jason Gunthorpe wrote: > For SMMUv3 the parent must be a S2 domain, which can be composed > into a IOMMU_DOMAIN_NESTED. > > In future the S2 parent will also need a VMID linked to the VIOMMU and > even to KVM. > > Signed-off-by: Jason Gunthorpe > --- > drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c | 11 ++++++++++- > 1 file changed, 10 insertions(+), 1 deletion(-) > > diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c > index 6bbe4aa7b9511c..5faaccef707ef1 100644 > --- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c > +++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c > @@ -3103,7 +3103,8 @@ arm_smmu_domain_alloc_user(struct device *dev, u32 flags, > const struct iommu_user_data *user_data) > { > struct arm_smmu_master *master = dev_iommu_priv_get(dev); > - const u32 PAGING_FLAGS = IOMMU_HWPT_ALLOC_DIRTY_TRACKING; > + const u32 PAGING_FLAGS = IOMMU_HWPT_ALLOC_DIRTY_TRACKING | > + IOMMU_HWPT_ALLOC_NEST_PARENT; > struct arm_smmu_domain *smmu_domain; > int ret; > > @@ -3116,6 +3117,14 @@ arm_smmu_domain_alloc_user(struct device *dev, u32 flags, > if (!smmu_domain) > return ERR_PTR(-ENOMEM); > > + if (flags & IOMMU_HWPT_ALLOC_NEST_PARENT) { > + if (!(master->smmu->features & ARM_SMMU_FEAT_TRANS_S2)) { Nope, nesting needs to rely on FEAT_NESTING, that's why it exists. S2 alone isn't sufficient - without S1 there's nothing to expose to userspace, so zero point in having a "nested" domain with nothing to nest into it - but furthermore we need S2 *without* unsafe broken TLBs. Thanks, Robin. > + ret = -EOPNOTSUPP; > + goto err_free; > + } > + smmu_domain->stage = ARM_SMMU_DOMAIN_S2; > + } > + > smmu_domain->domain.type = IOMMU_DOMAIN_UNMANAGED; > smmu_domain->domain.ops = arm_smmu_ops.default_domain_ops; > ret = arm_smmu_domain_finalise(smmu_domain, master->smmu, flags);