From nobody Mon Apr 7 03:59:34 2025 Delivered-To: importer@patchew.org Authentication-Results: mx.zohomail.com; spf=pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; dmarc=pass(p=none dis=none) header.from=nongnu.org ARC-Seal: i=1; a=rsa-sha256; t=1741702549; cv=none; d=zohomail.com; s=zohoarc; b=PLNkn55TkSr0mERcfGm0m/xxRYIxxy836nXFMvve3Ts6s7B9+BjBZvFtMrGKGlJfgXpao9xh+pULC1MKRcZ+bg5zsP/xoYOOLzvtuwDBS/LMi39V8Z612IWc427kdClGvxM0jAfA6D0/vML2bLPHMLOU94AN2WA4TMwfUVABW1U= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=zohomail.com; s=zohoarc; t=1741702549; h=Content-Type:Cc:Cc:Date:Date:From:From:In-Reply-To:List-Subscribe:List-Post:List-Id:List-Archive:List-Help:List-Unsubscribe:MIME-Version:Message-ID:Reply-To:Reply-To:References:Sender:Subject:Subject:To:To:Message-Id; bh=G5z5zixkeY9kaY2v/YD+76iMvMlnGLuYBMP/HFXOIvY=; b=QXY+MMHu2yvaiHgheXjhr4CfEEqzXyeyGPlAx5/ewfVaaypawwBUSILqLSQfOjvMYuEZnvpwc8Z6g5hD8RVD/9Y+1UwrfBRHNNxdbMp/n+w/lWRCnLOrl90/AKU/84cacG75UE1yMu7o6AYRwpzpNGwLFjdZfCLRjpSNqtv/XBk= ARC-Authentication-Results: i=1; mx.zohomail.com; spf=pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; dmarc=pass header.from= (p=none dis=none) Return-Path: Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) by mx.zohomail.com with SMTPS id 174170254973297.79062714520308; Tue, 11 Mar 2025 07:15:49 -0700 (PDT) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1ts0OB-0002oV-S6; Tue, 11 Mar 2025 10:15:23 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1ts0Nc-0002RN-Ho; Tue, 11 Mar 2025 10:14:49 -0400 Received: from frasgout.his.huawei.com ([185.176.79.56]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1ts0NZ-0007Gi-5T; Tue, 11 Mar 2025 10:14:48 -0400 Received: from mail.maildlp.com (unknown [172.18.186.216]) by frasgout.his.huawei.com (SkyGuard) with ESMTP id 4ZBwfw4b6sz6D9b5; Tue, 11 Mar 2025 22:11:36 +0800 (CST) Received: from frapeml500008.china.huawei.com (unknown [7.182.85.71]) by mail.maildlp.com (Postfix) with ESMTPS id 7D2B71404F5; Tue, 11 Mar 2025 22:14:43 +0800 (CST) Received: from A2303104131.china.huawei.com (10.203.177.241) by frapeml500008.china.huawei.com (7.182.85.71) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.1.2507.39; Tue, 11 Mar 2025 15:14:36 +0100 To: , CC: , , , , , , , , , , , , , Subject: [RFC PATCH v2 18/20] hw/arm/smmu-common: Bypass emulated IOTLB for a accel SMMUv3 Date: Tue, 11 Mar 2025 14:10:43 +0000 Message-ID: <20250311141045.66620-19-shameerali.kolothum.thodi@huawei.com> X-Mailer: git-send-email 2.12.0.windows.1 In-Reply-To: <20250311141045.66620-1-shameerali.kolothum.thodi@huawei.com> References: <20250311141045.66620-1-shameerali.kolothum.thodi@huawei.com> MIME-Version: 1.0 X-Originating-IP: [10.203.177.241] X-ClientProxiedBy: dggems705-chm.china.huawei.com (10.3.19.182) To frapeml500008.china.huawei.com (7.182.85.71) Received-SPF: pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) client-ip=209.51.188.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Received-SPF: pass client-ip=185.176.79.56; envelope-from=shameerali.kolothum.thodi@huawei.com; helo=frasgout.his.huawei.com X-Spam_score_int: -41 X-Spam_score: -4.2 X-Spam_bar: ---- X-Spam_report: (-4.2 / 5.0 requ) BAYES_00=-1.9, RCVD_IN_DNSWL_MED=-2.3, RCVD_IN_MSPIKE_H2=0.001, RCVD_IN_VALIDITY_CERTIFIED_BLOCKED=0.001, RCVD_IN_VALIDITY_RPBL_BLOCKED=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Reply-to: Shameer Kolothum From: Shameer Kolothum via Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: qemu-devel-bounces+importer=patchew.org@nongnu.org X-ZM-MESSAGEID: 1741702558697019000 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" From: Nicolin Chen If a vSMMU is configured as a accelerated one, HW IOTLB will be used and all cache invalidation should be done to the HW IOTLB too, v.s. the emulated iotlb. In this case, an iommu notifier isn't registered, as the devices behind a SMMUv3-accel would stay in the system address space for stage-2 mappings. However, the KVM code still requests an iommu address space to translate an MSI doorbell gIOVA via get_msi_address_space() and translate(). Since a SMMUv3-accel doesn't register an iommu notifier to flush emulated iotlb, bypass the emulated IOTLB and always walk through the guest-level IO page table. Signed-off-by: Nicolin Chen Signed-off-by: Shameer Kolothum --- hw/arm/smmu-common.c | 21 +++++++++++++++++++++ 1 file changed, 21 insertions(+) diff --git a/hw/arm/smmu-common.c b/hw/arm/smmu-common.c index 9fd455baa0..fd10df8866 100644 --- a/hw/arm/smmu-common.c +++ b/hw/arm/smmu-common.c @@ -77,6 +77,17 @@ static SMMUTLBEntry *smmu_iotlb_lookup_all_levels(SMMUSt= ate *bs, uint8_t level =3D 4 - (inputsize - 4) / stride; SMMUTLBEntry *entry =3D NULL; =20 + /* + * Stage-1 translation with a accel SMMU in general uses HW IOTLB. How= ever, + * KVM still requests for an iommu address space for an MSI fixup by l= ooking + * up stage-1 page table. Make sure we don't go through the emulated p= athway + * so that the emulated iotlb will not need any invalidation. + */ + + if (bs->accel) { + return NULL; + } + while (level <=3D 3) { uint64_t subpage_size =3D 1ULL << level_shift(level, tt->granule_s= z); uint64_t mask =3D subpage_size - 1; @@ -142,6 +153,16 @@ void smmu_iotlb_insert(SMMUState *bs, SMMUTransCfg *cf= g, SMMUTLBEntry *new) SMMUIOTLBKey *key =3D g_new0(SMMUIOTLBKey, 1); uint8_t tg =3D (new->granule - 10) / 2; =20 + /* + * Stage-1 translation with a accel SMMU in general uses HW IOTLB. How= ever, + * KVM still requests for an iommu address space for an MSI fixup by l= ooking + * up stage-1 page table. Make sure we don't go through the emulated p= athway + * so that the emulated iotlb will not need any invalidation. + */ + if (bs->accel) { + return; + } + if (g_hash_table_size(bs->iotlb) >=3D SMMU_IOTLB_MAX_SIZE) { smmu_iotlb_inv_all(bs); } --=20 2.34.1