From nobody Wed Oct 29 09:06:53 2025 Delivered-To: importer@patchew.org Received-SPF: pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) client-ip=208.118.235.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Authentication-Results: mx.zohomail.com; spf=pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; dmarc=fail(p=none dis=none) header.from=redhat.com Return-Path: Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) by mx.zohomail.com with SMTPS id 1526628792233720.7672777078633; Fri, 18 May 2018 00:33:12 -0700 (PDT) Received: from localhost ([::1]:37087 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fJZsx-0004Jt-Cu for importer@patchew.org; Fri, 18 May 2018 03:33:07 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:43620) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fJZli-0006xp-Is for qemu-devel@nongnu.org; Fri, 18 May 2018 03:25:42 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1fJZlh-0005hx-Am for qemu-devel@nongnu.org; Fri, 18 May 2018 03:25:38 -0400 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:59670 helo=mx1.redhat.com) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1fJZlh-0005hk-56; Fri, 18 May 2018 03:25:37 -0400 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.rdu2.redhat.com [10.11.54.4]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id B94084023112; Fri, 18 May 2018 07:25:36 +0000 (UTC) Received: from xz-mi.nay.redhat.com (dhcp-14-151.nay.redhat.com [10.66.14.151]) by smtp.corp.redhat.com (Postfix) with ESMTP id ACA622024CBC; Fri, 18 May 2018 07:25:33 +0000 (UTC) From: Peter Xu To: qemu-devel@nongnu.org Date: Fri, 18 May 2018 15:25:12 +0800 Message-Id: <20180518072517.20901-5-peterx@redhat.com> In-Reply-To: <20180518072517.20901-1-peterx@redhat.com> References: <20180518072517.20901-1-peterx@redhat.com> X-Scanned-By: MIMEDefang 2.78 on 10.11.54.4 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.6]); Fri, 18 May 2018 07:25:36 +0000 (UTC) X-Greylist: inspected by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.6]); Fri, 18 May 2018 07:25:36 +0000 (UTC) for IP:'10.11.54.4' DOMAIN:'int-mx04.intmail.prod.int.rdu2.redhat.com' HELO:'smtp.corp.redhat.com' FROM:'peterx@redhat.com' RCPT:'' X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 66.187.233.73 Subject: [Qemu-devel] [PATCH v4 4/9] intel-iommu: only do page walk for MAP notifiers X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Tian Kevin , "Michael S . Tsirkin" , Jason Wang , QEMU Stable , peterx@redhat.com, Alex Williamson , Jintack Lim Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" X-ZohoMail: RSF_0 Z_629925259 SPT_0 Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" For UNMAP-only IOMMU notifiers, we don't need to walk the page tables. Fasten that procedure by skipping the page table walk. That should boost performance for UNMAP-only notifiers like vhost. CC: QEMU Stable Signed-off-by: Peter Xu --- include/hw/i386/intel_iommu.h | 2 ++ hw/i386/intel_iommu.c | 44 +++++++++++++++++++++++++++++++---- 2 files changed, 41 insertions(+), 5 deletions(-) diff --git a/include/hw/i386/intel_iommu.h b/include/hw/i386/intel_iommu.h index 016e74bedb..156f35e919 100644 --- a/include/hw/i386/intel_iommu.h +++ b/include/hw/i386/intel_iommu.h @@ -93,6 +93,8 @@ struct VTDAddressSpace { IntelIOMMUState *iommu_state; VTDContextCacheEntry context_cache_entry; QLIST_ENTRY(VTDAddressSpace) next; + /* Superset of notifier flags that this address space has */ + IOMMUNotifierFlag notifier_flags; }; =20 struct VTDBus { diff --git a/hw/i386/intel_iommu.c b/hw/i386/intel_iommu.c index 8d4069de9f..38ccc741f9 100644 --- a/hw/i386/intel_iommu.c +++ b/hw/i386/intel_iommu.c @@ -138,6 +138,12 @@ static inline void vtd_iommu_unlock(IntelIOMMUState *s) qemu_mutex_unlock(&s->iommu_lock); } =20 +/* Whether the address space needs to notify new mappings */ +static inline gboolean vtd_as_has_map_notifier(VTDAddressSpace *as) +{ + return as->notifier_flags & IOMMU_NOTIFIER_MAP; +} + /* GHashTable functions */ static gboolean vtd_uint64_equal(gconstpointer v1, gconstpointer v2) { @@ -1436,14 +1442,36 @@ static void vtd_iotlb_page_invalidate_notify(IntelI= OMMUState *s, VTDAddressSpace *vtd_as; VTDContextEntry ce; int ret; + hwaddr size =3D (1 << am) * VTD_PAGE_SIZE; =20 QLIST_FOREACH(vtd_as, &(s->vtd_as_with_notifiers), next) { ret =3D vtd_dev_to_context_entry(s, pci_bus_num(vtd_as->bus), vtd_as->devfn, &ce); if (!ret && domain_id =3D=3D VTD_CONTEXT_ENTRY_DID(ce.hi)) { - vtd_page_walk(&ce, addr, addr + (1 << am) * VTD_PAGE_SIZE, - vtd_page_invalidate_notify_hook, - (void *)&vtd_as->iommu, true, s->aw_bits); + if (vtd_as_has_map_notifier(vtd_as)) { + /* + * As long as we have MAP notifications registered in + * any of our IOMMU notifiers, we need to sync the + * shadow page table. + */ + vtd_page_walk(&ce, addr, addr + size, + vtd_page_invalidate_notify_hook, + (void *)&vtd_as->iommu, true, s->aw_bits); + } else { + /* + * For UNMAP-only notifiers, we don't need to walk the + * page tables. We just deliver the PSI down to + * invalidate caches. + */ + IOMMUTLBEntry entry =3D { + .target_as =3D &address_space_memory, + .iova =3D addr, + .translated_addr =3D 0, + .addr_mask =3D size - 1, + .perm =3D IOMMU_NONE, + }; + memory_region_notify_iommu(&vtd_as->iommu, entry); + } } } } @@ -2383,6 +2411,9 @@ static void vtd_iommu_notify_flag_changed(IOMMUMemory= Region *iommu, exit(1); } =20 + /* Update per-address-space notifier flags */ + vtd_as->notifier_flags =3D new; + if (old =3D=3D IOMMU_NOTIFIER_NONE) { QLIST_INSERT_HEAD(&s->vtd_as_with_notifiers, vtd_as, next); } else if (new =3D=3D IOMMU_NOTIFIER_NONE) { @@ -2891,8 +2922,11 @@ static void vtd_iommu_replay(IOMMUMemoryRegion *iomm= u_mr, IOMMUNotifier *n) PCI_FUNC(vtd_as->devfn), VTD_CONTEXT_ENTRY_DID(ce.hi), ce.hi, ce.lo); - vtd_page_walk(&ce, 0, ~0ULL, vtd_replay_hook, (void *)n, false, - s->aw_bits); + if (vtd_as_has_map_notifier(vtd_as)) { + /* This is required only for MAP typed notifiers */ + vtd_page_walk(&ce, 0, ~0ULL, vtd_replay_hook, (void *)n, false, + s->aw_bits); + } } else { trace_vtd_replay_ce_invalid(bus_n, PCI_SLOT(vtd_as->devfn), PCI_FUNC(vtd_as->devfn)); --=20 2.17.0