From nobody Wed Apr 16 03:26:11 2025 Delivered-To: importer@patchew.org Authentication-Results: mx.zohomail.com; dkim=fail; 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=fail(p=none dis=none) header.from=redhat.com Return-Path: Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) by mx.zohomail.com with SMTPS id 1646880610474757.6715579880954; Wed, 9 Mar 2022 18:50:10 -0800 (PST) Received: from localhost ([::1]:59826 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1nS8sT-0007LU-Bt for importer@patchew.org; Wed, 09 Mar 2022 21:50:09 -0500 Received: from eggs.gnu.org ([209.51.188.92]:38834) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1nS8jA-0005B9-QG for qemu-devel@nongnu.org; Wed, 09 Mar 2022 21:40:32 -0500 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]:31605) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1nS8j8-0004MT-Vy for qemu-devel@nongnu.org; Wed, 09 Mar 2022 21:40:32 -0500 Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-602-B5dTGpmuOqafnx4krG1bGA-1; Wed, 09 Mar 2022 21:40:29 -0500 Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.phx2.redhat.com [10.5.11.22]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 560EB1091DA2; Thu, 10 Mar 2022 02:40:28 +0000 (UTC) Received: from localhost.localdomain (ovpn-13-194.pek2.redhat.com [10.72.13.194]) by smtp.corp.redhat.com (Postfix) with ESMTP id 9E810100685F; Thu, 10 Mar 2022 02:39:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1646880030; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=h8EDag4l01bIm9ZS9LW9b0GpXk1jYfeOcsuT5c8x3+M=; b=A72zd1qitHXlJRBqh00yPY+mdsK/kGNqTGgymRonazN/odCq6o44PNOKJB8KHLEGHj0blA iOrfmHT0hEO6vNyYiaCpN56f4scSVXjDC9cvHsoPkEaVILNL0bPyJGYvHUQdN+omERdud9 uGh+DsVByGYiqaRm+F1kYrd0SSK8idI= X-MC-Unique: B5dTGpmuOqafnx4krG1bGA-1 From: Jason Wang To: qemu-devel@nongnu.org, peter.maydell@linaro.org Subject: [PULL V2 09/15] util: Add iova_tree_alloc_map Date: Thu, 10 Mar 2022 10:39:01 +0800 Message-Id: <20220310023907.2443-10-jasowang@redhat.com> In-Reply-To: <20220310023907.2443-1-jasowang@redhat.com> References: <20220310023907.2443-1-jasowang@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.84 on 10.5.11.22 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=jasowang@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable 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=170.10.133.124; envelope-from=jasowang@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -21 X-Spam_score: -2.2 X-Spam_bar: -- X-Spam_report: (-2.2 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.082, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H5=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, T_SCC_BODY_TEXT_LINE=-0.01 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: , Cc: =?UTF-8?q?Eugenio=20P=C3=A9rez?= , Jason Wang , Peter Xu , "Michael S . Tsirkin" Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" X-ZohoMail-DKIM: fail (Header signature does not verify) X-ZM-MESSAGEID: 1646880612133100001 From: Eugenio P=C3=A9rez This iova tree function allows it to look for a hole in allocated regions and return a totally new translation for a given translated address. It's usage is mainly to allow devices to access qemu address space, remapping guest's one into a new iova space where qemu can add chunks of addresses. Acked-by: Michael S. Tsirkin Signed-off-by: Eugenio P=C3=A9rez Reviewed-by: Peter Xu Signed-off-by: Jason Wang --- include/qemu/iova-tree.h | 18 +++++++ util/iova-tree.c | 135 +++++++++++++++++++++++++++++++++++++++++++= ++++ 2 files changed, 153 insertions(+) diff --git a/include/qemu/iova-tree.h b/include/qemu/iova-tree.h index 8249edd..d066400 100644 --- a/include/qemu/iova-tree.h +++ b/include/qemu/iova-tree.h @@ -29,6 +29,7 @@ #define IOVA_OK (0) #define IOVA_ERR_INVALID (-1) /* Invalid parameters */ #define IOVA_ERR_OVERLAP (-2) /* IOVA range overlapped */ +#define IOVA_ERR_NOMEM (-3) /* Cannot allocate */ =20 typedef struct IOVATree IOVATree; typedef struct DMAMap { @@ -120,6 +121,23 @@ const DMAMap *iova_tree_find_address(const IOVATree *t= ree, hwaddr iova); void iova_tree_foreach(IOVATree *tree, iova_tree_iterator iterator); =20 /** + * iova_tree_alloc_map: + * + * @tree: the iova tree to allocate from + * @map: the new map (as translated addr & size) to allocate in the iova r= egion + * @iova_begin: the minimum address of the allocation + * @iova_end: the maximum addressable direction of the allocation + * + * Allocates a new region of a given size, between iova_min and iova_max. + * + * Return: Same as iova_tree_insert, but cannot overlap and can return err= or if + * iova tree is out of free contiguous range. The caller gets the assigned= iova + * in map->iova. + */ +int iova_tree_alloc_map(IOVATree *tree, DMAMap *map, hwaddr iova_begin, + hwaddr iova_end); + +/** * iova_tree_destroy: * * @tree: the iova tree to destroy diff --git a/util/iova-tree.c b/util/iova-tree.c index 23ea35b..3160c50 100644 --- a/util/iova-tree.c +++ b/util/iova-tree.c @@ -16,6 +16,39 @@ struct IOVATree { GTree *tree; }; =20 +/* Args to pass to iova_tree_alloc foreach function. */ +struct IOVATreeAllocArgs { + /* Size of the desired allocation */ + size_t new_size; + + /* The minimum address allowed in the allocation */ + hwaddr iova_begin; + + /* Map at the left of the hole, can be NULL if "this" is first one */ + const DMAMap *prev; + + /* Map at the right of the hole, can be NULL if "prev" is the last one= */ + const DMAMap *this; + + /* If found, we fill in the IOVA here */ + hwaddr iova_result; + + /* Whether have we found a valid IOVA */ + bool iova_found; +}; + +/** + * Iterate args to the next hole + * + * @args: The alloc arguments + * @next: The next mapping in the tree. Can be NULL to signal the last one + */ +static void iova_tree_alloc_args_iterate(struct IOVATreeAllocArgs *args, + const DMAMap *next) { + args->prev =3D args->this; + args->this =3D next; +} + static int iova_tree_compare(gconstpointer a, gconstpointer b, gpointer da= ta) { const DMAMap *m1 =3D a, *m2 =3D b; @@ -107,6 +140,108 @@ int iova_tree_remove(IOVATree *tree, const DMAMap *ma= p) return IOVA_OK; } =20 +/** + * Try to find an unallocated IOVA range between prev and this elements. + * + * @args: Arguments to allocation + * + * Cases: + * + * (1) !prev, !this: No entries allocated, always succeed + * + * (2) !prev, this: We're iterating at the 1st element. + * + * (3) prev, !this: We're iterating at the last element. + * + * (4) prev, this: this is the most common case, we'll try to find a hole + * between "prev" and "this" mapping. + * + * Note that this function assumes the last valid iova is HWADDR_MAX, but = it + * searches linearly so it's easy to discard the result if it's not the ca= se. + */ +static void iova_tree_alloc_map_in_hole(struct IOVATreeAllocArgs *args) +{ + const DMAMap *prev =3D args->prev, *this =3D args->this; + uint64_t hole_start, hole_last; + + if (this && this->iova + this->size < args->iova_begin) { + return; + } + + hole_start =3D MAX(prev ? prev->iova + prev->size + 1 : 0, args->iova_= begin); + hole_last =3D this ? this->iova : HWADDR_MAX; + + if (hole_last - hole_start > args->new_size) { + args->iova_result =3D hole_start; + args->iova_found =3D true; + } +} + +/** + * Foreach dma node in the tree, compare if there is a hole with its previ= ous + * node (or minimum iova address allowed) and the node. + * + * @key: Node iterating + * @value: Node iterating + * @pargs: Struct to communicate with the outside world + * + * Return: false to keep iterating, true if needs break. + */ +static gboolean iova_tree_alloc_traverse(gpointer key, gpointer value, + gpointer pargs) +{ + struct IOVATreeAllocArgs *args =3D pargs; + DMAMap *node =3D value; + + assert(key =3D=3D value); + + iova_tree_alloc_args_iterate(args, node); + iova_tree_alloc_map_in_hole(args); + return args->iova_found; +} + +int iova_tree_alloc_map(IOVATree *tree, DMAMap *map, hwaddr iova_begin, + hwaddr iova_last) +{ + struct IOVATreeAllocArgs args =3D { + .new_size =3D map->size, + .iova_begin =3D iova_begin, + }; + + if (unlikely(iova_last < iova_begin)) { + return IOVA_ERR_INVALID; + } + + /* + * Find a valid hole for the mapping + * + * Assuming low iova_begin, so no need to do a binary search to + * locate the first node. + * + * TODO: Replace all this with g_tree_node_first/next/last when availa= ble + * (from glib since 2.68). To do it with g_tree_foreach complicates the + * code a lot. + * + */ + g_tree_foreach(tree->tree, iova_tree_alloc_traverse, &args); + if (!args.iova_found) { + /* + * Either tree is empty or the last hole is still not checked. + * g_tree_foreach does not compare (last, iova_last] range, so we = check + * it here. + */ + iova_tree_alloc_args_iterate(&args, NULL); + iova_tree_alloc_map_in_hole(&args); + } + + if (!args.iova_found || args.iova_result + map->size > iova_last) { + return IOVA_ERR_NOMEM; + } + + map->iova =3D args.iova_result; + return iova_tree_insert(tree, map); +} + void iova_tree_destroy(IOVATree *tree) { g_tree_destroy(tree->tree); --=20 2.7.4