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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id EE0FEC433FE for ; Fri, 29 Oct 2021 19:02:31 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 860A560F9B for ; Fri, 29 Oct 2021 19:02:31 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 860A560F9B Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=nongnu.org Received: from localhost ([::1]:54212 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1mgX94-0005gS-IW for qemu-devel@archiver.kernel.org; Fri, 29 Oct 2021 15:02:30 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:46788) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1mgWrX-00067L-EN for qemu-devel@nongnu.org; Fri, 29 Oct 2021 14:44:23 -0400 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:48552) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1mgWrV-000325-HW for qemu-devel@nongnu.org; Fri, 29 Oct 2021 14:44:23 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1635533061; 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=5ZojVu0fk8FjansgHvqLHFb4eAzNUMTeqdPgEQIsaxM=; b=KUXdHsmYefZCmRPt+hBkO09TlTFobnmPf8wcrzEKeHJakE+LtMNcDbPBJlvJ8yiDiRQrKW LzrmwY34fBHdnFY51x5TOyeuSlnF7qDYLZoluOAKB6GxH2EM3uE4a/rOVM/WJFlzeEibNo WPjCVYBzwhf0gBDVyz/A9RNGa/eGP58= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-589-d0qilp7iNnmGgGfMV0cP0w-1; Fri, 29 Oct 2021 14:44:17 -0400 X-MC-Unique: d0qilp7iNnmGgGfMV0cP0w-1 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.phx2.redhat.com [10.5.11.15]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 510A310A8E04; Fri, 29 Oct 2021 18:44:16 +0000 (UTC) Received: from eperezma.remote.csb (unknown [10.39.192.75]) by smtp.corp.redhat.com (Postfix) with ESMTP id 30EC65D6CF; Fri, 29 Oct 2021 18:44:12 +0000 (UTC) From: =?UTF-8?q?Eugenio=20P=C3=A9rez?= To: qemu-devel@nongnu.org Subject: [RFC PATCH v5 23/26] util: Add iova_tree_alloc Date: Fri, 29 Oct 2021 20:35:22 +0200 Message-Id: <20211029183525.1776416-24-eperezma@redhat.com> In-Reply-To: <20211029183525.1776416-1-eperezma@redhat.com> References: <20211029183525.1776416-1-eperezma@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.15 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=eperezma@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Received-SPF: pass client-ip=216.205.24.124; envelope-from=eperezma@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -27 X-Spam_score: -2.8 X-Spam_bar: -- X-Spam_report: (-2.8 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.001, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_LOW=-0.7, RCVD_IN_MSPIKE_H2=-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: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Laurent Vivier , Parav Pandit , "Michael S. Tsirkin" , Jason Wang , Juan Quintela , Richard Henderson , Stefan Hajnoczi , Peter Xu , Markus Armbruster , Harpreet Singh Anand , Xiao W Wang , Eli Cohen , Paolo Bonzini , Stefano Garzarella , Eric Blake , virtualization@lists.linux-foundation.org, Eduardo Habkost Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" 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. Signed-off-by: Eugenio Pérez --- include/qemu/iova-tree.h | 17 +++++ util/iova-tree.c | 139 +++++++++++++++++++++++++++++++++++++++ 2 files changed, 156 insertions(+) diff --git a/include/qemu/iova-tree.h b/include/qemu/iova-tree.h index 8249edd764..33f9b2e13f 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 */ typedef struct IOVATree IOVATree; typedef struct DMAMap { @@ -119,6 +120,22 @@ const DMAMap *iova_tree_find_address(const IOVATree *tree, hwaddr iova); */ void iova_tree_foreach(IOVATree *tree, iova_tree_iterator iterator); +/** + * iova_tree_alloc: + * + * @tree: the iova tree to allocate from + * @map: the new map (as translated addr & size) to allocate in iova region + * @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 be out of + * free contiguous range. Caller can get the assigned iova in map->iova. + */ +int iova_tree_alloc(IOVATree *tree, DMAMap *map, hwaddr iova_begin, + hwaddr iova_end); + /** * iova_tree_destroy: * diff --git a/util/iova-tree.c b/util/iova-tree.c index 23ea35b7a4..27c921c4e2 100644 --- a/util/iova-tree.c +++ b/util/iova-tree.c @@ -16,6 +16,36 @@ struct IOVATree { GTree *tree; }; +/* 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; + + /* The last addressable allowed in the allocation */ + hwaddr iova_last; + + /* Previously-to-last iterated map, can be NULL in the first node */ + const DMAMap *hole_left; + + /* Last iterated map */ + const DMAMap *hole_right; +}; + +/** + * Iterate args to tne 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->hole_left = args->hole_right; + args->hole_right = next; +} + static int iova_tree_compare(gconstpointer a, gconstpointer b, gpointer data) { const DMAMap *m1 = a, *m2 = b; @@ -107,6 +137,115 @@ int iova_tree_remove(IOVATree *tree, const DMAMap *map) return IOVA_OK; } +/** + * Try to accomodate a map of size ret->size in a hole between + * max(end(hole_left), iova_start). + * + * @args Arguments to allocation + */ +static bool iova_tree_alloc_map_in_hole(const struct IOVATreeAllocArgs *args) +{ + const DMAMap *left = args->hole_left, *right = args->hole_right; + uint64_t hole_start, hole_last; + + if (right && right->iova + right->size < args->iova_begin) { + return false; + } + + if (left && left->iova > args->iova_last) { + return false; + } + + hole_start = MAX(left ? left->iova + left->size + 1 : 0, args->iova_begin); + hole_last = MIN(right ? right->iova : HWADDR_MAX, args->iova_last); + + if (hole_last - hole_start > args->new_size) { + /* We found a valid hole. */ + return true; + } + + /* Keep iterating */ + return false; +} + +/** + * Foreach dma node in the tree, compare if there is a hole wit its previous + * 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 = pargs; + DMAMap *node = value; + + assert(key == value); + + iova_tree_alloc_args_iterate(args, node); + if (args->hole_left && args->hole_left->iova > args->iova_last) { + return true; + } + + if (iova_tree_alloc_map_in_hole(args)) { + return true; + } + + return false; +} + +int iova_tree_alloc(IOVATree *tree, DMAMap *map, hwaddr iova_begin, + hwaddr iova_last) +{ + struct IOVATreeAllocArgs args = { + .new_size = map->size, + .iova_begin = iova_begin, + .iova_last = iova_last, + }; + + if (iova_begin == 0) { + /* Some devices does not like addr 0 */ + iova_begin += qemu_real_host_page_size; + } + + assert(iova_begin < iova_last); + + /* + * 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: We can improve the search speed if we save the beginning and the + * end of holes, so we don't iterate over the previous saved ones. + * + * TODO: Replace all this with g_tree_node_first/next/last when available + * (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 (!iova_tree_alloc_map_in_hole(&args)) { + /* + * 2nd try: Last iteration left args->right as the last DMAMap. But + * (right, end) hole needs to be checked too + */ + iova_tree_alloc_args_iterate(&args, NULL); + if (!iova_tree_alloc_map_in_hole(&args)) { + return IOVA_ERR_NOMEM; + } + } + + map->iova = MAX(iova_begin, + args.hole_left ? + args.hole_left->iova + args.hole_left->size + 1 : 0); + return iova_tree_insert(tree, map); +} + void iova_tree_destroy(IOVATree *tree) { g_tree_destroy(tree->tree); -- 2.27.0