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 X-Spam-Level: X-Spam-Status: No, score=-13.6 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 21272C433ED for ; Wed, 28 Apr 2021 13:42:43 +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 6654E61155 for ; Wed, 28 Apr 2021 13:42:42 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 6654E61155 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:53726 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1lbkSf-0002td-9U for qemu-devel@archiver.kernel.org; Wed, 28 Apr 2021 09:42:41 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:57990) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lbkQm-0001Tq-A1 for qemu-devel@nongnu.org; Wed, 28 Apr 2021 09:40:44 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]:23150) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lbkQk-0006wF-9V for qemu-devel@nongnu.org; Wed, 28 Apr 2021 09:40:44 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1619617241; 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=1AuyFLgbrhSLl+Xc/bn3QakF+zY/5tyHpGNlgisVbh8=; b=hmnnNVWqn8aPnUYdymNe0mWGV62IH3TQvDxI7RO2+AD06XqWW7RGB0zlWZNrsTLwd1JjFr 0dxkkO23Ut4sEvVLqswEqoL2AZS1r+waTdBPqTSARjDcLtF5m+fLjj/gEm0U09ZARx85gW tYeE0+vlAabL6/7RYNZZDliG7+c1oeo= 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-176-8MTIZQ8RNSO9MKn5RYAsPQ-1; Wed, 28 Apr 2021 09:40:37 -0400 X-MC-Unique: 8MTIZQ8RNSO9MKn5RYAsPQ-1 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id A0E2E9F92D; Wed, 28 Apr 2021 13:40:36 +0000 (UTC) Received: from t480s.redhat.com (ovpn-114-36.ams2.redhat.com [10.36.114.36]) by smtp.corp.redhat.com (Postfix) with ESMTP id B4BD560CC9; Wed, 28 Apr 2021 13:40:16 +0000 (UTC) From: David Hildenbrand To: qemu-devel@nongnu.org Subject: [PATCH v7 03/15] util/mmap-alloc: Factor out activating of memory to mmap_activate() Date: Wed, 28 Apr 2021 15:37:42 +0200 Message-Id: <20210428133754.10713-4-david@redhat.com> In-Reply-To: <20210428133754.10713-1-david@redhat.com> References: <20210428133754.10713-1-david@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=david@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset="US-ASCII" Received-SPF: pass client-ip=170.10.133.124; envelope-from=david@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -29 X-Spam_score: -3.0 X-Spam_bar: --- X-Spam_report: (-3.0 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.22, 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_H4=0.001, RCVD_IN_MSPIKE_WL=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: Marcel Apfelbaum , Murilo Opsfelder Araujo , Eduardo Habkost , "Michael S. Tsirkin" , David Hildenbrand , Richard Henderson , "Dr. David Alan Gilbert" , Peter Xu , Greg Kurz , Stefan Hajnoczi , Igor Mammedov , Paolo Bonzini , Nitesh Lal , =?UTF-8?q?Philippe=20Mathieu-Daud=C3=A9?= Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" We want to activate memory within a reserved memory region, to make it accessible. Let's factor that out. Reviewed-by: Richard Henderson Acked-by: Murilo Opsfelder Araujo Reviewed-by: Peter Xu Acked-by: Eduardo Habkost for memory backend and machine core Signed-off-by: David Hildenbrand --- util/mmap-alloc.c | 94 +++++++++++++++++++++++++---------------------- 1 file changed, 50 insertions(+), 44 deletions(-) diff --git a/util/mmap-alloc.c b/util/mmap-alloc.c index 223d66219c..0e2bd7bc0e 100644 --- a/util/mmap-alloc.c +++ b/util/mmap-alloc.c @@ -114,6 +114,52 @@ static void *mmap_reserve(size_t size, int fd) return mmap(0, size, PROT_NONE, flags, fd, 0); } +/* + * Activate memory in a reserved region from the given fd (if any), to make + * it accessible. + */ +static void *mmap_activate(void *ptr, size_t size, int fd, bool readonly, + bool shared, bool is_pmem, off_t map_offset) +{ + const int prot = PROT_READ | (readonly ? 0 : PROT_WRITE); + int map_sync_flags = 0; + int flags = MAP_FIXED; + void *activated_ptr; + + flags |= fd == -1 ? MAP_ANONYMOUS : 0; + flags |= shared ? MAP_SHARED : MAP_PRIVATE; + if (shared && is_pmem) { + map_sync_flags = MAP_SYNC | MAP_SHARED_VALIDATE; + } + + activated_ptr = mmap(ptr, size, prot, flags | map_sync_flags, fd, + map_offset); + if (activated_ptr == MAP_FAILED && map_sync_flags) { + if (errno == ENOTSUP) { + char *proc_link = g_strdup_printf("/proc/self/fd/%d", fd); + char *file_name = g_malloc0(PATH_MAX); + int len = readlink(proc_link, file_name, PATH_MAX - 1); + + if (len < 0) { + len = 0; + } + file_name[len] = '\0'; + fprintf(stderr, "Warning: requesting persistence across crashes " + "for backend file %s failed. Proceeding without " + "persistence, data might become corrupted in case of host " + "crash.\n", file_name); + g_free(proc_link); + g_free(file_name); + } + /* + * If mmap failed with MAP_SHARED_VALIDATE | MAP_SYNC, we will try + * again without these flags to handle backwards compatibility. + */ + activated_ptr = mmap(ptr, size, prot, flags, fd, map_offset); + } + return activated_ptr; +} + static inline size_t mmap_guard_pagesize(int fd) { #if defined(__powerpc64__) && defined(__linux__) @@ -133,13 +179,8 @@ void *qemu_ram_mmap(int fd, off_t map_offset) { const size_t guard_pagesize = mmap_guard_pagesize(fd); - int prot; - int flags; - int map_sync_flags = 0; - size_t offset; - size_t total; - void *guardptr; - void *ptr; + size_t offset, total; + void *ptr, *guardptr; /* * Note: this always allocates at least one extra page of virtual address @@ -156,45 +197,10 @@ void *qemu_ram_mmap(int fd, /* Always align to host page size */ assert(align >= guard_pagesize); - flags = MAP_FIXED; - flags |= fd == -1 ? MAP_ANONYMOUS : 0; - flags |= shared ? MAP_SHARED : MAP_PRIVATE; - if (shared && is_pmem) { - map_sync_flags = MAP_SYNC | MAP_SHARED_VALIDATE; - } - offset = QEMU_ALIGN_UP((uintptr_t)guardptr, align) - (uintptr_t)guardptr; - prot = PROT_READ | (readonly ? 0 : PROT_WRITE); - - ptr = mmap(guardptr + offset, size, prot, - flags | map_sync_flags, fd, map_offset); - - if (ptr == MAP_FAILED && map_sync_flags) { - if (errno == ENOTSUP) { - char *proc_link, *file_name; - int len; - proc_link = g_strdup_printf("/proc/self/fd/%d", fd); - file_name = g_malloc0(PATH_MAX); - len = readlink(proc_link, file_name, PATH_MAX - 1); - if (len < 0) { - len = 0; - } - file_name[len] = '\0'; - fprintf(stderr, "Warning: requesting persistence across crashes " - "for backend file %s failed. Proceeding without " - "persistence, data might become corrupted in case of host " - "crash.\n", file_name); - g_free(proc_link); - g_free(file_name); - } - /* - * if map failed with MAP_SHARED_VALIDATE | MAP_SYNC, - * we will remove these flags to handle compatibility. - */ - ptr = mmap(guardptr + offset, size, prot, flags, fd, map_offset); - } - + ptr = mmap_activate(guardptr + offset, size, fd, readonly, shared, is_pmem, + map_offset); if (ptr == MAP_FAILED) { munmap(guardptr, total); return MAP_FAILED; -- 2.30.2