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=-6.5 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 22E3EC35247 for ; Mon, 3 Feb 2020 18:34:12 +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 E836D2082E for ; Mon, 3 Feb 2020 18:34:11 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="YcUvN3tB" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org E836D2082E 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]:45796 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1iygXz-0001Q7-5L for qemu-devel@archiver.kernel.org; Mon, 03 Feb 2020 13:34:11 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:59625) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1iygWH-000848-2W for qemu-devel@nongnu.org; Mon, 03 Feb 2020 13:32:26 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1iygWD-0001jk-Mf for qemu-devel@nongnu.org; Mon, 03 Feb 2020 13:32:22 -0500 Received: from us-smtp-2.mimecast.com ([205.139.110.61]:24087 helo=us-smtp-delivery-1.mimecast.com) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1iygWD-0001fA-DQ for qemu-devel@nongnu.org; Mon, 03 Feb 2020 13:32:21 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1580754738; 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=iotoBDjapXBODfuOrmI0IiH4IjpUHAEYPrSI8vW5zX4=; b=YcUvN3tBQ6OaHRf1MyGXRlQsmoIlHpRXfv+RBVqDacdGAQtPYl+ItxAzfTLV/9sz4y63ef BMaD2W1piKgcrFNapbcfOaziSHevZfSbjB0btFOOhSnWXGuaW5y252IlG0PiUTjwdsiyz4 +jidr44e1KMLZznmaMINl0xqqKQNg3k= 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-64-dBTHPXKnNYetJeBZc9Skug-1; Mon, 03 Feb 2020 13:32:07 -0500 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id B8256800D4E; Mon, 3 Feb 2020 18:32:05 +0000 (UTC) Received: from t480s.redhat.com (ovpn-117-77.ams2.redhat.com [10.36.117.77]) by smtp.corp.redhat.com (Postfix) with ESMTP id D63345D9CA; Mon, 3 Feb 2020 18:32:02 +0000 (UTC) From: David Hildenbrand To: qemu-devel@nongnu.org Subject: [PATCH v1 07/13] util/mmap-alloc: Factor out populating of memory to mmap_populate() Date: Mon, 3 Feb 2020 19:31:19 +0100 Message-Id: <20200203183125.164879-8-david@redhat.com> In-Reply-To: <20200203183125.164879-1-david@redhat.com> References: <20200203183125.164879-1-david@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 X-MC-Unique: dBTHPXKnNYetJeBZc9Skug-1 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: quoted-printable X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 205.139.110.61 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: Eduardo Habkost , "Michael S . Tsirkin" , David Hildenbrand , "Dr . David Alan Gilbert" , Greg Kurz , Murilo Opsfelder Araujo , Paolo Bonzini , Richard Henderson Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" We want to populate memory within a reserved memory region. Let's factor that out. Cc: "Michael S. Tsirkin" Cc: Greg Kurz Cc: Murilo Opsfelder Araujo Cc: Eduardo Habkost Cc: "Dr. David Alan Gilbert" Signed-off-by: David Hildenbrand --- util/mmap-alloc.c | 89 +++++++++++++++++++++++++---------------------- 1 file changed, 47 insertions(+), 42 deletions(-) diff --git a/util/mmap-alloc.c b/util/mmap-alloc.c index 43a26f38a8..f043ccb0ab 100644 --- a/util/mmap-alloc.c +++ b/util/mmap-alloc.c @@ -114,6 +114,50 @@ static void *mmap_reserve(size_t size, int fd) return mmap(0, size, PROT_NONE, flags, fd, 0); } =20 +/* + * Populate memory in a reserved region from the given fd (if any). + */ +static void *mmap_populate(void *ptr, size_t size, int fd, bool shared, + bool is_pmem) +{ + int map_sync_flags =3D 0; + int flags =3D MAP_FIXED; + void *new_ptr; + + flags |=3D fd =3D=3D -1 ? MAP_ANONYMOUS : 0; + flags |=3D shared ? MAP_SHARED : MAP_PRIVATE; + if (shared && is_pmem) { + map_sync_flags =3D MAP_SYNC | MAP_SHARED_VALIDATE; + } + + new_ptr =3D mmap(ptr, size, PROT_READ | PROT_WRITE, flags | map_sync_f= lags, + fd, 0); + if (new_ptr =3D=3D MAP_FAILED && map_sync_flags) { + if (errno =3D=3D ENOTSUP) { + char *proc_link =3D g_strdup_printf("/proc/self/fd/%d", fd); + char *file_name =3D g_malloc0(PATH_MAX); + int len =3D readlink(proc_link, file_name, PATH_MAX - 1); + + if (len < 0) { + len =3D 0; + } + file_name[len] =3D '\0'; + fprintf(stderr, "Warning: requesting persistence across crashe= s " + "for backend file %s failed. Proceeding without " + "persistence, data might become corrupted in case of h= ost " + "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. + */ + new_ptr =3D mmap(ptr, size, PROT_READ | PROT_WRITE, flags, fd, 0); + } + return new_ptr; +} + static inline size_t mmap_pagesize(int fd) { #if defined(__powerpc64__) && defined(__linux__) @@ -131,12 +175,8 @@ void *qemu_ram_mmap(int fd, bool is_pmem) { const size_t pagesize =3D mmap_pagesize(fd); - int flags; - int map_sync_flags =3D 0; - size_t offset; - size_t total; - void *guardptr; - void *ptr; + size_t offset, total; + void *ptr, *guardptr; =20 /* * Note: this always allocates at least one extra page of virtual addr= ess @@ -153,44 +193,9 @@ void *qemu_ram_mmap(int fd, /* Always align to host page size */ assert(align >=3D pagesize); =20 - flags =3D MAP_FIXED; - flags |=3D fd =3D=3D -1 ? MAP_ANONYMOUS : 0; - flags |=3D shared ? MAP_SHARED : MAP_PRIVATE; - if (shared && is_pmem) { - map_sync_flags =3D MAP_SYNC | MAP_SHARED_VALIDATE; - } - offset =3D QEMU_ALIGN_UP((uintptr_t)guardptr, align) - (uintptr_t)guar= dptr; =20 - ptr =3D mmap(guardptr + offset, size, PROT_READ | PROT_WRITE, - flags | map_sync_flags, fd, 0); - - if (ptr =3D=3D MAP_FAILED && map_sync_flags) { - if (errno =3D=3D ENOTSUP) { - char *proc_link, *file_name; - int len; - proc_link =3D g_strdup_printf("/proc/self/fd/%d", fd); - file_name =3D g_malloc0(PATH_MAX); - len =3D readlink(proc_link, file_name, PATH_MAX - 1); - if (len < 0) { - len =3D 0; - } - file_name[len] =3D '\0'; - fprintf(stderr, "Warning: requesting persistence across crashe= s " - "for backend file %s failed. Proceeding without " - "persistence, data might become corrupted in case of h= ost " - "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 =3D mmap(guardptr + offset, size, PROT_READ | PROT_WRITE, - flags, fd, 0); - } - + ptr =3D mmap_populate(guardptr + offset, size, fd, shared, is_pmem); if (ptr =3D=3D MAP_FAILED) { munmap(guardptr, total); return MAP_FAILED; --=20 2.24.1