From nobody Tue Feb 10 18:38:14 2026 Delivered-To: importer2@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+importer2=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 1623765573587434.46617579971746; Tue, 15 Jun 2021 06:59:33 -0700 (PDT) Received: from localhost ([::1]:43066 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1lt9bI-0006ce-1c for importer2@patchew.org; Tue, 15 Jun 2021 09:59:32 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:59452) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lt9Hj-00061f-UQ for qemu-devel@nongnu.org; Tue, 15 Jun 2021 09:39:20 -0400 Received: from mail-ed1-x530.google.com ([2a00:1450:4864:20::530]:36545) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1lt9Hi-0002nX-3q for qemu-devel@nongnu.org; Tue, 15 Jun 2021 09:39:19 -0400 Received: by mail-ed1-x530.google.com with SMTP id w21so51111463edv.3 for ; Tue, 15 Jun 2021 06:39:17 -0700 (PDT) Received: from avogadro.lan ([2001:b07:6468:f312:c8dd:75d4:99ab:290a]) by smtp.gmail.com with ESMTPSA id r17sm11843769edt.33.2021.06.15.06.39.16 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 15 Jun 2021 06:39:16 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=sender:from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=EUJcgMbiy+TJhdc0JIxQcF5/rLoJrViqR3WCrNaqHgA=; b=nv3Lk7Tti3H2EvstXvD8N5bmVk4YQk801eJQHHH4YLr74Remx+b0i8I8xcL5ixQWG6 gjOGn0nwwdHlyoYVQnJJq21Ni2UaRnzBy6ok4n2MQ7KxKQMFGFZcAgtlUhygB+Hi4thY 4UuJshzWNvqThZhqQf978RWy96ABsP8NCmlriwbxq/BcOMdrvcl/RQQOCW46OoMOv/79 5NetO6QFOBGrsl2ei3nGH1j3bWgxqfHvc9cZ5iWGPEwyZD36eP5+9bemRnIuBTngJbs1 xlOXbq59gNEFFxOYhfFL6GzC/95liVzV2E9WznY9OWmiosV40upB5iVaWnT+5KHjIAWG IQKQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:sender:from:to:cc:subject:date:message-id :in-reply-to:references:mime-version:content-transfer-encoding; bh=EUJcgMbiy+TJhdc0JIxQcF5/rLoJrViqR3WCrNaqHgA=; b=UJkG2pLhieW9kjK4t9eNRiAgIU3zxoCCAtb+Cd7gVKe+Wa1WjjxPXpoE9TweerehBO N4aSj5Bz2iVytCERHepChy/3dR1jA0NrsG5jc2MINB5vIJS7ze8jsU/5rOF0+6OiHfJ+ me/s6+CRnCtqrMyl8nxwZ4xxdseGcFtG689ZN5Beg4W8K0a8Owj3xw0OzresR4JiYaGz XmjNJ0FD8mrVQ0yw97e04y4023iKGu9VEBJSPcxdx6XX85UsneRUoOwRzGpEFDpwyccv 5zK/vPO8imnh5evFJnou4iiJJLF9UwWgLroytivHs/8FIOR31Ab0/VQX2X4nZa5kWyFq IdxQ== X-Gm-Message-State: AOAM532H43ELco36LjmXxMab5TIormaJVtCf0xUf+V396UhiKOZqYz0V mKqVqE0ZAgG9aZ3R0IrGfX/K+eKp2KY= X-Google-Smtp-Source: ABdhPJyCoXxKzGXYb9CG8NlkpusC9dM1rv0DCesdVvkwzIJ93I5Yq/7h91GCfsM8qbVuFPyuIvGZJA== X-Received: by 2002:aa7:cd9a:: with SMTP id x26mr23261241edv.185.1623764356819; Tue, 15 Jun 2021 06:39:16 -0700 (PDT) From: Paolo Bonzini To: qemu-devel@nongnu.org Subject: [PULL 20/33] util/mmap-alloc: Factor out activating of memory to mmap_activate() Date: Tue, 15 Jun 2021 15:38:42 +0200 Message-Id: <20210615133855.775687-21-pbonzini@redhat.com> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20210615133855.775687-1-pbonzini@redhat.com> References: <20210615133855.775687-1-pbonzini@redhat.com> MIME-Version: 1.0 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+importer2=patchew.org@nongnu.org; helo=lists.gnu.org; Received-SPF: pass client-ip=2a00:1450:4864:20::530; envelope-from=paolo.bonzini@gmail.com; helo=mail-ed1-x530.google.com X-Spam_score_int: -14 X-Spam_score: -1.5 X-Spam_bar: - X-Spam_report: (-1.5 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_EF=-0.1, FREEMAIL_FORGED_FROMDOMAIN=0.25, FREEMAIL_FROM=0.001, HEADER_FROM_DIFFERENT_DOMAINS=0.249, RCVD_IN_DNSWL_NONE=-0.0001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=no 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: Murilo Opsfelder Araujo , Richard Henderson , Eduardo Habkost , Peter Xu , David Hildenbrand Errors-To: qemu-devel-bounces+importer2=patchew.org@nongnu.org Sender: "Qemu-devel" X-ZohoMail-DKIM: fail (Header signature does not verify) Content-Type: text/plain; charset="utf-8" From: David Hildenbrand 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 mach= ine core Signed-off-by: David Hildenbrand Message-Id: <20210510114328.21835-4-david@redhat.com> Signed-off-by: Paolo Bonzini --- 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); } =20 +/* + * 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 =3D PROT_READ | (readonly ? 0 : PROT_WRITE); + int map_sync_flags =3D 0; + int flags =3D MAP_FIXED; + void *activated_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; + } + + activated_ptr =3D mmap(ptr, size, prot, flags | map_sync_flags, fd, + map_offset); + if (activated_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. + */ + activated_ptr =3D 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 =3D mmap_guard_pagesize(fd); - int prot; - 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 @@ -156,45 +197,10 @@ void *qemu_ram_mmap(int fd, /* Always align to host page size */ assert(align >=3D guard_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 - prot =3D PROT_READ | (readonly ? 0 : PROT_WRITE); - - ptr =3D mmap(guardptr + offset, size, prot, - flags | map_sync_flags, fd, map_offset); - - 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, flags, fd, map_offset); - } - + ptr =3D mmap_activate(guardptr + offset, size, fd, readonly, shared, i= s_pmem, + map_offset); if (ptr =3D=3D MAP_FAILED) { munmap(guardptr, total); return MAP_FAILED; --=20 2.31.1