From nobody Tue Feb 10 03:38:29 2026 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 1623923317786389.91187379423434; Thu, 17 Jun 2021 02:48:37 -0700 (PDT) Received: from localhost ([::1]:33124 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1ltodY-0006G5-MU for importer@patchew.org; Thu, 17 Jun 2021 05:48:36 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:55120) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1ltoNR-0002rJ-35 for qemu-devel@nongnu.org; Thu, 17 Jun 2021 05:31:58 -0400 Received: from mail-ed1-x52f.google.com ([2a00:1450:4864:20::52f]:45598) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1ltoNM-0006Ar-OW for qemu-devel@nongnu.org; Thu, 17 Jun 2021 05:31:56 -0400 Received: by mail-ed1-x52f.google.com with SMTP id r7so3016122edv.12 for ; Thu, 17 Jun 2021 02:31:50 -0700 (PDT) Received: from avogadro.lan ([2001:b07:6468:f312:c8dd:75d4:99ab:290a]) by smtp.gmail.com with ESMTPSA id m18sm3328140ejx.56.2021.06.17.02.31.49 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 17 Jun 2021 02:31:49 -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=a4gAdIymstt98imS5Cx+cdFYsrLWt8PxrffQqIficYfqF5Qrz7a1UyaKQlMmyjkg6a v2jGgmgrxGdPrtcZsXpDF+8+KPtB7UsX+pJpYY+WxWvuBavGuvt3HoFQKzoTGFbHsvHa kTJoiasmwIJ324m0GvbrSVTj54vqSPqN2hQ95IDC0+lGo7zBS3PR9U/m7Am1llXw6NBf tMfcBAsv7ytag1elSPq8S1AhUj/sayiRajeCSeywBSbI1ZRJ+rKYnQ4H+1dgW8PVqPT4 vyWnslcEbFexahTKqwTK1GeNw33O228S7Ldz4USZys+3xUtXP1bpt5rEDbU9BfuwAFdn lxsg== 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=bUL2/6heFSvmw9JkqpIC5n2rhFTZH99An5nUk6D5UWD5PR3SiDHvFQncIkrHPnI4TV 6o9/9q2GK4dfBfS/+7EtU1hOMfrwkdUPFIAikNPuP1S9Bb9oaDGBbXUfNRLevMX8A/+v Nph9nRtaT6CVD+mKS+44M2/qbk+beVFoQs3t79Ic4fzhafk3B3VHQb+GP239WOqSK4jF 4NC0DT5ASjt3kEQmT4Uv83Qg9cpVSwY3oF0A7uFcppcXO+r0mT1IVe+eB/fR+B7FaoYr wdldir3xC1LahRTDd8iXt8u1L5inRVmgnqmHSDAAT6NFpraKBIEWz/yRy+0vmA11PvXM mD2A== X-Gm-Message-State: AOAM532+/JQOjx6oXylrpyf1oLaQTeH7k4VndE/LEBn7YIqe5Cel+irw 07DQz4ThUYQ3J/GVo4/+zcr4l/+l0N4= X-Google-Smtp-Source: ABdhPJycg246I3U4KrjDnTQVkCFR/hjMU5kdXQGJ7E6vYXiT/HR80lRp1E5Kh1Oe31leAsqQ7Ngkxg== X-Received: by 2002:aa7:d892:: with SMTP id u18mr5366258edq.196.1623922309751; Thu, 17 Jun 2021 02:31:49 -0700 (PDT) From: Paolo Bonzini To: qemu-devel@nongnu.org Subject: [PULL 20/45] util/mmap-alloc: Factor out activating of memory to mmap_activate() Date: Thu, 17 Jun 2021 11:31:09 +0200 Message-Id: <20210617093134.900014-21-pbonzini@redhat.com> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20210617093134.900014-1-pbonzini@redhat.com> References: <20210617093134.900014-1-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+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Received-SPF: pass client-ip=2a00:1450:4864:20::52f; envelope-from=paolo.bonzini@gmail.com; helo=mail-ed1-x52f.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=0.248, 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+importer=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