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 052CFC433E0 for ; Mon, 8 Mar 2021 15:22:02 +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 7646665235 for ; Mon, 8 Mar 2021 15:22:01 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 7646665235 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]:54244 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1lJHho-0006gD-Cs for qemu-devel@archiver.kernel.org; Mon, 08 Mar 2021 10:22:00 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:46674) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lJHUw-0008Tn-0F for qemu-devel@nongnu.org; Mon, 08 Mar 2021 10:08:43 -0500 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:45149) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA1:256) (Exim 4.90_1) (envelope-from ) id 1lJHUq-0001zT-W4 for qemu-devel@nongnu.org; Mon, 08 Mar 2021 10:08:41 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1615216116; 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=000A2Kzvuldjk5CK/R2/a6cUGZhusis3M8m5/x7Qvzo=; b=hPX1X4XzGDSpgOIcgHhauI9sPRWCeSW77TtkkvHlF6FHuPGQF5RXdx/2MOYckA2irOoR/f mrsB5pfHrLEF/Nc0UphXVQyNwxYv0SBB8AffjVpCWsQS6y9I/g1cf9dUxH8bHDsT5uDij8 Te3CfrOsWA7tV4qQzZzDUcIhcGucSH8= 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-35-hbFlU2yaM3OOgT2Nvvaltw-1; Mon, 08 Mar 2021 10:08:33 -0500 X-MC-Unique: hbFlU2yaM3OOgT2Nvvaltw-1 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 260C68143F0; Mon, 8 Mar 2021 15:08:32 +0000 (UTC) Received: from t480s.redhat.com (ovpn-113-123.ams2.redhat.com [10.36.113.123]) by smtp.corp.redhat.com (Postfix) with ESMTP id 12C645D9CD; Mon, 8 Mar 2021 15:08:27 +0000 (UTC) From: David Hildenbrand To: qemu-devel@nongnu.org Subject: [PATCH v3 12/12] hostmem: Wire up RAM_NORESERVE via "reserve" property Date: Mon, 8 Mar 2021 16:06:00 +0100 Message-Id: <20210308150600.14440-13-david@redhat.com> In-Reply-To: <20210308150600.14440-1-david@redhat.com> References: <20210308150600.14440-1-david@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 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=216.205.24.124; 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=-0.251, 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_H3=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, T_FILL_THIS_FORM_SHORT=0.01 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 , Cornelia Huck , Eduardo Habkost , "Michael S. Tsirkin" , Stefan Weil , David Hildenbrand , Richard Henderson , "Dr. David Alan Gilbert" , Peter Xu , Greg Kurz , Halil Pasic , Christian Borntraeger , Stefan Hajnoczi , Igor Mammedov , Thomas Huth , Paolo Bonzini , =?UTF-8?q?Philippe=20Mathieu-Daud=C3=A9?= , Igor Kotrasinski , Juan Quintela Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" Let's provide a way to control the use of RAM_NORESERVE via memory backends using the "reserve" property which defaults to true (old behavior). Only POSIX supports setting the flag (and Linux support is checked at runtime, depending on the setting of "/proc/sys/vm/overcommit_memory"). Windows will bail out. The target use case is virtio-mem, which dynamically exposes memory inside a large, sparse memory area to the VM. This essentially allows avoiding to set "/proc/sys/vm/overcommit_memory == 0") when using virtio-mem and also supporting hugetlbfs in the future. Reviewed-by: Peter Xu Reviewed-by: Eduardo Habkost Signed-off-by: David Hildenbrand --- backends/hostmem-file.c | 11 ++++++----- backends/hostmem-memfd.c | 1 + backends/hostmem-ram.c | 1 + backends/hostmem.c | 33 +++++++++++++++++++++++++++++++++ include/sysemu/hostmem.h | 2 +- 5 files changed, 42 insertions(+), 6 deletions(-) diff --git a/backends/hostmem-file.c b/backends/hostmem-file.c index b683da9daf..9d550e53d4 100644 --- a/backends/hostmem-file.c +++ b/backends/hostmem-file.c @@ -40,6 +40,7 @@ file_backend_memory_alloc(HostMemoryBackend *backend, Error **errp) object_get_typename(OBJECT(backend))); #else HostMemoryBackendFile *fb = MEMORY_BACKEND_FILE(backend); + uint32_t ram_flags; gchar *name; if (!backend->size) { @@ -52,11 +53,11 @@ file_backend_memory_alloc(HostMemoryBackend *backend, Error **errp) } name = host_memory_backend_get_name(backend); - memory_region_init_ram_from_file(&backend->mr, OBJECT(backend), - name, - backend->size, fb->align, - (backend->share ? RAM_SHARED : 0) | - (fb->is_pmem ? RAM_PMEM : 0), + ram_flags = backend->share ? RAM_SHARED : 0; + ram_flags |= backend->reserve ? 0 : RAM_NORESERVE; + ram_flags |= fb->is_pmem ? RAM_PMEM : 0; + memory_region_init_ram_from_file(&backend->mr, OBJECT(backend), name, + backend->size, fb->align, ram_flags, fb->mem_path, fb->readonly, errp); g_free(name); #endif diff --git a/backends/hostmem-memfd.c b/backends/hostmem-memfd.c index 93b5d1a4cf..f3436b623d 100644 --- a/backends/hostmem-memfd.c +++ b/backends/hostmem-memfd.c @@ -55,6 +55,7 @@ memfd_backend_memory_alloc(HostMemoryBackend *backend, Error **errp) name = host_memory_backend_get_name(backend); ram_flags = backend->share ? RAM_SHARED : 0; + ram_flags |= backend->reserve ? 0 : RAM_NORESERVE; memory_region_init_ram_from_fd(&backend->mr, OBJECT(backend), name, backend->size, ram_flags, fd, 0, errp); g_free(name); diff --git a/backends/hostmem-ram.c b/backends/hostmem-ram.c index 741e701062..b8e55cdbd0 100644 --- a/backends/hostmem-ram.c +++ b/backends/hostmem-ram.c @@ -29,6 +29,7 @@ ram_backend_memory_alloc(HostMemoryBackend *backend, Error **errp) name = host_memory_backend_get_name(backend); ram_flags = backend->share ? RAM_SHARED : 0; + ram_flags |= backend->reserve ? 0 : RAM_NORESERVE; memory_region_init_ram_flags_nomigrate(&backend->mr, OBJECT(backend), name, backend->size, ram_flags, errp); g_free(name); diff --git a/backends/hostmem.c b/backends/hostmem.c index c6c1ff5b99..4e80162915 100644 --- a/backends/hostmem.c +++ b/backends/hostmem.c @@ -217,6 +217,11 @@ static void host_memory_backend_set_prealloc(Object *obj, bool value, Error *local_err = NULL; HostMemoryBackend *backend = MEMORY_BACKEND(obj); + if (!backend->reserve && value) { + error_setg(errp, "'prealloc=on' and 'reserve=off' are incompatible"); + return; + } + if (!host_memory_backend_mr_inited(backend)) { backend->prealloc = value; return; @@ -268,6 +273,7 @@ static void host_memory_backend_init(Object *obj) /* TODO: convert access to globals to compat properties */ backend->merge = machine_mem_merge(machine); backend->dump = machine_dump_guest_core(machine); + backend->reserve = true; backend->prealloc_threads = 1; } @@ -426,6 +432,28 @@ static void host_memory_backend_set_share(Object *o, bool value, Error **errp) backend->share = value; } +static bool host_memory_backend_get_reserve(Object *o, Error **errp) +{ + HostMemoryBackend *backend = MEMORY_BACKEND(o); + + return backend->reserve; +} + +static void host_memory_backend_set_reserve(Object *o, bool value, Error **errp) +{ + HostMemoryBackend *backend = MEMORY_BACKEND(o); + + if (host_memory_backend_mr_inited(backend)) { + error_setg(errp, "cannot change property value"); + return; + } + if (backend->prealloc && !value) { + error_setg(errp, "'prealloc=on' and 'reserve=off' are incompatible"); + return; + } + backend->reserve = value; +} + static bool host_memory_backend_get_use_canonical_path(Object *obj, Error **errp) { @@ -494,6 +522,11 @@ host_memory_backend_class_init(ObjectClass *oc, void *data) host_memory_backend_get_share, host_memory_backend_set_share); object_class_property_set_description(oc, "share", "Mark the memory as private to QEMU or shared"); + object_class_property_add_bool(oc, "reserve", + host_memory_backend_get_reserve, host_memory_backend_set_reserve); + object_class_property_set_description(oc, "reserve", + "Reserve swap space (or huge pages under Linux) for the whole memory" + " backend, if supported by the OS."); /* * Do not delete/rename option. This option must be considered stable * (as if it didn't have the 'x-' prefix including deprecation period) as diff --git a/include/sysemu/hostmem.h b/include/sysemu/hostmem.h index df5644723a..9ff5c16963 100644 --- a/include/sysemu/hostmem.h +++ b/include/sysemu/hostmem.h @@ -64,7 +64,7 @@ struct HostMemoryBackend { /* protected */ uint64_t size; bool merge, dump, use_canonical_path; - bool prealloc, is_mapped, share; + bool prealloc, is_mapped, share, reserve; uint32_t prealloc_threads; DECLARE_BITMAP(host_nodes, MAX_NODES + 1); HostMemPolicy policy; -- 2.29.2