From patchwork Wed Apr 28 13:37:39 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: David Hildenbrand X-Patchwork-Id: 12228785 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=-8.6 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,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 D061BC433B4 for ; Wed, 28 Apr 2021 13:40:22 +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 DD29D61151 for ; Wed, 28 Apr 2021 13:40:21 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org DD29D61151 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]:49658 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1lbkQO-00012f-QZ for qemu-devel@archiver.kernel.org; Wed, 28 Apr 2021 09:40:20 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:57220) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lbkPA-0000SF-0w for qemu-devel@nongnu.org; Wed, 28 Apr 2021 09:39:04 -0400 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:47572) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lbkP7-0005v6-47 for qemu-devel@nongnu.org; Wed, 28 Apr 2021 09:39:03 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1619617139; 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; bh=XyhLO2FX7UrkS+3WDGkW3e0d5CNbhi4HHefUw+Aunwk=; b=Y7ZFHlU22pbmevpNevleGXpTchU6UHfuJb0sWfzRKOlL8Z2UR2ltL9GWrHKRPrFO5EXhVF 2/cwPX/QRRPDwNUiZ3aXn3tKySCbQQy7dK9u6dvslyumuzwOV5Cak5T8xd9d8WK2VXOyjF P/YtziE/a/Ma60CsVHuM4AWeONF7LIY= 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-441-eH1XodPaN163wmqjh-LS_g-1; Wed, 28 Apr 2021 09:38:58 -0400 X-MC-Unique: eH1XodPaN163wmqjh-LS_g-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 E878780ED8B; Wed, 28 Apr 2021 13:38:56 +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 B0DE361093; Wed, 28 Apr 2021 13:37:55 +0000 (UTC) From: David Hildenbrand To: qemu-devel@nongnu.org Subject: [PATCH v7 00/15] RAM_NORESERVE, MAP_NORESERVE and hostmem "reserve" property Date: Wed, 28 Apr 2021 15:37:39 +0200 Message-Id: <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 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=-0.22, 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_Mathieu-Daud=C3=A9?= Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" Based-on: 20210406080126.24010-1-david@redhat.com Some cleanups previously sent in other context (resizeable allocations), followed by RAM_NORESERVE, implementing it under Linux using MAP_NORESERVE, and letting users configure it for memory backens using the "reserve" property (default: true). MAP_NORESERVE under Linux has in the context of QEMU an effect on 1) Private/shared anonymous memory -> memory-backend-ram,id=mem0,size=10G 2) Private fd-based mappings -> memory-backend-file,id=mem0,size=10G,mem-path=/dev/shm/0 -> memory-backend-memfd,id=mem0,size=10G 3) Private/shared hugetlb mappings -> memory-backend-memfd,id=mem0,size=10G,hugetlb=on,hugetlbsize=2M With MAP_NORESERVE/"reserve=off", we won't be reserving swap space (1/2) or huge pages (3) for the whole memory region. The target use case is virtio-mem, which dynamically exposes memory inside a large, sparse memory area to the VM. MAP_NORESERVE tells the OS "this mapping might be very sparse". This essentially allows avoiding having to set "/proc/sys/vm/overcommit_memory == 1") when using virtio-mem and also supporting hugetlbfs in the future. v6 -> v7: - Collected ACKs and RBs - "hostmem: Wire up RAM_NORESERVE via "reserve" property" -- Extended qapi/qom.json documentation - "qmp: Include "reserve" property of memory backends" -- Extended property description v5 -> v6: - "softmmu/memory: Pass ram_flags to memory_region_init ..." -- Split up into two patches ---> "softmmu/memory: Pass ram_flags to memory_region.." ---> "softmmu/memory: Pass ram_flags to qemu_ram_alloc() ..." -- Also set RAM_PREALLOC from qemu_ram_alloc_from_ptr() - Collected acks/rbs v4 -> v5: - Sent out shared anonymous RAM fixes separately - Rebased - "hostmem: Wire up RAM_NORESERVE via "reserve" property" -- Adjusted/simplified description of new "reserve" property -- Properly add it to qapi/qom.json - "qmp: Clarify memory backend properties returned via query-memdev" -- Added - "qmp: Include "share" property of memory backends" -- Added - "hmp: Print "share" property of memory backends with "info memdev"" - Added - "qmp: Include "reserve" property of memory backends" -- Adjust description of new "reserve" property v3 -> v4: - Minor comment/description updates - "softmmu/physmem: Fix ram_block_discard_range() to handle shared ..." -- Extended description - "util/mmap-alloc: Pass flags instead of separate bools to ..." -- Move flags to include/qemu/osdep.h and rename to "QEMU_MAP_*" - "memory: Introduce RAM_NORESERVE and wire it up in qemu_ram_mmap()" -- Adjust to new flags. Handle errors in mmap_activate() for now. - "util/mmap-alloc: Support RAM_NORESERVE via MAP_NORESERVE under Linux" -- Restrict support to Linux only for now - "qmp: Include "reserve" property of memory backends" -- Added - "hmp: Print "reserve" property of memory backends with ..." -- Added v2 -> v3: - Renamed "softmmu/physmem: Drop "shared" parameter from ram_block_add()" to "softmmu/physmem: Mark shared anonymous memory RAM_SHARED" and adjusted the description - Added "softmmu/physmem: Fix ram_block_discard_range() to handle shared anonymous memory" - Added "softmmu/physmem: Fix qemu_ram_remap() to handle shared anonymous memory" - Added "util/mmap-alloc: Pass flags instead of separate bools to qemu_ram_mmap()" - "util/mmap-alloc: Support RAM_NORESERVE via MAP_NORESERVE" -- Further tweak code comments -- Handle shared anonymous memory v1 -> v2: - Rebased to upstream and phs_mem_alloc simplifications -- Upsteam added the "map_offset" parameter to many RAM allocation interfaces. - "softmmu/physmem: Drop "shared" parameter from ram_block_add()" -- Use local variable "shared" - "memory: introduce RAM_NORESERVE and wire it up in qemu_ram_mmap()" -- Simplify due to phs_mem_alloc changes - "util/mmap-alloc: Support RAM_NORESERVE via MAP_NORESERVE" -- Add a whole bunch of comments. -- Exclude shared anonymous memory that QEMU doesn't use -- Special-case readonly mappings Cc: Peter Xu Cc: "Michael S. Tsirkin" Cc: Eduardo Habkost Cc: "Dr. David Alan Gilbert" Cc: Richard Henderson Cc: Paolo Bonzini Cc: Igor Mammedov Cc: "Philippe Mathieu-Daudé" Cc: Stefan Hajnoczi Cc: Murilo Opsfelder Araujo Cc: Greg Kurz Cc: Liam Merwick Cc: Marcel Apfelbaum Cc: Nitesh Lal David Hildenbrand (15): util/mmap-alloc: Factor out calculation of the pagesize for the guard page util/mmap-alloc: Factor out reserving of a memory region to mmap_reserve() util/mmap-alloc: Factor out activating of memory to mmap_activate() softmmu/memory: Pass ram_flags to qemu_ram_alloc_from_fd() softmmu/memory: Pass ram_flags to memory_region_init_ram_shared_nomigrate() softmmu/memory: Pass ram_flags to qemu_ram_alloc() and qemu_ram_alloc_internal() util/mmap-alloc: Pass flags instead of separate bools to qemu_ram_mmap() memory: Introduce RAM_NORESERVE and wire it up in qemu_ram_mmap() util/mmap-alloc: Support RAM_NORESERVE via MAP_NORESERVE under Linux hostmem: Wire up RAM_NORESERVE via "reserve" property qmp: Clarify memory backend properties returned via query-memdev qmp: Include "share" property of memory backends hmp: Print "share" property of memory backends with "info memdev" qmp: Include "reserve" property of memory backends hmp: Print "reserve" property of memory backends with "info memdev" backends/hostmem-file.c | 11 +- backends/hostmem-memfd.c | 8 +- backends/hostmem-ram.c | 7 +- backends/hostmem.c | 32 +++ hw/core/machine-hmp-cmds.c | 4 + hw/core/machine-qmp-cmds.c | 2 + hw/m68k/next-cube.c | 4 +- hw/misc/ivshmem.c | 5 +- include/exec/cpu-common.h | 1 + include/exec/memory.h | 42 ++-- include/exec/ram_addr.h | 9 +- include/qemu/mmap-alloc.h | 16 +- include/qemu/osdep.h | 30 ++- include/sysemu/hostmem.h | 2 +- migration/ram.c | 3 +- qapi/machine.json | 16 +- qapi/qom.json | 10 + .../memory-region-housekeeping.cocci | 8 +- softmmu/memory.c | 27 ++- softmmu/physmem.c | 51 +++-- util/mmap-alloc.c | 212 +++++++++++++----- util/oslib-posix.c | 7 +- util/oslib-win32.c | 13 +- 23 files changed, 362 insertions(+), 158 deletions(-)