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,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 F34D3C07E95 for ; Tue, 20 Jul 2021 13:19:06 +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 B771261106 for ; Tue, 20 Jul 2021 13:19:06 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org B771261106 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]:53956 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1m5peL-00087N-Uz for qemu-devel@archiver.kernel.org; Tue, 20 Jul 2021 09:19:05 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:52858) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1m5pQH-0006DQ-EI for qemu-devel@nongnu.org; Tue, 20 Jul 2021 09:04:33 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]:59678) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1m5pQF-0001LL-Di for qemu-devel@nongnu.org; Tue, 20 Jul 2021 09:04:33 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1626786270; 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=dvx1x+YAKC4ggmFKmjEd4OCra8Milqq4WgUXQwGODzE=; b=NCVd9XieeAfr4hiJhpiVS+yzNATCX/PdftY2MaCpyBcZMR+k2h5fhk/ho+6zvh7zOrJ9Ne NZjvanZ9PuyTnq2Un/Ri0/QVeOTiI0veNsxEDG4qhQrQ0iwl9sk6lWq2Oa7VdrRKZjxELV 84rgDxTlk3vMSuogoK9SMPwnY0MVQh8= 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-484-BkdLB57jM-SDULKw31-Xlg-1; Tue, 20 Jul 2021 09:04:27 -0400 X-MC-Unique: BkdLB57jM-SDULKw31-Xlg-1 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 5E134804143; Tue, 20 Jul 2021 13:04:26 +0000 (UTC) Received: from t480s.redhat.com (ovpn-114-112.ams2.redhat.com [10.36.114.112]) by smtp.corp.redhat.com (Postfix) with ESMTP id 514E169CB4; Tue, 20 Jul 2021 13:04:16 +0000 (UTC) From: David Hildenbrand To: qemu-devel@nongnu.org Subject: [PATCH resend v2 5/5] softmmu/memory_mapping: optimize for RamDiscardManager sections Date: Tue, 20 Jul 2021 15:03:04 +0200 Message-Id: <20210720130304.26323-6-david@redhat.com> In-Reply-To: <20210720130304.26323-1-david@redhat.com> References: <20210720130304.26323-1-david@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.11 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-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Received-SPF: pass client-ip=170.10.133.124; envelope-from=david@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -42 X-Spam_score: -4.3 X-Spam_bar: ---- X-Spam_report: (-4.3 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-1.474, 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: Laurent Vivier , Thomas Huth , Eduardo Habkost , "Michael S. Tsirkin" , David Hildenbrand , "Dr . David Alan Gilbert" , Peter Xu , Alex Williamson , Claudio Fontana , Paolo Bonzini , =?UTF-8?q?Marc-Andr=C3=A9=20Lureau?= , =?UTF-8?q?Alex=20Benn=C3=A9e?= , Igor Mammedov , Stefan Berger Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" virtio-mem logically plugs/unplugs memory within a sparse memory region and notifies via the RamDiscardManager interface when parts become plugged (populated) or unplugged (discarded). Currently, we end up (via the two users) 1) zeroing all logically unplugged/discarded memory during TPM resets. 2) reading all logically unplugged/discarded memory when dumping, to figure out the content is zero. 1) is always bad, because we assume unplugged memory stays discarded (and is already implicitly zero). 2) isn't that bad with anonymous memory, we end up reading the zero page (slow and unnecessary, though). However, once we use some file-backed memory (future use case), even reading will populate memory. Let's cut out all parts marked as not-populated (discarded) via the RamDiscardManager. As virtio-mem is the single user, this now means that logically unplugged memory ranges will no longer be included in the dump, which results in smaller dump files and faster dumping. virtio-mem has a minimum granularity of 1 MiB (and the default is usually 2 MiB). Theoretically, we can see quite some fragmentation, in practice we won't have it completely fragmented in 1 MiB pieces. Still, we might end up with many physical ranges. Both, the ELF format and kdump seem to be ready to support many individual ranges (e.g., for ELF it seems to be UINT32_MAX, kdump has a linear bitmap). Cc: Marc-André Lureau Cc: Paolo Bonzini Cc: "Michael S. Tsirkin" Cc: Eduardo Habkost Cc: Alex Williamson Cc: Dr. David Alan Gilbert Cc: Igor Mammedov Cc: Claudio Fontana Cc: Thomas Huth Cc: "Alex Bennée" Cc: Peter Xu Cc: Laurent Vivier Cc: Stefan Berger Signed-off-by: David Hildenbrand --- softmmu/memory_mapping.c | 20 ++++++++++++++++++++ 1 file changed, 20 insertions(+) diff --git a/softmmu/memory_mapping.c b/softmmu/memory_mapping.c index b7e4f3f788..856778a109 100644 --- a/softmmu/memory_mapping.c +++ b/softmmu/memory_mapping.c @@ -246,6 +246,15 @@ static void guest_phys_block_add_section(GuestPhysListener *g, #endif } +static int guest_phys_ram_populate_cb(MemoryRegionSection *section, + void *opaque) +{ + GuestPhysListener *g = opaque; + + guest_phys_block_add_section(g, section); + return 0; +} + static void guest_phys_blocks_region_add(MemoryListener *listener, MemoryRegionSection *section) { @@ -257,6 +266,17 @@ static void guest_phys_blocks_region_add(MemoryListener *listener, memory_region_is_nonvolatile(section->mr)) { return; } + + /* for special sparse regions, only add populated parts */ + if (memory_region_has_ram_discard_manager(section->mr)) { + RamDiscardManager *rdm; + + rdm = memory_region_get_ram_discard_manager(section->mr); + ram_discard_manager_replay_populated(rdm, section, + guest_phys_ram_populate_cb, g); + return; + } + guest_phys_block_add_section(g, section); } -- 2.31.1