From patchwork Fri Sep 8 14:21:28 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Hildenbrand X-Patchwork-Id: 13377513 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id ED32BEE800E for ; Fri, 8 Sep 2023 14:22:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S243809AbjIHOW4 (ORCPT ); Fri, 8 Sep 2023 10:22:56 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45702 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S243789AbjIHOWz (ORCPT ); Fri, 8 Sep 2023 10:22:55 -0400 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id EFB021BFF for ; Fri, 8 Sep 2023 07:22:07 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1694182927; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=IcjRBlX23B58QlEcv5JOZ+Baolj2SxlkLTfiV4y7RyI=; b=HMUGXfsIPG/mhdK9VP37Sw8ExfQLU6EkOeI6Ng/MPvJQ/PYvrE/Vj0AFoDhYSMDmGPPbBu dwx+YlVIAs7XBD12IcWS3n7Gm1qQ0zs39k2KNf/yQ2+UK8OrilsByyjC0Ke/z2AQ62Z1SE Ynd+DcM+NFEB6HfKHK8bkUorRfHShcw= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-130-016hA699OFCXNjq0SAiorw-1; Fri, 08 Sep 2023 10:22:04 -0400 X-MC-Unique: 016hA699OFCXNjq0SAiorw-1 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.rdu2.redhat.com [10.11.54.8]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id A0CAB816525; Fri, 8 Sep 2023 14:22:03 +0000 (UTC) Received: from t14s.redhat.com (unknown [10.39.194.76]) by smtp.corp.redhat.com (Postfix) with ESMTP id 0A20AC03295; Fri, 8 Sep 2023 14:22:00 +0000 (UTC) From: David Hildenbrand To: qemu-devel@nongnu.org Cc: David Hildenbrand , Paolo Bonzini , Igor Mammedov , Xiao Guangrong , "Michael S. Tsirkin" , Peter Xu , =?utf-8?q?Philippe_Mathieu-Daud=C3=A9?= , Eduardo Habkost , Marcel Apfelbaum , Yanan Wang , Michal Privoznik , =?utf-8?q?Daniel_P_=2E_Berrang=C3=A9?= , Gavin Shan , Alex Williamson , Stefan Hajnoczi , "Maciej S . Szmigiero" , kvm@vger.kernel.org Subject: [PATCH v3 08/16] memory-device: Track required and actually used memslots in DeviceMemoryState Date: Fri, 8 Sep 2023 16:21:28 +0200 Message-ID: <20230908142136.403541-9-david@redhat.com> In-Reply-To: <20230908142136.403541-1-david@redhat.com> References: <20230908142136.403541-1-david@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.1 on 10.11.54.8 Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org Let's track how many memslots are required by plugged memory devices and how many are currently actually getting used by plugged memory devices. "required - used" is the number of reserved memslots. For now, the number of used and required memslots is always equal, and there are no reservations. This is a preparation for memory devices that want to dynamically consume memslots after initially specifying how many they require -- where we'll end up with reserved memslots. To track the number of used memslots, create a new address space for our device memory and register a memory listener (add/remove) for that address space. Signed-off-by: David Hildenbrand Reviewed-by: Maciej S. Szmigiero --- hw/mem/memory-device.c | 54 ++++++++++++++++++++++++++++++++++++++++++ include/hw/boards.h | 10 +++++++- 2 files changed, 63 insertions(+), 1 deletion(-) diff --git a/hw/mem/memory-device.c b/hw/mem/memory-device.c index 0eec0872a9..d37cfbd65d 100644 --- a/hw/mem/memory-device.c +++ b/hw/mem/memory-device.c @@ -286,6 +286,7 @@ void memory_device_plug(MemoryDeviceState *md, MachineState *ms) g_assert(ms->device_memory); ms->device_memory->used_region_size += memory_region_size(mr); + ms->device_memory->required_memslots += memory_device_get_memslots(md); memory_region_add_subregion(&ms->device_memory->mr, addr - ms->device_memory->base, mr); trace_memory_device_plug(DEVICE(md)->id ? DEVICE(md)->id : "", addr); @@ -305,6 +306,7 @@ void memory_device_unplug(MemoryDeviceState *md, MachineState *ms) memory_region_del_subregion(&ms->device_memory->mr, mr); ms->device_memory->used_region_size -= memory_region_size(mr); + ms->device_memory->required_memslots -= memory_device_get_memslots(md); trace_memory_device_unplug(DEVICE(md)->id ? DEVICE(md)->id : "", mdc->get_addr(md)); } @@ -324,6 +326,50 @@ uint64_t memory_device_get_region_size(const MemoryDeviceState *md, return memory_region_size(mr); } +static void memory_devices_region_mod(MemoryListener *listener, + MemoryRegionSection *mrs, bool add) +{ + DeviceMemoryState *dms = container_of(listener, DeviceMemoryState, + listener); + + if (!memory_region_is_ram(mrs->mr)) { + warn_report("Unexpected memory region mapped into device memory region."); + return; + } + + /* + * The expectation is that each distinct RAM memory region section in + * our region for memory devices consumes exactly one memslot in KVM + * and in vhost. For vhost, this is true, except: + * * ROM memory regions don't consume a memslot. These get used very + * rarely for memory devices (R/O NVDIMMs). + * * Memslots without a fd (memory-backend-ram) don't necessarily + * consume a memslot. Such setups are quite rare and possibly bogus: + * the memory would be inaccessible by such vhost devices. + * + * So for vhost, in corner cases we might over-estimate the number of + * memslots that are currently used or that might still be reserved + * (required - used). + */ + dms->used_memslots += add ? 1 : -1; + + if (dms->used_memslots > dms->required_memslots) { + warn_report("Memory devices use more memory slots than indicated as required."); + } +} + +static void memory_devices_region_add(MemoryListener *listener, + MemoryRegionSection *mrs) +{ + return memory_devices_region_mod(listener, mrs, true); +} + +static void memory_devices_region_del(MemoryListener *listener, + MemoryRegionSection *mrs) +{ + return memory_devices_region_mod(listener, mrs, false); +} + void machine_memory_devices_init(MachineState *ms, hwaddr base, uint64_t size) { g_assert(size); @@ -333,8 +379,16 @@ void machine_memory_devices_init(MachineState *ms, hwaddr base, uint64_t size) memory_region_init(&ms->device_memory->mr, OBJECT(ms), "device-memory", size); + address_space_init(&ms->device_memory->as, &ms->device_memory->mr, + "device-memory"); memory_region_add_subregion(get_system_memory(), ms->device_memory->base, &ms->device_memory->mr); + + /* Track the number of memslots used by memory devices. */ + ms->device_memory->listener.region_add = memory_devices_region_add; + ms->device_memory->listener.region_del = memory_devices_region_del; + memory_listener_register(&ms->device_memory->listener, + &ms->device_memory->as); } static const TypeInfo memory_device_info = { diff --git a/include/hw/boards.h b/include/hw/boards.h index 3b541ffd24..e344ded607 100644 --- a/include/hw/boards.h +++ b/include/hw/boards.h @@ -296,15 +296,23 @@ struct MachineClass { * DeviceMemoryState: * @base: address in guest physical address space where the memory * address space for memory devices starts - * @mr: address space container for memory devices + * @mr: memory region container for memory devices + * @as: address space for memory devices + * @listener: memory listener used to track used memslots in the address space * @dimm_size: the sum of plugged DIMMs' sizes * @used_region_size: the part of @mr already used by memory devices + * @required_memslots: the number of memslots required by memory devices + * @used_memslots: the number of memslots currently used by memory devices */ typedef struct DeviceMemoryState { hwaddr base; MemoryRegion mr; + AddressSpace as; + MemoryListener listener; uint64_t dimm_size; uint64_t used_region_size; + unsigned int required_memslots; + unsigned int used_memslots; } DeviceMemoryState; /**