From patchwork Thu Mar 4 10:55:51 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Hildenbrand X-Patchwork-Id: 12115865 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 5B513C433DB for ; Thu, 4 Mar 2021 11:00:10 +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 F0A1D64F2B for ; Thu, 4 Mar 2021 11:00:09 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org F0A1D64F2B 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]:49554 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1lHliC-0005YV-U1 for qemu-devel@archiver.kernel.org; Thu, 04 Mar 2021 06:00:08 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:58218) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lHleP-0000qQ-FN for qemu-devel@nongnu.org; Thu, 04 Mar 2021 05:56:13 -0500 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:55175) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA1:256) (Exim 4.90_1) (envelope-from ) id 1lHleL-0002zD-O4 for qemu-devel@nongnu.org; Thu, 04 Mar 2021 05:56:13 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1614855369; 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=h1oqOv9ujfdg7iaVJ+d6rkkdDrpGXlQd9pg+qtORuCk=; b=evPenxBO3ER/yzkbsG3bxdMCLX8/Y0zJwv9tR08R/rWoOBbhyU79lDvzx+1rzrsKCIC0CC 1vzi5UWmtOrbWB4k5FzFg+RMPpmzyCzB4HAv4NuyYLDb8SdtuMF0G4CtwAgMCQ6qrtFpWx 6TY0vH9WQYgqL7fzothY+qQ9u70+P1Y= 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-411-PZ_tFZ29Msu1VHez9m2Kjw-1; Thu, 04 Mar 2021 05:56:07 -0500 X-MC-Unique: PZ_tFZ29Msu1VHez9m2Kjw-1 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.phx2.redhat.com [10.5.11.15]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id EF62A80432A; Thu, 4 Mar 2021 10:56:05 +0000 (UTC) Received: from t480s.redhat.com (ovpn-113-171.ams2.redhat.com [10.36.113.171]) by smtp.corp.redhat.com (Postfix) with ESMTP id 96EA55D720; Thu, 4 Mar 2021 10:56:03 +0000 (UTC) From: David Hildenbrand To: qemu-devel@nongnu.org Subject: [PATCH v3 1/4] acpi: Set proper maximum size for "etc/table-loader" blob Date: Thu, 4 Mar 2021 11:55:51 +0100 Message-Id: <20210304105554.121674-2-david@redhat.com> In-Reply-To: <20210304105554.121674-1-david@redhat.com> References: <20210304105554.121674-1-david@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.15 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: -27 X-Spam_score: -2.8 X-Spam_bar: -- X-Spam_report: (-2.8 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.001, 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 autolearn=unavailable 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: Peter Maydell , "Michael S. Tsirkin" , David Hildenbrand , Richard Henderson , Alistair Francis , Shannon Zhao , qemu-arm@nongnu.org, Paolo Bonzini , Igor Mammedov , Laszlo Ersek Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" The resizeable memory region / RAMBlock that is created for the cmd blob has a maximum size of whole host pages (e.g., 4k), because RAMBlocks work on full host pages. In addition, in i386 ACPI code: acpi_align_size(tables->linker->cmd_blob, ACPI_BUILD_ALIGN_SIZE); makes sure to align to multiples of 4k, padding with 0. For example, if our cmd_blob is created with a size of 2k, the maximum size is 4k - we cannot grow beyond that. Growing might be required due to guest action when rebuilding the tables, but also on incoming migration. This automatic generation of the maximum size used to be sufficient, however, there are cases where we cross host pages now when growing at runtime: we exceed the maximum size of the RAMBlock and can crash QEMU when trying to resize the resizeable memory region / RAMBlock: $ build/qemu-system-x86_64 --enable-kvm \ -machine q35,nvdimm=on \ -smp 1 \ -cpu host \ -m size=2G,slots=8,maxmem=4G \ -object memory-backend-file,id=mem0,mem-path=/tmp/nvdimm,size=256M \ -device nvdimm,label-size=131072,memdev=mem0,id=nvdimm0,slot=1 \ -nodefaults \ -device vmgenid \ -device intel-iommu Results in: Unexpected error in qemu_ram_resize() at ../softmmu/physmem.c:1850: qemu-system-x86_64: Size too large: /rom@etc/table-loader: 0x2000 > 0x1000: Invalid argument In this configuration, we consume exactly 4k (32 entries, 128 bytes each) when creating the VM. However, once the guest boots up and maps the MCFG, we also create the MCFG table and end up consuming 2 additional entries (pointer + checksum) -- which is where we try resizing the memory region / RAMBlock, however, the maximum size does not allow for it. Currently, we get the following maximum sizes for our different mutable tables based on behavior of resizeable RAMBlock: hw table max_size ------- --------------------------------------------------------- virt "etc/acpi/tables" ACPI_BUILD_TABLE_MAX_SIZE (0x200000) virt "etc/table-loader" HOST_PAGE_ALIGN(initial_size) virt "etc/acpi/rsdp" HOST_PAGE_ALIGN(initial_size) i386 "etc/acpi/tables" ACPI_BUILD_TABLE_MAX_SIZE (0x200000) i386 "etc/table-loader" HOST_PAGE_ALIGN(initial_size) i386 "etc/acpi/rsdp" HOST_PAGE_ALIGN(initial_size) microvm "etc/acpi/tables" ACPI_BUILD_TABLE_MAX_SIZE (0x200000) microvm "etc/table-loader" HOST_PAGE_ALIGN(initial_size) microvm "etc/acpi/rsdp" HOST_PAGE_ALIGN(initial_size) Let's set the maximum table size for "etc/table-loader" to 64k, so we can properly grow at runtime, which should be good enough for the future. Migration is not concerned with the maximum size of a RAMBlock, only with the used size - so existing setups are not affected. Of course, we cannot migrate a VM that would have crash when started on older QEMU from new QEMU to older QEMU without failing early on the destination when synchronizing the RAM state: qemu-system-x86_64: Size too large: /rom@etc/table-loader: 0x2000 > 0x1000: Invalid argument qemu-system-x86_64: error while loading state for instance 0x0 of device 'ram' qemu-system-x86_64: load of migration failed: Invalid argument We'll refactor the code next, to make sure we get rid of this implicit behavior for "etc/acpi/rsdp" as well and to make the code easier to grasp. Reviewed-by: Igor Mammedov Cc: Alistair Francis Cc: Paolo Bonzini Cc: "Michael S. Tsirkin" Cc: Igor Mammedov Cc: Peter Maydell Cc: Shannon Zhao Cc: Marcel Apfelbaum Cc: Paolo Bonzini Cc: Richard Henderson Cc: Laszlo Ersek Signed-off-by: David Hildenbrand --- hw/arm/virt-acpi-build.c | 3 ++- hw/i386/acpi-build.c | 3 ++- hw/i386/acpi-microvm.c | 2 +- include/hw/acpi/aml-build.h | 1 + 4 files changed, 6 insertions(+), 3 deletions(-) diff --git a/hw/arm/virt-acpi-build.c b/hw/arm/virt-acpi-build.c index f9c9df916c..a91550de6f 100644 --- a/hw/arm/virt-acpi-build.c +++ b/hw/arm/virt-acpi-build.c @@ -865,7 +865,8 @@ void virt_acpi_setup(VirtMachineState *vms) build_state->linker_mr = acpi_add_rom_blob(virt_acpi_build_update, build_state, - tables.linker->cmd_blob, ACPI_BUILD_LOADER_FILE, 0); + tables.linker->cmd_blob, ACPI_BUILD_LOADER_FILE, + ACPI_BUILD_LOADER_MAX_SIZE); fw_cfg_add_file(vms->fw_cfg, ACPI_BUILD_TPMLOG_FILE, tables.tcpalog->data, acpi_data_len(tables.tcpalog)); diff --git a/hw/i386/acpi-build.c b/hw/i386/acpi-build.c index 31a5f6f4a5..a75138ea5a 100644 --- a/hw/i386/acpi-build.c +++ b/hw/i386/acpi-build.c @@ -2524,7 +2524,8 @@ void acpi_setup(void) build_state->linker_mr = acpi_add_rom_blob(acpi_build_update, build_state, - tables.linker->cmd_blob, ACPI_BUILD_LOADER_FILE, 0); + tables.linker->cmd_blob, ACPI_BUILD_LOADER_FILE, + ACPI_BUILD_LOADER_MAX_SIZE); fw_cfg_add_file(x86ms->fw_cfg, ACPI_BUILD_TPMLOG_FILE, tables.tcpalog->data, acpi_data_len(tables.tcpalog)); diff --git a/hw/i386/acpi-microvm.c b/hw/i386/acpi-microvm.c index 54b3af478a..01f1945ac1 100644 --- a/hw/i386/acpi-microvm.c +++ b/hw/i386/acpi-microvm.c @@ -255,7 +255,7 @@ void acpi_setup_microvm(MicrovmMachineState *mms) ACPI_BUILD_TABLE_MAX_SIZE); acpi_add_rom_blob(acpi_build_no_update, NULL, tables.linker->cmd_blob, - "etc/table-loader", 0); + "etc/table-loader", ACPI_BUILD_LOADER_MAX_SIZE); acpi_add_rom_blob(acpi_build_no_update, NULL, tables.rsdp, ACPI_BUILD_RSDP_FILE, 0); diff --git a/include/hw/acpi/aml-build.h b/include/hw/acpi/aml-build.h index 380d3e3924..a22c6a4c86 100644 --- a/include/hw/acpi/aml-build.h +++ b/include/hw/acpi/aml-build.h @@ -6,6 +6,7 @@ /* Reserve RAM space for tables: add another order of magnitude. */ #define ACPI_BUILD_TABLE_MAX_SIZE 0x200000 +#define ACPI_BUILD_LOADER_MAX_SIZE 0x10000 #define ACPI_BUILD_APPNAME6 "BOCHS " #define ACPI_BUILD_APPNAME8 "BXPC "