From patchwork Sat Nov 5 17:18:30 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Michael S. Tsirkin" X-Patchwork-Id: 13033175 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 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 smtp.lore.kernel.org (Postfix) with ESMTPS id 15DFBC4332F for ; Sat, 5 Nov 2022 17:41:38 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1orMqq-0000p9-15; Sat, 05 Nov 2022 13:21:00 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1orMoZ-0007X1-J4 for qemu-devel@nongnu.org; Sat, 05 Nov 2022 13:18:48 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.129.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1orMoX-0007ks-Nf for qemu-devel@nongnu.org; Sat, 05 Nov 2022 13:18:39 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1667668716; 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: in-reply-to:in-reply-to:references:references; bh=5PFs7dvFWSm4KAxARiJdmAa3zvpoXTxhtCqbnGVoPOY=; b=bXeCBvq1V5RzmF48XkECV4a0a/0MmPThRVgeMwtf3MaoPWER4PjHuUpMyums1HPsD6g9ie TYMVUUFBPQGuTSuhsRanOIZaaH7s70rHHtfLyCyvTwK3Y5yqpFP/nuT5Lil3BE87Di+oWN V+qjjeVYwFz4jg0OARSBNDlPksPS1y4= Received: from mail-wm1-f70.google.com (mail-wm1-f70.google.com [209.85.128.70]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_128_GCM_SHA256) id us-mta-79-wCj9JuBCMeuy8l2X01FjIA-1; Sat, 05 Nov 2022 13:18:35 -0400 X-MC-Unique: wCj9JuBCMeuy8l2X01FjIA-1 Received: by mail-wm1-f70.google.com with SMTP id m34-20020a05600c3b2200b003cf549cb32bso6010106wms.1 for ; Sat, 05 Nov 2022 10:18:35 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=5PFs7dvFWSm4KAxARiJdmAa3zvpoXTxhtCqbnGVoPOY=; b=ZI/JDqeFdgDBgdjEZwIYQwABmF3yZXuCx+TnpQfym2/HMv3FFEyc2HB7ibq6KP/vkV Ng1xELeiAXTjuK4yBcJtLOXaBSx/XGORgVKENoOpL8VQq37+XjX/opqZQnYGiJRJywOc eHJF6++f9ZjVVjoa7Q6veVdLOusXpnG77xHmVbJBPKNgw6pRRVSRHFwHS1/qaTqBq5d4 baB0DIve3qpfdzI5Lst7V2409UwNACPS6TqswrwFLyMiLJTosPIai7qR1B4iNj0eLelv IuSffdDE3cKH9Zur5z2qf3bRMPzffT8K7rEJFEVLUws6BAM3e0KL/OGNNdrO5e7SmTAv eh/Q== X-Gm-Message-State: ACrzQf1DpCohaWqhZuSeiyRSnTKu1nKxN/qXv6X30JZVdRI4Rcx8DQl/ pujK89sNkuwVn+o+5qFHBAWadT/uCk99Q0y6P1FpSyjwq2nD55VriYb7yxo1yPdszBAH1Pqxx+G ZnH/7OgIk8EhNtN0bQ87OpGcxfBhJlR0Jey+tyIoF7/nDSIhXQc4Z12epkbcz X-Received: by 2002:adf:df82:0:b0:236:563b:6f5d with SMTP id z2-20020adfdf82000000b00236563b6f5dmr377963wrl.532.1667668713732; Sat, 05 Nov 2022 10:18:33 -0700 (PDT) X-Google-Smtp-Source: AMsMyM5uSEPFb90O+DPoXwnANE8NJsjQqa8ChPGoueC9wmW7jySa1Xen6lEwaoHCTK8uUIBvPpweVw== X-Received: by 2002:adf:df82:0:b0:236:563b:6f5d with SMTP id z2-20020adfdf82000000b00236563b6f5dmr377952wrl.532.1667668713203; Sat, 05 Nov 2022 10:18:33 -0700 (PDT) Received: from redhat.com ([2.52.152.137]) by smtp.gmail.com with ESMTPSA id m6-20020a05600c3b0600b003cf6c2f9513sm3383649wms.2.2022.11.05.10.18.31 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sat, 05 Nov 2022 10:18:32 -0700 (PDT) Date: Sat, 5 Nov 2022 13:18:30 -0400 From: "Michael S. Tsirkin" To: qemu-devel@nongnu.org Cc: Peter Maydell , Gregory Price , Gregory Price , Jonathan Cameron , Marcel Apfelbaum , Paolo Bonzini , Richard Henderson , Eduardo Habkost Subject: [PULL v3 63/81] hw/i386/pc.c: CXL Fixed Memory Window should not reserve e820 in bios Message-ID: <20221105171116.432921-64-mst@redhat.com> References: <20221105171116.432921-1-mst@redhat.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20221105171116.432921-1-mst@redhat.com> X-Mailer: git-send-email 2.27.0.106.g8ac3dc51b1 X-Mutt-Fcc: =sent Received-SPF: pass client-ip=170.10.129.124; envelope-from=mst@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -30 X-Spam_score: -3.1 X-Spam_bar: --- X-Spam_report: (-3.1 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-1.045, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H2=-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: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "Qemu-devel" Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org From: Gregory Price Early-boot e820 records will be inserted by the bios/efi/early boot software and be reported to the kernel via insert_resource. Later, when CXL drivers iterate through the regions again, they will insert another resource and make the RESERVED memory area a child. This RESERVED memory area causes the memory region to become unusable, and as a result attempting to create memory regions with `cxl create-region ...` Will fail due to the RESERVED area intersecting with the CXL window. During boot the following traceback is observed: 0xffffffff81101650 in insert_resource_expand_to_fit () 0xffffffff83d964c5 in e820__reserve_resources_late () 0xffffffff83e03210 in pcibios_resource_survey () 0xffffffff83e04f4a in pcibios_init () Which produces a call to reserve the CFMWS area: (gdb) p *new $54 = {start = 0x290000000, end = 0x2cfffffff, name = "Reserved", flags = 0x200, desc = 0x7, parent = 0x0, sibling = 0x0, child = 0x0} Later the Kernel parses ACPI tables and reserves the exact same area as the CXL Fixed Memory Window: 0xffffffff811016a4 in insert_resource_conflict () insert_resource () 0xffffffff81a81389 in cxl_parse_cfmws () 0xffffffff818c4a81 in call_handler () acpi_parse_entries_array () (gdb) p/x *new $59 = {start = 0x290000000, end = 0x2cfffffff, name = "CXL Window 0", flags = 0x200, desc = 0x0, parent = 0x0, sibling = 0x0, child = 0x0} This produces the following output in /proc/iomem: 590000000-68fffffff : CXL Window 0 590000000-68fffffff : Reserved This reserved area causes `get_free_mem_region()` to fail due to a check against `__region_intersects()`. Due to this reserved area, the intersect check will only ever return REGION_INTERSECTS, which causes `cxl create-region` to always fail. Signed-off-by: Gregory Price Message-Id: <20221026205912.8579-1-gregory.price@memverge.com> Reviewed-by: Michael S. Tsirkin Signed-off-by: Michael S. Tsirkin Acked-by: Jonathan Cameron --- hw/i386/pc.c | 2 -- 1 file changed, 2 deletions(-) diff --git a/hw/i386/pc.c b/hw/i386/pc.c index ef14da5094..546b703cb4 100644 --- a/hw/i386/pc.c +++ b/hw/i386/pc.c @@ -1061,7 +1061,6 @@ void pc_memory_init(PCMachineState *pcms, hwaddr cxl_size = MiB; cxl_base = pc_get_cxl_range_start(pcms); - e820_add_entry(cxl_base, cxl_size, E820_RESERVED); memory_region_init(mr, OBJECT(machine), "cxl_host_reg", cxl_size); memory_region_add_subregion(system_memory, cxl_base, mr); cxl_resv_end = cxl_base + cxl_size; @@ -1077,7 +1076,6 @@ void pc_memory_init(PCMachineState *pcms, memory_region_init_io(&fw->mr, OBJECT(machine), &cfmws_ops, fw, "cxl-fixed-memory-region", fw->size); memory_region_add_subregion(system_memory, fw->base, &fw->mr); - e820_add_entry(fw->base, fw->size, E820_RESERVED); cxl_fmw_base += fw->size; cxl_resv_end = cxl_fmw_base; }