From nobody Tue Feb 10 12:39:43 2026 Delivered-To: importer@patchew.org Received-SPF: pass (zohomail.com: domain of groups.io designates 66.175.222.108 as permitted sender) client-ip=66.175.222.108; envelope-from=bounce+27952+104260+1787277+3901457@groups.io; helo=mail02.groups.io; Authentication-Results: mx.zohomail.com; dkim=pass; spf=pass (zohomail.com: domain of groups.io designates 66.175.222.108 as permitted sender) smtp.mailfrom=bounce+27952+104260+1787277+3901457@groups.io; dmarc=fail(p=none dis=none) header.from=intel.com ARC-Seal: i=1; a=rsa-sha256; t=1683533858; cv=none; d=zohomail.com; s=zohoarc; b=BRaTlsoMMyVrreO+ORampc8SqrpwiKVVJgVRjvJ1SrosX9PwRlRr6W0VR/BhsnuHNOvWl7qrGE/pm3viVeVVfGVf/pPi1NaiWm3WgAB/vFxUSMqVKHt7mcNstQQh9YF2+eWSRkiwHGLmHt5S6dEgdAA7+CBVvNGdKTgA0Qi/P1o= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=zohomail.com; s=zohoarc; t=1683533858; h=Content-Transfer-Encoding:Cc:Date:From:In-Reply-To:List-Subscribe:List-Id:List-Help:List-Unsubscribe:MIME-Version:Message-ID:Reply-To:References:Sender:Subject:To; bh=xpJ6NYupmjTqmatorYX8QdHkzkpAesfuypJ4ngshDIk=; b=B0M2AoWCRIGcTgS2njvx3+vJXtSkq6yMmNxcaVVaN/p9OtTz5FJzqITeqZ6HmK2XalLgl6Saq7G2F20xkr4NbYQ6o0j/c0eWAxiD5FQzG2pAhOfYh6Z1PpWY4U3kLgs0TP8BXV1UTD+Uu73w/4L1dRShoTymtl/juiSkI190dR0= ARC-Authentication-Results: i=1; mx.zohomail.com; dkim=pass; spf=pass (zohomail.com: domain of groups.io designates 66.175.222.108 as permitted sender) smtp.mailfrom=bounce+27952+104260+1787277+3901457@groups.io; dmarc=fail header.from= (p=none dis=none) Received: from mail02.groups.io (mail02.groups.io [66.175.222.108]) by mx.zohomail.com with SMTPS id 1683533858363254.1732863556573; Mon, 8 May 2023 01:17:38 -0700 (PDT) Return-Path: X-Received: by 127.0.0.2 with SMTP id SHy2YY1788612xk8RaguvVb1; Mon, 08 May 2023 01:17:38 -0700 X-Received: from mga17.intel.com (mga17.intel.com [192.55.52.151]) by mx.groups.io with SMTP id smtpd.web11.102325.1683533854228983101 for ; Mon, 08 May 2023 01:17:37 -0700 X-IronPort-AV: E=McAfee;i="6600,9927,10703"; a="329948476" X-IronPort-AV: E=Sophos;i="5.99,258,1677571200"; d="scan'208";a="329948476" X-Received: from orsmga001.jf.intel.com ([10.7.209.18]) by fmsmga107.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 08 May 2023 01:17:12 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6600,9927,10703"; a="731219054" X-IronPort-AV: E=Sophos;i="5.99,258,1677571200"; d="scan'208";a="731219054" X-Received: from shwdesfp01.ccr.corp.intel.com ([10.239.158.151]) by orsmga001-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 08 May 2023 01:17:10 -0700 From: "Zhiguang Liu" To: devel@edk2.groups.io Cc: Zhiguang Liu , Eric Dong , Ray Ni , Rahul Kumar , Gerd Hoffmann , Debkumar De , Catharine West Subject: [edk2-devel] [PATCH v5 4/5] UefiCpuPkg/ResetVector: Modify Page Table in ResetVector Date: Mon, 8 May 2023 16:15:03 +0800 Message-Id: <20230508081504.1067-5-zhiguang.liu@intel.com> In-Reply-To: <20230508081504.1067-1-zhiguang.liu@intel.com> References: <20230508081504.1067-1-zhiguang.liu@intel.com> MIME-Version: 1.0 Precedence: Bulk List-Unsubscribe: List-Subscribe: List-Help: Sender: devel@edk2.groups.io List-Id: Mailing-List: list devel@edk2.groups.io; contact devel+owner@edk2.groups.io Reply-To: devel@edk2.groups.io,zhiguang.liu@intel.com X-Gm-Message-State: uzRyKVy4nkme08NEZmDtSLa5x1787277AA= Content-Transfer-Encoding: quoted-printable DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=groups.io; q=dns/txt; s=20140610; t=1683533858; bh=pK7XzfIjB9+6zOos7xY6K5QKHd5dKPbujMoAFqniHXk=; h=Cc:Date:From:Reply-To:Subject:To; b=v3/f+W+7Rx5LmQ3y/YEc/T+OhleFVRoW2jA871VYA7ni4JZO0ugdfFAV8pBw9MX1fTb 1wE3sK2/W1/qWlt786otiTJkTNvKz0AmGv9ZYHR8yq/xmmeQpKTFeH/sOWabF5NJ/QrBL 86SQLHwziEoQZEiYQc/4Ml2oN0JyVi5SA1o= X-ZohoMail-DKIM: pass (identity @groups.io) X-ZM-MESSAGEID: 1683533859439100004 Content-Type: text/plain; charset="utf-8" In ResetVector, if create page table, its highest address is fixed because after page table, code layout is fixed(4K for normal code, and another 4K only contains reset vector code). Today's implementation organizes the page table as following if 1G page table is used: 4G-16K: PML4 page (PML4[0] points to 4G-12K) 4G-12K: PDP page CR3 is set to 4G-16K When 2M page table is used, the layout is as following: 4G-32K: PML4 page (PML4[0] points to 4G-28K) 4G-28K: PDP page (PDP entries point to PD pages) 4G-24K: PD page mapping 0-1G 4G-20K: PD page mapping 1-2G 4G-16K: PD page mapping 2-3G 4G-12K: PD page mapping 3-4G CR3 is set to 4G-32K CR3 doesn't point to a fixed location which is a bit hard to debug at runtime. The new page table layout will always put PML4 in highest address When 1G page table is used, the layout is as following: 4G-16K: PDP page 4G-12K: PML4 page (PML4[0] points to 4G-16K) When 2M page table is used, the layout is as following: 4G-32K: PD page mapping 0-1G 4G-28K: PD page mapping 1-2G 4G-24K: PD page mapping 2-3G 4G-20K: PD page mapping 3-4G 4G-16K: PDP page (PDP entries point to PD pages) 4G-12K: PML4 page (PML4[0] points to 4G-16K) CR3 is always set to 4G-12K So, this patch can improve debuggability by make sure the init CR3 pointing to a fixed address(4G-12K). Cc: Eric Dong Cc: Ray Ni Cc: Rahul Kumar Cc: Gerd Hoffmann Cc: Debkumar De Cc: Catharine West Signed-off-by: Zhiguang Liu --- .../ResetVector/Vtf0/X64/PageTables.asm | 33 ++++++++++--------- 1 file changed, 17 insertions(+), 16 deletions(-) diff --git a/UefiCpuPkg/ResetVector/Vtf0/X64/PageTables.asm b/UefiCpuPkg/Re= setVector/Vtf0/X64/PageTables.asm index 9b492b063f..d66fb62c34 100644 --- a/UefiCpuPkg/ResetVector/Vtf0/X64/PageTables.asm +++ b/UefiCpuPkg/ResetVector/Vtf0/X64/PageTables.asm @@ -41,13 +41,6 @@ BITS 64 =20 ALIGN 16 =20 -Pml4: - ; - ; PML4 (1 * 512GB entry) - ; - DQ PAGE_NLE(Pdp) - TIMES 0x1000 - ($ - Pml4) DB 0 - %ifdef PAGE_TABLE_1G Pdp: ; @@ -59,15 +52,6 @@ Pdp: %assign i i+1 %endrep %else -Pdp: - ; - ; Page-directory pointer table (4 * 1GB entries =3D> 4GB) - ; - DQ PAGE_NLE(Pd) - DQ PAGE_NLE(Pd + 0x1000) - DQ PAGE_NLE(Pd + 0x2000) - DQ PAGE_NLE(Pd + 0x3000) - TIMES 0x1000 - ($ - Pdp) DB 0 =20 Pd: ; @@ -79,5 +63,22 @@ Pd: DQ PAGE_PDE_2MB(i) %assign i i+1 %endrep +Pdp: + ; + ; Page-directory pointer table (4 * 1GB entries =3D> 4GB) + ; + DQ PAGE_NLE(Pd) + DQ PAGE_NLE(Pd + 0x1000) + DQ PAGE_NLE(Pd + 0x2000) + DQ PAGE_NLE(Pd + 0x3000) + TIMES 0x1000 - ($ - Pdp) DB 0 + %endif + +Pml4: + ; + ; PML4 (1 * 512GB entry) + ; + DQ PAGE_NLE(Pdp) + TIMES 0x1000 - ($ - Pml4) DB 0 EndOfPageTables: --=20 2.31.1.windows.1 -=3D-=3D-=3D-=3D-=3D-=3D-=3D-=3D-=3D-=3D-=3D- Groups.io Links: You receive all messages sent to this group. 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