From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by mx.groups.io with SMTP id smtpd.web10.227.1684853942728408083 for ; Tue, 23 May 2023 07:59:02 -0700 Authentication-Results: mx.groups.io; dkim=pass header.i=@kernel.org header.s=k20201202 header.b=oqH+CcSr; spf=pass (domain: kernel.org, ip: 139.178.84.217, mailfrom: ardb@kernel.org) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 31CC062987 for ; Tue, 23 May 2023 14:59:02 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 9368CC4339C for ; Tue, 23 May 2023 14:59:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1684853941; bh=Efgowx+NmcPyevklWn/tUtsvEAVM1DfVaGBaYx6lzL4=; h=References:In-Reply-To:From:Date:Subject:To:Cc:From; b=oqH+CcSrLfC7CXWRonDFz3XxZIjypV22hSpQeX92lscJZdOoLJQwsRrKL+2vUQCje vQ0NLGwtmppUuNW2qOGBlKFKBnGhwo6P77dV6exD5Z9GxrA2BYVvQp68X6iq5kHeQy 0Vy1n58GBNR4Vi0FqNtL0IvbEfTI5Jxjkanc4BenK60t9cLOH2dKlGzzSyGCM5QZW5 vLNfYLa544vkKWu0DLYh8Oup73puFZDQfzMUKhyAWX+IfBgCeLOGYLViIiqpRvAvlq iIU8fSw6p6uWnmU6ljwfp1rfIa0+bIfMDOkMh59Tf+/U9sDM53W3sITb0e4dDg0jmD ADRDlFwHcRRfw== Received: by mail-lf1-f43.google.com with SMTP id 2adb3069b0e04-4f3bb395e69so3641831e87.2 for ; Tue, 23 May 2023 07:59:01 -0700 (PDT) X-Gm-Message-State: AC+VfDwmLk5YAmxTCHNli3RJBtg9N2vS6oa/EZYEaQ1Rxe+Ia8cEV6Le g5u9g7mea4n4onRpWXEO5bWrQ1u0DkVYz6HgtL8= X-Google-Smtp-Source: ACHHUZ6H3LKLuSn0j8lg6DY0Ew/HbPotDCxXlG2E/owWaQJ+tz73Z5Ky9/NYnMv3NjCC6Vwt0M8X31bph/VSMMc8ZLY= X-Received: by 2002:ac2:4352:0:b0:4f0:124:b56b with SMTP id o18-20020ac24352000000b004f00124b56bmr4380968lfl.7.1684853939477; Tue, 23 May 2023 07:58:59 -0700 (PDT) MIME-Version: 1.0 References: <1718e8ad-6ba3-5da8-85c5-76e48c42110d@redhat.com> <2e04e9da-5b5a-9c00-76fe-c149538ddc80@redhat.com> In-Reply-To: From: "Ard Biesheuvel" Date: Tue, 23 May 2023 16:58:47 +0200 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: [edk2-devel] managing memory attributes in PEI To: "Kinney, Michael D" Cc: "devel@edk2.groups.io" , "lersek@redhat.com" , "Ni, Ray" , "Yao, Jiewen" , Gerd Hoffmann , Taylor Beebe , Oliver Smith-Denny Content-Type: text/plain; charset="UTF-8" On Tue, 23 May 2023 at 16:49, Kinney, Michael D wrote: > > Ard, > > I would prefer to keep the IA32 PEI support for OVMF. > Sure. But does that imply that all enhancements regarding memory protections should be introduced there as well? If so, could you help figure out whether or not running IA32 PEI in 32-bit compatible long mode with 4 level page tables would be feasible? That would greatly reduce the complexity, given that PEI and DXE will be able to share page tables, and will only need one version of the page table logic. > Ray had proposed an idea to introduce a library class to help > with the DXEIPL complexity. Perhaps that can be combines with > this effort. > Indeed. But the problem remains that creating a set of page tables that are incompatible with the present execution mode is highly specific to IA32 PEI + X64 DXE, and this impacts the code for all other architectures.