From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by mx.groups.io with SMTP id smtpd.web10.9472.1672993859831798076 for ; Fri, 06 Jan 2023 00:31:00 -0800 Authentication-Results: mx.groups.io; dkim=pass header.i=@redhat.com header.s=mimecast20190719 header.b=W+9uFfkF; spf=pass (domain: redhat.com, ip: 170.10.133.124, mailfrom: lersek@redhat.com) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1672993858; 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=RveJMuvxVeN6HldyaXUDwGEYO781j2uKWwucJGsx5wg=; b=W+9uFfkFuTLkYZn8KsBu9iUxOncIA8w8HUMAKYurjpJIN2OhVAGSOFVwxVtT7ZNxNBMYsj OVGizh0mC/xdwTDtf75dD4dKb7VSNRABS+pQKOcvR+t4R3SkWABrWavEjJY/713+5EL9tH kq7Y6RIXcWJ49WBvLgV8PHtTs0xi3Kw= 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-528-IbGmiOPPMf26mjQXQehHcQ-1; Fri, 06 Jan 2023 03:30:53 -0500 X-MC-Unique: IbGmiOPPMf26mjQXQehHcQ-1 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.rdu2.redhat.com [10.11.54.6]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id C186C802D1A; Fri, 6 Jan 2023 08:30:52 +0000 (UTC) Received: from [10.39.192.26] (unknown [10.39.192.26]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 4A9862166B30; Fri, 6 Jan 2023 08:30:51 +0000 (UTC) Message-ID: Date: Fri, 6 Jan 2023 09:30:49 +0100 MIME-Version: 1.0 Subject: Re: [edk2-devel] [PATCH] UefiCpuPkg:Fixed AsmRelocateApLoopStart and ensure allocated memory <4GB To: Gerd Hoffmann Cc: devel@edk2.groups.io, ray.ni@intel.com, "ardb@kernel.org" , "Xie, Yuanhao" , thomas.lendacky@amd.com References: <20230105062108.1796-1-yuanhao.xie@intel.com> <20230106080300.tsohpx24ddxjo5x4@sirius.home.kraxel.org> From: "Laszlo Ersek" In-Reply-To: <20230106080300.tsohpx24ddxjo5x4@sirius.home.kraxel.org> X-Scanned-By: MIMEDefang 3.1 on 10.11.54.6 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Language: en-US Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 1/6/23 09:03, Gerd Hoffmann wrote: > On Fri, Jan 06, 2023 at 07:42:20AM +0100, Laszlo Ersek wrote: >> On 1/6/23 05:12, Ni, Ray wrote: >>> >>> Ard, >>> >>> Only AMD X64 (including SEV and without SEV) runs the code that >>> switches to 32bit paging disabled mode. >>> Intel X64 runs the code that stays at 64bit paging mode. So no need >>> for <4G memory. >>> All IA32 CPUs (including intel and AMD) stays at 32bit paging disabled >>> mode. The AllocateReservedPages() call should not return a memory >>> above 4GB in 32bit env. >> >> This argument about the allocations sounds valid, thanks. >> >> The code still remains incredibly hard to read. It needs serious >> cleanup. >> >> (1) Wherever we have "Amd" in an identifier, let's rename it to "Amd64", >> to better reflect the revised check. > > Maybe even better: Use PcdConfidentialComputingGuestAttr to figure > whenever SEV is active, if so branch into Amd assembler code. Rename > "Amd" to "AmdSev". > > Otherwise just call normal X64 / Ia32 code. > > Amd assembler code can subsequently be simplified, the checks for SEV > are not needed any more (but should not harm either). > > [ Adding Tom to CC ] > >> Commit 73ccde8f6d04 ("UefiCpuPkg: Has APs in 64 bit long-mode before >> booting to OS.", 2022-12-20) *removed* the executable marking. >> >> (4a) Is that not a problem? > > I think so. Ah... OK, my fault: one should never ask questions in English the negative! :) So, based on your next paragraph, I think you agree that this *is* a problem. (I first thought you agreed with the lack of executable marking *not* being a problem -- again, my mistake for formulating the question in the negative!) > > Booting with strict NX checking (PcdDxeNxMemoryProtectionPolicy = > 0xC000000000007FD5) and "qemu -smp 2" makes my qemu hang with 200% CPU, > so probably both vcpus are spinning in a dead loop. For the BSP this is > expected behavior (buggy grub.efi, see parallel thread). For the AP it > is not, so apparently it is not running idle in hlt like it is supposed > to. > >> Honestly, at this point I'm *even more convinced* that the original >> series should be reverted, and redone from the ground up. > > Yes, "back to drawing board" looks like the best option at this point. Let me see if I can post a revert series today. Thanks Laszlo