From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail02.groups.io (mail02.groups.io [66.175.222.108]) by spool.mail.gandi.net (Postfix) with ESMTPS id AF375740035 for ; Tue, 13 Feb 2024 14:56:42 +0000 (UTC) DKIM-Signature: a=rsa-sha256; bh=kA0uM3VCkMk4u3DDcLlpl6YHAJzSCmrNHELpWSMypzM=; c=relaxed/simple; d=groups.io; h=MIME-Version:References:In-Reply-To:From:Date:Message-ID:Subject:To:Cc:Precedence:List-Subscribe:List-Help:Sender:List-Id:Mailing-List:Delivered-To:Reply-To:List-Unsubscribe-Post:List-Unsubscribe:Content-Type:Content-Transfer-Encoding; s=20140610; t=1707836201; v=1; b=SlwNxaCdBURpsZTgDX74ZqcdIbume96zfZ9KcXmbOWw6a2FaDTKMwsOR6VAG9+d/KfE6sI8+ ns8iIwYTlXZtmjwugvs1ByakRYH6CdQARWiV/qDJjfs0IdhINAslQ5Hi5MCQQNxZatvfMDd4qun v1mqYtqSBtJI5okauK5fNZdA= X-Received: by 127.0.0.2 with SMTP id yGlFYY7687511xkzwJp4kkR6; Tue, 13 Feb 2024 06:56:41 -0800 X-Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by mx.groups.io with SMTP id smtpd.web11.13541.1707836200779679695 for ; Tue, 13 Feb 2024 06:56:40 -0800 X-Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by dfw.source.kernel.org (Postfix) with ESMTP id 3F0D1614B9 for ; Tue, 13 Feb 2024 14:56:40 +0000 (UTC) X-Received: by smtp.kernel.org (Postfix) with ESMTPSA id DD962C433B1 for ; Tue, 13 Feb 2024 14:56:39 +0000 (UTC) X-Received: by mail-lf1-f49.google.com with SMTP id 2adb3069b0e04-5114c05806eso7114825e87.1 for ; Tue, 13 Feb 2024 06:56:39 -0800 (PST) X-Gm-Message-State: 9CwTt9WMbsnvLHHevDCn7Gtbx7686176AA= X-Google-Smtp-Source: AGHT+IGoQxvlyte/4LhRfIfa1RcK53ebx/9ZqHmNV9CHsz5e1PVwlFh0OkEzudNbsQ5JiB8TYFjBGOBiSBWtO1rqEeA= X-Received: by 2002:ac2:4833:0:b0:511:4b70:76ca with SMTP id 19-20020ac24833000000b005114b7076camr6043848lft.58.1707836197972; Tue, 13 Feb 2024 06:56:37 -0800 (PST) MIME-Version: 1.0 References: <20240213085925.687848-1-kraxel@redhat.com> <64005185-3cfd-de56-f086-da301aff13ba@redhat.com> In-Reply-To: From: "Ard Biesheuvel" Date: Tue, 13 Feb 2024 15:56:26 +0100 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: [edk2-devel] [PATCH 1/1] OvmfPkg/QemuVideoDxe: purge VbeShim To: devel@edk2.groups.io, pedro.falcato@gmail.com Cc: kraxel@redhat.com, Laszlo Ersek , Oliver Steffen , Ard Biesheuvel , Jiewen Yao , dun.tan@intel.com Precedence: Bulk 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,ardb@kernel.org List-Unsubscribe-Post: List-Unsubscribe=One-Click List-Unsubscribe: Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-GND-Status: LEGIT Authentication-Results: spool.mail.gandi.net; dkim=pass header.d=groups.io header.s=20140610 header.b=SlwNxaCd; dmarc=fail reason="SPF not aligned (relaxed), DKIM not aligned (relaxed)" header.from=kernel.org (policy=none); spf=pass (spool.mail.gandi.net: domain of bounce@groups.io designates 66.175.222.108 as permitted sender) smtp.mailfrom=bounce@groups.io On Tue, 13 Feb 2024 at 15:55, Pedro Falcato wrote= : > > On Tue, Feb 13, 2024 at 2:02=E2=80=AFPM Gerd Hoffmann = wrote: > > > > On Tue, Feb 13, 2024 at 11:44:17AM +0100, Laszlo Ersek wrote: > > > Hi Gerd, > > > > > > On 2/13/24 09:59, Gerd Hoffmann wrote: > > > > Removing CSM support broke VbeShim. > > > > > > > > I see ASSERTS being triggered, both in vbeshim code and elsewhere. > > > > Didn't investigate in detail, but apparently the real mode address = space > > > > is not considered being special any more, which invalidates some > > > > assumptions of the vbeshim code. > > > > > > > > The guest os which depends on vbeshim for video support is -- accor= ding > > > > to the comments -- Windows 2008 R2. Which went EOL in January 2020= , > > > > more than four years ago. > > > > > > > > Time to retire VbeShim. RIP. > > > > > > I don't understand this, and/or disagree. > > > > > > (1) Please collect more information about the ASSERT()s (the failure = mode you are seeing). > > > Because, (a) in the code that's being removed in this patch, I don't = see any ASSERT() that should fire, and (b) I cannot reproduce the issue. (I= n fact my log contains "InstallVbeShim: VBE shim installed".) > > > > Fair enough. The ASSERT() I see firing is this: > > > > ASSERT /home/kraxel/projects/edk2/OvmfPkg/QemuVideoDxe/VbeShim.c(142): = Int0x10->Segment =3D=3D 0x0000 > > > > It reproduces for me when booting with a bunch of hot-pluggable CPUs (q= emu -smp 2,maxcpus=3D32). > > > > I bisected this, and it seems indeed totally unrelated to CSM removal: > > > > 725acd0b9cc047b20a1b9379e46f05d3ebcf485e is the first bad commit > > commit 725acd0b9cc047b20a1b9379e46f05d3ebcf485e > > Author: Dun Tan > > Date: Fri Dec 1 10:53:32 2023 +0800 > > > > UefiCpuPkg: Avoid assuming only one smmbasehob > > > > New theory: This is a NULL pointer dereference corrupting the zero page= . > > Tangentially related: Maybe it's time to unmap the NULL page? :) > That would break many 3rd party GPU and network drivers. -=3D-=3D-=3D-=3D-=3D-=3D-=3D-=3D-=3D-=3D-=3D- Groups.io Links: You receive all messages sent to this group. View/Reply Online (#115385): https://edk2.groups.io/g/devel/message/115385 Mute This Topic: https://groups.io/mt/104329097/7686176 Group Owner: devel+owner@edk2.groups.io Unsubscribe: https://edk2.groups.io/g/devel/unsub [rebecca@openfw.io] -=3D-=3D-=3D-=3D-=3D-=3D-=3D-=3D-=3D-=3D-=3D-