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 0429CD80550 for ; Tue, 13 Feb 2024 14:55:28 +0000 (UTC) DKIM-Signature: a=rsa-sha256; bh=GxkH13toKlnjQqX9ehSyDCaCNmOu59umbKFCpshGk1E=; 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=1707836127; v=1; b=MLvJxBJYCfQPgi/AkUd0VbWiVvWuczbq/yMYz544Ak95oGOf1zNzZrp3kb0Sbhecg1SkOXz2 yzOQsaiA1ujgfMwXRp18OpR7n2LrcRRSFfp0fSIE75UUVQ2TYij85OvIke2j2H4+/TdZMDnZIra dJlt4/72keJAxzHI9IjMGIn4= X-Received: by 127.0.0.2 with SMTP id RFe6YY7687511xvdCbrOnlk7; Tue, 13 Feb 2024 06:55:27 -0800 X-Received: from mail-vs1-f53.google.com (mail-vs1-f53.google.com [209.85.217.53]) by mx.groups.io with SMTP id smtpd.web11.13506.1707836127036865832 for ; Tue, 13 Feb 2024 06:55:27 -0800 X-Received: by mail-vs1-f53.google.com with SMTP id ada2fe7eead31-46d5f87548fso2394414137.0 for ; Tue, 13 Feb 2024 06:55:26 -0800 (PST) X-Gm-Message-State: pLoO8EbzWB0Qp7hE1Rn8VlPVx7686176AA= X-Google-Smtp-Source: AGHT+IHY37AK9nLl9etur12NIYLD8jLs5wbX2yzGYK0bOYxJUbAO0447Ng/l3qXJDeUcKRamC2vV2k23gFy4LxEbvIU= X-Received: by 2002:a67:f3cf:0:b0:46e:c3e4:297d with SMTP id j15-20020a67f3cf000000b0046ec3e4297dmr2835858vsn.11.1707836125097; Tue, 13 Feb 2024 06:55:25 -0800 (PST) MIME-Version: 1.0 References: <20240213085925.687848-1-kraxel@redhat.com> <64005185-3cfd-de56-f086-da301aff13ba@redhat.com> In-Reply-To: From: "Pedro Falcato" Date: Tue, 13 Feb 2024 14:55:13 +0000 Message-ID: Subject: Re: [edk2-devel] [PATCH 1/1] OvmfPkg/QemuVideoDxe: purge VbeShim To: devel@edk2.groups.io, kraxel@redhat.com Cc: 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,pedro.falcato@gmail.com 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=MLvJxBJY; spf=pass (spool.mail.gandi.net: domain of bounce@groups.io designates 66.175.222.108 as permitted sender) smtp.mailfrom=bounce@groups.io; dmarc=fail reason="SPF not aligned (relaxed), DKIM not aligned (relaxed)" header.from=gmail.com (policy=none) On Tue, Feb 13, 2024 at 2:02=E2=80=AFPM Gerd Hoffmann w= rote: > > 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 sp= ace > > > 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 -- accordi= ng > > > 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 mo= de you are seeing). > > Because, (a) in the code that's being removed in this patch, I don't se= e any ASSERT() that should fire, and (b) I cannot reproduce the issue. (In = 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): In= t0x10->Segment =3D=3D 0x0000 > > It reproduces for me when booting with a bunch of hot-pluggable CPUs (qem= u -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? :) --=20 Pedro -=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 (#115384): https://edk2.groups.io/g/devel/message/115384 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-