From nobody Sat Feb 7 21:08:09 2026 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 195F4C88CB2 for ; Tue, 13 Jun 2023 07:13:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239069AbjFMHNY (ORCPT ); Tue, 13 Jun 2023 03:13:24 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55506 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238669AbjFMHNV (ORCPT ); Tue, 13 Jun 2023 03:13:21 -0400 Received: from linux.microsoft.com (linux.microsoft.com [13.77.154.182]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 4CF0ECE; Tue, 13 Jun 2023 00:13:19 -0700 (PDT) Received: from linuxonhyperv3.guj3yctzbm1etfxqx2vob5hsef.xx.internal.cloudapp.net (linux.microsoft.com [13.77.154.182]) by linux.microsoft.com (Postfix) with ESMTPSA id AF6D320FE88D; Tue, 13 Jun 2023 00:13:18 -0700 (PDT) DKIM-Filter: OpenDKIM Filter v2.11.0 linux.microsoft.com AF6D320FE88D DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.microsoft.com; s=default; t=1686640398; bh=/PT81JOy5+bQnTFFKIvi5pPXC/tbbHKChswSnu/pguk=; h=From:To:Subject:Date:From; b=V0Db+28uycwdF4LyY20ikpS4q2z84hTbVu/y2Alw28k2dkzMg2Q1YQnUHdjrk98ry 0pUJQZh+OXbB+VMThRoCMf69fz/KXJ/NSBt/Ax/a++xb93ROR30TTIKXmIDGDYYlUE MFwpCm1c25Ul/GVzqCnmYWc9GoP+owhi/j9ncVpM= From: Saurabh Sengar To: kys@microsoft.com, haiyangz@microsoft.com, wei.liu@kernel.org, decui@microsoft.com, tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, dave.hansen@linux.intel.com, x86@kernel.org, mikelley@microsoft.com, linux-kernel@vger.kernel.org, linux-hyperv@vger.kernel.org, hpa@zytor.com Subject: [PATCH v2] x86/hyperv: add noop functions to x86_init mpparse functions Date: Tue, 13 Jun 2023 00:13:11 -0700 Message-Id: <1686640391-13001-1-git-send-email-ssengar@linux.microsoft.com> X-Mailer: git-send-email 1.8.3.1 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" In certain configurations, VTL0 and VTL2 can share the same VM partition and hence share the same memory address space. In such systems VTL2 has visibility of all of the VTL0 memory space. When CONFIG_X86_MPPARSE is enabled for VTL2, the kernel performs a scan of low memory to search for MP tables. However, in systems where VTL0 controls the low memory and may contain valid tables specific to VTL0, this scanning process can lead to confusion within the VTL2 kernel. In !ACPI system, there is no way to disable CONFIG_X86_MPPARSE hence add the noop function instead. Signed-off-by: Saurabh Sengar --- [V2]: Improve commit message arch/x86/hyperv/hv_vtl.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/arch/x86/hyperv/hv_vtl.c b/arch/x86/hyperv/hv_vtl.c index 85d38b9f3586..db5d2ea39fc0 100644 --- a/arch/x86/hyperv/hv_vtl.c +++ b/arch/x86/hyperv/hv_vtl.c @@ -25,6 +25,10 @@ void __init hv_vtl_init_platform(void) x86_init.irqs.pre_vector_init =3D x86_init_noop; x86_init.timers.timer_init =3D x86_init_noop; =20 + /* Avoid searching for BIOS MP tables */ + x86_init.mpparse.find_smp_config =3D x86_init_noop; + x86_init.mpparse.get_smp_config =3D x86_init_uint_noop; + x86_platform.get_wallclock =3D get_rtc_noop; x86_platform.set_wallclock =3D set_rtc_noop; x86_platform.get_nmi_reason =3D hv_get_nmi_reason; --=20 2.34.1