From mboxrd@z Thu Jan 1 00:00:00 1970 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 8100EC001B3 for ; Fri, 23 Jun 2023 16:28:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232013AbjFWQ2Q (ORCPT ); Fri, 23 Jun 2023 12:28:16 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42548 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231773AbjFWQ2Q (ORCPT ); Fri, 23 Jun 2023 12:28:16 -0400 Received: from linux.microsoft.com (linux.microsoft.com [13.77.154.182]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 2E73E2710; Fri, 23 Jun 2023 09:28:15 -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 8FD8D21C2534; Fri, 23 Jun 2023 09:28:14 -0700 (PDT) DKIM-Filter: OpenDKIM Filter v2.11.0 linux.microsoft.com 8FD8D21C2534 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.microsoft.com; s=default; t=1687537694; bh=uUfUVqQEgw+ilqrVChAV82J5lEYGJvj7rlgWsv6YSw4=; h=From:To:Subject:Date:From; b=cqHRvziEAvf0RxzqcfNW+exJH4CcnrVS1eBGZD39s6fAfgq3ftupa+o/VlRst20Sm jeNNVPXTHHDXiUcvLVk9cuosBriMbnXql3akrDHZNRcSnm5G8EdmkF3XnPdDV8WxM8 QGpjZW9Zf6aUmU9/1zP/rGKjQL1YmxORyyDuV2yM= 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 v3] x86/hyperv: add noop functions to x86_init mpparse functions Date: Fri, 23 Jun 2023 09:28:08 -0700 Message-Id: <1687537688-5397-1-git-send-email-ssengar@linux.microsoft.com> X-Mailer: git-send-email 1.8.3.1 Precedence: bulk List-ID: X-Mailing-List: linux-hyperv@vger.kernel.org Hyper-V can run VMs at different privilege "levels" known as Virtual Trust Levels (VTL). Sometimes, it chooses to run two different VMs at different levels but they share some of their address space. In such setups VTL2 (higher level VM) has visibility of all of the VTL0 (level 0) memory space. When the CONFIG_X86_MPPARSE is enabled for VTL2, the VTL2 kernel performs a search within the low memory to locate MP tables. However, in systems where VTL0 manages the low memory and may contain valid tables, this scanning can result in incorrect MP table information being provided to the VTL2 kernel, mistakenly considering VTL0's MP table as its own Add noop functions to avoid MP parse scan by VTL2. Signed-off-by: Saurabh Sengar --- [V3] - modify 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 = x86_init_noop; x86_init.timers.timer_init = x86_init_noop; + /* Avoid searching for BIOS MP tables */ + x86_init.mpparse.find_smp_config = x86_init_noop; + x86_init.mpparse.get_smp_config = x86_init_uint_noop; + x86_platform.get_wallclock = get_rtc_noop; x86_platform.set_wallclock = set_rtc_noop; x86_platform.get_nmi_reason = hv_get_nmi_reason; -- 2.34.1