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 X-Spam-Level: X-Spam-Status: No, score=-26.3 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT, USER_IN_DEF_DKIM_WL autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id B009AC433B4 for ; Wed, 21 Apr 2021 14:07:09 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7753961457 for ; Wed, 21 Apr 2021 14:07:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S243338AbhDUOHk (ORCPT ); Wed, 21 Apr 2021 10:07:40 -0400 Received: from linux.microsoft.com ([13.77.154.182]:36990 "EHLO linux.microsoft.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S243325AbhDUOHi (ORCPT ); Wed, 21 Apr 2021 10:07:38 -0400 Received: from viremana-dev.fwjladdvyuiujdukmejncen4mf.xx.internal.cloudapp.net (unknown [13.66.132.26]) by linux.microsoft.com (Postfix) with ESMTPSA id BB3C320B8002; Wed, 21 Apr 2021 07:07:04 -0700 (PDT) DKIM-Filter: OpenDKIM Filter v2.11.0 linux.microsoft.com BB3C320B8002 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.microsoft.com; s=default; t=1619014024; bh=Ej89Qm9LLMSPxt8OXtylVuc32Z7Yd+HfBt+EQT9qOcM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=e1hmnl5o7jJjdPHO+UTWuZZfRw6460kHg7YwZrt8dptet2McqPR/Pl9m8lewDv5Zj a4ABS+9+myFvA0jjAxPyihFnGMPyE1ng5SlXP+1FpLVbz4Vtbpg0LAWXevVXm+XitC kBOJtjq0/g1lZ1VwRbtu0gp2T+Y22a9j6g4AiJOE= From: Vineeth Pillai To: Lan Tianyu , Michael Kelley , Paolo Bonzini , Sean Christopherson , Vitaly Kuznetsov , Wanpeng Li , Jim Mattson , Joerg Roedel , Wei Liu , Stephen Hemminger , Haiyang Zhang Cc: Vineeth Pillai , "H. Peter Anvin" , Thomas Gleixner , Ingo Molnar , Borislav Petkov , "K. Y. Srinivasan" , x86@kernel.org, kvm@vger.kernel.org, linux-kernel@vger.kernel.org, linux-hyperv@vger.kernel.org Subject: [PATCH v3 1/7] hyperv: Detect Nested virtualization support for SVM Date: Wed, 21 Apr 2021 14:06:48 +0000 Message-Id: <9d832252e556f4eddacf9a2b33008fbcf993a44b.1619013347.git.viremana@linux.microsoft.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: References: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-hyperv@vger.kernel.org Previously, to detect nested virtualization enlightenment support, we were using HV_X64_ENLIGHTENED_VMCS_RECOMMENDED feature bit of HYPERV_CPUID_ENLIGHTMENT_INFO.EAX CPUID as docuemented in TLFS: "Bit 14: Recommend a nested hypervisor using the enlightened VMCS interface. Also indicates that additional nested enlightenments may be available (see leaf 0x4000000A)". Enlightened VMCS, however, is an Intel only feature so the above detection method doesn't work for AMD. So, use the HYPERV_CPUID_VENDOR_AND_MAX_FUNCTIONS.EAX CPUID information ("The maximum input value for hypervisor CPUID information.") and this works for both AMD and Intel. Signed-off-by: Vineeth Pillai --- arch/x86/kernel/cpu/mshyperv.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-) diff --git a/arch/x86/kernel/cpu/mshyperv.c b/arch/x86/kernel/cpu/mshyperv.c index 3546d3e21787..c6f812851e37 100644 --- a/arch/x86/kernel/cpu/mshyperv.c +++ b/arch/x86/kernel/cpu/mshyperv.c @@ -252,6 +252,7 @@ static void __init hv_smp_prepare_cpus(unsigned int max_cpus) static void __init ms_hyperv_init_platform(void) { + int hv_max_functions_eax; int hv_host_info_eax; int hv_host_info_ebx; int hv_host_info_ecx; @@ -269,6 +270,8 @@ static void __init ms_hyperv_init_platform(void) ms_hyperv.misc_features = cpuid_edx(HYPERV_CPUID_FEATURES); ms_hyperv.hints = cpuid_eax(HYPERV_CPUID_ENLIGHTMENT_INFO); + hv_max_functions_eax = cpuid_eax(HYPERV_CPUID_VENDOR_AND_MAX_FUNCTIONS); + pr_info("Hyper-V: privilege flags low 0x%x, high 0x%x, hints 0x%x, misc 0x%x\n", ms_hyperv.features, ms_hyperv.priv_high, ms_hyperv.hints, ms_hyperv.misc_features); @@ -298,8 +301,7 @@ static void __init ms_hyperv_init_platform(void) /* * Extract host information. */ - if (cpuid_eax(HYPERV_CPUID_VENDOR_AND_MAX_FUNCTIONS) >= - HYPERV_CPUID_VERSION) { + if (hv_max_functions_eax >= HYPERV_CPUID_VERSION) { hv_host_info_eax = cpuid_eax(HYPERV_CPUID_VERSION); hv_host_info_ebx = cpuid_ebx(HYPERV_CPUID_VERSION); hv_host_info_ecx = cpuid_ecx(HYPERV_CPUID_VERSION); @@ -325,9 +327,11 @@ static void __init ms_hyperv_init_platform(void) ms_hyperv.isolation_config_a, ms_hyperv.isolation_config_b); } - if (ms_hyperv.hints & HV_X64_ENLIGHTENED_VMCS_RECOMMENDED) { + if (hv_max_functions_eax >= HYPERV_CPUID_NESTED_FEATURES) { ms_hyperv.nested_features = cpuid_eax(HYPERV_CPUID_NESTED_FEATURES); + pr_info("Hyper-V: Nested features: 0x%x\n", + ms_hyperv.nested_features); } /* -- 2.25.1