From patchwork Mon Dec 13 10:46:31 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Maxim Levitsky X-Patchwork-Id: 12673703 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 45E59C433F5 for ; Mon, 13 Dec 2021 10:48:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234458AbhLMKsK (ORCPT ); Mon, 13 Dec 2021 05:48:10 -0500 Received: from us-smtp-delivery-124.mimecast.com ([170.10.129.124]:39503 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230033AbhLMKsJ (ORCPT ); Mon, 13 Dec 2021 05:48:09 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1639392488; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=jnXL5IiyKlqaAw3UKpSxxZyirByxfhySDRurZ1Ij+oA=; b=LSvT6HTwg1+tCPJReYwkLDU22+VgBlyu3xyhh01babzCRP/17R1CA1mHKUGRpUUNFO6l5Y j/sBmfB+zczxSdpYIR7pmt7UA2GKibQkRJWuFDRCVTT1Pl+5RQBhK4CEVtAOEj3YA/q4vv V4lvqLUyiMXJ9jwwOthP7mTR4LM+jkU= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-537-XBVA_j1IOd2ehJoQPF96TQ-1; Mon, 13 Dec 2021 05:48:05 -0500 X-MC-Unique: XBVA_j1IOd2ehJoQPF96TQ-1 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 9D49664083; Mon, 13 Dec 2021 10:48:03 +0000 (UTC) Received: from localhost.localdomain (unknown [10.40.192.24]) by smtp.corp.redhat.com (Postfix) with ESMTP id D46595F70B; Mon, 13 Dec 2021 10:47:49 +0000 (UTC) From: Maxim Levitsky To: kvm@vger.kernel.org Cc: Jim Mattson , Thomas Gleixner , Joerg Roedel , x86@kernel.org (maintainer:X86 ARCHITECTURE (32-BIT AND 64-BIT)), Vitaly Kuznetsov , Borislav Petkov , linux-kernel@vger.kernel.org, Paolo Bonzini , Dave Hansen , "H. Peter Anvin" , Sean Christopherson , Wanpeng Li , Ingo Molnar , Maxim Levitsky Subject: [PATCH v2 2/5] KVM: SVM: allow to force AVIC to be enabled Date: Mon, 13 Dec 2021 12:46:31 +0200 Message-Id: <20211213104634.199141-3-mlevitsk@redhat.com> In-Reply-To: <20211213104634.199141-1-mlevitsk@redhat.com> References: <20211213104634.199141-1-mlevitsk@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org Apparently on some systems AVIC is disabled in CPUID but still usable. Allow the user to override the CPUID if the user is willing to take the risk. Signed-off-by: Maxim Levitsky --- arch/x86/kvm/svm/svm.c | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-) diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c index c9668a3b51011..468cc385c35f0 100644 --- a/arch/x86/kvm/svm/svm.c +++ b/arch/x86/kvm/svm/svm.c @@ -206,6 +206,9 @@ module_param(tsc_scaling, int, 0444); static bool avic; module_param(avic, bool, 0444); +static bool force_avic; +module_param_unsafe(force_avic, bool, 0444); + bool __read_mostly dump_invalid_vmcb; module_param(dump_invalid_vmcb, bool, 0644); @@ -4656,10 +4659,14 @@ static __init int svm_hardware_setup(void) nrips = false; } - enable_apicv = avic = avic && npt_enabled && boot_cpu_has(X86_FEATURE_AVIC); + enable_apicv = avic = avic && npt_enabled && (boot_cpu_has(X86_FEATURE_AVIC) || force_avic); if (enable_apicv) { - pr_info("AVIC enabled\n"); + if (!boot_cpu_has(X86_FEATURE_AVIC)) { + pr_warn("AVIC is not supported in CPUID but force enabled"); + pr_warn("Your system might crash and burn"); + } else + pr_info("AVIC enabled\n"); amd_iommu_register_ga_log_notifier(&avic_ga_log_notifier); } else {