From patchwork Mon Feb 7 15:54:33 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Maxim Levitsky X-Patchwork-Id: 12737576 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 95ACCC41535 for ; Mon, 7 Feb 2022 16:05:45 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1390514AbiBGQEM (ORCPT ); Mon, 7 Feb 2022 11:04:12 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38282 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S240006AbiBGP6r (ORCPT ); Mon, 7 Feb 2022 10:58:47 -0500 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 303D1C0401CE for ; Mon, 7 Feb 2022 07:58:47 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1644249526; 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=JIz72i323mNLi2DkTwdrDXZhWqpT5EG0EiEDO8eaza0=; b=Q2UMtfD/dqUHrm6Uq45HfDH27v2JGBDZjBGgqTuUdUYIn39LHUOtsCooloR5DDW1Xn+ZiA Jrx1QaTEBwxC5M/0i6JZ5M3A2QZ5vpHu73PH+KjvRQ3eDO/cVtJ+pKgkGuFSnGDKqp7Byq D7cpXjC06KpvQbpR5HuNcRjyz4Gopm4= 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-624-1uywd_D1N1C3NLAYKqlggA-1; Mon, 07 Feb 2022 10:58:43 -0500 X-MC-Unique: 1uywd_D1N1C3NLAYKqlggA-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 E95F4814503; Mon, 7 Feb 2022 15:58:39 +0000 (UTC) Received: from localhost.localdomain (unknown [10.40.192.15]) by smtp.corp.redhat.com (Postfix) with ESMTP id 896937DE5C; Mon, 7 Feb 2022 15:58:31 +0000 (UTC) From: Maxim Levitsky To: kvm@vger.kernel.org Cc: Tony Luck , "Chang S. Bae" , Thomas Gleixner , Wanpeng Li , Ingo Molnar , Vitaly Kuznetsov , Pawan Gupta , Dave Hansen , Paolo Bonzini , linux-kernel@vger.kernel.org, Rodrigo Vivi , "H. Peter Anvin" , intel-gvt-dev@lists.freedesktop.org, Joonas Lahtinen , Joerg Roedel , Sean Christopherson , David Airlie , Zhi Wang , Brijesh Singh , Jim Mattson , x86@kernel.org, Daniel Vetter , Borislav Petkov , Zhenyu Wang , Kan Liang , Jani Nikula , Maxim Levitsky Subject: [PATCH RESEND 16/30] KVM: x86: SVM: allow to force AVIC to be enabled Date: Mon, 7 Feb 2022 17:54:33 +0200 Message-Id: <20220207155447.840194-17-mlevitsk@redhat.com> In-Reply-To: <20220207155447.840194-1-mlevitsk@redhat.com> References: <20220207155447.840194-1-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 85035324ed762..b88ca7f07a0fc 100644 --- a/arch/x86/kvm/svm/svm.c +++ b/arch/x86/kvm/svm/svm.c @@ -202,6 +202,9 @@ 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); @@ -4839,10 +4842,14 @@ 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 {