From patchwork Tue Mar 1 14:36:49 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Maxim Levitsky X-Patchwork-Id: 12764801 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 BB279C433F5 for ; Tue, 1 Mar 2022 14:38:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233196AbiCAOjL (ORCPT ); Tue, 1 Mar 2022 09:39:11 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36238 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235416AbiCAOip (ORCPT ); Tue, 1 Mar 2022 09:38:45 -0500 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id DB9BDBF6C for ; Tue, 1 Mar 2022 06:37:45 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1646145465; 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=ACp8ZVG8qwchATOM/Upzz6ZCjFCAYAdWJqd0ApBf+8w=; b=G8+C+DQu3V8g96puxQzG3bNYM/Z+6w3CeC/iNy3bb5fFLqbwsASs+ysNOLWA6ihDHC6XvO K5y4NWbEGgX4zCVHN6g5JKWMFwfRVmQubgEzwDtx5W0Tp1rpiaO8fNtAo0X7bXvC8zGLOo nPVkrBLvAQw3Qz5EV9gej6SIzq/jCCY= 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-453-5d0OUrfOOruQ9A_D5gtbrw-1; Tue, 01 Mar 2022 09:37:42 -0500 X-MC-Unique: 5d0OUrfOOruQ9A_D5gtbrw-1 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 2EF9A1091DA1; Tue, 1 Mar 2022 14:37:39 +0000 (UTC) Received: from localhost.localdomain (unknown [10.40.195.190]) by smtp.corp.redhat.com (Postfix) with ESMTP id 9ABA2842C9; Tue, 1 Mar 2022 14:37:32 +0000 (UTC) From: Maxim Levitsky To: kvm@vger.kernel.org Cc: Ingo Molnar , Dave Hansen , Sean Christopherson , Borislav Petkov , "H. Peter Anvin" , Thomas Gleixner , Jim Mattson , x86@kernel.org, Vitaly Kuznetsov , Joerg Roedel , linux-kernel@vger.kernel.org, Paolo Bonzini , Wanpeng Li , Maxim Levitsky Subject: [PATCH v3 6/7] KVM: x86: SVM: allow to force AVIC to be enabled Date: Tue, 1 Mar 2022 16:36:49 +0200 Message-Id: <20220301143650.143749-7-mlevitsk@redhat.com> In-Reply-To: <20220301143650.143749-1-mlevitsk@redhat.com> References: <20220301143650.143749-1-mlevitsk@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 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 776585dd77769..a26b4c899899e 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); @@ -4896,10 +4899,14 @@ 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 {