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=-8.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 autolearn=ham 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 D08D4C3A5A3 for ; Tue, 27 Aug 2019 19:52:29 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id AD04C2184D for ; Tue, 27 Aug 2019 19:52:29 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731451AbfH0Tw2 (ORCPT ); Tue, 27 Aug 2019 15:52:28 -0400 Received: from mga14.intel.com ([192.55.52.115]:28013 "EHLO mga14.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731424AbfH0TwZ (ORCPT ); Tue, 27 Aug 2019 15:52:25 -0400 X-Amp-Result: UNKNOWN X-Amp-Original-Verdict: FILE UNKNOWN X-Amp-File-Uploaded: False Received: from orsmga007.jf.intel.com ([10.7.209.58]) by fmsmga103.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 27 Aug 2019 12:52:24 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.64,438,1559545200"; d="scan'208";a="171307402" Received: from sjchrist-coffee.jf.intel.com (HELO linux.intel.com) ([10.54.74.41]) by orsmga007.jf.intel.com with ESMTP; 27 Aug 2019 12:52:24 -0700 Date: Tue, 27 Aug 2019 12:52:24 -0700 From: Sean Christopherson To: Jim Mattson Cc: Vitaly Kuznetsov , kvm list , LKML , Paolo Bonzini , Radim =?utf-8?B?S3LEjW3DocWZ?= , Joerg Roedel , Roman Kagan Subject: Re: [PATCH 3/3] KVM: x86: announce KVM_CAP_HYPERV_ENLIGHTENED_VMCS support only when it is available Message-ID: <20190827195224.GI27459@linux.intel.com> References: <20190827160404.14098-1-vkuznets@redhat.com> <20190827160404.14098-4-vkuznets@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.24 (2015-08-30) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Aug 27, 2019 at 09:54:39AM -0700, Jim Mattson wrote: > On Tue, Aug 27, 2019 at 9:04 AM Vitaly Kuznetsov wrote: > > > > It was discovered that after commit 65efa61dc0d5 ("selftests: kvm: provide > > common function to enable eVMCS") hyperv_cpuid selftest is failing on AMD. > > The reason is that the commit changed _vcpu_ioctl() to vcpu_ioctl() in the > > test and this one can't fail. > > > > Instead of fixing the test is seems to make more sense to not announce > > KVM_CAP_HYPERV_ENLIGHTENED_VMCS support if it is definitely missing > > (on svm and in case kvm_intel.nested=0). > > > > Signed-off-by: Vitaly Kuznetsov > > --- > > arch/x86/kvm/x86.c | 3 ++- > > 1 file changed, 2 insertions(+), 1 deletion(-) > > > > diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c > > index d1cd0fcff9e7..ef2e8b138300 100644 > > --- a/arch/x86/kvm/x86.c > > +++ b/arch/x86/kvm/x86.c > > @@ -3106,7 +3106,6 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext) > > case KVM_CAP_HYPERV_EVENTFD: > > case KVM_CAP_HYPERV_TLBFLUSH: > > case KVM_CAP_HYPERV_SEND_IPI: > > - case KVM_CAP_HYPERV_ENLIGHTENED_VMCS: > > case KVM_CAP_HYPERV_CPUID: > > case KVM_CAP_PCI_SEGMENT: > > case KVM_CAP_DEBUGREGS: > > @@ -3183,6 +3182,8 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext) > > r = kvm_x86_ops->get_nested_state ? > > kvm_x86_ops->get_nested_state(NULL, NULL, 0) : 0; > > break; > > + case KVM_CAP_HYPERV_ENLIGHTENED_VMCS: > > + r = kvm_x86_ops->nested_enable_evmcs != NULL; > > You should probably have an explicit break here, in case someone later > adds another case below. Yep, this will trigger a warning on compilers with -Wimplicit-fallthrough.