From patchwork Wed May 3 19:37:33 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?b?UmFkaW0gS3LEjW3DocWZ?= X-Patchwork-Id: 9710329 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 3BFC660351 for ; Wed, 3 May 2017 19:39:00 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 28BB528616 for ; Wed, 3 May 2017 19:39:00 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 1D98528657; Wed, 3 May 2017 19:39:00 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=2.0 tests=BAYES_00,HK_RANDOM_FROM, RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id BA4D628616 for ; Wed, 3 May 2017 19:38:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932103AbdECTiv (ORCPT ); Wed, 3 May 2017 15:38:51 -0400 Received: from mx1.redhat.com ([209.132.183.28]:39838 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932109AbdECTiU (ORCPT ); Wed, 3 May 2017 15:38:20 -0400 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 mx1.redhat.com (Postfix) with ESMTPS id 1C89461D03; Wed, 3 May 2017 19:38:20 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mx1.redhat.com 1C89461D03 Authentication-Results: ext-mx10.extmail.prod.ext.phx2.redhat.com; dmarc=none (p=none dis=none) header.from=redhat.com Authentication-Results: ext-mx10.extmail.prod.ext.phx2.redhat.com; spf=pass smtp.mailfrom=rkrcmar@redhat.com DKIM-Filter: OpenDKIM Filter v2.11.0 mx1.redhat.com 1C89461D03 Received: from potion (dhcp-1-124.brq.redhat.com [10.34.1.124]) by smtp.corp.redhat.com (Postfix) with SMTP id E59987445E; Wed, 3 May 2017 19:38:17 +0000 (UTC) Received: by potion (sSMTP sendmail emulation); Wed, 03 May 2017 21:38:17 +0200 From: =?UTF-8?q?Radim=20Kr=C4=8Dm=C3=A1=C5=99?= To: linux-kernel@vger.kernel.org, kvm@vger.kernel.org Cc: Paolo Bonzini , Alexander Graf , "Michael S. Tsirkin" , "Gabriel L. Somlo" Subject: [PATCH 4/4] KVM: x86: simplify kvm_mwait_in_guest() Date: Wed, 3 May 2017 21:37:33 +0200 Message-Id: <20170503193733.13409-5-rkrcmar@redhat.com> In-Reply-To: <20170503193733.13409-1-rkrcmar@redhat.com> References: <20170503193733.13409-1-rkrcmar@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.39]); Wed, 03 May 2017 19:38:20 +0000 (UTC) Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP If Intel/AMD implements MWAIT, we expect that it works well and only reject known bugs; no reason to do it the other way around for minor vendors. (Not that they are relevant ATM.) This allows further simplification of kvm_mwait_in_guest(). Signed-off-by: Radim Krčmář --- arch/x86/kvm/x86.h | 14 +++----------- 1 file changed, 3 insertions(+), 11 deletions(-) diff --git a/arch/x86/kvm/x86.h b/arch/x86/kvm/x86.h index 8ea4e80c24d1..b49add75ea35 100644 --- a/arch/x86/kvm/x86.h +++ b/arch/x86/kvm/x86.h @@ -216,17 +216,9 @@ static inline u64 nsec_to_cycles(struct kvm_vcpu *vcpu, u64 nsec) static inline bool kvm_mwait_in_guest(void) { - if (!cpu_has(&boot_cpu_data, X86_FEATURE_MWAIT)) - return false; - - switch (boot_cpu_data.x86_vendor) { - case X86_VENDOR_AMD: - return !boot_cpu_has_bug(X86_BUG_AMD_E400); - case X86_VENDOR_INTEL: - return !boot_cpu_has_bug(X86_BUG_MONITOR); - default: - return false; - } + return boot_cpu_has(X86_FEATURE_MWAIT) && + !boot_cpu_has_bug(X86_BUG_AMD_E400) && + !boot_cpu_has_bug(X86_BUG_MONITOR); } #endif