From patchwork Tue Nov 24 03:33:56 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Haozhong Zhang X-Patchwork-Id: 7687431 Return-Path: X-Original-To: patchwork-kvm@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork2.web.kernel.org (Postfix) with ESMTP id 3DC8DBF90C for ; Tue, 24 Nov 2015 03:34:46 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 5C1022087C for ; Tue, 24 Nov 2015 03:34:45 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 602AA2087A for ; Tue, 24 Nov 2015 03:34:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752860AbbKXDei (ORCPT ); Mon, 23 Nov 2015 22:34:38 -0500 Received: from mga03.intel.com ([134.134.136.65]:58618 "EHLO mga03.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752830AbbKXDeH (ORCPT ); Mon, 23 Nov 2015 22:34:07 -0500 Received: from orsmga003.jf.intel.com ([10.7.209.27]) by orsmga103.jf.intel.com with ESMTP; 23 Nov 2015 19:34:07 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.20,338,1444719600"; d="scan'208";a="693089075" Received: from hzzhang-optiplex-9020.sh.intel.com (HELO localhost) ([10.239.12.31]) by orsmga003.jf.intel.com with ESMTP; 23 Nov 2015 19:34:06 -0800 From: Haozhong Zhang To: , Eduardo Habkost , "Dr. David Alan Gilbert" Cc: Paolo Bonzini , Richard Henderson , "Michael S. Tsirkin" , , Marcelo Tosatti , kvm@vger.kernel.org, Haozhong Zhang Subject: [PATCH v6 2/3] target-i386: reorganize TSC rate setting code Date: Tue, 24 Nov 2015 11:33:56 +0800 Message-Id: <1448336037-6035-3-git-send-email-haozhong.zhang@intel.com> X-Mailer: git-send-email 2.4.8 In-Reply-To: <1448336037-6035-1-git-send-email-haozhong.zhang@intel.com> References: <1448336037-6035-1-git-send-email-haozhong.zhang@intel.com> Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org X-Spam-Status: No, score=-7.5 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Following changes are made to the TSC rate setting code in kvm_arch_init_vcpu(): * The code is moved to a new function kvm_arch_set_tsc_khz(). * If kvm_arch_set_tsc_khz() fails, i.e. following two conditions are both satisfied: * KVM does not support the TSC scaling or it fails to set vcpu's TSC rate by KVM_SET_TSC_KHZ, * the TSC rate to be set is different than the value currently used by KVM, then kvm_arch_init_vcpu() will fail. Prevously, * the lack of TSC scaling never failed kvm_arch_init_vcpu(), * the failure of KVM_SET_TSC_KHZ failed kvm_arch_init_vcpu() unconditionally, even though the TSC rate to be set is identical to the value currently used by KVM. Signed-off-by: Haozhong Zhang Reviewed-by: Eduardo Habkost --- target-i386/kvm.c | 40 +++++++++++++++++++++++++++++++++------- 1 file changed, 33 insertions(+), 7 deletions(-) diff --git a/target-i386/kvm.c b/target-i386/kvm.c index a0fe9d4..1e811ee 100644 --- a/target-i386/kvm.c +++ b/target-i386/kvm.c @@ -524,6 +524,36 @@ static bool hyperv_enabled(X86CPU *cpu) cpu->hyperv_runtime); } +static int kvm_arch_set_tsc_khz(CPUState *cs) +{ + X86CPU *cpu = X86_CPU(cs); + CPUX86State *env = &cpu->env; + int r; + + if (!env->tsc_khz) { + return 0; + } + + r = kvm_check_extension(cs->kvm_state, KVM_CAP_TSC_CONTROL) ? + kvm_vcpu_ioctl(cs, KVM_SET_TSC_KHZ, env->tsc_khz) : + -ENOTSUP; + if (r < 0) { + /* When KVM_SET_TSC_KHZ fails, it's an error only if the current + * TSC frequency doesn't match the one we want. + */ + int cur_freq = kvm_check_extension(cs->kvm_state, KVM_CAP_GET_TSC_KHZ) ? + kvm_vcpu_ioctl(cs, KVM_GET_TSC_KHZ) : + -ENOTSUP; + if (cur_freq <= 0 || cur_freq != env->tsc_khz) { + error_report("warning: TSC frequency mismatch between " + "VM and host, and TSC scaling unavailable"); + return r; + } + } + + return 0; +} + static Error *invtsc_mig_blocker; #define KVM_MAX_CPUID_ENTRIES 100 @@ -823,13 +853,9 @@ int kvm_arch_init_vcpu(CPUState *cs) return r; } - r = kvm_check_extension(cs->kvm_state, KVM_CAP_TSC_CONTROL); - if (r && env->tsc_khz) { - r = kvm_vcpu_ioctl(cs, KVM_SET_TSC_KHZ, env->tsc_khz); - if (r < 0) { - fprintf(stderr, "KVM_SET_TSC_KHZ failed\n"); - return r; - } + r = kvm_arch_set_tsc_khz(cs); + if (r < 0) { + return r; } /* vcpu's TSC frequency is either specified by user, or following