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=-8.3 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=unavailable 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 980E9C43331 for ; Mon, 11 Nov 2019 05:10:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6E67920B7C for ; Mon, 11 Nov 2019 05:10:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726805AbfKKFKx (ORCPT ); Mon, 11 Nov 2019 00:10:53 -0500 Received: from mga09.intel.com ([134.134.136.24]:31379 "EHLO mga09.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725860AbfKKFKw (ORCPT ); Mon, 11 Nov 2019 00:10:52 -0500 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga006.jf.intel.com ([10.7.209.51]) by orsmga102.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 10 Nov 2019 21:10:51 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.68,291,1569308400"; d="scan'208";a="207021996" Received: from cqiang-mobl.ccr.corp.intel.com (HELO [10.239.198.110]) ([10.239.198.110]) by orsmga006.jf.intel.com with ESMTP; 10 Nov 2019 21:10:49 -0800 Subject: Re: [PATCH v2] KVM: X86: Fix initialization of MSR lists(msrs_to_save[], emulated_msrs[] and msr_based_features[]) From: cqiang To: Paolo Bonzini , =?UTF-8?B?UmFkaW0gS3LEjW3DocWZ?= , Sean Christopherson , Vitaly Kuznetsov , Jim Mattson , Joerg Roedel Cc: Xiaoyao Li , kvm@vger.kernel.org, linux-kernel@vger.kernel.org, stable@vger.kernel.org References: <20191106063520.1915-1-chenyi.qiang@intel.com> Message-ID: <7a148552-f5d2-2415-c33d-a162e095a3e5@intel.com> Date: Mon, 11 Nov 2019 13:10:49 +0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:60.0) Gecko/20100101 Thunderbird/60.9.1 MIME-Version: 1.0 In-Reply-To: <20191106063520.1915-1-chenyi.qiang@intel.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Ping for comments :) On 11/6/2019 2:35 PM, Chenyi Qiang wrote: > The three MSR lists(msrs_to_save[], emulated_msrs[] and > msr_based_features[]) are global arrays of kvm.ko, which are > adjusted (copy supported MSRs forward to override the unsupported MSRs) > when insmod kvm-{intel,amd}.ko, but it doesn't reset these three arrays > to their initial value when rmmod kvm-{intel,amd}.ko. Thus, at the next > installation, kvm-{intel,amd}.ko will do operations on the modified > arrays with some MSRs lost and some MSRs duplicated. > > So define three constant arrays to hold the initial MSR lists and > initialize msrs_to_save[], emulated_msrs[] and msr_based_features[] > based on the constant arrays. > > Cc: stable@vger.kernel.org > Reviewed-by: Xiaoyao Li > Signed-off-by: Chenyi Qiang > --- > Changes in v2: > - define initial MSR lists with static const. > - change the dynamic allocation of supported MSR lists to static allocation. > > arch/x86/kvm/x86.c | 51 +++++++++++++++++++++++++--------------------- > 1 file changed, 28 insertions(+), 23 deletions(-) > > diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c > index 89621025577a..0b4b6db5b13f 100644 > --- a/arch/x86/kvm/x86.c > +++ b/arch/x86/kvm/x86.c > @@ -1138,13 +1138,15 @@ EXPORT_SYMBOL_GPL(kvm_rdpmc); > * List of msr numbers which we expose to userspace through KVM_GET_MSRS > * and KVM_SET_MSRS, and KVM_GET_MSR_INDEX_LIST. > * > - * This list is modified at module load time to reflect the > + * The three MSR lists(msrs_to_save, emulated_msrs, msr_based_features) > + * extract the supported MSRs from the related const lists. > + * msrs_to_save is selected from the msrs_to_save_all to reflect the > * capabilities of the host cpu. This capabilities test skips MSRs that are > - * kvm-specific. Those are put in emulated_msrs; filtering of emulated_msrs > + * kvm-specific. Those are put in emulated_msrs_all; filtering of emulated_msrs > * may depend on host virtualization features rather than host cpu features. > */ > > -static u32 msrs_to_save[] = { > +static const u32 msrs_to_save_all[] = { > MSR_IA32_SYSENTER_CS, MSR_IA32_SYSENTER_ESP, MSR_IA32_SYSENTER_EIP, > MSR_STAR, > #ifdef CONFIG_X86_64 > @@ -1185,9 +1187,10 @@ static u32 msrs_to_save[] = { > MSR_ARCH_PERFMON_EVENTSEL0 + 16, MSR_ARCH_PERFMON_EVENTSEL0 + 17, > }; > > +static u32 msrs_to_save[ARRAY_SIZE(msrs_to_save_all)]; > static unsigned num_msrs_to_save; > > -static u32 emulated_msrs[] = { > +static const u32 emulated_msrs_all[] = { > MSR_KVM_SYSTEM_TIME, MSR_KVM_WALL_CLOCK, > MSR_KVM_SYSTEM_TIME_NEW, MSR_KVM_WALL_CLOCK_NEW, > HV_X64_MSR_GUEST_OS_ID, HV_X64_MSR_HYPERCALL, > @@ -1226,7 +1229,7 @@ static u32 emulated_msrs[] = { > * by arch/x86/kvm/vmx/nested.c based on CPUID or other MSRs. > * We always support the "true" VMX control MSRs, even if the host > * processor does not, so I am putting these registers here rather > - * than in msrs_to_save. > + * than in msrs_to_save_all. > */ > MSR_IA32_VMX_BASIC, > MSR_IA32_VMX_TRUE_PINBASED_CTLS, > @@ -1245,13 +1248,14 @@ static u32 emulated_msrs[] = { > MSR_KVM_POLL_CONTROL, > }; > > +static u32 emulated_msrs[ARRAY_SIZE(emulated_msrs_all)]; > static unsigned num_emulated_msrs; > > /* > * List of msr numbers which are used to expose MSR-based features that > * can be used by a hypervisor to validate requested CPU features. > */ > -static u32 msr_based_features[] = { > +static const u32 msr_based_features_all[] = { > MSR_IA32_VMX_BASIC, > MSR_IA32_VMX_TRUE_PINBASED_CTLS, > MSR_IA32_VMX_PINBASED_CTLS, > @@ -1276,6 +1280,7 @@ static u32 msr_based_features[] = { > MSR_IA32_ARCH_CAPABILITIES, > }; > > +static u32 msr_based_features[ARRAY_SIZE(msr_based_features_all)]; > static unsigned int num_msr_based_features; > > static u64 kvm_get_arch_capabilities(void) > @@ -5131,19 +5136,19 @@ static void kvm_init_msr_list(void) > unsigned i, j; > > BUILD_BUG_ON_MSG(INTEL_PMC_MAX_FIXED != 4, > - "Please update the fixed PMCs in msrs_to_save[]"); > + "Please update the fixed PMCs in msrs_to_saved_all[]"); > > perf_get_x86_pmu_capability(&x86_pmu); > > - for (i = j = 0; i < ARRAY_SIZE(msrs_to_save); i++) { > - if (rdmsr_safe(msrs_to_save[i], &dummy[0], &dummy[1]) < 0) > + for (i = j = 0; i < ARRAY_SIZE(msrs_to_save_all); i++) { > + if (rdmsr_safe(msrs_to_save_all[i], &dummy[0], &dummy[1]) < 0) > continue; > > /* > * Even MSRs that are valid in the host may not be exposed > * to the guests in some cases. > */ > - switch (msrs_to_save[i]) { > + switch (msrs_to_save_all[i]) { > case MSR_IA32_BNDCFGS: > if (!kvm_mpx_supported()) > continue; > @@ -5171,17 +5176,17 @@ static void kvm_init_msr_list(void) > break; > case MSR_IA32_RTIT_ADDR0_A ... MSR_IA32_RTIT_ADDR3_B: { > if (!kvm_x86_ops->pt_supported() || > - msrs_to_save[i] - MSR_IA32_RTIT_ADDR0_A >= > + msrs_to_save_all[i] - MSR_IA32_RTIT_ADDR0_A >= > intel_pt_validate_hw_cap(PT_CAP_num_address_ranges) * 2) > continue; > break; > case MSR_ARCH_PERFMON_PERFCTR0 ... MSR_ARCH_PERFMON_PERFCTR0 + 17: > - if (msrs_to_save[i] - MSR_ARCH_PERFMON_PERFCTR0 >= > + if (msrs_to_save_all[i] - MSR_ARCH_PERFMON_PERFCTR0 >= > min(INTEL_PMC_MAX_GENERIC, x86_pmu.num_counters_gp)) > continue; > break; > case MSR_ARCH_PERFMON_EVENTSEL0 ... MSR_ARCH_PERFMON_EVENTSEL0 + 17: > - if (msrs_to_save[i] - MSR_ARCH_PERFMON_EVENTSEL0 >= > + if (msrs_to_save_all[i] - MSR_ARCH_PERFMON_EVENTSEL0 >= > min(INTEL_PMC_MAX_GENERIC, x86_pmu.num_counters_gp)) > continue; > } > @@ -5189,31 +5194,31 @@ static void kvm_init_msr_list(void) > break; > } > > - if (j < i) > - msrs_to_save[j] = msrs_to_save[i]; > + if (j <= i) > + msrs_to_save[j] = msrs_to_save_all[i]; > j++; > } > num_msrs_to_save = j; > > - for (i = j = 0; i < ARRAY_SIZE(emulated_msrs); i++) { > - if (!kvm_x86_ops->has_emulated_msr(emulated_msrs[i])) > + for (i = j = 0; i < ARRAY_SIZE(emulated_msrs_all); i++) { > + if (!kvm_x86_ops->has_emulated_msr(emulated_msrs_all[i])) > continue; > > - if (j < i) > - emulated_msrs[j] = emulated_msrs[i]; > + if (j <= i) > + emulated_msrs[j] = emulated_msrs_all[i]; > j++; > } > num_emulated_msrs = j; > > - for (i = j = 0; i < ARRAY_SIZE(msr_based_features); i++) { > + for (i = j = 0; i < ARRAY_SIZE(msr_based_features_all); i++) { > struct kvm_msr_entry msr; > > - msr.index = msr_based_features[i]; > + msr.index = msr_based_features_all[i]; > if (kvm_get_msr_feature(&msr)) > continue; > > - if (j < i) > - msr_based_features[j] = msr_based_features[i]; > + if (j <= i) > + msr_based_features[j] = msr_based_features_all[i]; > j++; > } > num_msr_based_features = j; >