From patchwork Sun Jun 16 09:33:42 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Tao Xu X-Patchwork-Id: 10997319 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 812BC1395 for ; Sun, 16 Jun 2019 09:36:35 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 7319E287C5 for ; Sun, 16 Jun 2019 09:36:35 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 53AC6287C2; Sun, 16 Jun 2019 09:36:35 +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=-7.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, 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 9D1D228735 for ; Sun, 16 Jun 2019 09:36:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726495AbfFPJgV (ORCPT ); Sun, 16 Jun 2019 05:36:21 -0400 Received: from mga12.intel.com ([192.55.52.136]:50557 "EHLO mga12.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725766AbfFPJgV (ORCPT ); Sun, 16 Jun 2019 05:36:21 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga002.fm.intel.com ([10.253.24.26]) by fmsmga106.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 16 Jun 2019 02:36:20 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.63,381,1557212400"; d="scan'208";a="185427968" Received: from tao-optiplex-7060.sh.intel.com ([10.239.13.104]) by fmsmga002.fm.intel.com with ESMTP; 16 Jun 2019 02:36:18 -0700 From: Tao Xu To: pbonzini@redhat.com, rkrcmar@redhat.com, corbet@lwn.net, tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, hpa@zytor.com, sean.j.christopherson@intel.com, fenghua.yu@intel.com Cc: kvm@vger.kernel.org, linux-kernel@vger.kernel.org, tao3.xu@intel.com, jingqi.liu@intel.com Subject: [PATCH v3 1/3] KVM: x86: add support for user wait instructions Date: Sun, 16 Jun 2019 17:33:42 +0800 Message-Id: <20190616093344.12582-2-tao3.xu@intel.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190616093344.12582-1-tao3.xu@intel.com> References: <20190616093344.12582-1-tao3.xu@intel.com> MIME-Version: 1.0 Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP UMONITOR, UMWAIT and TPAUSE are a set of user wait instructions. This patch adds support for user wait instructions in KVM. Availability of the user wait instructions is indicated by the presence of the CPUID feature flag WAITPKG CPUID.0x07.0x0:ECX[5]. User wait instructions may be executed at any privilege level, and use IA32_UMWAIT_CONTROL MSR to set the maximum time. The behavior of user wait instructions in VMX non-root operation is determined first by the setting of the "enable user wait and pause" secondary processor-based VM-execution control bit 26. If the VM-execution control is 0, UMONITOR/UMWAIT/TPAUSE cause an invalid-opcode exception (#UD). If the VM-execution control is 1, treatment is based on the setting of the “RDTSC exiting” VM-execution control. Because KVM never enables RDTSC exiting, if the instruction causes a delay, the amount of time delayed is called here the physical delay. The physical delay is first computed by determining the virtual delay. If IA32_UMWAIT_CONTROL[31:2] is zero, the virtual delay is the value in EDX:EAX minus the value that RDTSC would return; if IA32_UMWAIT_CONTROL[31:2] is not zero, the virtual delay is the minimum of that difference and AND(IA32_UMWAIT_CONTROL,FFFFFFFCH). Because umwait and tpause can put a (psysical) CPU into a power saving state, by default we dont't expose it to kvm and enable it only when guest CPUID has it. Detailed information about user wait instructions can be found in the latest Intel 64 and IA-32 Architectures Software Developer's Manual. Co-developed-by: Jingqi Liu Signed-off-by: Jingqi Liu Signed-off-by: Tao Xu --- arch/x86/include/asm/vmx.h | 1 + arch/x86/kvm/cpuid.c | 2 +- arch/x86/kvm/vmx/capabilities.h | 6 ++++++ arch/x86/kvm/vmx/vmx.c | 4 ++++ 4 files changed, 12 insertions(+), 1 deletion(-) diff --git a/arch/x86/include/asm/vmx.h b/arch/x86/include/asm/vmx.h index a39136b0d509..8f00882664d3 100644 --- a/arch/x86/include/asm/vmx.h +++ b/arch/x86/include/asm/vmx.h @@ -69,6 +69,7 @@ #define SECONDARY_EXEC_PT_USE_GPA 0x01000000 #define SECONDARY_EXEC_MODE_BASED_EPT_EXEC 0x00400000 #define SECONDARY_EXEC_TSC_SCALING 0x02000000 +#define SECONDARY_EXEC_ENABLE_USR_WAIT_PAUSE 0x04000000 #define PIN_BASED_EXT_INTR_MASK 0x00000001 #define PIN_BASED_NMI_EXITING 0x00000008 diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c index e18a9f9f65b5..48bd851a6ae5 100644 --- a/arch/x86/kvm/cpuid.c +++ b/arch/x86/kvm/cpuid.c @@ -405,7 +405,7 @@ static inline int __do_cpuid_ent(struct kvm_cpuid_entry2 *entry, u32 function, F(AVX512VBMI) | F(LA57) | F(PKU) | 0 /*OSPKE*/ | F(AVX512_VPOPCNTDQ) | F(UMIP) | F(AVX512_VBMI2) | F(GFNI) | F(VAES) | F(VPCLMULQDQ) | F(AVX512_VNNI) | F(AVX512_BITALG) | - F(CLDEMOTE) | F(MOVDIRI) | F(MOVDIR64B); + F(CLDEMOTE) | F(MOVDIRI) | F(MOVDIR64B) | 0 /*WAITPKG*/; /* cpuid 7.0.edx*/ const u32 kvm_cpuid_7_0_edx_x86_features = diff --git a/arch/x86/kvm/vmx/capabilities.h b/arch/x86/kvm/vmx/capabilities.h index d6664ee3d127..fd77e17651b4 100644 --- a/arch/x86/kvm/vmx/capabilities.h +++ b/arch/x86/kvm/vmx/capabilities.h @@ -253,6 +253,12 @@ static inline bool cpu_has_vmx_tsc_scaling(void) SECONDARY_EXEC_TSC_SCALING; } +static inline bool vmx_waitpkg_supported(void) +{ + return vmcs_config.cpu_based_2nd_exec_ctrl & + SECONDARY_EXEC_ENABLE_USR_WAIT_PAUSE; +} + static inline bool cpu_has_vmx_apicv(void) { return cpu_has_vmx_apic_register_virt() && diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c index b93e36ddee5e..b35bfac30a34 100644 --- a/arch/x86/kvm/vmx/vmx.c +++ b/arch/x86/kvm/vmx/vmx.c @@ -2250,6 +2250,7 @@ static __init int setup_vmcs_config(struct vmcs_config *vmcs_conf, SECONDARY_EXEC_RDRAND_EXITING | SECONDARY_EXEC_ENABLE_PML | SECONDARY_EXEC_TSC_SCALING | + SECONDARY_EXEC_ENABLE_USR_WAIT_PAUSE | SECONDARY_EXEC_PT_USE_GPA | SECONDARY_EXEC_PT_CONCEAL_VMX | SECONDARY_EXEC_ENABLE_VMFUNC | @@ -3987,6 +3988,9 @@ static void vmx_compute_secondary_exec_control(struct vcpu_vmx *vmx) } } + if (!guest_cpuid_has(vcpu, X86_FEATURE_WAITPKG)) + exec_control &= ~SECONDARY_EXEC_ENABLE_USR_WAIT_PAUSE; + vmx->secondary_exec_control = exec_control; }