From patchwork Fri May 24 08:18:38 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Tao Xu X-Patchwork-Id: 10959335 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 0FD9215A6 for ; Fri, 24 May 2019 08:21:07 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id F385E287C0 for ; Fri, 24 May 2019 08:21:06 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id E6F11287E8; Fri, 24 May 2019 08:21:06 +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 62DDE287C0 for ; Fri, 24 May 2019 08:21:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2389663AbfEXIVF (ORCPT ); Fri, 24 May 2019 04:21:05 -0400 Received: from mga07.intel.com ([134.134.136.100]:38552 "EHLO mga07.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2389462AbfEXIVE (ORCPT ); Fri, 24 May 2019 04:21:04 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga007.fm.intel.com ([10.253.24.52]) by orsmga105.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 24 May 2019 01:21:04 -0700 X-ExtLoop1: 1 Received: from tao-optiplex-7060.sh.intel.com ([10.239.13.104]) by fmsmga007.fm.intel.com with ESMTP; 24 May 2019 01:21:02 -0700 From: Tao Xu To: pbonzini@redhat.com, rth@twiddle.net, ehabkost@redhat.com Cc: cohuck@redhat.com, mst@redhat.com, mtosatti@redhat.com, qemu-devel@nongnu.org, kvm@vger.kernel.org, tao3.xu@intel.com, jingqi.liu@intel.com Subject: [PATCH v2 1/2] x86/cpu: Add support for UMONITOR/UMWAIT/TPAUSE Date: Fri, 24 May 2019 16:18:38 +0800 Message-Id: <20190524081839.6228-2-tao3.xu@intel.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190524081839.6228-1-tao3.xu@intel.com> References: <20190524081839.6228-1-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. Availability of the user wait instructions is indicated by the presence of the CPUID feature flag WAITPKG CPUID.0x07.0x0:ECX[5]. The patch enable the umonitor, umwait and tpause features in KVM. Because umwait and tpause can put a (psysical) CPU into a power saving state, by default we dont't expose it in kvm and provide a capability to enable it. Use kvm capability to enable UMONITOR, UMWAIT and TPAUSE when QEMU use "-overcommit cpu-pm=on, a VM can use UMONITOR, UMWAIT and TPAUSE instructions. 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 (the time to delay relative to the VM’s timestamp counter). Otherwise, UMONITOR, UMWAIT and TPAUSE cause an invalid-opcode exception(#UD). The release document ref below link: https://software.intel.com/sites/default/files/\ managed/39/c5/325462-sdm-vol-1-2abcd-3abcd.pdf Co-developed-by: Jingqi Liu Signed-off-by: Jingqi Liu Signed-off-by: Tao Xu --- linux-headers/linux/kvm.h | 1 + target/i386/cpu.c | 3 ++- target/i386/cpu.h | 1 + target/i386/kvm.c | 13 +++++++++++++ 4 files changed, 17 insertions(+), 1 deletion(-) diff --git a/linux-headers/linux/kvm.h b/linux-headers/linux/kvm.h index c8423e760c..86cc2dbdd0 100644 --- a/linux-headers/linux/kvm.h +++ b/linux-headers/linux/kvm.h @@ -993,6 +993,7 @@ struct kvm_ppc_resize_hpt { #define KVM_CAP_ARM_SVE 170 #define KVM_CAP_ARM_PTRAUTH_ADDRESS 171 #define KVM_CAP_ARM_PTRAUTH_GENERIC 172 +#define KVM_CAP_ENABLE_USR_WAIT_PAUSE 173 #ifdef KVM_CAP_IRQ_ROUTING diff --git a/target/i386/cpu.c b/target/i386/cpu.c index 2df56fa977..c2ad7866a5 100644 --- a/target/i386/cpu.c +++ b/target/i386/cpu.c @@ -1057,7 +1057,7 @@ static FeatureWordInfo feature_word_info[FEATURE_WORDS] = { .type = CPUID_FEATURE_WORD, .feat_names = { NULL, "avx512vbmi", "umip", "pku", - NULL /* ospke */, NULL, "avx512vbmi2", NULL, + NULL /* ospke */, "waitpkg", "avx512vbmi2", NULL, "gfni", "vaes", "vpclmulqdq", "avx512vnni", "avx512bitalg", NULL, "avx512-vpopcntdq", NULL, "la57", NULL, NULL, NULL, @@ -5196,6 +5196,7 @@ static void x86_cpu_realizefn(DeviceState *dev, Error **errp) host_cpuid(5, 0, &cpu->mwait.eax, &cpu->mwait.ebx, &cpu->mwait.ecx, &cpu->mwait.edx); env->features[FEAT_1_ECX] |= CPUID_EXT_MONITOR; + env->features[FEAT_7_0_ECX] |= CPUID_7_0_ECX_WAITPKG; } } diff --git a/target/i386/cpu.h b/target/i386/cpu.h index fce6660bac..66fa61f02b 100644 --- a/target/i386/cpu.h +++ b/target/i386/cpu.h @@ -679,6 +679,7 @@ typedef uint32_t FeatureWordArray[FEATURE_WORDS]; #define CPUID_7_0_ECX_UMIP (1U << 2) #define CPUID_7_0_ECX_PKU (1U << 3) #define CPUID_7_0_ECX_OSPKE (1U << 4) +#define CPUID_7_0_ECX_WAITPKG (1U << 5) /* UMONITOR/UMWAIT/TPAUSE Instructions */ #define CPUID_7_0_ECX_VBMI2 (1U << 6) /* Additional VBMI Instrs */ #define CPUID_7_0_ECX_GFNI (1U << 8) #define CPUID_7_0_ECX_VAES (1U << 9) diff --git a/target/i386/kvm.c b/target/i386/kvm.c index 3b29ce5c0d..b58fc7ab3a 100644 --- a/target/i386/kvm.c +++ b/target/i386/kvm.c @@ -389,6 +389,10 @@ uint32_t kvm_arch_get_supported_cpuid(KVMState *s, uint32_t function, if (host_tsx_blacklisted()) { ret &= ~(CPUID_7_0_EBX_RTM | CPUID_7_0_EBX_HLE); } + } else if (function == 7 && index == 0 && reg == R_ECX) { + if (enable_cpu_pm) { + ret |= CPUID_7_0_ECX_WAITPKG; + } } else if (function == 7 && index == 0 && reg == R_EDX) { /* * Linux v4.17-v4.20 incorrectly return ARCH_CAPABILITIES on SVM hosts. @@ -1654,6 +1658,15 @@ int kvm_arch_init(MachineState *ms, KVMState *s) error_report("kvm: guest stopping CPU not supported: %s", strerror(-ret)); } + + if (kvm_check_extension(s, KVM_CAP_ENABLE_USR_WAIT_PAUSE)) { + ret = kvm_vm_enable_cap(s, KVM_CAP_ENABLE_USR_WAIT_PAUSE, 0); + if (ret < 0) { + error_report("kvm: guest can't enable user-level" + " wait and pause: %s", + strerror(-ret)); + } + } } return 0;