From patchwork Tue Jul 16 07:44:58 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Tao Xu X-Patchwork-Id: 1132484 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (mailfrom) smtp.mailfrom=nongnu.org (client-ip=209.51.188.17; helo=lists.gnu.org; envelope-from=qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org; receiver=) Authentication-Results: ozlabs.org; dmarc=fail (p=none dis=none) header.from=intel.com Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 45nsvg27H9z9sNC for ; Tue, 16 Jul 2019 17:48:15 +1000 (AEST) Received: from localhost ([::1]:45968 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.86_2) (envelope-from ) id 1hnIC4-0006Qi-UO for incoming@patchwork.ozlabs.org; Tue, 16 Jul 2019 03:48:12 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:52440) by lists.gnu.org with esmtp (Exim 4.86_2) (envelope-from ) id 1hnIBu-0006QQ-UX for qemu-devel@nongnu.org; Tue, 16 Jul 2019 03:48:04 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1hnIBt-0000rq-KV for qemu-devel@nongnu.org; Tue, 16 Jul 2019 03:48:02 -0400 Received: from mga04.intel.com ([192.55.52.120]:44116) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1hnIBt-0000k5-El for qemu-devel@nongnu.org; Tue, 16 Jul 2019 03:48:01 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga007.jf.intel.com ([10.7.209.58]) by fmsmga104.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 16 Jul 2019 00:47:53 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.63,497,1557212400"; d="scan'208";a="158066383" Received: from tao-optiplex-7060.sh.intel.com ([10.239.13.104]) by orsmga007.jf.intel.com with ESMTP; 16 Jul 2019 00:47:50 -0700 From: Tao Xu To: pbonzini@redhat.com, rth@twiddle.net, ehabkost@redhat.com, cohuck@redhat.com, mst@redhat.com, mtosatti@redhat.com Date: Tue, 16 Jul 2019 15:44:58 +0800 Message-Id: <20190716074459.6026-2-tao3.xu@intel.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190716074459.6026-1-tao3.xu@intel.com> References: <20190716074459.6026-1-tao3.xu@intel.com> MIME-Version: 1.0 X-detected-operating-system: by eggs.gnu.org: Genre and OS details not recognized. X-Received-From: 192.55.52.120 Subject: [Qemu-devel] [PATCH v4 1/2] x86/cpu: Add support for UMONITOR/UMWAIT/TPAUSE X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: jingqi.liu@intel.com, tao3.xu@intel.com, qemu-devel@nongnu.org, kvm@vger.kernel.org Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: "Qemu-devel" 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 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 to kvm and enable it only when guest CPUID has it. And use QEMU command-line "-overcommit cpu-pm=on" (enable_cpu_pm is enabled), 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 --- No changes in v4. --- target/i386/cpu.c | 3 ++- target/i386/cpu.h | 1 + target/i386/kvm.c | 4 ++++ 3 files changed, 7 insertions(+), 1 deletion(-) diff --git a/target/i386/cpu.c b/target/i386/cpu.c index 805ce95247..9546a40d8a 100644 --- a/target/i386/cpu.c +++ b/target/i386/cpu.c @@ -1061,7 +1061,7 @@ 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, @@ -5193,6 +5193,7 @@ 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 05393cf9d1..19caf82729 100644 --- a/target/i386/cpu.h +++ b/target/i386/cpu.h @@ -672,6 +672,7 @@ 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 ec7870c6af..f8daa13f10 100644 --- a/target/i386/kvm.c +++ b/target/i386/kvm.c @@ -390,6 +390,10 @@ 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.