From patchwork Fri Jun 15 22:29:04 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Michael S. Tsirkin" X-Patchwork-Id: 10467777 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 08E0F60384 for ; Fri, 15 Jun 2018 22:29:12 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id C3A9A2891B for ; Fri, 15 Jun 2018 22:29:11 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id B847C2898F; Fri, 15 Jun 2018 22:29:11 +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 511982891B for ; Fri, 15 Jun 2018 22:29:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756688AbeFOW3J (ORCPT ); Fri, 15 Jun 2018 18:29:09 -0400 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:58882 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1756592AbeFOW3F (ORCPT ); Fri, 15 Jun 2018 18:29:05 -0400 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.rdu2.redhat.com [10.11.54.6]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id C3CD1401EF03; Fri, 15 Jun 2018 22:29:04 +0000 (UTC) Received: from redhat.com (ovpn-120-197.rdu2.redhat.com [10.10.120.197]) by smtp.corp.redhat.com (Postfix) with SMTP id 509892166BB2; Fri, 15 Jun 2018 22:29:04 +0000 (UTC) Date: Sat, 16 Jun 2018 01:29:04 +0300 From: "Michael S. Tsirkin" To: qemu-devel@nongnu.org Cc: Paolo Bonzini , Richard Henderson , Eduardo Habkost , Marcelo Tosatti , kvm@vger.kernel.org Subject: [PATCH v3 2/2] i386/cpu: make -cpu host support monitor/mwait Message-ID: <20180615222855.44421-3-mst@redhat.com> References: <20180615222855.44421-1-mst@redhat.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20180615222855.44421-1-mst@redhat.com> X-Mutt-Fcc: =sent X-Scanned-By: MIMEDefang 2.78 on 10.11.54.6 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.5]); Fri, 15 Jun 2018 22:29:04 +0000 (UTC) X-Greylist: inspected by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.5]); Fri, 15 Jun 2018 22:29:04 +0000 (UTC) for IP:'10.11.54.6' DOMAIN:'int-mx06.intmail.prod.int.rdu2.redhat.com' HELO:'smtp.corp.redhat.com' FROM:'mst@redhat.com' RCPT:'' Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP When guest CPU PM is enabled, and with -cpu host, expose the host CPU MWAIT leaf in the CPUID so guest can make good PM decisions. Note: the result is 100% CPU utilization reported by host as host no longer knows that the CPU is halted. Signed-off-by: Michael S. Tsirkin --- target/i386/cpu.h | 9 +++++++++ target/i386/cpu.c | 19 ++++++++++++++----- target/i386/kvm.c | 9 +++++++++ 3 files changed, 32 insertions(+), 5 deletions(-) diff --git a/target/i386/cpu.h b/target/i386/cpu.h index 664504610e..309f804573 100644 --- a/target/i386/cpu.h +++ b/target/i386/cpu.h @@ -1378,6 +1378,15 @@ struct X86CPU { /* if true the CPUID code directly forward host cache leaves to the guest */ bool cache_info_passthrough; + /* if true the CPUID code directly forwards + * host monitor/mwait leaves to the guest */ + struct { + uint32_t eax; + uint32_t ebx; + uint32_t ecx; + uint32_t edx; + } mwait; + /* Features that were filtered out because of missing host capabilities */ uint32_t filtered_features[FEATURE_WORDS]; diff --git a/target/i386/cpu.c b/target/i386/cpu.c index 94260412e2..a4fb856d58 100644 --- a/target/i386/cpu.c +++ b/target/i386/cpu.c @@ -3760,11 +3760,11 @@ void cpu_x86_cpuid(CPUX86State *env, uint32_t index, uint32_t count, } break; case 5: - /* mwait info: needed for Core compatibility */ - *eax = 0; /* Smallest monitor-line size in bytes */ - *ebx = 0; /* Largest monitor-line size in bytes */ - *ecx = CPUID_MWAIT_EMX | CPUID_MWAIT_IBE; - *edx = 0; + /* MONITOR/MWAIT Leaf */ + *eax = cpu->mwait.eax; /* Smallest monitor-line size in bytes */ + *ebx = cpu->mwait.ebx; /* Largest monitor-line size in bytes */ + *ecx = cpu->mwait.ecx; /* flags */ + *edx = cpu->mwait.edx; /* mwait substates */ break; case 6: /* Thermal and Power Leaf */ @@ -4595,6 +4595,15 @@ static void x86_cpu_realizefn(DeviceState *dev, Error **errp) goto out; } + if (xcc->host_cpuid_required && enable_cpu_pm) { + host_cpuid(5, 0, &cpu->mwait.eax, &cpu->mwait.ebx, + &cpu->mwait.ecx, &cpu->mwait.edx); + env->features[FEAT_1_ECX] |= CPUID_EXT_MONITOR; + } + /* mwait extended info: needed for Core compatibility */ + /* We always wake on interrupt even if host does not have the capability */ + cpu->mwait.ecx |= CPUID_MWAIT_EMX | CPUID_MWAIT_IBE; + if (cpu->apic_id == UNASSIGNED_APIC_ID) { error_setg(errp, "apic-id property was not initialized properly"); return; diff --git a/target/i386/kvm.c b/target/i386/kvm.c index cf9107be4b..805968d5b7 100644 --- a/target/i386/kvm.c +++ b/target/i386/kvm.c @@ -366,6 +366,15 @@ uint32_t kvm_arch_get_supported_cpuid(KVMState *s, uint32_t function, if (!kvm_irqchip_in_kernel()) { ret &= ~CPUID_EXT_X2APIC; } + + if (enable_cpu_pm) { + int disable_exits = kvm_check_extension(s, + KVM_CAP_X86_DISABLE_EXITS); + + if (disable_exits & KVM_X86_DISABLE_EXITS_MWAIT) { + ret |= CPUID_EXT_MONITOR; + } + } } else if (function == 6 && reg == R_EAX) { ret |= CPUID_6_EAX_ARAT; /* safe to allow because of emulated APIC */ } else if (function == 7 && index == 0 && reg == R_EBX) {