From nobody Thu May 2 02:12:24 2024 Delivered-To: importer@patchew.org Received-SPF: pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) client-ip=208.118.235.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Authentication-Results: mx.zohomail.com; spf=pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; dmarc=fail(p=none dis=none) header.from=redhat.com Return-Path: Received: from lists.gnu.org (208.118.235.17 [208.118.235.17]) by mx.zohomail.com with SMTPS id 1529695537970132.07703820941344; Fri, 22 Jun 2018 12:25:37 -0700 (PDT) Received: from localhost ([::1]:35779 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fWRgR-0007kf-Pr for importer@patchew.org; Fri, 22 Jun 2018 15:25:23 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:43175) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fWRdI-0005Tw-TQ for qemu-devel@nongnu.org; Fri, 22 Jun 2018 15:22:10 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1fWRdG-0002eE-9q for qemu-devel@nongnu.org; Fri, 22 Jun 2018 15:22:08 -0400 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:48682 helo=mx1.redhat.com) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1fWRdG-0002e7-2Y for qemu-devel@nongnu.org; Fri, 22 Jun 2018 15:22:06 -0400 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.rdu2.redhat.com [10.11.54.4]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id B3E9487AAC; Fri, 22 Jun 2018 19:22:05 +0000 (UTC) Received: from redhat.com (ovpn-122-22.rdu2.redhat.com [10.10.122.22]) by smtp.corp.redhat.com (Postfix) with SMTP id 38FE92026D6C; Fri, 22 Jun 2018 19:22:05 +0000 (UTC) Date: Fri, 22 Jun 2018 22:22:05 +0300 From: "Michael S. Tsirkin" To: qemu-devel@nongnu.org Message-ID: <20180622192148.178309-2-mst@redhat.com> References: <20180622192148.178309-1-mst@redhat.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20180622192148.178309-1-mst@redhat.com> X-Mutt-Fcc: =sent X-Scanned-By: MIMEDefang 2.78 on 10.11.54.4 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.1]); Fri, 22 Jun 2018 19:22:05 +0000 (UTC) X-Greylist: inspected by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.1]); Fri, 22 Jun 2018 19:22:05 +0000 (UTC) for IP:'10.11.54.4' DOMAIN:'int-mx04.intmail.prod.int.rdu2.redhat.com' HELO:'smtp.corp.redhat.com' FROM:'mst@redhat.com' RCPT:'' X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 66.187.233.73 Subject: [Qemu-devel] [PATCH v6 1/2] kvm: support -overcommit cpu-pm=on|off X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Paolo Bonzini , Marcelo Tosatti , Eduardo Habkost , kvm@vger.kernel.org, Richard Henderson Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" X-ZohoMail: RSF_0 Z_629925259 SPT_0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" With this flag, kvm allows guest to control host CPU power state. This increases latency for other processes using same host CPU in an unpredictable way, but if decreases idle entry/exit times for the running VCPU, so to use it QEMU needs a hint about whether host CPU is overcommitted, hence the flag name. Follow-up patches will expose this capability to guest (using mwait leaf). Based on a patch by Wanpeng Li . Signed-off-by: Michael S. Tsirkin Reviewed-by: Eduardo Habkost --- include/sysemu/sysemu.h | 1 + target/i386/kvm.c | 23 +++++++++++++++++++++++ vl.c | 32 +++++++++++++++++++++++++++++++- qemu-options.hx | 27 +++++++++++++++++++++++++-- 4 files changed, 80 insertions(+), 3 deletions(-) diff --git a/include/sysemu/sysemu.h b/include/sysemu/sysemu.h index e893f72f3b..b921c6f3b7 100644 --- a/include/sysemu/sysemu.h +++ b/include/sysemu/sysemu.h @@ -128,6 +128,7 @@ extern bool boot_strict; extern uint8_t *boot_splash_filedata; extern size_t boot_splash_filedata_size; extern bool enable_mlock; +extern bool enable_cpu_pm; extern uint8_t qemu_extra_params_fw[2]; extern QEMUClockType rtc_clock; extern const char *mem_path; diff --git a/target/i386/kvm.c b/target/i386/kvm.c index 44f70733e7..cf9107be4b 100644 --- a/target/i386/kvm.c +++ b/target/i386/kvm.c @@ -1357,6 +1357,29 @@ int kvm_arch_init(MachineState *ms, KVMState *s) smram_machine_done.notify =3D register_smram_listener; qemu_add_machine_init_done_notifier(&smram_machine_done); } + + if (enable_cpu_pm) { + int disable_exits =3D kvm_check_extension(s, KVM_CAP_X86_DISABLE_E= XITS); + int ret; + +/* Work around for kernel header with a typo. TODO: fix header and drop. */ +#if defined(KVM_X86_DISABLE_EXITS_HTL) && !defined(KVM_X86_DISABLE_EXITS_H= LT) +#define KVM_X86_DISABLE_EXITS_HLT KVM_X86_DISABLE_EXITS_HTL +#endif + if (disable_exits) { + disable_exits &=3D (KVM_X86_DISABLE_EXITS_MWAIT | + KVM_X86_DISABLE_EXITS_HLT | + KVM_X86_DISABLE_EXITS_PAUSE); + } + + ret =3D kvm_vm_enable_cap(s, KVM_CAP_X86_DISABLE_EXITS, 0, + disable_exits); + if (ret < 0) { + error_report("kvm: guest stopping CPU not supported: %s", + strerror(-ret)); + } + } + return 0; } =20 diff --git a/vl.c b/vl.c index 06031715ac..c9530efed5 100644 --- a/vl.c +++ b/vl.c @@ -142,6 +142,7 @@ ram_addr_t ram_size; const char *mem_path =3D NULL; int mem_prealloc =3D 0; /* force preallocation of physical target memory */ bool enable_mlock =3D false; +bool enable_cpu_pm =3D false; int nb_nics; NICInfo nd_table[MAX_NICS]; int autostart; @@ -390,6 +391,22 @@ static QemuOptsList qemu_realtime_opts =3D { }, }; =20 +static QemuOptsList qemu_overcommit_opts =3D { + .name =3D "overcommit", + .head =3D QTAILQ_HEAD_INITIALIZER(qemu_overcommit_opts.head), + .desc =3D { + { + .name =3D "mem-lock", + .type =3D QEMU_OPT_BOOL, + }, + { + .name =3D "cpu-pm", + .type =3D QEMU_OPT_BOOL, + }, + { /* end of list */ } + }, +}; + static QemuOptsList qemu_msg_opts =3D { .name =3D "msg", .head =3D QTAILQ_HEAD_INITIALIZER(qemu_msg_opts.head), @@ -3903,7 +3920,20 @@ int main(int argc, char **argv, char **envp) if (!opts) { exit(1); } - enable_mlock =3D qemu_opt_get_bool(opts, "mlock", true); + /* Don't override the -overcommit option if set */ + enable_mlock =3D enable_mlock || + qemu_opt_get_bool(opts, "mlock", true); + break; + case QEMU_OPTION_overcommit: + opts =3D qemu_opts_parse_noisily(qemu_find_opts("overcommi= t"), + optarg, false); + if (!opts) { + exit(1); + } + /* Don't override the -realtime option if set */ + enable_mlock =3D enable_mlock || + qemu_opt_get_bool(opts, "mem-lock", false); + enable_cpu_pm =3D qemu_opt_get_bool(opts, "cpu-pm", false); break; case QEMU_OPTION_msg: opts =3D qemu_opts_parse_noisily(qemu_find_opts("msg"), op= targ, diff --git a/qemu-options.hx b/qemu-options.hx index c0d3951e9f..1bba3d258b 100644 --- a/qemu-options.hx +++ b/qemu-options.hx @@ -3328,8 +3328,7 @@ DEF("realtime", HAS_ARG, QEMU_OPTION_realtime, "-realtime [mlock=3Don|off]\n" " run qemu with realtime features\n" " mlock=3Don|off controls mlock support (default: on)\n= ", - QEMU_ARCH_ALL) -STEXI + QEMU_ARCH_ALL) STEXI @item -realtime mlock=3Don|off @findex -realtime Run qemu with realtime features. @@ -3337,6 +3336,30 @@ mlocking qemu and guest memory can be enabled via @o= ption{mlock=3Don} (enabled by default). ETEXI =20 +DEF("overcommit", HAS_ARG, QEMU_OPTION_overcommit, + "--overcommit [mem-lock=3Don|off][cpu-pm=3Don|off]\n" + " run qemu with overcommit hints\n" + " mem-lock=3Don|off controls memory lock support (defau= lt: off)\n" + " cpu-pm=3Don|off controls cpu power management (defaul= t: off)\n", + QEMU_ARCH_ALL) +STEXI +@item -overcommit mem-lock=3Don|off +@item -overcommit cpu-pm=3Don|off +@findex -overcommit +Run qemu with hints about host resource overcommit. The default is +to assume that host overcommits all resources. + +Locking qemu and guest memory can be enabled via @option{mem-lock=3Don} (d= isabled +by default). This works when host memory is not overcommitted and reduces= the +worst-case latency for guest. This is equivalent to @option{realtime}. + +Guest ability to manage power state of host cpus (increasing latency for o= ther +processes on the same host cpu, but decreasing latency for guest) can be +enabled via @option{cpu-pm=3Don} (disabled by default). This works best w= hen +host CPU is not overcommitted. When used, host estimates of CPU cycle and = power +utilization will be incorrect, not taking into account guest idle time. +ETEXI + DEF("gdb", HAS_ARG, QEMU_OPTION_gdb, \ "-gdb dev wait for gdb connection on 'dev'\n", QEMU_ARCH_ALL) STEXI --=20 MST From nobody Thu May 2 02:12:24 2024 Delivered-To: importer@patchew.org Received-SPF: pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) client-ip=208.118.235.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Authentication-Results: mx.zohomail.com; spf=pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; dmarc=fail(p=none dis=none) header.from=redhat.com Return-Path: Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) by mx.zohomail.com with SMTPS id 1529695428453334.0407631346387; Fri, 22 Jun 2018 12:23:48 -0700 (PDT) Received: from localhost ([::1]:35768 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fWRet-0006LG-Mq for importer@patchew.org; Fri, 22 Jun 2018 15:23:47 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:43174) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fWRdI-0005Tv-TO for qemu-devel@nongnu.org; Fri, 22 Jun 2018 15:22:10 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1fWRdG-0002eP-Qz for qemu-devel@nongnu.org; Fri, 22 Jun 2018 15:22:08 -0400 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:36892 helo=mx1.redhat.com) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1fWRdG-0002eI-Kn for qemu-devel@nongnu.org; Fri, 22 Jun 2018 15:22:06 -0400 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.rdu2.redhat.com [10.11.54.5]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 45180400E9BA; Fri, 22 Jun 2018 19:22:06 +0000 (UTC) Received: from redhat.com (ovpn-122-22.rdu2.redhat.com [10.10.122.22]) by smtp.corp.redhat.com (Postfix) with SMTP id ECD031C5A3; Fri, 22 Jun 2018 19:22:05 +0000 (UTC) Date: Fri, 22 Jun 2018 22:22:05 +0300 From: "Michael S. Tsirkin" To: qemu-devel@nongnu.org Message-ID: <20180622192148.178309-3-mst@redhat.com> References: <20180622192148.178309-1-mst@redhat.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20180622192148.178309-1-mst@redhat.com> X-Mutt-Fcc: =sent X-Scanned-By: MIMEDefang 2.79 on 10.11.54.5 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.7]); Fri, 22 Jun 2018 19:22:06 +0000 (UTC) X-Greylist: inspected by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.7]); Fri, 22 Jun 2018 19:22:06 +0000 (UTC) for IP:'10.11.54.5' DOMAIN:'int-mx05.intmail.prod.int.rdu2.redhat.com' HELO:'smtp.corp.redhat.com' FROM:'mst@redhat.com' RCPT:'' X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 66.187.233.73 Subject: [Qemu-devel] [PATCH v6 2/2] i386/cpu: make -cpu host support monitor/mwait X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Paolo Bonzini , Marcelo Tosatti , Eduardo Habkost , kvm@vger.kernel.org, Richard Henderson Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" X-ZohoMail: RSF_0 Z_629925259 SPT_0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" 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 Reviewed-by: Eduardo Habkost --- 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 gu= est */ bool cache_info_passthrough; =20 + /* 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 capabilitie= s */ uint32_t filtered_features[FEATURE_WORDS]; =20 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 =3D 0; /* Smallest monitor-line size in bytes */ - *ebx =3D 0; /* Largest monitor-line size in bytes */ - *ecx =3D CPUID_MWAIT_EMX | CPUID_MWAIT_IBE; - *edx =3D 0; + /* MONITOR/MWAIT Leaf */ + *eax =3D cpu->mwait.eax; /* Smallest monitor-line size in bytes */ + *ebx =3D cpu->mwait.ebx; /* Largest monitor-line size in bytes */ + *ecx =3D cpu->mwait.ecx; /* flags */ + *edx =3D cpu->mwait.edx; /* mwait substates */ break; case 6: /* Thermal and Power Leaf */ @@ -4595,6 +4595,15 @@ static void x86_cpu_realizefn(DeviceState *dev, Erro= r **errp) goto out; } =20 + 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] |=3D CPUID_EXT_MONITOR; + } + /* mwait extended info: needed for Core compatibility */ + /* We always wake on interrupt even if host does not have the capabili= ty */ + cpu->mwait.ecx |=3D CPUID_MWAIT_EMX | CPUID_MWAIT_IBE; + if (cpu->apic_id =3D=3D 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, uin= t32_t function, if (!kvm_irqchip_in_kernel()) { ret &=3D ~CPUID_EXT_X2APIC; } + + if (enable_cpu_pm) { + int disable_exits =3D kvm_check_extension(s, + KVM_CAP_X86_DISABLE_EX= ITS); + + if (disable_exits & KVM_X86_DISABLE_EXITS_MWAIT) { + ret |=3D CPUID_EXT_MONITOR; + } + } } else if (function =3D=3D 6 && reg =3D=3D R_EAX) { ret |=3D CPUID_6_EAX_ARAT; /* safe to allow because of emulated AP= IC */ } else if (function =3D=3D 7 && index =3D=3D 0 && reg =3D=3D R_EBX) { --=20 MST