From patchwork Fri Jun 15 22:29:03 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: 10467775 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 D5125601C2 for ; Fri, 15 Jun 2018 22:29:11 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id E48A2288F9 for ; Fri, 15 Jun 2018 22:29:08 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id D8FAF28957; Fri, 15 Jun 2018 22:29:08 +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 5C52C288F9 for ; Fri, 15 Jun 2018 22:29:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756634AbeFOW3F (ORCPT ); Fri, 15 Jun 2018 18:29:05 -0400 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:59646 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1756519AbeFOW3E (ORCPT ); Fri, 15 Jun 2018 18:29:04 -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 0D4945821; 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 7A3B82026DEF; Fri, 15 Jun 2018 22:29:03 +0000 (UTC) Date: Sat, 16 Jun 2018 01:29:03 +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 1/2] kvm: support -dedicated cpu-pm=on|off Message-ID: <20180615222855.44421-2-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 10.11.54.4 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.1]); Fri, 15 Jun 2018 22:29:04 +0000 (UTC) X-Greylist: inspected by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.1]); Fri, 15 Jun 2018 22:29:04 +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:'' Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP 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 it works best if you use a dedicated host cpu, hence the 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 --- include/sysemu/sysemu.h | 1 + target/i386/kvm.c | 23 +++++++++++++++++++++++ vl.c | 32 +++++++++++++++++++++++++++++++- qemu-options.hx | 18 ++++++++++++++++++ 4 files changed, 73 insertions(+), 1 deletion(-) 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 = register_smram_listener; qemu_add_machine_init_done_notifier(&smram_machine_done); } + + if (enable_cpu_pm) { + int disable_exits = kvm_check_extension(s, KVM_CAP_X86_DISABLE_EXITS); + 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_HLT) +#define KVM_X86_DISABLE_EXITS_HLT KVM_X86_DISABLE_EXITS_HTL +#endif + if (disable_exits) { + disable_exits &= (KVM_X86_DISABLE_EXITS_MWAIT | + KVM_X86_DISABLE_EXITS_HLT | + KVM_X86_DISABLE_EXITS_PAUSE); + } + + ret = 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; } diff --git a/vl.c b/vl.c index 06031715ac..d53a9abcde 100644 --- a/vl.c +++ b/vl.c @@ -142,6 +142,7 @@ ram_addr_t ram_size; const char *mem_path = NULL; int mem_prealloc = 0; /* force preallocation of physical target memory */ bool enable_mlock = false; +bool enable_cpu_pm = false; int nb_nics; NICInfo nd_table[MAX_NICS]; int autostart; @@ -390,6 +391,22 @@ static QemuOptsList qemu_realtime_opts = { }, }; +static QemuOptsList qemu_dedicated_opts = { + .name = "dedicated", + .head = QTAILQ_HEAD_INITIALIZER(qemu_dedicated_opts.head), + .desc = { + { + .name = "mem-lock", + .type = QEMU_OPT_BOOL, + }, + { + .name = "cpu-pm", + .type = QEMU_OPT_BOOL, + }, + { /* end of list */ } + }, +}; + static QemuOptsList qemu_msg_opts = { .name = "msg", .head = 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 = qemu_opt_get_bool(opts, "mlock", true); + /* Don't override the -dedicated option if set */ + enable_mlock = enable_mlock || + qemu_opt_get_bool(opts, "mlock", true); + break; + case QEMU_OPTION_dedicated: + opts = qemu_opts_parse_noisily(qemu_find_opts("dedicated"), + optarg, false); + if (!opts) { + exit(1); + } + /* Don't override the -realtime option if set */ + enable_mlock = enable_mlock || + qemu_opt_get_bool(opts, "mem-lock", false); + enable_cpu_pm = qemu_opt_get_bool(opts, "cpu-pm", false); break; case QEMU_OPTION_msg: opts = qemu_opts_parse_noisily(qemu_find_opts("msg"), optarg, diff --git a/qemu-options.hx b/qemu-options.hx index c0d3951e9f..ddedb7eb92 100644 --- a/qemu-options.hx +++ b/qemu-options.hx @@ -3337,6 +3337,24 @@ mlocking qemu and guest memory can be enabled via @option{mlock=on} (enabled by default). ETEXI +DEF("dedicated", HAS_ARG, QEMU_OPTION_dedicated, + "-dedicated [mem-lock=on|off][cpu-pm=on|off]\n" + " run qemu with realtime features\n" + " mem-lock=on|off controls memory lock support (default: off)\n" + " cpu-pm=on|off controls cpu power management (default: off)\n", + QEMU_ARCH_ALL) +STEXI +@item -dedicated mem-lock=on|off +@item -dedicated cpu-pm=on|off +@findex -dedicated +Run qemu using dedicated host resources. +Locking qemu and guest memory can be enabled via @option{mem-lock=on} +(disabled by default). This is equivalent to @option{realtime}. +Guest ability to manage power state of host cpus (increasing latency for other +processes on the same host cpu, but decreasing latency for guest) +can be enabled via @option{cpu-pm=on} (disabled by default). +ETEXI + DEF("gdb", HAS_ARG, QEMU_OPTION_gdb, \ "-gdb dev wait for gdb connection on 'dev'\n", QEMU_ARCH_ALL) STEXI