From nobody Sun Feb 8 13:53:32 2026 Delivered-To: importer@patchew.org Received-SPF: pass (zohomail.com: domain of redhat.com designates 170.10.129.124 as permitted sender) client-ip=170.10.129.124; envelope-from=libvir-list-bounces@redhat.com; helo=us-smtp-delivery-124.mimecast.com; Authentication-Results: mx.zohomail.com; dkim=pass; spf=pass (zohomail.com: domain of redhat.com designates 170.10.129.124 as permitted sender) smtp.mailfrom=libvir-list-bounces@redhat.com; dmarc=pass(p=none dis=none) header.from=redhat.com Return-Path: Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by mx.zohomail.com with SMTPS id 1656326772563731.9241591915722; Mon, 27 Jun 2022 03:46:12 -0700 (PDT) Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-237-RwCZR0BZN-2QVApztqXSJw-1; Mon, 27 Jun 2022 06:44:53 -0400 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.rdu2.redhat.com [10.11.54.1]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 022AD805F3F; Mon, 27 Jun 2022 10:44:50 +0000 (UTC) Received: from mm-prod-listman-01.mail-001.prod.us-east-1.aws.redhat.com (unknown [10.30.29.100]) by smtp.corp.redhat.com (Postfix) with ESMTP id E094E40CFD05; Mon, 27 Jun 2022 10:44:49 +0000 (UTC) Received: from mm-prod-listman-01.mail-001.prod.us-east-1.aws.redhat.com (localhost [IPv6:::1]) by mm-prod-listman-01.mail-001.prod.us-east-1.aws.redhat.com (Postfix) with ESMTP id 416381947059; Mon, 27 Jun 2022 10:44:49 +0000 (UTC) Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.rdu2.redhat.com [10.11.54.6]) by mm-prod-listman-01.mail-001.prod.us-east-1.aws.redhat.com (Postfix) with ESMTP id D91FE1947041 for ; Mon, 27 Jun 2022 10:44:47 +0000 (UTC) Received: by smtp.corp.redhat.com (Postfix) id B53082166B29; Mon, 27 Jun 2022 10:44:47 +0000 (UTC) Received: from maggie.redhat.com (unknown [10.43.2.39]) by smtp.corp.redhat.com (Postfix) with ESMTP id 5E9292166B26 for ; Mon, 27 Jun 2022 10:44:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1656326771; h=from:from:sender:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:list-id:list-help: list-unsubscribe:list-subscribe:list-post; bh=j/jef51fuyB0kdDCAxfx6iZn/olsQuoutRO6N9Z/6zM=; b=dtTj2kvVA7mPzhVylfrMHWAKz09Ginl/fbH0/2/5FKyOD8A+OXBF3SghH8o1RdPisku6s3 TV7cRu4XXNeD/x7oF0k7EtSHzZNnD95QZ10tsGvFuZ4zYkeTuNWBANkp706UCK6Uh0cgt7 aA42VWqzWFslVaa6l1O5wT2roZBQY3w= X-MC-Unique: RwCZR0BZN-2QVApztqXSJw-1 X-Original-To: libvir-list@listman.corp.redhat.com From: Michal Privoznik To: libvir-list@redhat.com Subject: [PATCH v2 7/9] qemu_conf: Introduce a knob to set SCHED_CORE Date: Mon, 27 Jun 2022 12:44:39 +0200 Message-Id: In-Reply-To: References: MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.78 on 10.11.54.6 X-BeenThere: libvir-list@redhat.com X-Mailman-Version: 2.1.29 Precedence: list List-Id: Development discussions about the libvirt library & tools List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: libvir-list-bounces@redhat.com Sender: "libvir-list" X-Scanned-By: MIMEDefang 2.84 on 10.11.54.1 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=libvir-list-bounces@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Transfer-Encoding: quoted-printable X-ZohoMail-DKIM: pass (identity @redhat.com) X-ZM-MESSAGEID: 1656326773574100001 Content-Type: text/plain; charset="utf-8"; x-default="true" Ideally, we would just pick the best default and users wouldn't have to intervene at all. But in some cases it may be handy to not bother with SCHED_CORE at all or place helper processes into the same group as QEMU. Introduce a knob in qemu.conf to allow users control this behaviour. Signed-off-by: Michal Privoznik --- src/qemu/libvirtd_qemu.aug | 1 + src/qemu/qemu.conf.in | 14 ++++++++++ src/qemu/qemu_conf.c | 42 ++++++++++++++++++++++++++++++ src/qemu/qemu_conf.h | 11 ++++++++ src/qemu/test_libvirtd_qemu.aug.in | 1 + 5 files changed, 69 insertions(+) diff --git a/src/qemu/libvirtd_qemu.aug b/src/qemu/libvirtd_qemu.aug index 0f18775121..ed097ea3d9 100644 --- a/src/qemu/libvirtd_qemu.aug +++ b/src/qemu/libvirtd_qemu.aug @@ -110,6 +110,7 @@ module Libvirtd_qemu =3D | bool_entry "dump_guest_core" | str_entry "stdio_handler" | int_entry "max_threads_per_process" + | str_entry "sched_core" =20 let device_entry =3D bool_entry "mac_filter" | bool_entry "relaxed_acs_check" diff --git a/src/qemu/qemu.conf.in b/src/qemu/qemu.conf.in index 04b7740136..01c7ab5868 100644 --- a/src/qemu/qemu.conf.in +++ b/src/qemu/qemu.conf.in @@ -952,3 +952,17 @@ # DO NOT use in production. # #deprecation_behavior =3D "none" + +# If this is set then QEMU and its threads will run in a separate scheduli= ng +# group meaning no other process will share Hyper Threads of a single core= with +# QEMU. Each QEMU has its own group. +# +# Possible options are: +# "none" - nor QEMU nor any of its helper processes are placed into separa= te +# scheduling group +# "emulator" - (default) only QEMU and its threads (emulator + vCPUs) are +# placed into separate scheduling group, helper proccesses re= main +# outside of the group. +# "full" - both QEMU and its helper processes are placed into separate +# scheduling group. +#sched_core =3D "emulator" diff --git a/src/qemu/qemu_conf.c b/src/qemu/qemu_conf.c index 3b75cdeb95..d2c0dbf981 100644 --- a/src/qemu/qemu_conf.c +++ b/src/qemu/qemu_conf.c @@ -66,6 +66,14 @@ VIR_LOG_INIT("qemu.qemu_conf"); #define QEMU_MIGRATION_PORT_MIN 49152 #define QEMU_MIGRATION_PORT_MAX 49215 =20 +VIR_ENUM_DECL(virQEMUSchedCore); +VIR_ENUM_IMPL(virQEMUSchedCore, + QEMU_SCHED_CORE_LAST, + "none", + "emulator", + "full"); + + static virClass *virQEMUDriverConfigClass; static void virQEMUDriverConfigDispose(void *obj); =20 @@ -281,6 +289,9 @@ virQEMUDriverConfig *virQEMUDriverConfigNew(bool privil= eged, =20 cfg->deprecationBehavior =3D g_strdup("none"); =20 + if (virProcessSchedCoreAvailable() > 0) + cfg->schedCore =3D QEMU_SCHED_CORE_EMULATOR; + return g_steal_pointer(&cfg); } =20 @@ -629,6 +640,7 @@ virQEMUDriverConfigLoadProcessEntry(virQEMUDriverConfig= *cfg, g_auto(GStrv) hugetlbfs =3D NULL; g_autofree char *stdioHandler =3D NULL; g_autofree char *corestr =3D NULL; + g_autofree char *schedCore =3D NULL; size_t i; =20 if (virConfGetValueStringList(conf, "hugetlbfs_mount", true, @@ -706,6 +718,36 @@ virQEMUDriverConfigLoadProcessEntry(virQEMUDriverConfi= g *cfg, } } =20 + if (virConfGetValueString(conf, "sched_core", &schedCore) < 0) + return -1; + if (schedCore) { + int val =3D virQEMUSchedCoreTypeFromString(schedCore); + + if (val < 0) { + virReportError(VIR_ERR_CONFIG_UNSUPPORTED, + _("Unknown sched_core value %s"), + schedCore); + return -1; + } + + if (val =3D=3D QEMU_SCHED_CORE_EMULATOR || + val =3D=3D QEMU_SCHED_CORE_FULL) { + int rv =3D virProcessSchedCoreAvailable(); + + if (rv < 0) { + virReportSystemError(errno, "%s", + _("Unable to detect SCHED_CORE")); + return -1; + } else if (rv =3D=3D 0) { + virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s", + _("SCHED_CORE not supported by kernel")); + return -1; + } + } + + cfg->schedCore =3D val; + } + return 0; } =20 diff --git a/src/qemu/qemu_conf.h b/src/qemu/qemu_conf.h index c40c452f58..afc1af6073 100644 --- a/src/qemu/qemu_conf.h +++ b/src/qemu/qemu_conf.h @@ -44,6 +44,15 @@ =20 #define QEMU_DRIVER_NAME "QEMU" =20 +typedef enum { + QEMU_SCHED_CORE_NONE =3D 0, + QEMU_SCHED_CORE_EMULATOR, + QEMU_SCHED_CORE_FULL, + + QEMU_SCHED_CORE_LAST +} virQEMUSchedCore; + + typedef struct _virQEMUDriver virQEMUDriver; =20 typedef struct _virQEMUDriverConfig virQEMUDriverConfig; @@ -216,6 +225,8 @@ struct _virQEMUDriverConfig { char **capabilityfilters; =20 char *deprecationBehavior; + + virQEMUSchedCore schedCore; }; =20 G_DEFINE_AUTOPTR_CLEANUP_FUNC(virQEMUDriverConfig, virObjectUnref); diff --git a/src/qemu/test_libvirtd_qemu.aug.in b/src/qemu/test_libvirtd_qe= mu.aug.in index 757d21c33f..17caffdbd3 100644 --- a/src/qemu/test_libvirtd_qemu.aug.in +++ b/src/qemu/test_libvirtd_qemu.aug.in @@ -116,3 +116,4 @@ module Test_libvirtd_qemu =3D { "1" =3D "capname" } } { "deprecation_behavior" =3D "none" } +{ "sched_core" =3D "emulator" } --=20 2.35.1