From nobody Tue Nov 4 19:07:45 2025 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 1530530603627287.09047094044115; Mon, 2 Jul 2018 04:23:23 -0700 (PDT) Received: from localhost ([::1]:60114 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fZwvS-0005rO-So for importer@patchew.org; Mon, 02 Jul 2018 07:23:22 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:43882) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fZwqY-0002G9-Kw for qemu-devel@nongnu.org; Mon, 02 Jul 2018 07:18:19 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1fZwqX-0006Fh-MU for qemu-devel@nongnu.org; Mon, 02 Jul 2018 07:18:18 -0400 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:33490 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 1fZwqX-0006FT-Hm; Mon, 02 Jul 2018 07:18:17 -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 2B3BCC12BA; Mon, 2 Jul 2018 11:18:17 +0000 (UTC) Received: from localhost (ovpn-116-251.ams2.redhat.com [10.36.116.251]) by smtp.corp.redhat.com (Postfix) with ESMTPS id CFB46167FA; Mon, 2 Jul 2018 11:18:16 +0000 (UTC) From: Cornelia Huck To: Peter Maydell Date: Mon, 2 Jul 2018 13:17:34 +0200 Message-Id: <20180702111737.18970-13-cohuck@redhat.com> In-Reply-To: <20180702111737.18970-1-cohuck@redhat.com> References: <20180702111737.18970-1-cohuck@redhat.com> 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 [10.11.55.1]); Mon, 02 Jul 2018 11:18:17 +0000 (UTC) X-Greylist: inspected by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.1]); Mon, 02 Jul 2018 11:18:17 +0000 (UTC) for IP:'10.11.54.5' DOMAIN:'int-mx05.intmail.prod.int.rdu2.redhat.com' HELO:'smtp.corp.redhat.com' FROM:'cohuck@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] [PULL 12/15] s390x/tcg: fix CPU hotplug with single-threaded TCG 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: Thomas Huth , David Hildenbrand , Cornelia Huck , Alexander Graf , qemu-devel@nongnu.org, Christian Borntraeger , qemu-s390x@nongnu.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 MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" From: David Hildenbrand run_on_cpu() doesn't seem to work reliably until the CPU has been fully created if the single-threaded TCG main loop is already running. Therefore, hotplugging a CPU under single-threaded TCG does currently not work. We should use the direct call instead of going via run_on_cpu(). So let's use run_on_cpu() for KVM only - KVM requires it due to the initial CPU reset ioctl. As a nice side effect, we get rid of the ifdef. Reviewed-by: Thomas Huth Signed-off-by: David Hildenbrand Message-Id: <20180627134410.4901-10-david@redhat.com> Signed-off-by: Cornelia Huck --- target/s390x/cpu.c | 17 ++++++++++++----- 1 file changed, 12 insertions(+), 5 deletions(-) diff --git a/target/s390x/cpu.c b/target/s390x/cpu.c index 40d6980229..271c5ce652 100644 --- a/target/s390x/cpu.c +++ b/target/s390x/cpu.c @@ -218,11 +218,18 @@ static void s390_cpu_realizefn(DeviceState *dev, Erro= r **errp) #endif s390_cpu_gdb_init(cs); qemu_init_vcpu(cs); -#if !defined(CONFIG_USER_ONLY) - run_on_cpu(cs, s390_do_cpu_full_reset, RUN_ON_CPU_NULL); -#else - cpu_reset(cs); -#endif + + /* + * KVM requires the initial CPU reset ioctl to be executed on the targ= et + * CPU thread. CPU hotplug under single-threaded TCG will not work with + * run_on_cpu(), as run_on_cpu() will not work properly if called while + * the main thread is already running but the CPU hasn't been realized. + */ + if (kvm_enabled()) { + run_on_cpu(cs, s390_do_cpu_full_reset, RUN_ON_CPU_NULL); + } else { + cpu_reset(cs); + } =20 scc->parent_realize(dev, &err); out: --=20 2.14.4