From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:49144) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dpesX-0002nX-Gl for qemu-devel@nongnu.org; Wed, 06 Sep 2017 14:16:50 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1dpesT-00051r-G5 for qemu-devel@nongnu.org; Wed, 06 Sep 2017 14:16:45 -0400 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:43652 helo=mx0a-001b2d01.pphosted.com) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1dpesT-000509-A6 for qemu-devel@nongnu.org; Wed, 06 Sep 2017 14:16:41 -0400 Received: from pps.filterd (m0098416.ppops.net [127.0.0.1]) by mx0b-001b2d01.pphosted.com (8.16.0.21/8.16.0.21) with SMTP id v86IEVIl138062 for ; Wed, 6 Sep 2017 14:16:40 -0400 Received: from e11.ny.us.ibm.com (e11.ny.us.ibm.com [129.33.205.201]) by mx0b-001b2d01.pphosted.com with ESMTP id 2ctmrwf77s-1 (version=TLSv1.2 cipher=AES256-SHA bits=256 verify=NOT) for ; Wed, 06 Sep 2017 14:16:40 -0400 Received: from localhost by e11.ny.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Wed, 6 Sep 2017 14:16:40 -0400 References: <20170904154316.4148-1-david@redhat.com> <20170904154316.4148-12-david@redhat.com> From: Matthew Rosato Date: Wed, 6 Sep 2017 14:16:34 -0400 MIME-Version: 1.0 In-Reply-To: <20170904154316.4148-12-david@redhat.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Message-Id: <2c620927-0406-2fc1-895c-09ffc2e44a4e@linux.vnet.ibm.com> Subject: Re: [Qemu-devel] [PATCH v2 11/19] s390x: allow only 1 CPU with TCG List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: David Hildenbrand , qemu-devel@nongnu.org Cc: thuth@redhat.com, Eduardo Habkost , cohuck@redhat.com, Richard Henderson , Alexander Graf , borntraeger@de.ibm.com On 09/04/2017 11:43 AM, David Hildenbrand wrote: > Specifying more than 1 CPU (e.g. -smp 5) leads to SIGP errors (the > guest tries to bring these CPUs up but fails), because we don't support > multiple CPUs on s390x under TCG. > > Let's bail out if more than 1 is specified, so we don't raise people's > hope. Make it a define, so we can easily bump it up later. > > Signed-off-by: David Hildenbrand > --- Makes sense. Ran the described environment without this patch (errors) and again with this patch (graceful exit w/ message). Tested-by: Matthew Rosato > hw/s390x/s390-virtio-ccw.c | 7 +++++++ > target/s390x/cpu.h | 2 ++ > 2 files changed, 9 insertions(+) > > diff --git a/hw/s390x/s390-virtio-ccw.c b/hw/s390x/s390-virtio-ccw.c > index f67b4b5d58..f7ca20d77a 100644 > --- a/hw/s390x/s390-virtio-ccw.c > +++ b/hw/s390x/s390-virtio-ccw.c > @@ -23,6 +23,7 @@ > #include "hw/s390x/css.h" > #include "virtio-ccw.h" > #include "qemu/config-file.h" > +#include "qemu/error-report.h" > #include "s390-pci-bus.h" > #include "hw/s390x/storage-keys.h" > #include "hw/s390x/storage-attributes.h" > @@ -55,6 +56,12 @@ static void s390_init_cpus(MachineState *machine) > if (machine->cpu_model == NULL) { > machine->cpu_model = s390_default_cpu_model_name(); > } > + if (tcg_enabled() && max_cpus > S390_TCG_MAX_CPUS) { > + error_report("Number of SMP CPUs requested (%d) exceeds max CPUs " > + "supported by TCG (%d) on s390x", max_cpus, > + S390_TCG_MAX_CPUS); > + exit(1); > + } > > cpu_states = g_new0(S390CPU *, max_cpus); > > diff --git a/target/s390x/cpu.h b/target/s390x/cpu.h > index 147aceba28..dca6aa9aae 100644 > --- a/target/s390x/cpu.h > +++ b/target/s390x/cpu.h > @@ -209,6 +209,8 @@ static inline S390CPU *s390_env_get_cpu(CPUS390XState *env) > > #define ENV_OFFSET offsetof(S390CPU, env) > > +#define S390_TCG_MAX_CPUS 1 > + > #ifndef CONFIG_USER_ONLY > extern const struct VMStateDescription vmstate_s390_cpu; > #endif >