From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:58065) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dnR4M-0000cr-KC for qemu-devel@nongnu.org; Thu, 31 Aug 2017 11:07:51 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1dnR4H-0000bZ-MQ for qemu-devel@nongnu.org; Thu, 31 Aug 2017 11:07:46 -0400 Received: from mx1.redhat.com ([209.132.183.28]:57811) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1dnR4H-0000ae-G4 for qemu-devel@nongnu.org; Thu, 31 Aug 2017 11:07:41 -0400 Date: Thu, 31 Aug 2017 17:07:33 +0200 From: Cornelia Huck Message-ID: <20170831170733.7fe86dbc.cohuck@redhat.com> In-Reply-To: <9beeb7d0-edb8-2227-3182-9275567b2fb5@redhat.com> References: <20170830170601.15855-1-david@redhat.com> <20170830170601.15855-9-david@redhat.com> <20170831164142.607711ec.cohuck@redhat.com> <9beeb7d0-edb8-2227-3182-9275567b2fb5@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH v1 08/11] s390x: allow only 1 CPU with TCG List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: David Hildenbrand Cc: qemu-devel@nongnu.org, Richard Henderson , Aurelien Jarno , thuth@redhat.com, borntraeger@de.ibm.com, Alexander Graf On Thu, 31 Aug 2017 17:03:21 +0200 David Hildenbrand wrote: > On 31.08.2017 16:41, Cornelia Huck wrote: > > On Wed, 30 Aug 2017 19:05:58 +0200 > > 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 are specified, so we don't raise people's > >> hope. > >> > >> Signed-off-by: David Hildenbrand > >> --- > >> hw/s390x/s390-virtio-ccw.c | 6 ++++++ > >> 1 file changed, 6 insertions(+) > >> > >> diff --git a/hw/s390x/s390-virtio-ccw.c b/hw/s390x/s390-virtio-ccw.c > >> index 7754e3eaf9..eff96808c4 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" > >> @@ -56,6 +57,11 @@ 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 > 1) { > >> + error_report("Number of SMP CPUs requested (%d) exceeds max CPUs " > >> + "supported by TCG (1) on s390x", max_cpus); > > > > Make this a #define, so we can just flip the switch when smp support is > > ready? > > As an alternative: yield a warning? If we know that this can't work, it makes sense to stop immediately, no? > > > > >> + exit(1); > >> + } > >> > >> ms->cpus = g_new0(S390CPU *, max_cpus); > >> > > > >