From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:51970) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1abqQ5-0002EN-VV for qemu-devel@nongnu.org; Fri, 04 Mar 2016 09:09:30 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1abqQ1-000399-Tr for qemu-devel@nongnu.org; Fri, 04 Mar 2016 09:09:29 -0500 Received: from e19.ny.us.ibm.com ([129.33.205.209]:55459) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1abqQ1-00038c-Pm for qemu-devel@nongnu.org; Fri, 04 Mar 2016 09:09:25 -0500 Received: from localhost by e19.ny.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Fri, 4 Mar 2016 09:09:24 -0500 Received: from b01cxnp23034.gho.pok.ibm.com (b01cxnp23034.gho.pok.ibm.com [9.57.198.29]) by d01dlp03.pok.ibm.com (Postfix) with ESMTP id 7C251C90027 for ; Fri, 4 Mar 2016 09:09:19 -0500 (EST) Received: from d01av02.pok.ibm.com (d01av02.pok.ibm.com [9.56.224.216]) by b01cxnp23034.gho.pok.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id u24E9LJv28836048 for ; Fri, 4 Mar 2016 14:09:22 GMT Received: from d01av02.pok.ibm.com (localhost [127.0.0.1]) by d01av02.pok.ibm.com (8.14.4/8.14.4/NCO v10.0 AVout) with ESMTP id u24E9LqW027286 for ; Fri, 4 Mar 2016 09:09:21 -0500 References: <1457040633-30951-1-git-send-email-mjrosato@linux.vnet.ibm.com> <1457040633-30951-5-git-send-email-mjrosato@linux.vnet.ibm.com> <20160304090551.235f19af@thinkpad-w530> From: Matthew Rosato Message-ID: <56D9970D.9040704@linux.vnet.ibm.com> Date: Fri, 4 Mar 2016 09:09:17 -0500 MIME-Version: 1.0 In-Reply-To: <20160304090551.235f19af@thinkpad-w530> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH v8 4/7] s390x/cpu: Tolerate max_cpus List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: David Hildenbrand Cc: qemu-devel@nongnu.org, agraf@suse.de, borntraeger@de.ibm.com, pbonzini@redhat.com, bharata@linux.vnet.ibm.com, cornelia.huck@de.ibm.com, imammedo@redhat.com, afaerber@suse.de, rth@twiddle.net On 03/04/2016 03:05 AM, David Hildenbrand wrote: >> Once hotplug is enabled, interrupts may come in for CPUs >> with an address > smp_cpus. Allocate for this and allow >> search routines to look beyond smp_cpus. >> >> Signed-off-by: Matthew Rosato >> --- >> hw/s390x/s390-virtio.c | 13 +++++++------ >> 1 file changed, 7 insertions(+), 6 deletions(-) >> >> diff --git a/hw/s390x/s390-virtio.c b/hw/s390x/s390-virtio.c >> index c501a48..90bc58a 100644 >> --- a/hw/s390x/s390-virtio.c >> +++ b/hw/s390x/s390-virtio.c >> @@ -58,15 +58,16 @@ >> #define S390_TOD_CLOCK_VALUE_MISSING 0x00 >> #define S390_TOD_CLOCK_VALUE_PRESENT 0x01 >> >> -static S390CPU **ipi_states; >> +static S390CPU **cpu_states; >> >> S390CPU *s390_cpu_addr2state(uint16_t cpu_addr) >> { >> - if (cpu_addr >= smp_cpus) { >> + if (cpu_addr >= max_cpus) { >> return NULL; >> } >> >> - return ipi_states[cpu_addr]; >> + /* Fast lookup via CPU ID */ >> + return cpu_states[cpu_addr]; >> } >> >> void s390_init_ipl_dev(const char *kernel_filename, >> @@ -101,14 +102,14 @@ void s390_init_cpus(MachineState *machine) >> machine->cpu_model = "host"; >> } >> >> - ipi_states = g_malloc(sizeof(S390CPU *) * smp_cpus); >> + cpu_states = g_malloc0(sizeof(S390CPU *) * max_cpus); >> >> - for (i = 0; i < smp_cpus; i++) { >> + for (i = 0; i < max_cpus; i++) { >> S390CPU *cpu; >> >> cpu = cpu_s390x_init(machine->cpu_model); >> >> - ipi_states[i] = cpu; >> + cpu_states[i] = cpu; > > This looks wrong (creating all cpus). But the net patch fixes it again. > Ouch. Definitely wrong, error introduced during patch split. We allocate for max_cpus, but should only create smp_cpus cpus during init. > Can you make this patch a simple rename patch and move the max_cpu stuff into > the next patch if this makes sense? > > Or simply set the cpu_state for everything above smp_cpus to zero in this patch. This is done via the gmalloc0. If I hadn't messed up this loop, the net result would be the ability to handle > smp_cpus, but nobody will ever create one (yet). Matt