commit c0dd10991903c552811d8cbe9231055b1b3a7ebd
author Seeteena Thoufeek <s1seetee@linux.vnet.ibm.com> Mon Sep 04 13:13:51 2017 +0530
committer Eduardo Habkost <ehabkost@redhat.com> Mon Oct 09 23:21:52 2017 -0300
tree 53af4c035f216aa95a19a3ca4903ce49fc5d509d
parent 31b93521924dddb22621f8dba27cdce802406eb3

vl: exit if maxcpus is negative

Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>

---Steps to Reproduce---

When passed a negative number to 'maxcpus' parameter, Qemu aborts
with a core dump.

Run the following command with maxcpus argument as negative number

ppc64-softmmu/qemu-system-ppc64 --nographic -vga none -machine
pseries,accel=kvm,kvm-type=HV -m size=200g -device virtio-blk-pci,
drive=rootdisk -drive file=/home/images/pegas-1.0-ppc64le.qcow2,
if=none,cache=none,id=rootdisk,format=qcow2 -monitor telnet
:127.0.0.1:1234,server,nowait -net nic,model=virtio -net
user -redir tcp:2000::22 -device nec-usb-xhci -smp 8,cores=1,
threads=1,maxcpus=-12

(process:12149): GLib-ERROR **: gmem.c:130: failed to allocate
 18446744073709550568 bytes

Trace/breakpoint trap

Reported-by: R.Nageswara Sastry <rnsastry@linux.vnet.ibm.com>
Signed-off-by: Seeteena Thoufeek <s1seetee@linux.vnet.ibm.com>
Message-Id: <1504511031-26834-1-git-send-email-s1seetee@linux.vnet.ibm.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>

vl.c

diff --git a/vl.c b/vl.c
index ebea42e..d7c3492 100644
--- a/vl.c
+++ b/vl.c
@@ -161,7 +161,7 @@
 int win2k_install_hack = 0;
 int singlestep = 0;
 int smp_cpus = 1;
-int max_cpus = 1;
+unsigned int max_cpus = 1;
 int smp_cores = 1;
 int smp_threads = 1;
 int acpi_enabled = 1;
@@ -4331,8 +4331,8 @@
 
     machine_class->max_cpus = machine_class->max_cpus ?: 1; /* Default to UP */
     if (max_cpus > machine_class->max_cpus) {
-        error_report("Number of SMP CPUs requested (%d) exceeds max CPUs "
-                     "supported by machine '%s' (%d)", max_cpus,
+        error_report("Invalid SMP CPUs %d. The max CPUs "
+                     "supported by machine '%s' is %d", max_cpus,
                      machine_class->name, machine_class->max_cpus);
         exit(1);
     }