From: Thomas Huth <th...@redhat.com> The code in smp_parse already checks the topology information for sockets * cores * threads < cpus and bails out with an error in that case. However, it is still possible to supply a bad configuration the other way round, e.g. with:
qemu-system-xxx -smp 4,sockets=1,cores=4,threads=2 QEMU then still starts the guest, with topology configuration that is rather incomprehensible and likely not what the user wanted. So let's add another check to refuse such wrong configurations. Signed-off-by: Thomas Huth <th...@redhat.com> Reviewed-by: Eduardo Habkost <ehabk...@redhat.com> Acked-by: Cornelia Huck <cornelia.h...@de.ibm.com> Acked-by: Bastian Koppelmann <kbast...@mail.uni-paderborn.de> Signed-off-by: Eduardo Habkost <ehabk...@redhat.com> --- vl.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/vl.c b/vl.c index e211f6a..cbc8f25 100644 --- a/vl.c +++ b/vl.c @@ -1222,7 +1222,13 @@ static void smp_parse(QemuOpts *opts) exit(1); } - max_cpus = qemu_opt_get_number(opts, "maxcpus", 0); + max_cpus = qemu_opt_get_number(opts, "maxcpus", cpus); + if (sockets * cores * threads > max_cpus) { + fprintf(stderr, "cpu topology: error: " + "sockets (%u) * cores (%u) * threads (%u) > maxcpus (%u)\n", + sockets, cores, threads, max_cpus); + exit(1); + } smp_cpus = cpus; smp_cores = cores > 0 ? cores : 1; -- 2.1.0