From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:52926) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ZHuYw-0001fJ-Ra for qemu-devel@nongnu.org; Wed, 22 Jul 2015 09:59:59 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ZHuYs-0000i8-Sq for qemu-devel@nongnu.org; Wed, 22 Jul 2015 09:59:58 -0400 From: Thomas Huth Date: Wed, 22 Jul 2015 15:59:50 +0200 Message-Id: <1437573590-2801-1-git-send-email-thuth@redhat.com> Subject: [Qemu-devel] [PATCH] Add another sanity check to smp_parse() function List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org, Paolo Bonzini Cc: qemu-trivial@nongnu.org, Eduardo Habkost 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 --- vl.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/vl.c b/vl.c index 5856396..c8d24b1 100644 --- a/vl.c +++ b/vl.c @@ -1224,7 +1224,13 @@ 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; -- 1.8.3.1