From 5ec83c73e5ece590538878b24dfcb422904533e0 Mon Sep 17 00:00:00 2001 From: Bharata B Rao Date: Wed, 5 Mar 2014 14:02:36 +0530 Subject: [PATCH] target-ppc: Force CPU threads count to be a power of 2 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit PowerPC kernel expects the number of SMT threads in a core to be a power of 2. Since QEMU doesn't enforce this, it leads to an early guest kernel crash if invalid threads count is specified. Prevent this crash and make it a graceful exit from QEMU itself by validating the user-supplied threads count. Signed-off-by: Bharata B Rao Reviewed-by: Eric Blake Reviewed-by: Stewart Smith Signed-off-by: Andreas Färber --- target-ppc/translate_init.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/target-ppc/translate_init.c b/target-ppc/translate_init.c index 3269c3ebe4..5302bdc1b2 100644 --- a/target-ppc/translate_init.c +++ b/target-ppc/translate_init.c @@ -7848,6 +7848,12 @@ static void ppc_cpu_realizefn(DeviceState *dev, Error **errp) max_smt, kvm_enabled() ? "KVM" : "TCG"); return; } + if (!is_power_of_2(smp_threads)) { + error_setg(errp, "Cannot support %d threads on PPC with %s, " + "threads count must be a power of 2.", + smp_threads, kvm_enabled() ? "KVM" : "TCG"); + return; + } cpu->cpu_dt_id = (cs->cpu_index / smp_threads) * max_smt + (cs->cpu_index % smp_threads);