From: Bharata B Rao <bhar...@linux.vnet.ibm.com>
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 <bhar...@linux.vnet.ibm.com>
Reviewed-by: Eric Blake <ebl...@redhat.com>
Reviewed-by: Stewart Smith <stew...@linux.vnet.ibm.com>
Signed-off-by: Andreas Färber <afaer...@suse.de>
---
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 3269c3e..5302bdc 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);
--
1.8.4.5
