From: Marko Kohtala Date: Sun, 2 Dec 2007 11:18:43 +0000 (+0200) Subject: KVM: Fix hang on uniprocessor X-Git-Tag: v2.6.23.10~39 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=86a1b7f0192d2f66a302a681fd76ce701f711953;p=thirdparty%2Fkernel%2Fstable.git KVM: Fix hang on uniprocessor This is not in mainline, as it was fixed differently in that tree. first_cpu(cpus) returns the only CPU when NR_CPUS is 1 regardless of the cpus mask. Therefore we avoid a kernel hang in KVM_SET_MEMORY_REGION ioctl on uniprocessor by not entering the loop at all. Signed-off-by: Marko Kohtala Signed-off-by: Avi Kivity Signed-off-by: Greg Kroah-Hartman --- diff --git a/drivers/kvm/kvm_main.c b/drivers/kvm/kvm_main.c index cd0557954e50e..b514dfbb6758a 100644 --- a/drivers/kvm/kvm_main.c +++ b/drivers/kvm/kvm_main.c @@ -273,6 +273,11 @@ void kvm_flush_remote_tlbs(struct kvm *kvm) } } + /* Uniprocessor kernel does not respect cpus in first_cpu. So + * do not go there if we have nothing to do. */ + if (cpus_empty(cpus)) + return; + /* * We really want smp_call_function_mask() here. But that's not * available, so ipi all cpus in parallel and wait for them