Messages in this thread Patch in this message |  | | | Date | Wed, 12 Dec 2007 22:52:04 -0800 | | From | Greg KH <> | | Subject | [patch 22/60] KVM: Fix hang on uniprocessor |
| |
2.6.23-stable review patch. If anyone has any objections, please let us know.
------------------ From: Marko Kohtala <marko.kohtala@gmail.com> 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 <marko.kohtala@gmail.com> Signed-off-by: Avi Kivity <avi@qumranet.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
--- drivers/kvm/kvm_main.c | 5 +++++ 1 file changed, 5 insertions(+) --- a/drivers/kvm/kvm_main.c +++ b/drivers/kvm/kvm_main.c @@ -273,6 +273,11 @@ void kvm_flush_remote_tlbs(struct kvm *k } } + /* 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 --
|  |