On 07.08.2012, at 06:44, David Gibson wrote: > Currently for powerpc, kvm_arch_handle_exit() always returns 1, meaning > that its caller - kvm_cpu_exec() - will always exit immediately afterwards > to the loop in qemu_kvm_cpu_thread_fn(). > > There's no need to do this. Once we've handled the hypercall there's no > reason we can't go straight around and KVM_RUN again, which is what ret = 0 > will signal. The only exception might be for hypercalls which affect the > state of cpu_can_run(), however the only one that might do this is H_CEDE > and for kvm that is always handled in the kernel, not qemu. > > Furtherm setting ret = 0 means that when exit_requested is set from a > hypercall, we will enter KVM_RUN once more with a signal which lets the > the kernel do its internal logic to complete the hypercall with out > actually executing any more guest code. This is important if our hypercall > also triggered a reset, which previously would re-initialize everything > without completing the hypercall. This caused the kernel to get confused > because it thought the guest was still in the middle of a hypercall when > it has actually been reset. > > This patch therefore changes to ret = 0, which is both a bugfix and a small > optimization. > > Signed-off-by: David Gibson <da...@gibson.dropbear.id.au>
Thanks, applied to ppc-next. Alex
