"KVM: PPC: booke: Improve timer register emulation" breaks Book3s HV

[Alexander Graf]

On 06.12.2011, at 12:43, Paul Mackerras wrote:

> On Tue, Dec 06, 2011 at 03:03:00PM +1100, Paul Mackerras wrote:
>> I'm not sure why yet, but commit 8a97c432 ("KVM: PPC: booke: Improve
>> timer register emulation") in Alex's kvm-ppc-next branch is breaking
>> Book3S HV KVM on POWER7.  Guest cpus fail to spin up, and even with
>> just one cpu, the guest stalls every so often.  If I stop the guest
>> and inspect the state with qemu, PC is at 0x900.  Reverting 8a97c432
>> makes it work properly again.
> 
> This fixes it:
> 
> diff --git a/arch/powerpc/kvm/powerpc.c b/arch/powerpc/kvm/powerpc.c
> index 534cbe1..83bcb44 100644
> --- a/arch/powerpc/kvm/powerpc.c
> +++ b/arch/powerpc/kvm/powerpc.c
> @@ -560,7 +560,7 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *run)
> 
> void kvm_vcpu_kick(struct kvm_vcpu *vcpu)
> {
> -	if (waitqueue_active(&vcpu->wq)) {
> +	if (waitqueue_active(vcpu->arch.wqp)) {

:(

> 		wake_up_interruptible(vcpu->arch.wqp);
> 		vcpu->stat.halt_wakeup++;
> 	} else if (vcpu->cpu != -1) {
> 
> Alex, do you want to roll that in with Scott's patch, or do you want me
> to send a separate patch on top?

I usually like praise where praise belongs, so I'll put this right after Scott's patch if you give me a nice and shiny patch description with a signed-off-by line :)


Alex