Keep track of which task is running a KVM vcpu. This helps us figure out later what task to wake up if we want to boost a vcpu that got preempted. Unfortunately there are no guarantees that the same task always keeps the same vcpu, so we can only track the task across a single "run" of the vcpu. Signed-off-by: Rik van Riel <riel@xxxxxxxxxx> diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h index a055742..9d56ed5 100644 --- a/include/linux/kvm_host.h +++ b/include/linux/kvm_host.h @@ -81,6 +81,7 @@ struct kvm_vcpu { #endif int vcpu_id; struct mutex mutex; + struct pid *pid; int cpu; atomic_t guest_mode; struct kvm_run *run; diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index 5225052..65e997a 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -185,6 +185,7 @@ int kvm_vcpu_init(struct kvm_vcpu *vcpu, struct kvm *kvm, unsigned id) vcpu->cpu = -1; vcpu->kvm = kvm; vcpu->vcpu_id = id; + vcpu->pid = 0; init_waitqueue_head(&vcpu->wq); page = alloc_page(GFP_KERNEL | __GFP_ZERO); @@ -208,6 +209,8 @@ EXPORT_SYMBOL_GPL(kvm_vcpu_init); void kvm_vcpu_uninit(struct kvm_vcpu *vcpu) { + if (vcpu->pid) + put_pid(vcpu->pid); kvm_arch_vcpu_uninit(vcpu); free_page((unsigned long)vcpu->run); } @@ -1456,6 +1459,12 @@ static long kvm_vcpu_ioctl(struct file *filp, r = -EINVAL; if (arg) goto out; + if (unlikely(vcpu->pid != current->pids[PIDTYPE_PID].pid)) { + /* The thread running this VCPU changed. */ + struct pid *oldpid = vcpu->pid; + vcpu->pid = get_task_pid(current, PIDTYPE_PID); + put_pid(oldpid); + } r = kvm_arch_vcpu_ioctl_run(vcpu, vcpu->run); break; case KVM_GET_REGS: { -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html