diff options
Diffstat (limited to 'virt')
| -rw-r--r-- | virt/kvm/kvm_main.c | 48 |
1 files changed, 41 insertions, 7 deletions
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index 0c281760a1c5..32449e0e9aa8 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -66,6 +66,9 @@ MODULE_AUTHOR("Qumranet"); MODULE_LICENSE("GPL"); +unsigned int halt_poll_ns = 0; +module_param(halt_poll_ns, uint, S_IRUGO | S_IWUSR); + /* * Ordering of locks: * @@ -1813,29 +1816,60 @@ void mark_page_dirty(struct kvm *kvm, gfn_t gfn) } EXPORT_SYMBOL_GPL(mark_page_dirty); +static int kvm_vcpu_check_block(struct kvm_vcpu *vcpu) +{ + if (kvm_arch_vcpu_runnable(vcpu)) { + kvm_make_request(KVM_REQ_UNHALT, vcpu); + return -EINTR; + } + if (kvm_cpu_has_pending_timer(vcpu)) + return -EINTR; + if (signal_pending(current)) + return -EINTR; + + return 0; +} + /* * The vCPU has executed a HLT instruction with in-kernel mode enabled. */ void kvm_vcpu_block(struct kvm_vcpu *vcpu) { + ktime_t start, cur; DEFINE_WAIT(wait); + bool waited = false; + + start = cur = ktime_get(); + if (halt_poll_ns) { + ktime_t stop = ktime_add_ns(ktime_get(), halt_poll_ns); + do { + /* + * This sets KVM_REQ_UNHALT if an interrupt + * arrives. + */ + if (kvm_vcpu_check_block(vcpu) < 0) { + ++vcpu->stat.halt_successful_poll; + goto out; + } + cur = ktime_get(); + } while (single_task_running() && ktime_before(cur, stop)); + } for (;;) { prepare_to_wait(&vcpu->wq, &wait, TASK_INTERRUPTIBLE); - if (kvm_arch_vcpu_runnable(vcpu)) { - kvm_make_request(KVM_REQ_UNHALT, vcpu); - break; - } - if (kvm_cpu_has_pending_timer(vcpu)) - break; - if (signal_pending(current)) + if (kvm_vcpu_check_block(vcpu) < 0) break; + waited = true; schedule(); } finish_wait(&vcpu->wq, &wait); + cur = ktime_get(); + +out: + trace_kvm_vcpu_wakeup(ktime_to_ns(cur) - ktime_to_ns(start), waited); } EXPORT_SYMBOL_GPL(kvm_vcpu_block); |