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| author |   Eddie Dong <eddie.dong@intel.com> | 2007-07-18 12:15:21 +0300 |
|---|---|---|
| committer |   Avi Kivity <avi@qumranet.com> | 2007-10-13 10:18:25 +0200 |
| commit | b6958ce44a11a9e9425d2b67a653b1ca2a27796f (patch) | |
| tree | 503478ef27254df9b6ea21d2a6a279a7dfe2ef04 /drivers/kvm/kvm_main.c | |
| parent | KVM: In-kernel I/O APIC model (diff) | |
| download | linux-dev-b6958ce44a11a9e9425d2b67a653b1ca2a27796f.tar.xz linux-dev-b6958ce44a11a9e9425d2b67a653b1ca2a27796f.zip | |
KVM: Emulate hlt in the kernel
By sleeping in the kernel when hlt is executed, we simplify the in-kernel
guest interrupt path considerably.
Signed-off-by: Gregory Haskins <ghaskins@novell.com>
Signed-off-by: Yaozu (Eddie) Dong <eddie.dong@intel.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
Diffstat (limited to 'drivers/kvm/kvm_main.c')
| -rw-r--r-- | drivers/kvm/kvm_main.c | 41 |
1 files changed, 35 insertions, 6 deletions
diff --git a/drivers/kvm/kvm_main.c b/drivers/kvm/kvm_main.c index ffbdadd87971..4384364fc0c8 100644 --- a/drivers/kvm/kvm_main.c +++ b/drivers/kvm/kvm_main.c @@ -76,6 +76,7 @@ static struct kvm_stats_debugfs_item { { "signal_exits", STAT_OFFSET(signal_exits) }, { "irq_window", STAT_OFFSET(irq_window_exits) }, { "halt_exits", STAT_OFFSET(halt_exits) }, + { "halt_wakeup", STAT_OFFSET(halt_wakeup) }, { "request_irq", STAT_OFFSET(request_irq_exits) }, { "irq_exits", STAT_OFFSET(irq_exits) }, { "light_exits", STAT_OFFSET(light_exits) }, @@ -248,6 +249,7 @@ int kvm_vcpu_init(struct kvm_vcpu *vcpu, struct kvm *kvm, unsigned id) vcpu->mmu.root_hpa = INVALID_PAGE; vcpu->kvm = kvm; vcpu->vcpu_id = id; + init_waitqueue_head(&vcpu->wq); page = alloc_page(GFP_KERNEL | __GFP_ZERO); if (!page) { @@ -1307,15 +1309,41 @@ int emulate_instruction(struct kvm_vcpu *vcpu, } EXPORT_SYMBOL_GPL(emulate_instruction); -int kvm_emulate_halt(struct kvm_vcpu *vcpu) +/* + * The vCPU has executed a HLT instruction with in-kernel mode enabled. + */ +static void kvm_vcpu_kernel_halt(struct kvm_vcpu *vcpu) { - if (vcpu->irq_summary || - (irqchip_in_kernel(vcpu->kvm) && kvm_cpu_has_interrupt(vcpu))) - return 1; + DECLARE_WAITQUEUE(wait, current); + + add_wait_queue(&vcpu->wq, &wait); + + /* + * We will block until either an interrupt or a signal wakes us up + */ + while(!(irqchip_in_kernel(vcpu->kvm) && kvm_cpu_has_interrupt(vcpu)) + && !vcpu->irq_summary + && !signal_pending(current)) { + set_current_state(TASK_INTERRUPTIBLE); + vcpu_put(vcpu); + schedule(); + vcpu_load(vcpu); + } - vcpu->run->exit_reason = KVM_EXIT_HLT; + remove_wait_queue(&vcpu->wq, &wait); + set_current_state(TASK_RUNNING); +} + +int kvm_emulate_halt(struct kvm_vcpu *vcpu) +{ ++vcpu->stat.halt_exits; - return 0; + if (irqchip_in_kernel(vcpu->kvm)) { + kvm_vcpu_kernel_halt(vcpu); + return 1; + } else { + vcpu->run->exit_reason = KVM_EXIT_HLT; + return 0; + } } EXPORT_SYMBOL_GPL(kvm_emulate_halt); @@ -2916,6 +2944,7 @@ static long kvm_dev_ioctl(struct file *filp, switch (ext) { case KVM_CAP_IRQCHIP: + case KVM_CAP_HLT: r = 1; break; default: |