KVM: x86: do not execute halted vcpus

Offline or uninitialized vcpu's can be executed if requested to perform
userspace work.

Follow Avi's suggestion to handle halted vcpu's in the main loop,
simplifying kvm_emulate_halt(). Introduce a new vcpu->requests bit to
indicate events that promote state from halted to running.

Also standardize vcpu wake sites.

Signed-off-by: Marcelo Tosatti <mtosatti <at> redhat.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
This commit is contained in:
Marcelo Tosatti 2008-09-08 15:23:48 -03:00 committed by Avi Kivity
parent a6a3034cb9
commit d76901750a
5 changed files with 69 additions and 67 deletions

View File

@ -200,10 +200,9 @@ static int __pit_timer_fn(struct kvm_kpit_state *ps)
if (!atomic_inc_and_test(&pt->pending))
set_bit(KVM_REQ_PENDING_TIMER, &vcpu0->requests);
if (vcpu0 && waitqueue_active(&vcpu0->wq)) {
vcpu0->arch.mp_state = KVM_MP_STATE_RUNNABLE;
if (vcpu0 && waitqueue_active(&vcpu0->wq))
wake_up_interruptible(&vcpu0->wq);
}
pt->timer.expires = ktime_add_ns(pt->timer.expires, pt->period);
pt->scheduled = ktime_to_ns(pt->timer.expires);

View File

@ -339,13 +339,7 @@ static int __apic_accept_irq(struct kvm_lapic *apic, int delivery_mode,
} else
apic_clear_vector(vector, apic->regs + APIC_TMR);
if (vcpu->arch.mp_state == KVM_MP_STATE_RUNNABLE)
kvm_vcpu_kick(vcpu);
else if (vcpu->arch.mp_state == KVM_MP_STATE_HALTED) {
vcpu->arch.mp_state = KVM_MP_STATE_RUNNABLE;
if (waitqueue_active(&vcpu->wq))
wake_up_interruptible(&vcpu->wq);
}
kvm_vcpu_kick(vcpu);
result = (orig_irr == 0);
break;
@ -384,8 +378,7 @@ static int __apic_accept_irq(struct kvm_lapic *apic, int delivery_mode,
if (vcpu->arch.mp_state == KVM_MP_STATE_INIT_RECEIVED) {
vcpu->arch.sipi_vector = vector;
vcpu->arch.mp_state = KVM_MP_STATE_SIPI_RECEIVED;
if (waitqueue_active(&vcpu->wq))
wake_up_interruptible(&vcpu->wq);
kvm_vcpu_kick(vcpu);
}
break;
@ -950,10 +943,9 @@ static int __apic_timer_fn(struct kvm_lapic *apic)
if(!atomic_inc_and_test(&apic->timer.pending))
set_bit(KVM_REQ_PENDING_TIMER, &apic->vcpu->requests);
if (waitqueue_active(q)) {
apic->vcpu->arch.mp_state = KVM_MP_STATE_RUNNABLE;
if (waitqueue_active(q))
wake_up_interruptible(q);
}
if (apic_lvtt_period(apic)) {
result = 1;
apic->timer.dev.expires = ktime_add_ns(

View File

@ -2798,11 +2798,6 @@ int kvm_emulate_halt(struct kvm_vcpu *vcpu)
KVMTRACE_0D(HLT, vcpu, handler);
if (irqchip_in_kernel(vcpu->kvm)) {
vcpu->arch.mp_state = KVM_MP_STATE_HALTED;
up_read(&vcpu->kvm->slots_lock);
kvm_vcpu_block(vcpu);
down_read(&vcpu->kvm->slots_lock);
if (vcpu->arch.mp_state != KVM_MP_STATE_RUNNABLE)
return -EINTR;
return 1;
} else {
vcpu->run->exit_reason = KVM_EXIT_HLT;
@ -3097,24 +3092,10 @@ static void vapic_exit(struct kvm_vcpu *vcpu)
up_read(&vcpu->kvm->slots_lock);
}
static int __vcpu_run(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
static int vcpu_enter_guest(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
{
int r;
if (unlikely(vcpu->arch.mp_state == KVM_MP_STATE_SIPI_RECEIVED)) {
pr_debug("vcpu %d received sipi with vector # %x\n",
vcpu->vcpu_id, vcpu->arch.sipi_vector);
kvm_lapic_reset(vcpu);
r = kvm_x86_ops->vcpu_reset(vcpu);
if (r)
return r;
vcpu->arch.mp_state = KVM_MP_STATE_RUNNABLE;
}
down_read(&vcpu->kvm->slots_lock);
vapic_enter(vcpu);
again:
if (vcpu->requests)
if (test_and_clear_bit(KVM_REQ_MMU_RELOAD, &vcpu->requests))
kvm_mmu_unload(vcpu);
@ -3151,22 +3132,13 @@ again:
local_irq_disable();
if (vcpu->requests || need_resched()) {
if (vcpu->requests || need_resched() || signal_pending(current)) {
local_irq_enable();
preempt_enable();
r = 1;
goto out;
}
if (signal_pending(current)) {
local_irq_enable();
preempt_enable();
r = -EINTR;
kvm_run->exit_reason = KVM_EXIT_INTR;
++vcpu->stat.signal_exits;
goto out;
}
if (vcpu->guest_debug.enabled)
kvm_x86_ops->guest_debug_pre(vcpu);
@ -3227,26 +3199,63 @@ again:
kvm_lapic_sync_from_vapic(vcpu);
r = kvm_x86_ops->handle_exit(kvm_run, vcpu);
if (r > 0) {
if (dm_request_for_irq_injection(vcpu, kvm_run)) {
r = -EINTR;
kvm_run->exit_reason = KVM_EXIT_INTR;
++vcpu->stat.request_irq_exits;
goto out;
}
if (!need_resched())
goto again;
}
out:
up_read(&vcpu->kvm->slots_lock);
if (r > 0) {
kvm_resched(vcpu);
down_read(&vcpu->kvm->slots_lock);
goto again;
return r;
}
static int __vcpu_run(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
{
int r;
if (unlikely(vcpu->arch.mp_state == KVM_MP_STATE_SIPI_RECEIVED)) {
printk("vcpu %d received sipi with vector # %x\n",
vcpu->vcpu_id, vcpu->arch.sipi_vector);
kvm_lapic_reset(vcpu);
r = kvm_x86_ops->vcpu_reset(vcpu);
if (r)
return r;
vcpu->arch.mp_state = KVM_MP_STATE_RUNNABLE;
}
down_read(&vcpu->kvm->slots_lock);
vapic_enter(vcpu);
r = 1;
while (r > 0) {
if (kvm_arch_vcpu_runnable(vcpu))
r = vcpu_enter_guest(vcpu, kvm_run);
else {
up_read(&vcpu->kvm->slots_lock);
kvm_vcpu_block(vcpu);
down_read(&vcpu->kvm->slots_lock);
if (test_and_clear_bit(KVM_REQ_UNHALT, &vcpu->requests))
if (vcpu->arch.mp_state == KVM_MP_STATE_HALTED)
vcpu->arch.mp_state =
KVM_MP_STATE_RUNNABLE;
if (vcpu->arch.mp_state != KVM_MP_STATE_RUNNABLE)
r = -EINTR;
}
if (r > 0) {
if (dm_request_for_irq_injection(vcpu, kvm_run)) {
r = -EINTR;
kvm_run->exit_reason = KVM_EXIT_INTR;
++vcpu->stat.request_irq_exits;
}
if (signal_pending(current)) {
r = -EINTR;
kvm_run->exit_reason = KVM_EXIT_INTR;
++vcpu->stat.signal_exits;
}
if (need_resched()) {
up_read(&vcpu->kvm->slots_lock);
kvm_resched(vcpu);
down_read(&vcpu->kvm->slots_lock);
}
}
}
up_read(&vcpu->kvm->slots_lock);
post_kvm_run_save(vcpu, kvm_run);
vapic_exit(vcpu);
@ -3266,6 +3275,7 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
if (unlikely(vcpu->arch.mp_state == KVM_MP_STATE_UNINITIALIZED)) {
kvm_vcpu_block(vcpu);
clear_bit(KVM_REQ_UNHALT, &vcpu->requests);
r = -EAGAIN;
goto out;
}

View File

@ -34,6 +34,7 @@
#define KVM_REQ_MMU_RELOAD 3
#define KVM_REQ_TRIPLE_FAULT 4
#define KVM_REQ_PENDING_TIMER 5
#define KVM_REQ_UNHALT 6
struct kvm_vcpu;
extern struct kmem_cache *kvm_vcpu_cache;

View File

@ -980,12 +980,12 @@ void kvm_vcpu_block(struct kvm_vcpu *vcpu)
for (;;) {
prepare_to_wait(&vcpu->wq, &wait, TASK_INTERRUPTIBLE);
if (kvm_cpu_has_interrupt(vcpu))
break;
if (kvm_cpu_has_pending_timer(vcpu))
break;
if (kvm_arch_vcpu_runnable(vcpu))
if (kvm_cpu_has_interrupt(vcpu) ||
kvm_cpu_has_pending_timer(vcpu) ||
kvm_arch_vcpu_runnable(vcpu)) {
set_bit(KVM_REQ_UNHALT, &vcpu->requests);
break;
}
if (signal_pending(current))
break;