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KVM: x86: do not execute halted vcpus

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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
Download Patch File Download Diff File Expand all files Collapse all files

104
arch/x86/kvm/x86.c
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;
}