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| author | Avi Kivity <avi@redhat.com> | 2010-07-20 15:06:17 +0300 |
|---|---|---|
| committer | Avi Kivity <avi@redhat.com> | 2010-10-24 10:52:54 +0200 |
| commit | b463a6f744a263fccd7da14db1afdc880371a280 (patch) | |
| tree | 30dbb8d47f4a3a6b2036dd890d03cb53081eadef /arch/x86/kvm/x86.c | |
| parent | 83422e17c19d61399cab7dbf9bf40ff9af2a7dd2 (diff) | |
| download | lwn-b463a6f744a263fccd7da14db1afdc880371a280.tar.gz lwn-b463a6f744a263fccd7da14db1afdc880371a280.zip | |
KVM: Non-atomic interrupt injection
Change the interrupt injection code to work from preemptible, interrupts
enabled context. This works by adding a ->cancel_injection() operation
that undoes an injection in case we were not able to actually enter the guest
(this condition could never happen with atomic injection).
Signed-off-by: Avi Kivity <avi@redhat.com>
Diffstat (limited to 'arch/x86/kvm/x86.c')
| -rw-r--r-- | arch/x86/kvm/x86.c | 36 |
1 files changed, 16 insertions, 20 deletions
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index e7198036db61..a465bd29f381 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -5005,7 +5005,6 @@ static int vcpu_enter_guest(struct kvm_vcpu *vcpu) int r; bool req_int_win = !irqchip_in_kernel(vcpu->kvm) && vcpu->run->request_interrupt_window; - bool req_event; if (vcpu->requests) { if (kvm_check_request(KVM_REQ_MMU_RELOAD, vcpu)) @@ -5041,6 +5040,21 @@ static int vcpu_enter_guest(struct kvm_vcpu *vcpu) if (unlikely(r)) goto out; + if (kvm_check_request(KVM_REQ_EVENT, vcpu) || req_int_win) { + inject_pending_event(vcpu); + + /* enable NMI/IRQ window open exits if needed */ + if (vcpu->arch.nmi_pending) + kvm_x86_ops->enable_nmi_window(vcpu); + else if (kvm_cpu_has_interrupt(vcpu) || req_int_win) + kvm_x86_ops->enable_irq_window(vcpu); + + if (kvm_lapic_enabled(vcpu)) { + update_cr8_intercept(vcpu); + kvm_lapic_sync_to_vapic(vcpu); + } + } + preempt_disable(); kvm_x86_ops->prepare_guest_switch(vcpu); @@ -5053,35 +5067,17 @@ static int vcpu_enter_guest(struct kvm_vcpu *vcpu) local_irq_disable(); - req_event = kvm_check_request(KVM_REQ_EVENT, vcpu); - if (!atomic_read(&vcpu->guest_mode) || vcpu->requests || need_resched() || signal_pending(current)) { - if (req_event) - kvm_make_request(KVM_REQ_EVENT, vcpu); atomic_set(&vcpu->guest_mode, 0); smp_wmb(); local_irq_enable(); preempt_enable(); + kvm_x86_ops->cancel_injection(vcpu); r = 1; goto out; } - if (req_event || req_int_win) { - inject_pending_event(vcpu); - - /* enable NMI/IRQ window open exits if needed */ - if (vcpu->arch.nmi_pending) - kvm_x86_ops->enable_nmi_window(vcpu); - else if (kvm_cpu_has_interrupt(vcpu) || req_int_win) - kvm_x86_ops->enable_irq_window(vcpu); - - if (kvm_lapic_enabled(vcpu)) { - update_cr8_intercept(vcpu); - kvm_lapic_sync_to_vapic(vcpu); - } - } - srcu_read_unlock(&vcpu->kvm->srcu, vcpu->srcu_idx); kvm_guest_enter(); |