KVM: Emulate local APIC in kernel

Because lightweight exits (exits which don't involve userspace) are many
times faster than heavyweight exits, it makes sense to emulate high usage
devices in the kernel.  The local APIC is one such device, especially for
Windows and for SMP, so we add an APIC model to kvm.

It also allows in-kernel host-side drivers to inject interrupts without
going through userspace.

[compile fix on i386 from Jindrich Makovicka]

Signed-off-by: Yaozu (Eddie) Dong <Eddie.Dong@intel.com>
Signed-off-by: Qing He <qing.he@intel.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>

1 files changed, 36 insertions, 17 deletions

diff --git a/drivers/kvm/irq.c b/drivers/kvm/irq.c
index b08005ca7050..0b4430a0cae0 100644
--- a/drivers/kvm/irq.c
+++ b/drivers/kvm/irq.c
@@ -30,14 +30,13 @@
  */
 int kvm_cpu_has_interrupt(struct kvm_vcpu *v)
 {
-        struct kvm_pic *s = pic_irqchip(v->kvm);
-
-        if (s->output)  /* PIC */
-                return 1;
-        /*
-         * TODO: APIC
-         */
-        return 0;
+        struct kvm_pic *s;
+
+        if (kvm_apic_has_interrupt(v) == -1) {  /* LAPIC */
+                s = pic_irqchip(v->kvm);        /* PIC */
+                return s->output;
+        }
+        return 1;
 }
 EXPORT_SYMBOL_GPL(kvm_cpu_has_interrupt);
 
@@ -46,16 +45,36 @@ EXPORT_SYMBOL_GPL(kvm_cpu_has_interrupt);
  */
 int kvm_cpu_get_interrupt(struct kvm_vcpu *v)
 {
-        struct kvm_pic *s = pic_irqchip(v->kvm);
+        struct kvm_pic *s;
         int vector;
 
-        s->output = 0;
-        vector = kvm_pic_read_irq(s);
-        if (vector != -1)
-                return vector;
-        /*
-         * TODO: APIC
-         */
-        return -1;
+        vector = kvm_get_apic_interrupt(v);     /* APIC */
+        if (vector == -1) {
+                s = pic_irqchip(v->kvm);
+                s->output = 0;          /* PIC */
+                vector = kvm_pic_read_irq(s);
+        }
+        return vector;
 }
 EXPORT_SYMBOL_GPL(kvm_cpu_get_interrupt);
+
+static void vcpu_kick_intr(void *info)
+{
+#ifdef DEBUG
+        struct kvm_vcpu *vcpu = (struct kvm_vcpu *)info;
+        printk(KERN_DEBUG "vcpu_kick_intr %p \n", vcpu);
+#endif
+}
+
+void kvm_vcpu_kick(struct kvm_vcpu *vcpu)
+{
+        int ipi_pcpu = vcpu->cpu;
+
+        if (vcpu->guest_mode)
+                smp_call_function_single(ipi_pcpu, vcpu_kick_intr, vcpu, 0, 0);
+}
+
+void kvm_ioapic_update_eoi(struct kvm *kvm, int vector)
+{
+        /* TODO: for kernel IOAPIC */
+}