kvm: x86: add support for KVM_CAP_SPLIT_IRQCHIP

This patch adds support for split IRQ chip mode. When
KVM_CAP_SPLIT_IRQCHIP is enabled:

    1.) The PIC, PIT, and IOAPIC are implemented in userspace while
    the LAPIC is implemented by KVM.

    2.) The software IOAPIC delivers interrupts to the KVM LAPIC via
    kvm_set_irq. Interrupt delivery is configured via the MSI routing
    table, for which routes are reserved in target-i386/kvm.c then
    configured in hw/intc/ioapic.c

    3.) KVM delivers IOAPIC EOIs via a new exit KVM_EXIT_IOAPIC_EOI,
    which is handled in target-i386/kvm.c and relayed to the software
    IOAPIC via ioapic_eoi_broadcast.

Signed-off-by: Matt Gingell <gingell@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

1 files changed, 7 insertions, 1 deletions

diff --git a/target-arm/kvm.c b/target-arm/kvm.c
index 84974bbd32..eca3a0037d 100644
--- a/target-arm/kvm.c
+++ b/target-arm/kvm.c
@@ -25,6 +25,7 @@
 #include "internals.h"
 #include "hw/arm/arm.h"
 #include "exec/memattrs.h"
+#include "hw/boards.h"
 
 const KVMCapabilityInfo kvm_arch_required_capabilities[] = {
     KVM_CAP_LAST_INFO
@@ -578,8 +579,13 @@ void kvm_arch_init_irq_routing(KVMState *s)
 {
 }
 
-int kvm_arch_irqchip_create(KVMState *s)
+int kvm_arch_irqchip_create(MachineState *ms, KVMState *s)
 {
+     if (machine_kernel_irqchip_split(ms)) {
+         perror("-machine kernel_irqchip=split is not supported on ARM.");
+         exit(1);
+    }
+
     /* If we can create the VGIC using the newer device control API, we
      * let the device do this when it initializes itself, otherwise we
      * fall back to the old API */