kvm: x86: Add user space part for in-kernel i8254

This provides the required user space stubs to enable the in-kernel
i8254 emulation of KVM.

The in-kernel model supports lost tick compensation according to the
"delay" policy. This is enabled by default and can be switched off via a
device property.

Depending on the feature set of the host kernel (before 2.6.32), we may
have to disable the HPET or lack sound output from the PC speaker.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Avi Kivity <avi@redhat.com>

1 files changed, 11 insertions, 0 deletions

diff --git a/hw/i8254.h b/hw/i8254.h
index a1d2e98..ba6b598 100644
--- a/hw/i8254.h
+++ b/hw/i8254.h
@@ -51,6 +51,17 @@ static inline ISADevice *pit_init(ISABus *bus, int base, int isa_irq,
     return dev;
 }
 
+static inline ISADevice *kvm_pit_init(ISABus *bus, int base)
+{
+    ISADevice *dev;
+
+    dev = isa_create(bus, "kvm-pit");
+    qdev_prop_set_uint32(&dev->qdev, "iobase", base);
+    qdev_init_nofail(&dev->qdev);
+
+    return dev;
+}
+
 void pit_set_gate(ISADevice *dev, int channel, int val);
 void pit_get_channel_info(ISADevice *dev, int channel, PITChannelInfo *info);