PPC: Cuda: Use cuda timer to expose tbfreq to guest

Mac OS X calibrates a number of frequencies on bootup based on reading
tb values on bootup and comparing them to via cuda timer values.

The only variable we can really steer well (thanks to KVM) is the cuda
frequency. So let's use that one to fake Mac OS X into believing the
bus frequency is tbfreq * 4. That way Mac OS X will automatically
calculate the correct timebase frequency.

With this patch and the patch set I posted earlier I can successfully
run Mac OS X 10.2, 10.3 and 10.4 guests with -M mac99 on TCG and KVM.

Suggested-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Alexander Graf <agraf@suse.de>

1 files changed, 10 insertions, 0 deletions

diff --git a/hw/misc/macio/macio.c b/hw/misc/macio/macio.c
index 35eaa00dce..e0f1e88f54 100644
--- a/hw/misc/macio/macio.c
+++ b/hw/misc/macio/macio.c
@@ -42,6 +42,7 @@ typedef struct MacIOState
     void *dbdma;
     MemoryRegion *pic_mem;
     MemoryRegion *escc_mem;
+    uint64_t frequency;
 } MacIOState;
 
 #define OLDWORLD_MACIO(obj) \
@@ -351,12 +352,19 @@ static void macio_newworld_class_init(ObjectClass *oc, void *data)
     pdc->device_id = PCI_DEVICE_ID_APPLE_UNI_N_KEYL;
 }
 
+static Property macio_properties[] = {
+    DEFINE_PROP_UINT64("frequency", MacIOState, frequency, 0),
+    DEFINE_PROP_END_OF_LIST()
+};
+
 static void macio_class_init(ObjectClass *klass, void *data)
 {
     PCIDeviceClass *k = PCI_DEVICE_CLASS(klass);
+    DeviceClass *dc = DEVICE_CLASS(klass);
 
     k->vendor_id = PCI_VENDOR_ID_APPLE;
     k->class_id = PCI_CLASS_OTHERS << 8;
+    dc->props = macio_properties;
 }
 
 static const TypeInfo macio_oldworld_type_info = {
@@ -403,6 +411,8 @@ void macio_init(PCIDevice *d,
     macio_state->escc_mem = escc_mem;
     /* Note: this code is strongly inspirated from the corresponding code
        in PearPC */
+    qdev_prop_set_uint64(DEVICE(&macio_state->cuda), "frequency",
+                         macio_state->frequency);
 
     qdev_init_nofail(DEVICE(d));
 }