xemu/target-ppc/kvm_ppc.h
Alexander Graf dc333cd609 PPC: tell the guest about the time base frequency
Our guest systems need to know by how much the timebase increases every second,
so there usually is a "timebase-frequency" property in the cpu leaf of the
device tree.

This property is missing in OpenBIOS.

With qemu, Linux's fallback timebase speed and qemu's internal timebase speed
match up. With KVM, that is no longer true. The guest is running at the same
timebase speed as the host.

This leads to massive timing problems. On my test machine, a "sleep 2" takes
about 14 seconds with KVM enabled.

This patch exports the timebase frequency to OpenBIOS, so it can then put them
into the device tree.

Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2010-02-14 16:10:54 +02:00

20 lines
469 B
C

/*
* Copyright 2008 IBM Corporation.
* Authors: Hollis Blanchard <hollisb@us.ibm.com>
*
* This work is licensed under the GNU GPL license version 2 or later.
*
*/
#ifndef __KVM_PPC_H__
#define __KVM_PPC_H__
void kvmppc_init(void);
void kvmppc_fdt_update(void *fdt);
int kvmppc_read_host_property(const char *node_path, const char *prop,
void *val, size_t len);
uint32_t kvmppc_get_tbfreq(void);
#endif /* __KVM_PPC_H__ */