diff options
| author | Alexander Graf <agraf@suse.de> | 2010-02-09 17:37:05 +0100 |
|---|---|---|
| committer | Michael S. Tsirkin <mst@redhat.com> | 2010-02-14 16:10:54 +0200 |
| commit | dc333cd60950185cdc069b4863b23fa262223d03 (patch) | |
| tree | 078084c03746d137f34f7032e66e246f1bccb287 /hw/ppc.h | |
| parent | fa0be69a175b7d0d6c49ac9e198409ad38a8e359 (diff) | |
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>
Diffstat (limited to 'hw/ppc.h')
| -rw-r--r-- | hw/ppc.h | 1 |
1 files changed, 1 insertions, 0 deletions
@@ -46,5 +46,6 @@ enum { #define FW_CFG_PPC_WIDTH (FW_CFG_ARCH_LOCAL + 0x00) #define FW_CFG_PPC_HEIGHT (FW_CFG_ARCH_LOCAL + 0x01) #define FW_CFG_PPC_DEPTH (FW_CFG_ARCH_LOCAL + 0x02) +#define FW_CFG_PPC_TBFREQ (FW_CFG_ARCH_LOCAL + 0x03) #define PPC_SERIAL_MM_BAUDBASE 399193 |