diff options
| author | Beth Kon <eak@us.ibm.com> | 2009-07-07 11:50:38 -0400 |
|---|---|---|
| committer | Avi Kivity <avi@redhat.com> | 2009-09-10 08:33:12 +0300 |
| commit | e9f4275732add046fed4a548b8dbb98dbe500d2f (patch) | |
| tree | 8d9e22bbc6a9557f95712aaa98534d5983034252 /virt/kvm/ioapic.c | |
| parent | 0d1de2d901f4ba0972a3886496a44fb1d3300dbd (diff) | |
KVM: PIT support for HPET legacy mode
When kvm is in hpet_legacy_mode, the hpet is providing the timer
interrupt and the pit should not be. So in legacy mode, the pit timer
is destroyed, but the *state* of the pit is maintained. So if kvm or
the guest tries to modify the state of the pit, this modification is
accepted, *except* that the timer isn't actually started. When we exit
hpet_legacy_mode, the current state of the pit (which is up to date
since we've been accepting modifications) is used to restart the pit
timer.
The saved_mode code in kvm_pit_load_count temporarily changes mode to
0xff in order to destroy the timer, but then restores the actual
value, again maintaining "current" state of the pit for possible later
reenablement.
[avi: add some reserved storage in the ioctl; make SET_PIT2 IOW]
[marcelo: fix memory corruption due to reserved storage]
Signed-off-by: Beth Kon <eak@us.ibm.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Diffstat (limited to 'virt/kvm/ioapic.c')
0 files changed, 0 insertions, 0 deletions