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| author | Beth Kon <eak@us.ibm.com> | 2009-07-07 15:50:38 (GMT) |
|---|---|---|
| committer | Avi Kivity <avi@redhat.com> | 2009-09-10 05:33:12 (GMT) |
| commit | e9f4275732add046fed4a548b8dbb98dbe500d2f (patch) | |
| tree | 8d9e22bbc6a9557f95712aaa98534d5983034252 /arch/x86/kvm/i8254.h | |
| parent | 0d1de2d901f4ba0972a3886496a44fb1d3300dbd (diff) | |
| download | linux-e9f4275732add046fed4a548b8dbb98dbe500d2f.tar.xz | |
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 'arch/x86/kvm/i8254.h')
| -rw-r--r-- | arch/x86/kvm/i8254.h | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/arch/x86/kvm/i8254.h b/arch/x86/kvm/i8254.h index b267018..d4c1c7f 100644 --- a/arch/x86/kvm/i8254.h +++ b/arch/x86/kvm/i8254.h @@ -21,6 +21,7 @@ struct kvm_kpit_channel_state { struct kvm_kpit_state { struct kvm_kpit_channel_state channels[3]; + u32 flags; struct kvm_timer pit_timer; bool is_periodic; u32 speaker_data_on; @@ -49,7 +50,7 @@ struct kvm_pit { #define KVM_PIT_CHANNEL_MASK 0x3 void kvm_inject_pit_timer_irqs(struct kvm_vcpu *vcpu); -void kvm_pit_load_count(struct kvm *kvm, int channel, u32 val); +void kvm_pit_load_count(struct kvm *kvm, int channel, u32 val, int hpet_legacy_start); struct kvm_pit *kvm_create_pit(struct kvm *kvm, u32 flags); void kvm_free_pit(struct kvm *kvm); void kvm_pit_reset(struct kvm_pit *pit); |