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authorBeth Kon <eak@us.ibm.com>2009-07-07 19:50:38 +0400
committerAvi Kivity <avi@redhat.com>2009-09-10 09:33:12 +0400
commite9f4275732add046fed4a548b8dbb98dbe500d2f (patch)
tree8d9e22bbc6a9557f95712aaa98534d5983034252 /arch/x86/kvm/i8254.h
parent0d1de2d901f4ba0972a3886496a44fb1d3300dbd (diff)
downloadlinux-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.h3
1 files changed, 2 insertions, 1 deletions
diff --git a/arch/x86/kvm/i8254.h b/arch/x86/kvm/i8254.h
index b2670180f225..d4c1c7ffdc09 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);