e9f4275732
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>
59 lines
1.4 KiB
C
59 lines
1.4 KiB
C
#ifndef __I8254_H
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#define __I8254_H
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#include "iodev.h"
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struct kvm_kpit_channel_state {
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u32 count; /* can be 65536 */
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u16 latched_count;
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u8 count_latched;
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u8 status_latched;
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u8 status;
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u8 read_state;
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u8 write_state;
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u8 write_latch;
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u8 rw_mode;
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u8 mode;
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u8 bcd; /* not supported */
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u8 gate; /* timer start */
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ktime_t count_load_time;
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};
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struct kvm_kpit_state {
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struct kvm_kpit_channel_state channels[3];
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u32 flags;
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struct kvm_timer pit_timer;
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bool is_periodic;
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u32 speaker_data_on;
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struct mutex lock;
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struct kvm_pit *pit;
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spinlock_t inject_lock;
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unsigned long irq_ack;
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struct kvm_irq_ack_notifier irq_ack_notifier;
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};
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struct kvm_pit {
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unsigned long base_addresss;
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struct kvm_io_device dev;
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struct kvm_io_device speaker_dev;
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struct kvm *kvm;
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struct kvm_kpit_state pit_state;
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int irq_source_id;
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struct kvm_irq_mask_notifier mask_notifier;
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};
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#define KVM_PIT_BASE_ADDRESS 0x40
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#define KVM_SPEAKER_BASE_ADDRESS 0x61
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#define KVM_PIT_MEM_LENGTH 4
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#define KVM_PIT_FREQ 1193181
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#define KVM_MAX_PIT_INTR_INTERVAL HZ / 100
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#define KVM_PIT_CHANNEL_MASK 0x3
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void kvm_inject_pit_timer_irqs(struct kvm_vcpu *vcpu);
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void kvm_pit_load_count(struct kvm *kvm, int channel, u32 val, int hpet_legacy_start);
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struct kvm_pit *kvm_create_pit(struct kvm *kvm, u32 flags);
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void kvm_free_pit(struct kvm *kvm);
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void kvm_pit_reset(struct kvm_pit *pit);
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#endif
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