linux/arch/x86/kvm/i8254.h
Beth Kon e9f4275732 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>
2009-09-10 08:33:12 +03:00

58 lines
1.4 KiB
C

#ifndef __I8254_H
#define __I8254_H
#include "iodev.h"
struct kvm_kpit_channel_state {
u32 count; /* can be 65536 */
u16 latched_count;
u8 count_latched;
u8 status_latched;
u8 status;
u8 read_state;
u8 write_state;
u8 write_latch;
u8 rw_mode;
u8 mode;
u8 bcd; /* not supported */
u8 gate; /* timer start */
ktime_t count_load_time;
};
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;
struct mutex lock;
struct kvm_pit *pit;
spinlock_t inject_lock;
unsigned long irq_ack;
struct kvm_irq_ack_notifier irq_ack_notifier;
};
struct kvm_pit {
unsigned long base_addresss;
struct kvm_io_device dev;
struct kvm_io_device speaker_dev;
struct kvm *kvm;
struct kvm_kpit_state pit_state;
int irq_source_id;
struct kvm_irq_mask_notifier mask_notifier;
};
#define KVM_PIT_BASE_ADDRESS 0x40
#define KVM_SPEAKER_BASE_ADDRESS 0x61
#define KVM_PIT_MEM_LENGTH 4
#define KVM_PIT_FREQ 1193181
#define KVM_MAX_PIT_INTR_INTERVAL HZ / 100
#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, 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);
#endif