KVM: In kernel PIT model
The patch moves the PIT model from userspace to kernel, and increases
the timer accuracy greatly.
[marcelo: make last_injected_time per-guest]
Signed-off-by: Sheng Yang <sheng.yang@intel.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Tested-and-Acked-by: Alex Davis <alex14641@yahoo.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
diff --git a/arch/x86/kvm/i8254.h b/arch/x86/kvm/i8254.h
new file mode 100644
index 0000000..d77d6b7
--- /dev/null
+++ b/arch/x86/kvm/i8254.h
@@ -0,0 +1,61 @@
+#ifndef __I8254_H
+#define __I8254_H
+
+#include "iodev.h"
+
+struct kvm_kpit_timer {
+ struct hrtimer timer;
+ int irq;
+ s64 period; /* unit: ns */
+ s64 scheduled;
+ ktime_t last_update;
+ atomic_t pending;
+};
+
+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];
+ struct kvm_kpit_timer pit_timer;
+ u32 speaker_data_on;
+ struct mutex lock;
+ struct kvm_pit *pit;
+ bool inject_pending; /* if inject pending interrupts */
+ unsigned long last_injected_time;
+};
+
+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;
+};
+
+#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_timer_intr_post(struct kvm_vcpu *vcpu, int vec);
+struct kvm_pit *kvm_create_pit(struct kvm *kvm);
+void kvm_free_pit(struct kvm *kvm);
+
+#endif