arch/x86/kvm/i8254.h
Source file repositories/reference/linux-study-clean/arch/x86/kvm/i8254.h
File Facts
- System
- Linux kernel
- Corpus path
arch/x86/kvm/i8254.h- Extension
.h- Size
- 1856 bytes
- Lines
- 73
- Domain
- Architecture Layer
- Bucket
- arch/x86
- Inferred role
- Architecture Layer: implementation source
- Status
- source implementation candidate
Why This File Exists
CPU and platform-specific kernel glue: boot entry, traps, syscall entry, interrupts, page tables, context switch, and low-level barriers.
- CPU and platform-specific kernel glue: boot entry, traps, syscall entry, interrupts, page tables, context switch, and low-level barriers.
- Uses kernel synchronization; read lock ordering, sleepability, and interrupt context assumptions before translating.
- Defines or uses C structs; map object ownership, embedded links, reference counts, and lock ownership.
Dependency Surface
linux/kthread.hkvm/iodev.huapi/asm/kvm.hioapic.h
Detected Declarations
struct kvm_kpit_channel_statestruct kvm_kpit_statestruct kvm_pit
Annotated Snippet
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 {
/* All members before "struct mutex lock" are protected by the lock. */
struct kvm_kpit_channel_state channels[3];
u32 flags;
bool is_periodic;
s64 period; /* unit: ns */
struct hrtimer timer;
struct mutex lock;
atomic_t reinject;
atomic_t pending; /* accumulated triggered timers */
atomic_t irq_ack;
struct kvm_irq_ack_notifier irq_ack_notifier;
};
struct kvm_pit {
struct kvm_io_device dev;
struct kvm_io_device speaker_dev;
struct kvm *kvm;
struct kvm_kpit_state pit_state;
struct kvm_irq_mask_notifier mask_notifier;
struct kthread_worker *worker;
struct kthread_work expired;
};
#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
int kvm_vm_ioctl_get_pit(struct kvm *kvm, struct kvm_pit_state *ps);
int kvm_vm_ioctl_set_pit(struct kvm *kvm, struct kvm_pit_state *ps);
int kvm_vm_ioctl_get_pit2(struct kvm *kvm, struct kvm_pit_state2 *ps);
int kvm_vm_ioctl_set_pit2(struct kvm *kvm, struct kvm_pit_state2 *ps);
int kvm_vm_ioctl_reinject(struct kvm *kvm, struct kvm_reinject_control *control);
struct kvm_pit *kvm_create_pit(struct kvm *kvm, u32 flags);
void kvm_free_pit(struct kvm *kvm);
#endif /* CONFIG_KVM_IOAPIC */
#endif
Annotation
- Immediate include surface: `linux/kthread.h`, `kvm/iodev.h`, `uapi/asm/kvm.h`, `ioapic.h`.
- Detected declarations: `struct kvm_kpit_channel_state`, `struct kvm_kpit_state`, `struct kvm_pit`.
- Atlas domain: Architecture Layer / arch/x86.
- Implementation status: source implementation candidate.
- Synchronization appears in or near this file; preserve lock ordering, sleepability, and interrupt-context constraints.
Implementation Notes
- This generated page is the file-by-file coverage layer; curated subsystem chapters should link here when they synthesize a multi-file control flow.
- Core OS pages should be promoted from atlas-only to deep-reviewed when they explain data structures, invariants, locking, lifecycle, and C implementation snippets.
- Driver-family pages are intentionally pattern-oriented unless they are part of the selected PCIe/NVMe representative device path.