arch/x86/xen/enlighten_pv.c

Source file repositories/reference/linux-study-clean/arch/x86/xen/enlighten_pv.c

File Facts

System: Linux kernel
Corpus path: arch/x86/xen/enlighten_pv.c
Extension: .c
Size: 40161 bytes
Lines: 1615
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.
Touches user memory; correctness depends on fault-safe copying and privilege boundary handling.
Uses kernel synchronization; read lock ordering, sleepability, and interrupt context assumptions before translating.
Allocates kernel memory; connect allocation flags and lifetime to context constraints.
Defines or uses C structs; map object ownership, embedded links, reference counts, and lock ownership.

Dependency Surface

linux/cpu.h
linux/kernel.h
linux/init.h
linux/smp.h
linux/preempt.h
linux/hardirq.h
linux/percpu.h
linux/delay.h
linux/start_kernel.h
linux/sched.h
linux/kprobes.h
linux/kstrtox.h
linux/memblock.h
linux/export.h
linux/mm.h
linux/page-flags.h
linux/pci.h
linux/gfp.h
linux/edd.h
linux/reboot.h
linux/virtio_anchor.h
linux/stackprotector.h
xen/xen.h
xen/events.h
xen/interface/xen.h
xen/interface/version.h
xen/interface/physdev.h
xen/interface/vcpu.h
xen/interface/memory.h
xen/interface/nmi.h
xen/interface/xen-mca.h
xen/features.h

Detected Declarations

struct tls_descs
struct trap_array_entry
function get_and_clear_inhcall
function restore_inhcall
function get_and_clear_inhcall
function restore_inhcall
function xen_is_cpu_lazy_mode
function parse_xen_msr_safe
function xen_set_mtrr_data
function xen_pv_init_platform
function xen_pv_guest_late_init
function xen_cpuid
function xen_check_mwait
function xen_check_xsave
function xen_init_capabilities
function xen_set_debugreg
function xen_get_debugreg
function xen_start_context_switch
function xen_end_context_switch
function xen_store_tr
function mapping
function xen_alloc_ldt
function xen_free_ldt
function xen_set_ldt
function xen_load_gdt
function xen_load_gdt_boot
function desc_equal
function load_TLS_descriptor
function xen_load_tls
function xen_load_gs_index
function xen_write_ldt_entry
function __xen_pv_evtchn_do_upcall
function xen_pv_evtchn_do_upcall
function get_trap_addr
function cvt_gate_to_trap
function xen_write_idt_entry
function xen_convert_trap_info
function xen_copy_trap_info
function xen_load_idt
function xen_write_gdt_entry
function xen_write_gdt_entry_boot
function xen_load_sp0
function xen_invalidate_io_bitmap
function xen_update_io_bitmap
function xen_read_cr0
function xen_write_cr0
function xen_write_cr4
function xen_do_read_msr

Annotated Snippet

#include <linux/start_kernel.h>
#include <linux/sched.h>
#include <linux/kprobes.h>
#include <linux/kstrtox.h>
#include <linux/memblock.h>
#include <linux/export.h>
#include <linux/mm.h>
#include <linux/page-flags.h>
#include <linux/pci.h>
#include <linux/gfp.h>
#include <linux/edd.h>
#include <linux/reboot.h>
#include <linux/virtio_anchor.h>
#include <linux/stackprotector.h>

#include <xen/xen.h>
#include <xen/events.h>
#include <xen/interface/xen.h>
#include <xen/interface/version.h>
#include <xen/interface/physdev.h>
#include <xen/interface/vcpu.h>
#include <xen/interface/memory.h>
#include <xen/interface/nmi.h>
#include <xen/interface/xen-mca.h>
#include <xen/features.h>
#include <xen/page.h>
#include <xen/hvc-console.h>
#include <xen/acpi.h>

#include <asm/cpuid/api.h>
#include <asm/paravirt.h>
#include <asm/apic.h>
#include <asm/page.h>
#include <asm/xen/pci.h>
#include <asm/xen/hypercall.h>
#include <asm/xen/hypervisor.h>
#include <asm/xen/cpuid.h>
#include <asm/fixmap.h>
#include <asm/processor.h>
#include <asm/proto.h>
#include <asm/msr-index.h>
#include <asm/msr.h>
#include <asm/traps.h>
#include <asm/setup.h>
#include <asm/desc.h>
#include <asm/pgalloc.h>
#include <asm/tlbflush.h>
#include <asm/reboot.h>
#include <asm/hypervisor.h>
#include <asm/mach_traps.h>
#include <asm/mtrr.h>
#include <asm/mwait.h>
#include <asm/pci_x86.h>
#include <asm/cpu.h>
#include <asm/irq_stack.h>
#ifdef CONFIG_X86_IOPL_IOPERM
#include <asm/io_bitmap.h>
#endif

#ifdef CONFIG_ACPI
#include <linux/acpi.h>
#include <asm/acpi.h>
#include <acpi/proc_cap_intel.h>
#include <acpi/processor.h>
#include <xen/interface/platform.h>
#endif

#include "xen-ops.h"

#include "../kernel/cpu/cpu.h" /* get_cpu_cap() */

void *xen_initial_gdt;

static int xen_cpu_up_prepare_pv(unsigned int cpu);
static int xen_cpu_dead_pv(unsigned int cpu);

#ifndef CONFIG_PREEMPTION
/*
 * Some hypercalls issued by the toolstack can take many 10s of
 * seconds. Allow tasks running hypercalls via the privcmd driver to
 * be voluntarily preempted even if full kernel preemption is
 * disabled.
 *
 * Such preemptible hypercalls are bracketed by
 * xen_preemptible_hcall_begin() and xen_preemptible_hcall_end()
 * calls.
 */
DEFINE_PER_CPU(bool, xen_in_preemptible_hcall);
EXPORT_PER_CPU_SYMBOL_GPL(xen_in_preemptible_hcall);

Annotation

Immediate include surface: `linux/cpu.h`, `linux/kernel.h`, `linux/init.h`, `linux/smp.h`, `linux/preempt.h`, `linux/hardirq.h`, `linux/percpu.h`, `linux/delay.h`.
Detected declarations: `struct tls_descs`, `struct trap_array_entry`, `function get_and_clear_inhcall`, `function restore_inhcall`, `function get_and_clear_inhcall`, `function restore_inhcall`, `function xen_is_cpu_lazy_mode`, `function parse_xen_msr_safe`, `function xen_set_mtrr_data`, `function xen_pv_init_platform`.
Atlas domain: Architecture Layer / arch/x86.
Implementation status: source implementation candidate.
This snippet crosses the user/kernel memory boundary; validate fault handling and access checks before translating the pattern.
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.