root/arch/x86/kernel/paravirt.c
// SPDX-License-Identifier: GPL-2.0-or-later
/*  Paravirtualization interfaces
    Copyright (C) 2006 Rusty Russell IBM Corporation


    2007 - x86_64 support added by Glauber de Oliveira Costa, Red Hat Inc
*/

#include <linux/errno.h>
#include <linux/init.h>
#include <linux/export.h>
#include <linux/efi.h>
#include <linux/bcd.h>
#include <linux/highmem.h>
#include <linux/kprobes.h>
#include <linux/pgtable.h>
#include <linux/static_call.h>

#include <asm/bug.h>
#include <asm/paravirt.h>
#include <asm/debugreg.h>
#include <asm/desc.h>
#include <asm/setup.h>
#include <asm/time.h>
#include <asm/pgalloc.h>
#include <asm/irq.h>
#include <asm/delay.h>
#include <asm/fixmap.h>
#include <asm/apic.h>
#include <asm/tlbflush.h>
#include <asm/timer.h>
#include <asm/special_insns.h>
#include <asm/tlb.h>
#include <asm/io_bitmap.h>
#include <asm/gsseg.h>
#include <asm/msr.h>

/* stub always returning 0. */
DEFINE_ASM_FUNC(paravirt_ret0, "xor %eax,%eax", .entry.text);

void __init default_banner(void)
{
        printk(KERN_INFO "Booting paravirtualized kernel on %s\n",
               pv_info.name);
}

#ifdef CONFIG_PARAVIRT_XXL
unsigned long pv_native_save_fl(void);
void pv_native_irq_disable(void);
void pv_native_irq_enable(void);
unsigned long pv_native_read_cr2(void);

DEFINE_ASM_FUNC(_paravirt_ident_64, "mov %rdi, %rax", .text);
DEFINE_ASM_FUNC(pv_native_save_fl, "pushf; pop %rax", .noinstr.text);
DEFINE_ASM_FUNC(pv_native_irq_disable, "cli", .noinstr.text);
DEFINE_ASM_FUNC(pv_native_irq_enable, "sti", .noinstr.text);
DEFINE_ASM_FUNC(pv_native_read_cr2, "mov %cr2, %rax", .noinstr.text);
#endif

static noinstr void pv_native_safe_halt(void)
{
        native_safe_halt();
}

#ifdef CONFIG_PARAVIRT_XXL
static noinstr void pv_native_write_cr2(unsigned long val)
{
        native_write_cr2(val);
}

static noinstr unsigned long pv_native_read_cr3(void)
{
        return __native_read_cr3();
}

static noinstr void pv_native_write_cr3(unsigned long cr3)
{
        native_write_cr3(cr3);
}

static noinstr unsigned long pv_native_get_debugreg(int regno)
{
        return native_get_debugreg(regno);
}

static noinstr void pv_native_set_debugreg(int regno, unsigned long val)
{
        native_set_debugreg(regno, val);
}
#endif

struct pv_info pv_info = {
        .name = "bare hardware",
#ifdef CONFIG_PARAVIRT_XXL
        .extra_user_64bit_cs = __USER_CS,
#endif
};

/* 64-bit pagetable entries */
#define PTE_IDENT       __PV_IS_CALLEE_SAVE(_paravirt_ident_64)

struct paravirt_patch_template pv_ops = {
        /* Cpu ops. */
        .cpu.io_delay           = native_io_delay,

#ifdef CONFIG_PARAVIRT_XXL
        .cpu.cpuid              = native_cpuid,
        .cpu.get_debugreg       = pv_native_get_debugreg,
        .cpu.set_debugreg       = pv_native_set_debugreg,
        .cpu.read_cr0           = native_read_cr0,
        .cpu.write_cr0          = native_write_cr0,
        .cpu.write_cr4          = native_write_cr4,
        .cpu.read_msr           = native_read_msr,
        .cpu.write_msr          = native_write_msr,
        .cpu.read_msr_safe      = native_read_msr_safe,
        .cpu.write_msr_safe     = native_write_msr_safe,
        .cpu.read_pmc           = native_read_pmc,
        .cpu.load_tr_desc       = native_load_tr_desc,
        .cpu.set_ldt            = native_set_ldt,
        .cpu.load_gdt           = native_load_gdt,
        .cpu.load_idt           = native_load_idt,
        .cpu.store_tr           = native_store_tr,
        .cpu.load_tls           = native_load_tls,
        .cpu.load_gs_index      = native_load_gs_index,
        .cpu.write_ldt_entry    = native_write_ldt_entry,
        .cpu.write_gdt_entry    = native_write_gdt_entry,
        .cpu.write_idt_entry    = native_write_idt_entry,

        .cpu.alloc_ldt          = paravirt_nop,
        .cpu.free_ldt           = paravirt_nop,

        .cpu.load_sp0           = native_load_sp0,

#ifdef CONFIG_X86_IOPL_IOPERM
        .cpu.invalidate_io_bitmap       = native_tss_invalidate_io_bitmap,
        .cpu.update_io_bitmap           = native_tss_update_io_bitmap,
#endif

        .cpu.start_context_switch       = paravirt_nop,
        .cpu.end_context_switch         = paravirt_nop,

        /* Irq ops. */
        .irq.save_fl            = __PV_IS_CALLEE_SAVE(pv_native_save_fl),
        .irq.irq_disable        = __PV_IS_CALLEE_SAVE(pv_native_irq_disable),
        .irq.irq_enable         = __PV_IS_CALLEE_SAVE(pv_native_irq_enable),
#endif /* CONFIG_PARAVIRT_XXL */

        /* Irq HLT ops. */
        .irq.safe_halt          = pv_native_safe_halt,
        .irq.halt               = native_halt,

        /* Mmu ops. */
        .mmu.flush_tlb_user     = native_flush_tlb_local,
        .mmu.flush_tlb_kernel   = native_flush_tlb_global,
        .mmu.flush_tlb_one_user = native_flush_tlb_one_user,
        .mmu.flush_tlb_multi    = native_flush_tlb_multi,

        .mmu.exit_mmap          = paravirt_nop,
        .mmu.notify_page_enc_status_changed     = paravirt_nop,

#ifdef CONFIG_PARAVIRT_XXL
        .mmu.read_cr2           = __PV_IS_CALLEE_SAVE(pv_native_read_cr2),
        .mmu.write_cr2          = pv_native_write_cr2,
        .mmu.read_cr3           = pv_native_read_cr3,
        .mmu.write_cr3          = pv_native_write_cr3,

        .mmu.pgd_alloc          = __paravirt_pgd_alloc,
        .mmu.pgd_free           = paravirt_nop,

        .mmu.alloc_pte          = paravirt_nop,
        .mmu.alloc_pmd          = paravirt_nop,
        .mmu.alloc_pud          = paravirt_nop,
        .mmu.alloc_p4d          = paravirt_nop,
        .mmu.release_pte        = paravirt_nop,
        .mmu.release_pmd        = paravirt_nop,
        .mmu.release_pud        = paravirt_nop,
        .mmu.release_p4d        = paravirt_nop,

        .mmu.set_pte            = native_set_pte,
        .mmu.set_pmd            = native_set_pmd,

        .mmu.ptep_modify_prot_start     = __ptep_modify_prot_start,
        .mmu.ptep_modify_prot_commit    = __ptep_modify_prot_commit,

        .mmu.set_pud            = native_set_pud,

        .mmu.pmd_val            = PTE_IDENT,
        .mmu.make_pmd           = PTE_IDENT,

        .mmu.pud_val            = PTE_IDENT,
        .mmu.make_pud           = PTE_IDENT,

        .mmu.set_p4d            = native_set_p4d,

        .mmu.p4d_val            = PTE_IDENT,
        .mmu.make_p4d           = PTE_IDENT,

        .mmu.set_pgd            = native_set_pgd,

        .mmu.pte_val            = PTE_IDENT,
        .mmu.pgd_val            = PTE_IDENT,

        .mmu.make_pte           = PTE_IDENT,
        .mmu.make_pgd           = PTE_IDENT,

        .mmu.enter_mmap         = paravirt_nop,

        .mmu.lazy_mode = {
                .enter          = paravirt_nop,
                .leave          = paravirt_nop,
                .flush          = paravirt_nop,
        },

        .mmu.set_fixmap         = native_set_fixmap,
#endif /* CONFIG_PARAVIRT_XXL */
};

#ifdef CONFIG_PARAVIRT_XXL
NOKPROBE_SYMBOL(native_load_idt);
#endif

EXPORT_SYMBOL(pv_ops);
EXPORT_SYMBOL_GPL(pv_info);