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- // 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>
- /*
- * nop stub, which must not clobber anything *including the stack* to
- * avoid confusing the entry prologues.
- */
- extern void _paravirt_nop(void);
- asm (".pushsection .entry.text, \"ax\"\n"
- ".global _paravirt_nop\n"
- "_paravirt_nop:\n\t"
- ASM_ENDBR
- ASM_RET
- ".size _paravirt_nop, . - _paravirt_nop\n\t"
- ".type _paravirt_nop, @function\n\t"
- ".popsection");
- /* stub always returning 0. */
- asm (".pushsection .entry.text, \"ax\"\n"
- ".global paravirt_ret0\n"
- "paravirt_ret0:\n\t"
- ASM_ENDBR
- "xor %" _ASM_AX ", %" _ASM_AX ";\n\t"
- ASM_RET
- ".size paravirt_ret0, . - paravirt_ret0\n\t"
- ".type paravirt_ret0, @function\n\t"
- ".popsection");
- void __init default_banner(void)
- {
- printk(KERN_INFO "Booting paravirtualized kernel on %s\n",
- pv_info.name);
- }
- /* Undefined instruction for dealing with missing ops pointers. */
- noinstr void paravirt_BUG(void)
- {
- BUG();
- }
- static unsigned paravirt_patch_call(void *insn_buff, const void *target,
- unsigned long addr, unsigned len)
- {
- __text_gen_insn(insn_buff, CALL_INSN_OPCODE,
- (void *)addr, target, CALL_INSN_SIZE);
- return CALL_INSN_SIZE;
- }
- #ifdef CONFIG_PARAVIRT_XXL
- /* identity function, which can be inlined */
- u64 notrace _paravirt_ident_64(u64 x)
- {
- return x;
- }
- #endif
- DEFINE_STATIC_KEY_TRUE(virt_spin_lock_key);
- void __init native_pv_lock_init(void)
- {
- if (!boot_cpu_has(X86_FEATURE_HYPERVISOR))
- static_branch_disable(&virt_spin_lock_key);
- }
- unsigned int paravirt_patch(u8 type, void *insn_buff, unsigned long addr,
- unsigned int len)
- {
- /*
- * Neat trick to map patch type back to the call within the
- * corresponding structure.
- */
- void *opfunc = *((void **)&pv_ops + type);
- unsigned ret;
- if (opfunc == NULL)
- /* If there's no function, patch it with paravirt_BUG() */
- ret = paravirt_patch_call(insn_buff, paravirt_BUG, addr, len);
- else if (opfunc == _paravirt_nop)
- ret = 0;
- else
- /* Otherwise call the function. */
- ret = paravirt_patch_call(insn_buff, opfunc, addr, len);
- return ret;
- }
- struct static_key paravirt_steal_enabled;
- struct static_key paravirt_steal_rq_enabled;
- static u64 native_steal_clock(int cpu)
- {
- return 0;
- }
- DEFINE_STATIC_CALL(pv_steal_clock, native_steal_clock);
- DEFINE_STATIC_CALL(pv_sched_clock, native_sched_clock);
- void paravirt_set_sched_clock(u64 (*func)(void))
- {
- static_call_update(pv_sched_clock, func);
- }
- /* These are in entry.S */
- static struct resource reserve_ioports = {
- .start = 0,
- .end = IO_SPACE_LIMIT,
- .name = "paravirt-ioport",
- .flags = IORESOURCE_IO | IORESOURCE_BUSY,
- };
- /*
- * Reserve the whole legacy IO space to prevent any legacy drivers
- * from wasting time probing for their hardware. This is a fairly
- * brute-force approach to disabling all non-virtual drivers.
- *
- * Note that this must be called very early to have any effect.
- */
- int paravirt_disable_iospace(void)
- {
- return request_resource(&ioport_resource, &reserve_ioports);
- }
- static DEFINE_PER_CPU(enum paravirt_lazy_mode, paravirt_lazy_mode) = PARAVIRT_LAZY_NONE;
- static inline void enter_lazy(enum paravirt_lazy_mode mode)
- {
- BUG_ON(this_cpu_read(paravirt_lazy_mode) != PARAVIRT_LAZY_NONE);
- this_cpu_write(paravirt_lazy_mode, mode);
- }
- static void leave_lazy(enum paravirt_lazy_mode mode)
- {
- BUG_ON(this_cpu_read(paravirt_lazy_mode) != mode);
- this_cpu_write(paravirt_lazy_mode, PARAVIRT_LAZY_NONE);
- }
- void paravirt_enter_lazy_mmu(void)
- {
- enter_lazy(PARAVIRT_LAZY_MMU);
- }
- void paravirt_leave_lazy_mmu(void)
- {
- leave_lazy(PARAVIRT_LAZY_MMU);
- }
- void paravirt_flush_lazy_mmu(void)
- {
- preempt_disable();
- if (paravirt_get_lazy_mode() == PARAVIRT_LAZY_MMU) {
- arch_leave_lazy_mmu_mode();
- arch_enter_lazy_mmu_mode();
- }
- preempt_enable();
- }
- #ifdef CONFIG_PARAVIRT_XXL
- void paravirt_start_context_switch(struct task_struct *prev)
- {
- BUG_ON(preemptible());
- if (this_cpu_read(paravirt_lazy_mode) == PARAVIRT_LAZY_MMU) {
- arch_leave_lazy_mmu_mode();
- set_ti_thread_flag(task_thread_info(prev), TIF_LAZY_MMU_UPDATES);
- }
- enter_lazy(PARAVIRT_LAZY_CPU);
- }
- void paravirt_end_context_switch(struct task_struct *next)
- {
- BUG_ON(preemptible());
- leave_lazy(PARAVIRT_LAZY_CPU);
- if (test_and_clear_ti_thread_flag(task_thread_info(next), TIF_LAZY_MMU_UPDATES))
- arch_enter_lazy_mmu_mode();
- }
- static noinstr unsigned long pv_native_read_cr2(void)
- {
- return native_read_cr2();
- }
- static noinstr void pv_native_write_cr2(unsigned long val)
- {
- native_write_cr2(val);
- }
- 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);
- }
- static noinstr void pv_native_irq_enable(void)
- {
- native_irq_enable();
- }
- static noinstr void pv_native_irq_disable(void)
- {
- native_irq_disable();
- }
- #endif
- enum paravirt_lazy_mode paravirt_get_lazy_mode(void)
- {
- if (in_interrupt())
- return PARAVIRT_LAZY_NONE;
- return this_cpu_read(paravirt_lazy_mode);
- }
- 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.wbinvd = native_wbinvd,
- .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(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),
- .irq.safe_halt = native_safe_halt,
- .irq.halt = native_halt,
- #endif /* CONFIG_PARAVIRT_XXL */
- /* 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.tlb_remove_table =
- (void (*)(struct mmu_gather *, void *))tlb_remove_page,
- .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 = __native_read_cr3,
- .mmu.write_cr3 = 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,
- #if CONFIG_PGTABLE_LEVELS >= 5
- .mmu.p4d_val = PTE_IDENT,
- .mmu.make_p4d = PTE_IDENT,
- .mmu.set_pgd = native_set_pgd,
- #endif /* CONFIG_PGTABLE_LEVELS >= 5 */
- .mmu.pte_val = PTE_IDENT,
- .mmu.pgd_val = PTE_IDENT,
- .mmu.make_pte = PTE_IDENT,
- .mmu.make_pgd = PTE_IDENT,
- .mmu.dup_mmap = paravirt_nop,
- .mmu.activate_mm = paravirt_nop,
- .mmu.lazy_mode = {
- .enter = paravirt_nop,
- .leave = paravirt_nop,
- .flush = paravirt_nop,
- },
- .mmu.set_fixmap = native_set_fixmap,
- #endif /* CONFIG_PARAVIRT_XXL */
- #if defined(CONFIG_PARAVIRT_SPINLOCKS)
- /* Lock ops. */
- #ifdef CONFIG_SMP
- .lock.queued_spin_lock_slowpath = native_queued_spin_lock_slowpath,
- .lock.queued_spin_unlock =
- PV_CALLEE_SAVE(__native_queued_spin_unlock),
- .lock.wait = paravirt_nop,
- .lock.kick = paravirt_nop,
- .lock.vcpu_is_preempted =
- PV_CALLEE_SAVE(__native_vcpu_is_preempted),
- #endif /* SMP */
- #endif
- };
- #ifdef CONFIG_PARAVIRT_XXL
- NOKPROBE_SYMBOL(native_load_idt);
- #endif
- EXPORT_SYMBOL(pv_ops);
- EXPORT_SYMBOL_GPL(pv_info);
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