123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204205206207208209210211212213214215216217218219220221222223224225226227228229230231232233234235236237238239240241242243244245246247248249250251252253254255256257258259260261262263264265266267268269270271272273274275276277278279280281282283284285286287288289290291292293294295296297298299300301302303304305306307308309310311312313314315316317318319320321322323324325326327328329330331332333334335336337338339340341342343344345346347348349350351352353354355356357358359360361362363364365366367368369370371372373374375376377378379380381382383384385386387388389390391392393394395396397398399400401402403404405406407408409410411412413414415416417418419420421422423424 |
- // 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 <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"
- "ret\n\t"
- ".size _paravirt_nop, . - _paravirt_nop\n\t"
- ".type _paravirt_nop, @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. */
- static const unsigned char ud2a[] = { 0x0f, 0x0b };
- struct branch {
- unsigned char opcode;
- u32 delta;
- } __attribute__((packed));
- static unsigned paravirt_patch_call(void *insn_buff, const void *target,
- unsigned long addr, unsigned len)
- {
- const int call_len = 5;
- struct branch *b = insn_buff;
- unsigned long delta = (unsigned long)target - (addr+call_len);
- if (len < call_len) {
- pr_warn("paravirt: Failed to patch indirect CALL at %ps\n", (void *)addr);
- /* Kernel might not be viable if patching fails, bail out: */
- BUG_ON(1);
- }
- b->opcode = 0xe8; /* call */
- b->delta = delta;
- BUILD_BUG_ON(sizeof(*b) != call_len);
- return call_len;
- }
- #ifdef CONFIG_PARAVIRT_XXL
- /* identity function, which can be inlined */
- u64 notrace _paravirt_ident_64(u64 x)
- {
- return x;
- }
- static unsigned paravirt_patch_jmp(void *insn_buff, const void *target,
- unsigned long addr, unsigned len)
- {
- struct branch *b = insn_buff;
- unsigned long delta = (unsigned long)target - (addr+5);
- if (len < 5) {
- #ifdef CONFIG_RETPOLINE
- WARN_ONCE(1, "Failing to patch indirect JMP in %ps\n", (void *)addr);
- #endif
- return len; /* call too long for patch site */
- }
- b->opcode = 0xe9; /* jmp */
- b->delta = delta;
- return 5;
- }
- #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 paravirt_patch_default(u8 type, void *insn_buff,
- unsigned long addr, unsigned 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 a ud2a (BUG) */
- ret = paravirt_patch_insns(insn_buff, len, ud2a, ud2a+sizeof(ud2a));
- else if (opfunc == _paravirt_nop)
- ret = 0;
- #ifdef CONFIG_PARAVIRT_XXL
- /* identity functions just return their single argument */
- else if (opfunc == _paravirt_ident_64)
- ret = paravirt_patch_ident_64(insn_buff, len);
- else if (type == PARAVIRT_PATCH(cpu.iret) ||
- type == PARAVIRT_PATCH(cpu.usergs_sysret64))
- /* If operation requires a jmp, then jmp */
- ret = paravirt_patch_jmp(insn_buff, opfunc, addr, len);
- #endif
- else
- /* Otherwise call the function. */
- ret = paravirt_patch_call(insn_buff, opfunc, addr, len);
- return ret;
- }
- unsigned paravirt_patch_insns(void *insn_buff, unsigned len,
- const char *start, const char *end)
- {
- unsigned insn_len = end - start;
- /* Alternative instruction is too large for the patch site and we cannot continue: */
- BUG_ON(insn_len > len || start == NULL);
- memcpy(insn_buff, start, insn_len);
- return insn_len;
- }
- struct static_key paravirt_steal_enabled;
- struct static_key paravirt_steal_rq_enabled;
- static u64 native_steal_clock(int cpu)
- {
- return 0;
- }
- /* These are in entry.S */
- extern void native_iret(void);
- extern void native_usergs_sysret64(void);
- 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();
- }
- #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 = {
- /* Init ops. */
- .init.patch = native_patch,
- /* Time ops. */
- .time.sched_clock = native_sched_clock,
- .time.steal_clock = native_steal_clock,
- /* Cpu ops. */
- .cpu.io_delay = native_io_delay,
- #ifdef CONFIG_PARAVIRT_XXL
- .cpu.cpuid = native_cpuid,
- .cpu.get_debugreg = native_get_debugreg,
- .cpu.set_debugreg = 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,
- .cpu.usergs_sysret64 = native_usergs_sysret64,
- .cpu.iret = native_iret,
- #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.restore_fl = __PV_IS_CALLEE_SAVE(native_restore_fl),
- .irq.irq_disable = __PV_IS_CALLEE_SAVE(native_irq_disable),
- .irq.irq_enable = __PV_IS_CALLEE_SAVE(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_others = native_flush_tlb_others,
- .mmu.tlb_remove_table =
- (void (*)(struct mmu_gather *, void *))tlb_remove_page,
- .mmu.exit_mmap = paravirt_nop,
- #ifdef CONFIG_PARAVIRT_XXL
- .mmu.read_cr2 = __PV_IS_CALLEE_SAVE(native_read_cr2),
- .mmu.write_cr2 = 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
- /* At this point, native_get/set_debugreg has real function entries */
- NOKPROBE_SYMBOL(native_get_debugreg);
- NOKPROBE_SYMBOL(native_set_debugreg);
- NOKPROBE_SYMBOL(native_load_idt);
- #endif
- EXPORT_SYMBOL(pv_ops);
- EXPORT_SYMBOL_GPL(pv_info);
|