/* Paravirtualization interfaces Copyright (C) 2006 Rusty Russell IBM Corporation This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA 2007 - x86_64 support added by Glauber de Oliveira Costa, Red Hat Inc */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include /* * 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"); /* identity function, which can be inlined */ u32 _paravirt_ident_32(u32 x) { return x; } u64 _paravirt_ident_64(u64 x) { return x; } 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)); unsigned paravirt_patch_call(void *insnbuf, const void *target, u16 tgt_clobbers, unsigned long addr, u16 site_clobbers, unsigned len) { struct branch *b = insnbuf; unsigned long delta = (unsigned long)target - (addr+5); if (tgt_clobbers & ~site_clobbers) return len; /* target would clobber too much for this site */ if (len < 5) return len; /* call too long for patch site */ b->opcode = 0xe8; /* call */ b->delta = delta; BUILD_BUG_ON(sizeof(*b) != 5); return 5; } unsigned paravirt_patch_jmp(void *insnbuf, const void *target, unsigned long addr, unsigned len) { struct branch *b = insnbuf; unsigned long delta = (unsigned long)target - (addr+5); if (len < 5) return len; /* call too long for patch site */ b->opcode = 0xe9; /* jmp */ b->delta = delta; return 5; } /* Neat trick to map patch type back to the call within the * corresponding structure. */ static void *get_call_destination(u8 type) { struct paravirt_patch_template tmpl = { .pv_init_ops = pv_init_ops, .pv_time_ops = pv_time_ops, .pv_cpu_ops = pv_cpu_ops, .pv_irq_ops = pv_irq_ops, .pv_mmu_ops = pv_mmu_ops, #ifdef CONFIG_PARAVIRT_SPINLOCKS .pv_lock_ops = pv_lock_ops, #endif }; return *((void **)&tmpl + type); } unsigned paravirt_patch_default(u8 type, u16 clobbers, void *insnbuf, unsigned long addr, unsigned len) { void *opfunc = get_call_destination(type); unsigned ret; if (opfunc == NULL) /* If there's no function, patch it with a ud2a (BUG) */ ret = paravirt_patch_insns(insnbuf, len, ud2a, ud2a+sizeof(ud2a)); else if (opfunc == _paravirt_nop) ret = 0; /* identity functions just return their single argument */ else if (opfunc == _paravirt_ident_32) ret = paravirt_patch_ident_32(insnbuf, len); else if (opfunc == _paravirt_ident_64) ret = paravirt_patch_ident_64(insnbuf, len); else if (type == PARAVIRT_PATCH(pv_cpu_ops.iret) || #ifdef CONFIG_X86_32 type == PARAVIRT_PATCH(pv_cpu_ops.irq_enable_sysexit) || #endif type == PARAVIRT_PATCH(pv_cpu_ops.usergs_sysret32) || type == PARAVIRT_PATCH(pv_cpu_ops.usergs_sysret64)) /* If operation requires a jmp, then jmp */ ret = paravirt_patch_jmp(insnbuf, opfunc, addr, len); else /* Otherwise call the function; assume target could clobber any caller-save reg */ ret = paravirt_patch_call(insnbuf, opfunc, CLBR_ANY, addr, clobbers, len); return ret; } unsigned paravirt_patch_insns(void *insnbuf, unsigned len, const char *start, const char *end) { unsigned insn_len = end - start; if (insn_len > len || start == NULL) insn_len = len; else memcpy(insnbuf, start, insn_len); return insn_len; } static void native_flush_tlb(void) { __native_flush_tlb(); } /* * Global pages have to be flushed a bit differently. Not a real * performance problem because this does not happen often. */ static void native_flush_tlb_global(void) { __native_flush_tlb_global(); } static void native_flush_tlb_single(unsigned long addr) { __native_flush_tlb_single(addr); } 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_irq_enable_sysexit(void); extern void native_usergs_sysret32(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(); } 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(); } 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", .paravirt_enabled = 0, .kernel_rpl = 0, .shared_kernel_pmd = 1, /* Only used when CONFIG_X86_PAE is set */ #ifdef CONFIG_X86_64 .extra_user_64bit_cs = __USER_CS, #endif }; struct pv_init_ops pv_init_ops = { .patch = native_patch, }; struct pv_time_ops pv_time_ops = { .sched_clock = native_sched_clock, .steal_clock = native_steal_clock, }; __visible struct pv_irq_ops pv_irq_ops = { .save_fl = __PV_IS_CALLEE_SAVE(native_save_fl), .restore_fl = __PV_IS_CALLEE_SAVE(native_restore_fl), .irq_disable = __PV_IS_CALLEE_SAVE(native_irq_disable), .irq_enable = __PV_IS_CALLEE_SAVE(native_irq_enable), .safe_halt = native_safe_halt, .halt = native_halt, #ifdef CONFIG_X86_64 .adjust_exception_frame = paravirt_nop, #endif }; __visible struct pv_cpu_ops pv_cpu_ops = { .cpuid = native_cpuid, .get_debugreg = native_get_debugreg, .set_debugreg = native_set_debugreg, .clts = native_clts, .read_cr0 = native_read_cr0, .write_cr0 = native_write_cr0, .read_cr4 = native_read_cr4, .read_cr4_safe = native_read_cr4_safe, .write_cr4 = native_write_cr4, #ifdef CONFIG_X86_64 .read_cr8 = native_read_cr8, .write_cr8 = native_write_cr8, #endif .wbinvd = native_wbinvd, .read_msr = native_read_msr_safe, .write_msr = native_write_msr_safe, .read_pmc = native_read_pmc, .load_tr_desc = native_load_tr_desc, .set_ldt = native_set_ldt, .load_gdt = native_load_gdt, .load_idt = native_load_idt, .store_idt = native_store_idt, .store_tr = native_store_tr, .load_tls = native_load_tls, #ifdef CONFIG_X86_64 .load_gs_index = native_load_gs_index, #endif .write_ldt_entry = native_write_ldt_entry, .write_gdt_entry = native_write_gdt_entry, .write_idt_entry = native_write_idt_entry, .alloc_ldt = paravirt_nop, .free_ldt = paravirt_nop, .load_sp0 = native_load_sp0, #if defined(CONFIG_X86_32) .irq_enable_sysexit = native_irq_enable_sysexit, #endif #ifdef CONFIG_X86_64 #ifdef CONFIG_IA32_EMULATION .usergs_sysret32 = native_usergs_sysret32, #endif .usergs_sysret64 = native_usergs_sysret64, #endif .iret = native_iret, .swapgs = native_swapgs, .set_iopl_mask = native_set_iopl_mask, .io_delay = native_io_delay, .start_context_switch = paravirt_nop, .end_context_switch = paravirt_nop, }; /* 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); #if defined(CONFIG_X86_32) && !defined(CONFIG_X86_PAE) /* 32-bit pagetable entries */ #define PTE_IDENT __PV_IS_CALLEE_SAVE(_paravirt_ident_32) #else /* 64-bit pagetable entries */ #define PTE_IDENT __PV_IS_CALLEE_SAVE(_paravirt_ident_64) #endif struct pv_mmu_ops pv_mmu_ops = { .read_cr2 = native_read_cr2, .write_cr2 = native_write_cr2, .read_cr3 = native_read_cr3, .write_cr3 = native_write_cr3, .flush_tlb_user = native_flush_tlb, .flush_tlb_kernel = native_flush_tlb_global, .flush_tlb_single = native_flush_tlb_single, .flush_tlb_others = native_flush_tlb_others, .pgd_alloc = __paravirt_pgd_alloc, .pgd_free = paravirt_nop, .alloc_pte = paravirt_nop, .alloc_pmd = paravirt_nop, .alloc_pud = paravirt_nop, .release_pte = paravirt_nop, .release_pmd = paravirt_nop, .release_pud = paravirt_nop, .set_pte = native_set_pte, .set_pte_at = native_set_pte_at, .set_pmd = native_set_pmd, .set_pmd_at = native_set_pmd_at, .pte_update = paravirt_nop, .ptep_modify_prot_start = __ptep_modify_prot_start, .ptep_modify_prot_commit = __ptep_modify_prot_commit, #if CONFIG_PGTABLE_LEVELS >= 3 #ifdef CONFIG_X86_PAE .set_pte_atomic = native_set_pte_atomic, .pte_clear = native_pte_clear, .pmd_clear = native_pmd_clear, #endif .set_pud = native_set_pud, .pmd_val = PTE_IDENT, .make_pmd = PTE_IDENT, #if CONFIG_PGTABLE_LEVELS == 4 .pud_val = PTE_IDENT, .make_pud = PTE_IDENT, .set_pgd = native_set_pgd, #endif #endif /* CONFIG_PGTABLE_LEVELS >= 3 */ .pte_val = PTE_IDENT, .pgd_val = PTE_IDENT, .make_pte = PTE_IDENT, .make_pgd = PTE_IDENT, .dup_mmap = paravirt_nop, .exit_mmap = paravirt_nop, .activate_mm = paravirt_nop, .lazy_mode = { .enter = paravirt_nop, .leave = paravirt_nop, .flush = paravirt_nop, }, .set_fixmap = native_set_fixmap, }; EXPORT_SYMBOL_GPL(pv_time_ops); EXPORT_SYMBOL (pv_cpu_ops); EXPORT_SYMBOL (pv_mmu_ops); EXPORT_SYMBOL_GPL(pv_info); EXPORT_SYMBOL (pv_irq_ops);