/* 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 */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include /* nop stub */ void _paravirt_nop(void) { } static void __init default_banner(void) { printk(KERN_INFO "Booting paravirtualized kernel on %s\n", pv_info.name); } char *memory_setup(void) { return pv_init_ops.memory_setup(); } /* Simple instruction patching code. */ #define DEF_NATIVE(ops, name, code) \ extern const char start_##ops##_##name[], end_##ops##_##name[]; \ asm("start_" #ops "_" #name ": " code "; end_" #ops "_" #name ":") DEF_NATIVE(pv_irq_ops, irq_disable, "cli"); DEF_NATIVE(pv_irq_ops, irq_enable, "sti"); DEF_NATIVE(pv_irq_ops, restore_fl, "push %eax; popf"); DEF_NATIVE(pv_irq_ops, save_fl, "pushf; pop %eax"); DEF_NATIVE(pv_cpu_ops, iret, "iret"); DEF_NATIVE(pv_cpu_ops, irq_enable_sysexit, "sti; sysexit"); DEF_NATIVE(pv_mmu_ops, read_cr2, "mov %cr2, %eax"); DEF_NATIVE(pv_mmu_ops, write_cr3, "mov %eax, %cr3"); DEF_NATIVE(pv_mmu_ops, read_cr3, "mov %cr3, %eax"); DEF_NATIVE(pv_cpu_ops, clts, "clts"); DEF_NATIVE(pv_cpu_ops, read_tsc, "rdtsc"); /* Undefined instruction for dealing with missing ops pointers. */ static const unsigned char ud2a[] = { 0x0f, 0x0b }; static unsigned native_patch(u8 type, u16 clobbers, void *ibuf, unsigned long addr, unsigned len) { const unsigned char *start, *end; unsigned ret; switch(type) { #define SITE(ops, x) \ case PARAVIRT_PATCH(ops.x): \ start = start_##ops##_##x; \ end = end_##ops##_##x; \ goto patch_site SITE(pv_irq_ops, irq_disable); SITE(pv_irq_ops, irq_enable); SITE(pv_irq_ops, restore_fl); SITE(pv_irq_ops, save_fl); SITE(pv_cpu_ops, iret); SITE(pv_cpu_ops, irq_enable_sysexit); SITE(pv_mmu_ops, read_cr2); SITE(pv_mmu_ops, read_cr3); SITE(pv_mmu_ops, write_cr3); SITE(pv_cpu_ops, clts); SITE(pv_cpu_ops, read_tsc); #undef SITE patch_site: ret = paravirt_patch_insns(ibuf, len, start, end); break; default: ret = paravirt_patch_default(type, clobbers, ibuf, addr, len); break; } return ret; } unsigned paravirt_patch_nop(void) { return 0; } unsigned paravirt_patch_ignore(unsigned len) { return len; } 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_apic_ops = pv_apic_ops, .pv_mmu_ops = pv_mmu_ops, }; 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) /* If the operation is a nop, then nop the callsite */ ret = paravirt_patch_nop(); else if (type == PARAVIRT_PATCH(pv_cpu_ops.iret) || type == PARAVIRT_PATCH(pv_cpu_ops.irq_enable_sysexit)) /* 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; } void init_IRQ(void) { pv_irq_ops.init_IRQ(); } 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); } /* These are in entry.S */ extern void native_iret(void); extern void native_irq_enable_sysexit(void); static int __init print_banner(void) { pv_init_ops.banner(); return 0; } core_initcall(print_banner); static struct resource reserve_ioports = { .start = 0, .end = IO_SPACE_LIMIT, .name = "paravirt-ioport", .flags = IORESOURCE_IO | IORESOURCE_BUSY, }; static struct resource reserve_iomem = { .start = 0, .end = -1, .name = "paravirt-iomem", .flags = IORESOURCE_MEM | 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) { int ret; ret = request_resource(&ioport_resource, &reserve_ioports); if (ret == 0) { ret = request_resource(&iomem_resource, &reserve_iomem); if (ret) release_resource(&reserve_ioports); } return ret; } 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(x86_read_percpu(paravirt_lazy_mode) != PARAVIRT_LAZY_NONE); BUG_ON(preemptible()); x86_write_percpu(paravirt_lazy_mode, mode); } void paravirt_leave_lazy(enum paravirt_lazy_mode mode) { BUG_ON(x86_read_percpu(paravirt_lazy_mode) != mode); BUG_ON(preemptible()); x86_write_percpu(paravirt_lazy_mode, PARAVIRT_LAZY_NONE); } void paravirt_enter_lazy_mmu(void) { enter_lazy(PARAVIRT_LAZY_MMU); } void paravirt_leave_lazy_mmu(void) { paravirt_leave_lazy(PARAVIRT_LAZY_MMU); } void paravirt_enter_lazy_cpu(void) { enter_lazy(PARAVIRT_LAZY_CPU); } void paravirt_leave_lazy_cpu(void) { paravirt_leave_lazy(PARAVIRT_LAZY_CPU); } enum paravirt_lazy_mode paravirt_get_lazy_mode(void) { return x86_read_percpu(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 */ }; struct pv_init_ops pv_init_ops = { .patch = native_patch, .banner = default_banner, .arch_setup = paravirt_nop, .memory_setup = machine_specific_memory_setup, }; struct pv_time_ops pv_time_ops = { .time_init = hpet_time_init, .get_wallclock = native_get_wallclock, .set_wallclock = native_set_wallclock, .sched_clock = native_sched_clock, .get_cpu_khz = native_calculate_cpu_khz, }; struct pv_irq_ops pv_irq_ops = { .init_IRQ = native_init_IRQ, .save_fl = native_save_fl, .restore_fl = native_restore_fl, .irq_disable = native_irq_disable, .irq_enable = native_irq_enable, .safe_halt = native_safe_halt, .halt = native_halt, }; 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, .wbinvd = native_wbinvd, .read_msr = native_read_msr_safe, .write_msr = native_write_msr_safe, .read_tsc = native_read_tsc, .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_gdt = native_store_gdt, .store_idt = native_store_idt, .store_tr = native_store_tr, .load_tls = native_load_tls, .write_ldt_entry = write_dt_entry, .write_gdt_entry = write_dt_entry, .write_idt_entry = write_dt_entry, .load_esp0 = native_load_esp0, .irq_enable_sysexit = native_irq_enable_sysexit, .iret = native_iret, .set_iopl_mask = native_set_iopl_mask, .io_delay = native_io_delay, .lazy_mode = { .enter = paravirt_nop, .leave = paravirt_nop, }, }; struct pv_apic_ops pv_apic_ops = { #ifdef CONFIG_X86_LOCAL_APIC .apic_write = native_apic_write, .apic_write_atomic = native_apic_write_atomic, .apic_read = native_apic_read, .setup_boot_clock = setup_boot_APIC_clock, .setup_secondary_clock = setup_secondary_APIC_clock, .startup_ipi_hook = paravirt_nop, #endif }; struct pv_mmu_ops pv_mmu_ops = { .pagetable_setup_start = native_pagetable_setup_start, .pagetable_setup_done = native_pagetable_setup_done, .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, .alloc_pt = paravirt_nop, .alloc_pd = paravirt_nop, .alloc_pd_clone = paravirt_nop, .release_pt = paravirt_nop, .release_pd = paravirt_nop, .set_pte = native_set_pte, .set_pte_at = native_set_pte_at, .set_pmd = native_set_pmd, .pte_update = paravirt_nop, .pte_update_defer = paravirt_nop, #ifdef CONFIG_HIGHPTE .kmap_atomic_pte = kmap_atomic, #endif #ifdef CONFIG_X86_PAE .set_pte_atomic = native_set_pte_atomic, .set_pte_present = native_set_pte_present, .set_pud = native_set_pud, .pte_clear = native_pte_clear, .pmd_clear = native_pmd_clear, .pmd_val = native_pmd_val, .make_pmd = native_make_pmd, #endif .pte_val = native_pte_val, .pgd_val = native_pgd_val, .make_pte = native_make_pte, .make_pgd = native_make_pgd, .dup_mmap = paravirt_nop, .exit_mmap = paravirt_nop, .activate_mm = paravirt_nop, .lazy_mode = { .enter = paravirt_nop, .leave = paravirt_nop, }, }; EXPORT_SYMBOL_GPL(pv_time_ops); EXPORT_SYMBOL (pv_cpu_ops); EXPORT_SYMBOL (pv_mmu_ops); EXPORT_SYMBOL_GPL(pv_apic_ops); EXPORT_SYMBOL_GPL(pv_info); EXPORT_SYMBOL (pv_irq_ops);