diff options
Diffstat (limited to 'arch/x86/kernel/paravirt.c')
| -rw-r--r-- | arch/x86/kernel/paravirt.c | 475 |
1 files changed, 475 insertions, 0 deletions
diff --git a/arch/x86/kernel/paravirt.c b/arch/x86/kernel/paravirt.c new file mode 100644 index 000000000000..1a170877f46c --- /dev/null +++ b/arch/x86/kernel/paravirt.c @@ -0,0 +1,475 @@ +/* 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 <linux/errno.h> +#include <linux/module.h> +#include <linux/efi.h> +#include <linux/bcd.h> +#include <linux/highmem.h> + +#include <asm/bug.h> +#include <asm/paravirt.h> +#include <asm/desc.h> +#include <asm/setup.h> +#include <asm/arch_hooks.h> +#include <asm/time.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> + +/* 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_syscall_ret, "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_syscall_ret); + 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_syscall_ret)) + /* 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_syscall_ret(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 = native_write_ldt_entry, + .write_gdt_entry = native_write_gdt_entry, + .write_idt_entry = native_write_idt_entry, + .load_sp0 = native_load_sp0, + + .irq_enable_syscall_ret = native_irq_enable_syscall_ret, + .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); |