diff options
Diffstat (limited to 'arch/x86/kernel/paravirt.c')
| -rw-r--r-- | arch/x86/kernel/paravirt.c | 520 |
1 files changed, 151 insertions, 369 deletions
diff --git a/arch/x86/kernel/paravirt.c b/arch/x86/kernel/paravirt.c index bc0a849589bb..ab3e172dcc69 100644 --- a/arch/x86/kernel/paravirt.c +++ b/arch/x86/kernel/paravirt.c @@ -1,19 +1,7 @@ +// SPDX-License-Identifier: GPL-2.0-or-later /* 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 */ @@ -25,13 +13,14 @@ #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/pgtable.h> #include <asm/time.h> #include <asm/pgalloc.h> #include <asm/irq.h> @@ -41,30 +30,13 @@ #include <asm/tlbflush.h> #include <asm/timer.h> #include <asm/special_insns.h> +#include <asm/tlb.h> +#include <asm/io_bitmap.h> +#include <asm/gsseg.h> +#include <asm/msr.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"); - -/* identity function, which can be inlined */ -u32 notrace _paravirt_ident_32(u32 x) -{ - return x; -} - -u64 notrace _paravirt_ident_64(u64 x) -{ - return x; -} +/* stub always returning 0. */ +DEFINE_ASM_FUNC(paravirt_ret0, "xor %eax,%eax", .entry.text); void __init default_banner(void) { @@ -72,127 +44,20 @@ void __init default_banner(void) 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, +#ifdef CONFIG_PARAVIRT_XXL +DEFINE_ASM_FUNC(_paravirt_ident_64, "mov %rdi, %rax", .text); +DEFINE_ASM_FUNC(pv_native_save_fl, "pushf; pop %rax", .noinstr.text); +DEFINE_ASM_FUNC(pv_native_irq_disable, "cli", .noinstr.text); +DEFINE_ASM_FUNC(pv_native_irq_enable, "sti", .noinstr.text); +DEFINE_ASM_FUNC(pv_native_read_cr2, "mov %cr2, %rax", .noinstr.text); #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) || - 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; -} +DEFINE_STATIC_KEY_FALSE(virt_spin_lock_key); -unsigned paravirt_patch_insns(void *insnbuf, unsigned len, - const char *start, const char *end) +void __init native_pv_lock_init(void) { - 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); + if (boot_cpu_has(X86_FEATURE_HYPERVISOR)) + static_branch_enable(&virt_spin_lock_key); } struct static_key paravirt_steal_enabled; @@ -203,271 +68,188 @@ 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; +DEFINE_STATIC_CALL(pv_steal_clock, native_steal_clock); +DEFINE_STATIC_CALL(pv_sched_clock, native_sched_clock); -static inline void enter_lazy(enum paravirt_lazy_mode mode) +void paravirt_set_sched_clock(u64 (*func)(void)) { - BUG_ON(this_cpu_read(paravirt_lazy_mode) != PARAVIRT_LAZY_NONE); - - this_cpu_write(paravirt_lazy_mode, mode); + static_call_update(pv_sched_clock, func); } -static void leave_lazy(enum paravirt_lazy_mode mode) +static noinstr void pv_native_safe_halt(void) { - BUG_ON(this_cpu_read(paravirt_lazy_mode) != mode); - - this_cpu_write(paravirt_lazy_mode, PARAVIRT_LAZY_NONE); + native_safe_halt(); } -void paravirt_enter_lazy_mmu(void) +#ifdef CONFIG_PARAVIRT_XXL +static noinstr void pv_native_write_cr2(unsigned long val) { - enter_lazy(PARAVIRT_LAZY_MMU); + native_write_cr2(val); } -void paravirt_leave_lazy_mmu(void) +static noinstr unsigned long pv_native_read_cr3(void) { - leave_lazy(PARAVIRT_LAZY_MMU); + return __native_read_cr3(); } -void paravirt_flush_lazy_mmu(void) +static noinstr void pv_native_write_cr3(unsigned long cr3) { - preempt_disable(); - - if (paravirt_get_lazy_mode() == PARAVIRT_LAZY_MMU) { - arch_leave_lazy_mmu_mode(); - arch_enter_lazy_mmu_mode(); - } - - preempt_enable(); + native_write_cr3(cr3); } -void paravirt_start_context_switch(struct task_struct *prev) +static noinstr unsigned long pv_native_get_debugreg(int regno) { - 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); + return native_get_debugreg(regno); } -void paravirt_end_context_switch(struct task_struct *next) +static noinstr void pv_native_set_debugreg(int regno, unsigned long val) { - 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); + native_set_debugreg(regno, val); } +#endif struct pv_info pv_info = { .name = "bare hardware", - .kernel_rpl = 0, - .shared_kernel_pmd = 1, /* Only used when CONFIG_X86_PAE is set */ - -#ifdef CONFIG_X86_64 +#ifdef CONFIG_PARAVIRT_XXL .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, -}; +/* 64-bit pagetable entries */ +#define PTE_IDENT __PV_IS_CALLEE_SAVE(_paravirt_ident_64) -__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, +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.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 -}; -__visible struct pv_cpu_ops pv_cpu_ops = { - .cpuid = native_cpuid, - .get_debugreg = native_get_debugreg, - .set_debugreg = native_set_debugreg, - .read_cr0 = native_read_cr0, - .write_cr0 = native_write_cr0, - .read_cr4 = native_read_cr4, - .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, - .write_msr = native_write_msr, - .read_msr_safe = native_read_msr_safe, - .write_msr_safe = 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, + .cpu.start_context_switch = paravirt_nop, + .cpu.end_context_switch = paravirt_nop, - .alloc_ldt = paravirt_nop, - .free_ldt = paravirt_nop, + /* Irq ops. */ + .irq.save_fl = __PV_IS_CALLEE_SAVE(pv_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), +#endif /* CONFIG_PARAVIRT_XXL */ - .load_sp0 = native_load_sp0, + /* Irq HLT ops. */ + .irq.safe_halt = pv_native_safe_halt, + .irq.halt = native_halt, -#ifdef CONFIG_X86_64 - .usergs_sysret64 = native_usergs_sysret64, -#endif - .iret = native_iret, - .swapgs = native_swapgs, + /* 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, - .set_iopl_mask = native_set_iopl_mask, - .io_delay = native_io_delay, + .mmu.exit_mmap = paravirt_nop, + .mmu.notify_page_enc_status_changed = paravirt_nop, - .start_context_switch = paravirt_nop, - .end_context_switch = 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 = pv_native_read_cr3, + .mmu.write_cr3 = pv_native_write_cr3, -/* 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); + .mmu.pgd_alloc = __paravirt_pgd_alloc, + .mmu.pgd_free = paravirt_nop, -#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 + .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, -struct pv_mmu_ops pv_mmu_ops __ro_after_init = { - - .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, - .alloc_p4d = paravirt_nop, - .release_pte = paravirt_nop, - .release_pmd = paravirt_nop, - .release_pud = paravirt_nop, - .release_p4d = 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, - .set_pud_at = native_set_pud_at, + .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, - .pmd_val = PTE_IDENT, - .make_pmd = PTE_IDENT, + .mmu.pmd_val = PTE_IDENT, + .mmu.make_pmd = PTE_IDENT, -#if CONFIG_PGTABLE_LEVELS >= 4 - .pud_val = PTE_IDENT, - .make_pud = PTE_IDENT, + .mmu.pud_val = PTE_IDENT, + .mmu.make_pud = PTE_IDENT, - .set_p4d = native_set_p4d, + .mmu.set_p4d = native_set_p4d, -#if CONFIG_PGTABLE_LEVELS >= 5 - .p4d_val = PTE_IDENT, - .make_p4d = PTE_IDENT, + .mmu.p4d_val = PTE_IDENT, + .mmu.make_p4d = PTE_IDENT, - .set_pgd = native_set_pgd, -#endif /* CONFIG_PGTABLE_LEVELS >= 5 */ -#endif /* CONFIG_PGTABLE_LEVELS >= 4 */ -#endif /* CONFIG_PGTABLE_LEVELS >= 3 */ + .mmu.set_pgd = native_set_pgd, - .pte_val = PTE_IDENT, - .pgd_val = PTE_IDENT, + .mmu.pte_val = PTE_IDENT, + .mmu.pgd_val = PTE_IDENT, - .make_pte = PTE_IDENT, - .make_pgd = PTE_IDENT, + .mmu.make_pte = PTE_IDENT, + .mmu.make_pgd = PTE_IDENT, - .dup_mmap = paravirt_nop, - .exit_mmap = paravirt_nop, - .activate_mm = paravirt_nop, + .mmu.enter_mmap = paravirt_nop, - .lazy_mode = { - .enter = paravirt_nop, - .leave = paravirt_nop, - .flush = paravirt_nop, + .mmu.lazy_mode = { + .enter = paravirt_nop, + .leave = paravirt_nop, + .flush = paravirt_nop, }, - .set_fixmap = native_set_fixmap, + .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 }; -EXPORT_SYMBOL_GPL(pv_time_ops); -EXPORT_SYMBOL (pv_cpu_ops); -EXPORT_SYMBOL (pv_mmu_ops); +#ifdef CONFIG_PARAVIRT_XXL +NOKPROBE_SYMBOL(native_load_idt); +#endif + +EXPORT_SYMBOL(pv_ops); EXPORT_SYMBOL_GPL(pv_info); -EXPORT_SYMBOL (pv_irq_ops); |