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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
commit | 2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch) | |
tree | 848558de17fb3008cdf4d861b01ac7781903ce39 /arch/x86/kernel/paravirt.c | |
parent | Initial commit. (diff) | |
download | linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.tar.xz linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.zip |
Adding upstream version 6.1.76.upstream/6.1.76
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'arch/x86/kernel/paravirt.c')
-rw-r--r-- | arch/x86/kernel/paravirt.c | 403 |
1 files changed, 403 insertions, 0 deletions
diff --git a/arch/x86/kernel/paravirt.c b/arch/x86/kernel/paravirt.c new file mode 100644 index 000000000..7ca2d46c0 --- /dev/null +++ b/arch/x86/kernel/paravirt.c @@ -0,0 +1,403 @@ +// 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 <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/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" + ASM_ENDBR + ASM_RET + ".size _paravirt_nop, . - _paravirt_nop\n\t" + ".type _paravirt_nop, @function\n\t" + ".popsection"); + +/* stub always returning 0. */ +asm (".pushsection .entry.text, \"ax\"\n" + ".global paravirt_ret0\n" + "paravirt_ret0:\n\t" + ASM_ENDBR + "xor %" _ASM_AX ", %" _ASM_AX ";\n\t" + ASM_RET + ".size paravirt_ret0, . - paravirt_ret0\n\t" + ".type paravirt_ret0, @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. */ +noinstr void paravirt_BUG(void) +{ + BUG(); +} + +static unsigned paravirt_patch_call(void *insn_buff, const void *target, + unsigned long addr, unsigned len) +{ + __text_gen_insn(insn_buff, CALL_INSN_OPCODE, + (void *)addr, target, CALL_INSN_SIZE); + return CALL_INSN_SIZE; +} + +#ifdef CONFIG_PARAVIRT_XXL +/* identity function, which can be inlined */ +u64 notrace _paravirt_ident_64(u64 x) +{ + return x; +} +#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 int paravirt_patch(u8 type, void *insn_buff, unsigned long addr, + unsigned int 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 paravirt_BUG() */ + ret = paravirt_patch_call(insn_buff, paravirt_BUG, addr, len); + else if (opfunc == _paravirt_nop) + ret = 0; + else + /* Otherwise call the function. */ + ret = paravirt_patch_call(insn_buff, opfunc, addr, len); + + return ret; +} + +struct static_key paravirt_steal_enabled; +struct static_key paravirt_steal_rq_enabled; + +static u64 native_steal_clock(int cpu) +{ + return 0; +} + +DEFINE_STATIC_CALL(pv_steal_clock, native_steal_clock); +DEFINE_STATIC_CALL(pv_sched_clock, native_sched_clock); + +void paravirt_set_sched_clock(u64 (*func)(void)) +{ + static_call_update(pv_sched_clock, func); +} + +/* These are in entry.S */ +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(); +} + +static noinstr unsigned long pv_native_read_cr2(void) +{ + return native_read_cr2(); +} + +static noinstr void pv_native_write_cr2(unsigned long val) +{ + native_write_cr2(val); +} + +static noinstr unsigned long pv_native_get_debugreg(int regno) +{ + return native_get_debugreg(regno); +} + +static noinstr void pv_native_set_debugreg(int regno, unsigned long val) +{ + native_set_debugreg(regno, val); +} + +static noinstr void pv_native_irq_enable(void) +{ + native_irq_enable(); +} + +static noinstr void pv_native_irq_disable(void) +{ + native_irq_disable(); +} +#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 = { + /* 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.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, + +#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.irq_disable = __PV_IS_CALLEE_SAVE(pv_native_irq_disable), + .irq.irq_enable = __PV_IS_CALLEE_SAVE(pv_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_multi = native_flush_tlb_multi, + .mmu.tlb_remove_table = + (void (*)(struct mmu_gather *, void *))tlb_remove_page, + + .mmu.exit_mmap = paravirt_nop, + .mmu.notify_page_enc_status_changed = 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 = __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 +NOKPROBE_SYMBOL(native_load_idt); +#endif + +EXPORT_SYMBOL(pv_ops); +EXPORT_SYMBOL_GPL(pv_info); |