/* * Core of Xen paravirt_ops implementation. * * This file contains the xen_paravirt_ops structure itself, and the * implementations for: * - privileged instructions * - interrupt flags * - segment operations * - booting and setup * * Jeremy Fitzhardinge , XenSource Inc, 2007 */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include "xen-ops.h" #include "mmu.h" #include "multicalls.h" EXPORT_SYMBOL_GPL(hypercall_page); DEFINE_PER_CPU(struct vcpu_info *, xen_vcpu); DEFINE_PER_CPU(struct vcpu_info, xen_vcpu_info); enum xen_domain_type xen_domain_type = XEN_NATIVE; EXPORT_SYMBOL_GPL(xen_domain_type); /* * Identity map, in addition to plain kernel map. This needs to be * large enough to allocate page table pages to allocate the rest. * Each page can map 2MB. */ static pte_t level1_ident_pgt[PTRS_PER_PTE * 4] __page_aligned_bss; #ifdef CONFIG_X86_64 /* l3 pud for userspace vsyscall mapping */ static pud_t level3_user_vsyscall[PTRS_PER_PUD] __page_aligned_bss; #endif /* CONFIG_X86_64 */ /* * Note about cr3 (pagetable base) values: * * xen_cr3 contains the current logical cr3 value; it contains the * last set cr3. This may not be the current effective cr3, because * its update may be being lazily deferred. However, a vcpu looking * at its own cr3 can use this value knowing that it everything will * be self-consistent. * * xen_current_cr3 contains the actual vcpu cr3; it is set once the * hypercall to set the vcpu cr3 is complete (so it may be a little * out of date, but it will never be set early). If one vcpu is * looking at another vcpu's cr3 value, it should use this variable. */ DEFINE_PER_CPU(unsigned long, xen_cr3); /* cr3 stored as physaddr */ DEFINE_PER_CPU(unsigned long, xen_current_cr3); /* actual vcpu cr3 */ struct start_info *xen_start_info; EXPORT_SYMBOL_GPL(xen_start_info); struct shared_info xen_dummy_shared_info; /* * Point at some empty memory to start with. We map the real shared_info * page as soon as fixmap is up and running. */ struct shared_info *HYPERVISOR_shared_info = (void *)&xen_dummy_shared_info; /* * Flag to determine whether vcpu info placement is available on all * VCPUs. We assume it is to start with, and then set it to zero on * the first failure. This is because it can succeed on some VCPUs * and not others, since it can involve hypervisor memory allocation, * or because the guest failed to guarantee all the appropriate * constraints on all VCPUs (ie buffer can't cross a page boundary). * * Note that any particular CPU may be using a placed vcpu structure, * but we can only optimise if the all are. * * 0: not available, 1: available */ static int have_vcpu_info_placement = #ifdef CONFIG_X86_32 1 #else 0 #endif ; static void xen_vcpu_setup(int cpu) { struct vcpu_register_vcpu_info info; int err; struct vcpu_info *vcpup; BUG_ON(HYPERVISOR_shared_info == &xen_dummy_shared_info); per_cpu(xen_vcpu, cpu) = &HYPERVISOR_shared_info->vcpu_info[cpu]; if (!have_vcpu_info_placement) return; /* already tested, not available */ vcpup = &per_cpu(xen_vcpu_info, cpu); info.mfn = virt_to_mfn(vcpup); info.offset = offset_in_page(vcpup); printk(KERN_DEBUG "trying to map vcpu_info %d at %p, mfn %llx, offset %d\n", cpu, vcpup, info.mfn, info.offset); /* Check to see if the hypervisor will put the vcpu_info structure where we want it, which allows direct access via a percpu-variable. */ err = HYPERVISOR_vcpu_op(VCPUOP_register_vcpu_info, cpu, &info); if (err) { printk(KERN_DEBUG "register_vcpu_info failed: err=%d\n", err); have_vcpu_info_placement = 0; } else { /* This cpu is using the registered vcpu info, even if later ones fail to. */ per_cpu(xen_vcpu, cpu) = vcpup; printk(KERN_DEBUG "cpu %d using vcpu_info at %p\n", cpu, vcpup); } } /* * On restore, set the vcpu placement up again. * If it fails, then we're in a bad state, since * we can't back out from using it... */ void xen_vcpu_restore(void) { if (have_vcpu_info_placement) { int cpu; for_each_online_cpu(cpu) { bool other_cpu = (cpu != smp_processor_id()); if (other_cpu && HYPERVISOR_vcpu_op(VCPUOP_down, cpu, NULL)) BUG(); xen_vcpu_setup(cpu); if (other_cpu && HYPERVISOR_vcpu_op(VCPUOP_up, cpu, NULL)) BUG(); } BUG_ON(!have_vcpu_info_placement); } } static void __init xen_banner(void) { unsigned version = HYPERVISOR_xen_version(XENVER_version, NULL); struct xen_extraversion extra; HYPERVISOR_xen_version(XENVER_extraversion, &extra); printk(KERN_INFO "Booting paravirtualized kernel on %s\n", pv_info.name); printk(KERN_INFO "Xen version: %d.%d%s%s\n", version >> 16, version & 0xffff, extra.extraversion, xen_feature(XENFEAT_mmu_pt_update_preserve_ad) ? " (preserve-AD)" : ""); } static void xen_cpuid(unsigned int *ax, unsigned int *bx, unsigned int *cx, unsigned int *dx) { unsigned maskedx = ~0; /* * Mask out inconvenient features, to try and disable as many * unsupported kernel subsystems as possible. */ if (*ax == 1) maskedx = ~((1 << X86_FEATURE_APIC) | /* disable APIC */ (1 << X86_FEATURE_ACPI) | /* disable ACPI */ (1 << X86_FEATURE_MCE) | /* disable MCE */ (1 << X86_FEATURE_MCA) | /* disable MCA */ (1 << X86_FEATURE_ACC)); /* thermal monitoring */ asm(XEN_EMULATE_PREFIX "cpuid" : "=a" (*ax), "=b" (*bx), "=c" (*cx), "=d" (*dx) : "0" (*ax), "2" (*cx)); *dx &= maskedx; } static void xen_set_debugreg(int reg, unsigned long val) { HYPERVISOR_set_debugreg(reg, val); } static unsigned long xen_get_debugreg(int reg) { return HYPERVISOR_get_debugreg(reg); } static void xen_leave_lazy(void) { paravirt_leave_lazy(paravirt_get_lazy_mode()); xen_mc_flush(); } static unsigned long xen_store_tr(void) { return 0; } /* * Set the page permissions for a particular virtual address. If the * address is a vmalloc mapping (or other non-linear mapping), then * find the linear mapping of the page and also set its protections to * match. */ static void set_aliased_prot(void *v, pgprot_t prot) { int level; pte_t *ptep; pte_t pte; unsigned long pfn; struct page *page; ptep = lookup_address((unsigned long)v, &level); BUG_ON(ptep == NULL); pfn = pte_pfn(*ptep); page = pfn_to_page(pfn); pte = pfn_pte(pfn, prot); if (HYPERVISOR_update_va_mapping((unsigned long)v, pte, 0)) BUG(); if (!PageHighMem(page)) { void *av = __va(PFN_PHYS(pfn)); if (av != v) if (HYPERVISOR_update_va_mapping((unsigned long)av, pte, 0)) BUG(); } else kmap_flush_unused(); } static void xen_alloc_ldt(struct desc_struct *ldt, unsigned entries) { const unsigned entries_per_page = PAGE_SIZE / LDT_ENTRY_SIZE; int i; for(i = 0; i < entries; i += entries_per_page) set_aliased_prot(ldt + i, PAGE_KERNEL_RO); } static void xen_free_ldt(struct desc_struct *ldt, unsigned entries) { const unsigned entries_per_page = PAGE_SIZE / LDT_ENTRY_SIZE; int i; for(i = 0; i < entries; i += entries_per_page) set_aliased_prot(ldt + i, PAGE_KERNEL); } static void xen_set_ldt(const void *addr, unsigned entries) { struct mmuext_op *op; struct multicall_space mcs = xen_mc_entry(sizeof(*op)); op = mcs.args; op->cmd = MMUEXT_SET_LDT; op->arg1.linear_addr = (unsigned long)addr; op->arg2.nr_ents = entries; MULTI_mmuext_op(mcs.mc, op, 1, NULL, DOMID_SELF); xen_mc_issue(PARAVIRT_LAZY_CPU); } static void xen_load_gdt(const struct desc_ptr *dtr) { unsigned long *frames; unsigned long va = dtr->address; unsigned int size = dtr->size + 1; unsigned pages = (size + PAGE_SIZE - 1) / PAGE_SIZE; int f; struct multicall_space mcs; /* A GDT can be up to 64k in size, which corresponds to 8192 8-byte entries, or 16 4k pages.. */ BUG_ON(size > 65536); BUG_ON(va & ~PAGE_MASK); mcs = xen_mc_entry(sizeof(*frames) * pages); frames = mcs.args; for (f = 0; va < dtr->address + size; va += PAGE_SIZE, f++) { frames[f] = virt_to_mfn(va); make_lowmem_page_readonly((void *)va); } MULTI_set_gdt(mcs.mc, frames, size / sizeof(struct desc_struct)); xen_mc_issue(PARAVIRT_LAZY_CPU); } static void load_TLS_descriptor(struct thread_struct *t, unsigned int cpu, unsigned int i) { struct desc_struct *gdt = get_cpu_gdt_table(cpu); xmaddr_t maddr = virt_to_machine(&gdt[GDT_ENTRY_TLS_MIN+i]); struct multicall_space mc = __xen_mc_entry(0); MULTI_update_descriptor(mc.mc, maddr.maddr, t->tls_array[i]); } static void xen_load_tls(struct thread_struct *t, unsigned int cpu) { /* * XXX sleazy hack: If we're being called in a lazy-cpu zone, * it means we're in a context switch, and %gs has just been * saved. This means we can zero it out to prevent faults on * exit from the hypervisor if the next process has no %gs. * Either way, it has been saved, and the new value will get * loaded properly. This will go away as soon as Xen has been * modified to not save/restore %gs for normal hypercalls. * * On x86_64, this hack is not used for %gs, because gs points * to KERNEL_GS_BASE (and uses it for PDA references), so we * must not zero %gs on x86_64 * * For x86_64, we need to zero %fs, otherwise we may get an * exception between the new %fs descriptor being loaded and * %fs being effectively cleared at __switch_to(). */ if (paravirt_get_lazy_mode() == PARAVIRT_LAZY_CPU) { #ifdef CONFIG_X86_32 loadsegment(gs, 0); #else loadsegment(fs, 0); #endif } xen_mc_batch(); load_TLS_descriptor(t, cpu, 0); load_TLS_descriptor(t, cpu, 1); load_TLS_descriptor(t, cpu, 2); xen_mc_issue(PARAVIRT_LAZY_CPU); } #ifdef CONFIG_X86_64 static void xen_load_gs_index(unsigned int idx) { if (HYPERVISOR_set_segment_base(SEGBASE_GS_USER_SEL, idx)) BUG(); } #endif static void xen_write_ldt_entry(struct desc_struct *dt, int entrynum, const void *ptr) { xmaddr_t mach_lp = arbitrary_virt_to_machine(&dt[entrynum]); u64 entry = *(u64 *)ptr; preempt_disable(); xen_mc_flush(); if (HYPERVISOR_update_descriptor(mach_lp.maddr, entry)) BUG(); preempt_enable(); } static int cvt_gate_to_trap(int vector, const gate_desc *val, struct trap_info *info) { if (val->type != 0xf && val->type != 0xe) return 0; info->vector = vector; info->address = gate_offset(*val); info->cs = gate_segment(*val); info->flags = val->dpl; /* interrupt gates clear IF */ if (val->type == 0xe) info->flags |= 4; return 1; } /* Locations of each CPU's IDT */ static DEFINE_PER_CPU(struct desc_ptr, idt_desc); /* Set an IDT entry. If the entry is part of the current IDT, then also update Xen. */ static void xen_write_idt_entry(gate_desc *dt, int entrynum, const gate_desc *g) { unsigned long p = (unsigned long)&dt[entrynum]; unsigned long start, end; preempt_disable(); start = __get_cpu_var(idt_desc).address; end = start + __get_cpu_var(idt_desc).size + 1; xen_mc_flush(); native_write_idt_entry(dt, entrynum, g); if (p >= start && (p + 8) <= end) { struct trap_info info[2]; info[1].address = 0; if (cvt_gate_to_trap(entrynum, g, &info[0])) if (HYPERVISOR_set_trap_table(info)) BUG(); } preempt_enable(); } static void xen_convert_trap_info(const struct desc_ptr *desc, struct trap_info *traps) { unsigned in, out, count; count = (desc->size+1) / sizeof(gate_desc); BUG_ON(count > 256); for (in = out = 0; in < count; in++) { gate_desc *entry = (gate_desc*)(desc->address) + in; if (cvt_gate_to_trap(in, entry, &traps[out])) out++; } traps[out].address = 0; } void xen_copy_trap_info(struct trap_info *traps) { const struct desc_ptr *desc = &__get_cpu_var(idt_desc); xen_convert_trap_info(desc, traps); } /* Load a new IDT into Xen. In principle this can be per-CPU, so we hold a spinlock to protect the static traps[] array (static because it avoids allocation, and saves stack space). */ static void xen_load_idt(const struct desc_ptr *desc) { static DEFINE_SPINLOCK(lock); static struct trap_info traps[257]; spin_lock(&lock); __get_cpu_var(idt_desc) = *desc; xen_convert_trap_info(desc, traps); xen_mc_flush(); if (HYPERVISOR_set_trap_table(traps)) BUG(); spin_unlock(&lock); } /* Write a GDT descriptor entry. Ignore LDT descriptors, since they're handled differently. */ static void xen_write_gdt_entry(struct desc_struct *dt, int entry, const void *desc, int type) { preempt_disable(); switch (type) { case DESC_LDT: case DESC_TSS: /* ignore */ break; default: { xmaddr_t maddr = virt_to_machine(&dt[entry]); xen_mc_flush(); if (HYPERVISOR_update_descriptor(maddr.maddr, *(u64 *)desc)) BUG(); } } preempt_enable(); } static void xen_load_sp0(struct tss_struct *tss, struct thread_struct *thread) { struct multicall_space mcs = xen_mc_entry(0); MULTI_stack_switch(mcs.mc, __KERNEL_DS, thread->sp0); xen_mc_issue(PARAVIRT_LAZY_CPU); } static void xen_set_iopl_mask(unsigned mask) { struct physdev_set_iopl set_iopl; /* Force the change at ring 0. */ set_iopl.iopl = (mask == 0) ? 1 : (mask >> 12) & 3; HYPERVISOR_physdev_op(PHYSDEVOP_set_iopl, &set_iopl); } static void xen_io_delay(void) { } #ifdef CONFIG_X86_LOCAL_APIC static u32 xen_apic_read(u32 reg) { return 0; } static void xen_apic_write(u32 reg, u32 val) { /* Warn to see if there's any stray references */ WARN_ON(1); } static u64 xen_apic_icr_read(void) { return 0; } static void xen_apic_icr_write(u32 low, u32 id) { /* Warn to see if there's any stray references */ WARN_ON(1); } static void xen_apic_wait_icr_idle(void) { return; } static u32 xen_safe_apic_wait_icr_idle(void) { return 0; } static struct apic_ops xen_basic_apic_ops = { .read = xen_apic_read, .write = xen_apic_write, .icr_read = xen_apic_icr_read, .icr_write = xen_apic_icr_write, .wait_icr_idle = xen_apic_wait_icr_idle, .safe_wait_icr_idle = xen_safe_apic_wait_icr_idle, }; #endif static void xen_flush_tlb(void) { struct mmuext_op *op; struct multicall_space mcs; preempt_disable(); mcs = xen_mc_entry(sizeof(*op)); op = mcs.args; op->cmd = MMUEXT_TLB_FLUSH_LOCAL; MULTI_mmuext_op(mcs.mc, op, 1, NULL, DOMID_SELF); xen_mc_issue(PARAVIRT_LAZY_MMU); preempt_enable(); } static void xen_flush_tlb_single(unsigned long addr) { struct mmuext_op *op; struct multicall_space mcs; preempt_disable(); mcs = xen_mc_entry(sizeof(*op)); op = mcs.args; op->cmd = MMUEXT_INVLPG_LOCAL; op->arg1.linear_addr = addr & PAGE_MASK; MULTI_mmuext_op(mcs.mc, op, 1, NULL, DOMID_SELF); xen_mc_issue(PARAVIRT_LAZY_MMU); preempt_enable(); } static void xen_flush_tlb_others(const cpumask_t *cpus, struct mm_struct *mm, unsigned long va) { struct { struct mmuext_op op; cpumask_t mask; } *args; cpumask_t cpumask = *cpus; struct multicall_space mcs; /* * A couple of (to be removed) sanity checks: * * - current CPU must not be in mask * - mask must exist :) */ BUG_ON(cpus_empty(cpumask)); BUG_ON(cpu_isset(smp_processor_id(), cpumask)); BUG_ON(!mm); /* If a CPU which we ran on has gone down, OK. */ cpus_and(cpumask, cpumask, cpu_online_map); if (cpus_empty(cpumask)) return; mcs = xen_mc_entry(sizeof(*args)); args = mcs.args; args->mask = cpumask; args->op.arg2.vcpumask = &args->mask; if (va == TLB_FLUSH_ALL) { args->op.cmd = MMUEXT_TLB_FLUSH_MULTI; } else { args->op.cmd = MMUEXT_INVLPG_MULTI; args->op.arg1.linear_addr = va; } MULTI_mmuext_op(mcs.mc, &args->op, 1, NULL, DOMID_SELF); xen_mc_issue(PARAVIRT_LAZY_MMU); } static void xen_clts(void) { struct multicall_space mcs; mcs = xen_mc_entry(0); MULTI_fpu_taskswitch(mcs.mc, 0); xen_mc_issue(PARAVIRT_LAZY_CPU); } static void xen_write_cr0(unsigned long cr0) { struct multicall_space mcs; /* Only pay attention to cr0.TS; everything else is ignored. */ mcs = xen_mc_entry(0); MULTI_fpu_taskswitch(mcs.mc, (cr0 & X86_CR0_TS) != 0); xen_mc_issue(PARAVIRT_LAZY_CPU); } static void xen_write_cr2(unsigned long cr2) { x86_read_percpu(xen_vcpu)->arch.cr2 = cr2; } static unsigned long xen_read_cr2(void) { return x86_read_percpu(xen_vcpu)->arch.cr2; } static unsigned long xen_read_cr2_direct(void) { return x86_read_percpu(xen_vcpu_info.arch.cr2); } static void xen_write_cr4(unsigned long cr4) { cr4 &= ~X86_CR4_PGE; cr4 &= ~X86_CR4_PSE; native_write_cr4(cr4); } static unsigned long xen_read_cr3(void) { return x86_read_percpu(xen_cr3); } static void set_current_cr3(void *v) { x86_write_percpu(xen_current_cr3, (unsigned long)v); } static void __xen_write_cr3(bool kernel, unsigned long cr3) { struct mmuext_op *op; struct multicall_space mcs; unsigned long mfn; if (cr3) mfn = pfn_to_mfn(PFN_DOWN(cr3)); else mfn = 0; WARN_ON(mfn == 0 && kernel); mcs = __xen_mc_entry(sizeof(*op)); op = mcs.args; op->cmd = kernel ? MMUEXT_NEW_BASEPTR : MMUEXT_NEW_USER_BASEPTR; op->arg1.mfn = mfn; MULTI_mmuext_op(mcs.mc, op, 1, NULL, DOMID_SELF); if (kernel) { x86_write_percpu(xen_cr3, cr3); /* Update xen_current_cr3 once the batch has actually been submitted. */ xen_mc_callback(set_current_cr3, (void *)cr3); } } static void xen_write_cr3(unsigned long cr3) { BUG_ON(preemptible()); xen_mc_batch(); /* disables interrupts */ /* Update while interrupts are disabled, so its atomic with respect to ipis */ x86_write_percpu(xen_cr3, cr3); __xen_write_cr3(true, cr3); #ifdef CONFIG_X86_64 { pgd_t *user_pgd = xen_get_user_pgd(__va(cr3)); if (user_pgd) __xen_write_cr3(false, __pa(user_pgd)); else __xen_write_cr3(false, 0); } #endif xen_mc_issue(PARAVIRT_LAZY_CPU); /* interrupts restored */ } static int xen_write_msr_safe(unsigned int msr, unsigned low, unsigned high) { int ret; ret = 0; switch(msr) { #ifdef CONFIG_X86_64 unsigned which; u64 base; case MSR_FS_BASE: which = SEGBASE_FS; goto set; case MSR_KERNEL_GS_BASE: which = SEGBASE_GS_USER; goto set; case MSR_GS_BASE: which = SEGBASE_GS_KERNEL; goto set; set: base = ((u64)high << 32) | low; if (HYPERVISOR_set_segment_base(which, base) != 0) ret = -EFAULT; break; #endif case MSR_STAR: case MSR_CSTAR: case MSR_LSTAR: case MSR_SYSCALL_MASK: case MSR_IA32_SYSENTER_CS: case MSR_IA32_SYSENTER_ESP: case MSR_IA32_SYSENTER_EIP: /* Fast syscall setup is all done in hypercalls, so these are all ignored. Stub them out here to stop Xen console noise. */ break; default: ret = native_write_msr_safe(msr, low, high); } return ret; } /* Early in boot, while setting up the initial pagetable, assume everything is pinned. */ static __init void xen_alloc_pte_init(struct mm_struct *mm, unsigned long pfn) { #ifdef CONFIG_FLATMEM BUG_ON(mem_map); /* should only be used early */ #endif make_lowmem_page_readonly(__va(PFN_PHYS(pfn))); } /* Early release_pte assumes that all pts are pinned, since there's only init_mm and anything attached to that is pinned. */ static void xen_release_pte_init(unsigned long pfn) { make_lowmem_page_readwrite(__va(PFN_PHYS(pfn))); } static void pin_pagetable_pfn(unsigned cmd, unsigned long pfn) { struct mmuext_op op; op.cmd = cmd; op.arg1.mfn = pfn_to_mfn(pfn); if (HYPERVISOR_mmuext_op(&op, 1, NULL, DOMID_SELF)) BUG(); } /* This needs to make sure the new pte page is pinned iff its being attached to a pinned pagetable. */ static void xen_alloc_ptpage(struct mm_struct *mm, unsigned long pfn, unsigned level) { struct page *page = pfn_to_page(pfn); if (PagePinned(virt_to_page(mm->pgd))) { SetPagePinned(page); if (!PageHighMem(page)) { make_lowmem_page_readonly(__va(PFN_PHYS((unsigned long)pfn))); if (level == PT_PTE && USE_SPLIT_PTLOCKS) pin_pagetable_pfn(MMUEXT_PIN_L1_TABLE, pfn); } else /* make sure there are no stray mappings of this page */ kmap_flush_unused(); vm_unmap_aliases(); } } static void xen_alloc_pte(struct mm_struct *mm, unsigned long pfn) { xen_alloc_ptpage(mm, pfn, PT_PTE); } static void xen_alloc_pmd(struct mm_struct *mm, unsigned long pfn) { xen_alloc_ptpage(mm, pfn, PT_PMD); } static int xen_pgd_alloc(struct mm_struct *mm) { pgd_t *pgd = mm->pgd; int ret = 0; BUG_ON(PagePinned(virt_to_page(pgd))); #ifdef CONFIG_X86_64 { struct page *page = virt_to_page(pgd); pgd_t *user_pgd; BUG_ON(page->private != 0); ret = -ENOMEM; user_pgd = (pgd_t *)__get_free_page(GFP_KERNEL | __GFP_ZERO); page->private = (unsigned long)user_pgd; if (user_pgd != NULL) { user_pgd[pgd_index(VSYSCALL_START)] = __pgd(__pa(level3_user_vsyscall) | _PAGE_TABLE); ret = 0; } BUG_ON(PagePinned(virt_to_page(xen_get_user_pgd(pgd)))); } #endif return ret; } static void xen_pgd_free(struct mm_struct *mm, pgd_t *pgd) { #ifdef CONFIG_X86_64 pgd_t *user_pgd = xen_get_user_pgd(pgd); if (user_pgd) free_page((unsigned long)user_pgd); #endif } /* This should never happen until we're OK to use struct page */ static void xen_release_ptpage(unsigned long pfn, unsigned level) { struct page *page = pfn_to_page(pfn); if (PagePinned(page)) { if (!PageHighMem(page)) { if (level == PT_PTE && USE_SPLIT_PTLOCKS) pin_pagetable_pfn(MMUEXT_UNPIN_TABLE, pfn); make_lowmem_page_readwrite(__va(PFN_PHYS(pfn))); } ClearPagePinned(page); } } static void xen_release_pte(unsigned long pfn) { xen_release_ptpage(pfn, PT_PTE); } static void xen_release_pmd(unsigned long pfn) { xen_release_ptpage(pfn, PT_PMD); } #if PAGETABLE_LEVELS == 4 static void xen_alloc_pud(struct mm_struct *mm, unsigned long pfn) { xen_alloc_ptpage(mm, pfn, PT_PUD); } static void xen_release_pud(unsigned long pfn) { xen_release_ptpage(pfn, PT_PUD); } #endif #ifdef CONFIG_HIGHPTE static void *xen_kmap_atomic_pte(struct page *page, enum km_type type) { pgprot_t prot = PAGE_KERNEL; if (PagePinned(page)) prot = PAGE_KERNEL_RO; if (0 && PageHighMem(page)) printk("mapping highpte %lx type %d prot %s\n", page_to_pfn(page), type, (unsigned long)pgprot_val(prot) & _PAGE_RW ? "WRITE" : "READ"); return kmap_atomic_prot(page, type, prot); } #endif #ifdef CONFIG_X86_32 static __init pte_t mask_rw_pte(pte_t *ptep, pte_t pte) { /* If there's an existing pte, then don't allow _PAGE_RW to be set */ if (pte_val_ma(*ptep) & _PAGE_PRESENT) pte = __pte_ma(((pte_val_ma(*ptep) & _PAGE_RW) | ~_PAGE_RW) & pte_val_ma(pte)); return pte; } /* Init-time set_pte while constructing initial pagetables, which doesn't allow RO pagetable pages to be remapped RW */ static __init void xen_set_pte_init(pte_t *ptep, pte_t pte) { pte = mask_rw_pte(ptep, pte); xen_set_pte(ptep, pte); } #endif static __init void xen_pagetable_setup_start(pgd_t *base) { } void xen_setup_shared_info(void) { if (!xen_feature(XENFEAT_auto_translated_physmap)) { set_fixmap(FIX_PARAVIRT_BOOTMAP, xen_start_info->shared_info); HYPERVISOR_shared_info = (struct shared_info *)fix_to_virt(FIX_PARAVIRT_BOOTMAP); } else HYPERVISOR_shared_info = (struct shared_info *)__va(xen_start_info->shared_info); #ifndef CONFIG_SMP /* In UP this is as good a place as any to set up shared info */ xen_setup_vcpu_info_placement(); #endif xen_setup_mfn_list_list(); } static __init void xen_pagetable_setup_done(pgd_t *base) { xen_setup_shared_info(); } static __init void xen_post_allocator_init(void) { pv_mmu_ops.set_pte = xen_set_pte; pv_mmu_ops.set_pmd = xen_set_pmd; pv_mmu_ops.set_pud = xen_set_pud; #if PAGETABLE_LEVELS == 4 pv_mmu_ops.set_pgd = xen_set_pgd; #endif /* This will work as long as patching hasn't happened yet (which it hasn't) */ pv_mmu_ops.alloc_pte = xen_alloc_pte; pv_mmu_ops.alloc_pmd = xen_alloc_pmd; pv_mmu_ops.release_pte = xen_release_pte; pv_mmu_ops.release_pmd = xen_release_pmd; #if PAGETABLE_LEVELS == 4 pv_mmu_ops.alloc_pud = xen_alloc_pud; pv_mmu_ops.release_pud = xen_release_pud; #endif #ifdef CONFIG_X86_64 SetPagePinned(virt_to_page(level3_user_vsyscall)); #endif xen_mark_init_mm_pinned(); } /* This is called once we have the cpu_possible_map */ void xen_setup_vcpu_info_placement(void) { int cpu; for_each_possible_cpu(cpu) xen_vcpu_setup(cpu); /* xen_vcpu_setup managed to place the vcpu_info within the percpu area for all cpus, so make use of it */ if (have_vcpu_info_placement) { printk(KERN_INFO "Xen: using vcpu_info placement\n"); pv_irq_ops.save_fl = xen_save_fl_direct; pv_irq_ops.restore_fl = xen_restore_fl_direct; pv_irq_ops.irq_disable = xen_irq_disable_direct; pv_irq_ops.irq_enable = xen_irq_enable_direct; pv_mmu_ops.read_cr2 = xen_read_cr2_direct; } } static unsigned xen_patch(u8 type, u16 clobbers, void *insnbuf, unsigned long addr, unsigned len) { char *start, *end, *reloc; unsigned ret; start = end = reloc = NULL; #define SITE(op, x) \ case PARAVIRT_PATCH(op.x): \ if (have_vcpu_info_placement) { \ start = (char *)xen_##x##_direct; \ end = xen_##x##_direct_end; \ reloc = xen_##x##_direct_reloc; \ } \ goto patch_site switch (type) { SITE(pv_irq_ops, irq_enable); SITE(pv_irq_ops, irq_disable); SITE(pv_irq_ops, save_fl); SITE(pv_irq_ops, restore_fl); #undef SITE patch_site: if (start == NULL || (end-start) > len) goto default_patch; ret = paravirt_patch_insns(insnbuf, len, start, end); /* Note: because reloc is assigned from something that appears to be an array, gcc assumes it's non-null, but doesn't know its relationship with start and end. */ if (reloc > start && reloc < end) { int reloc_off = reloc - start; long *relocp = (long *)(insnbuf + reloc_off); long delta = start - (char *)addr; *relocp += delta; } break; default_patch: default: ret = paravirt_patch_default(type, clobbers, insnbuf, addr, len); break; } return ret; } static void xen_set_fixmap(unsigned idx, unsigned long phys, pgprot_t prot) { pte_t pte; phys >>= PAGE_SHIFT; switch (idx) { case FIX_BTMAP_END ... FIX_BTMAP_BEGIN: #ifdef CONFIG_X86_F00F_BUG case FIX_F00F_IDT: #endif #ifdef CONFIG_X86_32 case FIX_WP_TEST: case FIX_VDSO: # ifdef CONFIG_HIGHMEM case FIX_KMAP_BEGIN ... FIX_KMAP_END: # endif #else case VSYSCALL_LAST_PAGE ... VSYSCALL_FIRST_PAGE: #endif #ifdef CONFIG_X86_LOCAL_APIC case FIX_APIC_BASE: /* maps dummy local APIC */ #endif pte = pfn_pte(phys, prot); break; default: pte = mfn_pte(phys, prot); break; } __native_set_fixmap(idx, pte); #ifdef CONFIG_X86_64 /* Replicate changes to map the vsyscall page into the user pagetable vsyscall mapping. */ if (idx >= VSYSCALL_LAST_PAGE && idx <= VSYSCALL_FIRST_PAGE) { unsigned long vaddr = __fix_to_virt(idx); set_pte_vaddr_pud(level3_user_vsyscall, vaddr, pte); } #endif } static const struct pv_info xen_info __initdata = { .paravirt_enabled = 1, .shared_kernel_pmd = 0, .name = "Xen", }; static const struct pv_init_ops xen_init_ops __initdata = { .patch = xen_patch, .banner = xen_banner, .memory_setup = xen_memory_setup, .arch_setup = xen_arch_setup, .post_allocator_init = xen_post_allocator_init, }; static const struct pv_time_ops xen_time_ops __initdata = { .time_init = xen_time_init, .set_wallclock = xen_set_wallclock, .get_wallclock = xen_get_wallclock, .get_tsc_khz = xen_tsc_khz, .sched_clock = xen_sched_clock, }; static const struct pv_cpu_ops xen_cpu_ops __initdata = { .cpuid = xen_cpuid, .set_debugreg = xen_set_debugreg, .get_debugreg = xen_get_debugreg, .clts = xen_clts, .read_cr0 = native_read_cr0, .write_cr0 = xen_write_cr0, .read_cr4 = native_read_cr4, .read_cr4_safe = native_read_cr4_safe, .write_cr4 = xen_write_cr4, .wbinvd = native_wbinvd, .read_msr = native_read_msr_safe, .write_msr = xen_write_msr_safe, .read_tsc = native_read_tsc, .read_pmc = native_read_pmc, .iret = xen_iret, .irq_enable_sysexit = xen_sysexit, #ifdef CONFIG_X86_64 .usergs_sysret32 = xen_sysret32, .usergs_sysret64 = xen_sysret64, #endif .load_tr_desc = paravirt_nop, .set_ldt = xen_set_ldt, .load_gdt = xen_load_gdt, .load_idt = xen_load_idt, .load_tls = xen_load_tls, #ifdef CONFIG_X86_64 .load_gs_index = xen_load_gs_index, #endif .alloc_ldt = xen_alloc_ldt, .free_ldt = xen_free_ldt, .store_gdt = native_store_gdt, .store_idt = native_store_idt, .store_tr = xen_store_tr, .write_ldt_entry = xen_write_ldt_entry, .write_gdt_entry = xen_write_gdt_entry, .write_idt_entry = xen_write_idt_entry, .load_sp0 = xen_load_sp0, .set_iopl_mask = xen_set_iopl_mask, .io_delay = xen_io_delay, /* Xen takes care of %gs when switching to usermode for us */ .swapgs = paravirt_nop, .lazy_mode = { .enter = paravirt_enter_lazy_cpu, .leave = xen_leave_lazy, }, }; static const struct pv_apic_ops xen_apic_ops __initdata = { #ifdef CONFIG_X86_LOCAL_APIC .setup_boot_clock = paravirt_nop, .setup_secondary_clock = paravirt_nop, .startup_ipi_hook = paravirt_nop, #endif }; static const struct pv_mmu_ops xen_mmu_ops __initdata = { .pagetable_setup_start = xen_pagetable_setup_start, .pagetable_setup_done = xen_pagetable_setup_done, .read_cr2 = xen_read_cr2, .write_cr2 = xen_write_cr2, .read_cr3 = xen_read_cr3, .write_cr3 = xen_write_cr3, .flush_tlb_user = xen_flush_tlb, .flush_tlb_kernel = xen_flush_tlb, .flush_tlb_single = xen_flush_tlb_single, .flush_tlb_others = xen_flush_tlb_others, .pte_update = paravirt_nop, .pte_update_defer = paravirt_nop, .pgd_alloc = xen_pgd_alloc, .pgd_free = xen_pgd_free, .alloc_pte = xen_alloc_pte_init, .release_pte = xen_release_pte_init, .alloc_pmd = xen_alloc_pte_init, .alloc_pmd_clone = paravirt_nop, .release_pmd = xen_release_pte_init, #ifdef CONFIG_HIGHPTE .kmap_atomic_pte = xen_kmap_atomic_pte, #endif #ifdef CONFIG_X86_64 .set_pte = xen_set_pte, #else .set_pte = xen_set_pte_init, #endif .set_pte_at = xen_set_pte_at, .set_pmd = xen_set_pmd_hyper, .ptep_modify_prot_start = __ptep_modify_prot_start, .ptep_modify_prot_commit = __ptep_modify_prot_commit, .pte_val = xen_pte_val, .pte_flags = native_pte_flags, .pgd_val = xen_pgd_val, .make_pte = xen_make_pte, .make_pgd = xen_make_pgd, #ifdef CONFIG_X86_PAE .set_pte_atomic = xen_set_pte_atomic, .set_pte_present = xen_set_pte_at, .pte_clear = xen_pte_clear, .pmd_clear = xen_pmd_clear, #endif /* CONFIG_X86_PAE */ .set_pud = xen_set_pud_hyper, .make_pmd = xen_make_pmd, .pmd_val = xen_pmd_val, #if PAGETABLE_LEVELS == 4 .pud_val = xen_pud_val, .make_pud = xen_make_pud, .set_pgd = xen_set_pgd_hyper, .alloc_pud = xen_alloc_pte_init, .release_pud = xen_release_pte_init, #endif /* PAGETABLE_LEVELS == 4 */ .activate_mm = xen_activate_mm, .dup_mmap = xen_dup_mmap, .exit_mmap = xen_exit_mmap, .lazy_mode = { .enter = paravirt_enter_lazy_mmu, .leave = xen_leave_lazy, }, .set_fixmap = xen_set_fixmap, }; static void xen_reboot(int reason) { struct sched_shutdown r = { .reason = reason }; #ifdef CONFIG_SMP smp_send_stop(); #endif if (HYPERVISOR_sched_op(SCHEDOP_shutdown, &r)) BUG(); } static void xen_restart(char *msg) { xen_reboot(SHUTDOWN_reboot); } static void xen_emergency_restart(void) { xen_reboot(SHUTDOWN_reboot); } static void xen_machine_halt(void) { xen_reboot(SHUTDOWN_poweroff); } static void xen_crash_shutdown(struct pt_regs *regs) { xen_reboot(SHUTDOWN_crash); } static const struct machine_ops __initdata xen_machine_ops = { .restart = xen_restart, .halt = xen_machine_halt, .power_off = xen_machine_halt, .shutdown = xen_machine_halt, .crash_shutdown = xen_crash_shutdown, .emergency_restart = xen_emergency_restart, }; static void __init xen_reserve_top(void) { #ifdef CONFIG_X86_32 unsigned long top = HYPERVISOR_VIRT_START; struct xen_platform_parameters pp; if (HYPERVISOR_xen_version(XENVER_platform_parameters, &pp) == 0) top = pp.virt_start; reserve_top_address(-top); #endif /* CONFIG_X86_32 */ } /* * Like __va(), but returns address in the kernel mapping (which is * all we have until the physical memory mapping has been set up. */ static void *__ka(phys_addr_t paddr) { #ifdef CONFIG_X86_64 return (void *)(paddr + __START_KERNEL_map); #else return __va(paddr); #endif } /* Convert a machine address to physical address */ static unsigned long m2p(phys_addr_t maddr) { phys_addr_t paddr; maddr &= PTE_PFN_MASK; paddr = mfn_to_pfn(maddr >> PAGE_SHIFT) << PAGE_SHIFT; return paddr; } /* Convert a machine address to kernel virtual */ static void *m2v(phys_addr_t maddr) { return __ka(m2p(maddr)); } static void set_page_prot(void *addr, pgprot_t prot) { unsigned long pfn = __pa(addr) >> PAGE_SHIFT; pte_t pte = pfn_pte(pfn, prot); if (HYPERVISOR_update_va_mapping((unsigned long)addr, pte, 0)) BUG(); } static __init void xen_map_identity_early(pmd_t *pmd, unsigned long max_pfn) { unsigned pmdidx, pteidx; unsigned ident_pte; unsigned long pfn; ident_pte = 0; pfn = 0; for(pmdidx = 0; pmdidx < PTRS_PER_PMD && pfn < max_pfn; pmdidx++) { pte_t *pte_page; /* Reuse or allocate a page of ptes */ if (pmd_present(pmd[pmdidx])) pte_page = m2v(pmd[pmdidx].pmd); else { /* Check for free pte pages */ if (ident_pte == ARRAY_SIZE(level1_ident_pgt)) break; pte_page = &level1_ident_pgt[ident_pte]; ident_pte += PTRS_PER_PTE; pmd[pmdidx] = __pmd(__pa(pte_page) | _PAGE_TABLE); } /* Install mappings */ for(pteidx = 0; pteidx < PTRS_PER_PTE; pteidx++, pfn++) { pte_t pte; if (pfn > max_pfn_mapped) max_pfn_mapped = pfn; if (!pte_none(pte_page[pteidx])) continue; pte = pfn_pte(pfn, PAGE_KERNEL_EXEC); pte_page[pteidx] = pte; } } for(pteidx = 0; pteidx < ident_pte; pteidx += PTRS_PER_PTE) set_page_prot(&level1_ident_pgt[pteidx], PAGE_KERNEL_RO); set_page_prot(pmd, PAGE_KERNEL_RO); } #ifdef CONFIG_X86_64 static void convert_pfn_mfn(void *v) { pte_t *pte = v; int i; /* All levels are converted the same way, so just treat them as ptes. */ for(i = 0; i < PTRS_PER_PTE; i++) pte[i] = xen_make_pte(pte[i].pte); } /* * Set up the inital kernel pagetable. * * We can construct this by grafting the Xen provided pagetable into * head_64.S's preconstructed pagetables. We copy the Xen L2's into * level2_ident_pgt, level2_kernel_pgt and level2_fixmap_pgt. This * means that only the kernel has a physical mapping to start with - * but that's enough to get __va working. We need to fill in the rest * of the physical mapping once some sort of allocator has been set * up. */ static __init pgd_t *xen_setup_kernel_pagetable(pgd_t *pgd, unsigned long max_pfn) { pud_t *l3; pmd_t *l2; /* Zap identity mapping */ init_level4_pgt[0] = __pgd(0); /* Pre-constructed entries are in pfn, so convert to mfn */ convert_pfn_mfn(init_level4_pgt); convert_pfn_mfn(level3_ident_pgt); convert_pfn_mfn(level3_kernel_pgt); l3 = m2v(pgd[pgd_index(__START_KERNEL_map)].pgd); l2 = m2v(l3[pud_index(__START_KERNEL_map)].pud); memcpy(level2_ident_pgt, l2, sizeof(pmd_t) * PTRS_PER_PMD); memcpy(level2_kernel_pgt, l2, sizeof(pmd_t) * PTRS_PER_PMD); l3 = m2v(pgd[pgd_index(__START_KERNEL_map + PMD_SIZE)].pgd); l2 = m2v(l3[pud_index(__START_KERNEL_map + PMD_SIZE)].pud); memcpy(level2_fixmap_pgt, l2, sizeof(pmd_t) * PTRS_PER_PMD); /* Set up identity map */ xen_map_identity_early(level2_ident_pgt, max_pfn); /* Make pagetable pieces RO */ set_page_prot(init_level4_pgt, PAGE_KERNEL_RO); set_page_prot(level3_ident_pgt, PAGE_KERNEL_RO); set_page_prot(level3_kernel_pgt, PAGE_KERNEL_RO); set_page_prot(level3_user_vsyscall, PAGE_KERNEL_RO); set_page_prot(level2_kernel_pgt, PAGE_KERNEL_RO); set_page_prot(level2_fixmap_pgt, PAGE_KERNEL_RO); /* Pin down new L4 */ pin_pagetable_pfn(MMUEXT_PIN_L4_TABLE, PFN_DOWN(__pa_symbol(init_level4_pgt))); /* Unpin Xen-provided one */ pin_pagetable_pfn(MMUEXT_UNPIN_TABLE, PFN_DOWN(__pa(pgd))); /* Switch over */ pgd = init_level4_pgt; /* * At this stage there can be no user pgd, and no page * structure to attach it to, so make sure we just set kernel * pgd. */ xen_mc_batch(); __xen_write_cr3(true, __pa(pgd)); xen_mc_issue(PARAVIRT_LAZY_CPU); reserve_early(__pa(xen_start_info->pt_base), __pa(xen_start_info->pt_base + xen_start_info->nr_pt_frames * PAGE_SIZE), "XEN PAGETABLES"); return pgd; } #else /* !CONFIG_X86_64 */ static pmd_t level2_kernel_pgt[PTRS_PER_PMD] __page_aligned_bss; static __init pgd_t *xen_setup_kernel_pagetable(pgd_t *pgd, unsigned long max_pfn) { pmd_t *kernel_pmd; init_pg_tables_start = __pa(pgd); init_pg_tables_end = __pa(pgd) + xen_start_info->nr_pt_frames*PAGE_SIZE; max_pfn_mapped = PFN_DOWN(init_pg_tables_end + 512*1024); kernel_pmd = m2v(pgd[KERNEL_PGD_BOUNDARY].pgd); memcpy(level2_kernel_pgt, kernel_pmd, sizeof(pmd_t) * PTRS_PER_PMD); xen_map_identity_early(level2_kernel_pgt, max_pfn); memcpy(swapper_pg_dir, pgd, sizeof(pgd_t) * PTRS_PER_PGD); set_pgd(&swapper_pg_dir[KERNEL_PGD_BOUNDARY], __pgd(__pa(level2_kernel_pgt) | _PAGE_PRESENT)); set_page_prot(level2_kernel_pgt, PAGE_KERNEL_RO); set_page_prot(swapper_pg_dir, PAGE_KERNEL_RO); set_page_prot(empty_zero_page, PAGE_KERNEL_RO); pin_pagetable_pfn(MMUEXT_UNPIN_TABLE, PFN_DOWN(__pa(pgd))); xen_write_cr3(__pa(swapper_pg_dir)); pin_pagetable_pfn(MMUEXT_PIN_L3_TABLE, PFN_DOWN(__pa(swapper_pg_dir))); return swapper_pg_dir; } #endif /* CONFIG_X86_64 */ /* First C function to be called on Xen boot */ asmlinkage void __init xen_start_kernel(void) { pgd_t *pgd; if (!xen_start_info) return; xen_domain_type = XEN_PV_DOMAIN; BUG_ON(memcmp(xen_start_info->magic, "xen-3", 5) != 0); xen_setup_features(); /* Install Xen paravirt ops */ pv_info = xen_info; pv_init_ops = xen_init_ops; pv_time_ops = xen_time_ops; pv_cpu_ops = xen_cpu_ops; pv_apic_ops = xen_apic_ops; pv_mmu_ops = xen_mmu_ops; xen_init_irq_ops(); #ifdef CONFIG_X86_LOCAL_APIC /* * set up the basic apic ops. */ apic_ops = &xen_basic_apic_ops; #endif if (xen_feature(XENFEAT_mmu_pt_update_preserve_ad)) { pv_mmu_ops.ptep_modify_prot_start = xen_ptep_modify_prot_start; pv_mmu_ops.ptep_modify_prot_commit = xen_ptep_modify_prot_commit; } machine_ops = xen_machine_ops; #ifdef CONFIG_X86_64 /* Disable until direct per-cpu data access. */ have_vcpu_info_placement = 0; x86_64_init_pda(); #endif xen_smp_init(); /* Get mfn list */ if (!xen_feature(XENFEAT_auto_translated_physmap)) xen_build_dynamic_phys_to_machine(); pgd = (pgd_t *)xen_start_info->pt_base; /* Prevent unwanted bits from being set in PTEs. */ __supported_pte_mask &= ~_PAGE_GLOBAL; if (!xen_initial_domain()) __supported_pte_mask &= ~(_PAGE_PWT | _PAGE_PCD); /* Don't do the full vcpu_info placement stuff until we have a possible map and a non-dummy shared_info. */ per_cpu(xen_vcpu, 0) = &HYPERVISOR_shared_info->vcpu_info[0]; xen_raw_console_write("mapping kernel into physical memory\n"); pgd = xen_setup_kernel_pagetable(pgd, xen_start_info->nr_pages); init_mm.pgd = pgd; /* keep using Xen gdt for now; no urgent need to change it */ pv_info.kernel_rpl = 1; if (xen_feature(XENFEAT_supervisor_mode_kernel)) pv_info.kernel_rpl = 0; /* set the limit of our address space */ xen_reserve_top(); #ifdef CONFIG_X86_32 /* set up basic CPUID stuff */ cpu_detect(&new_cpu_data); new_cpu_data.hard_math = 1; new_cpu_data.x86_capability[0] = cpuid_edx(1); #endif /* Poke various useful things into boot_params */ boot_params.hdr.type_of_loader = (9 << 4) | 0; boot_params.hdr.ramdisk_image = xen_start_info->mod_start ? __pa(xen_start_info->mod_start) : 0; boot_params.hdr.ramdisk_size = xen_start_info->mod_len; boot_params.hdr.cmd_line_ptr = __pa(xen_start_info->cmd_line); if (!xen_initial_domain()) { add_preferred_console("xenboot", 0, NULL); add_preferred_console("tty", 0, NULL); add_preferred_console("hvc", 0, NULL); } xen_raw_console_write("about to get started...\n"); /* Start the world */ #ifdef CONFIG_X86_32 i386_start_kernel(); #else x86_64_start_reservations((char *)__pa_symbol(&boot_params)); #endif }