/* * 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 #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #ifdef CONFIG_ACPI #include #include #include #include #include #endif #include "xen-ops.h" #include "mmu.h" #include "smp.h" #include "multicalls.h" EXPORT_SYMBOL_GPL(hypercall_page); /* * Pointer to the xen_vcpu_info structure or * &HYPERVISOR_shared_info->vcpu_info[cpu]. See xen_hvm_init_shared_info * and xen_vcpu_setup for details. By default it points to share_info->vcpu_info * but if the hypervisor supports VCPUOP_register_vcpu_info then it can point * to xen_vcpu_info. The pointer is used in __xen_evtchn_do_upcall to * acknowledge pending events. * Also more subtly it is used by the patched version of irq enable/disable * e.g. xen_irq_enable_direct and xen_iret in PV mode. * * The desire to be able to do those mask/unmask operations as a single * instruction by using the per-cpu offset held in %gs is the real reason * vcpu info is in a per-cpu pointer and the original reason for this * hypercall. * */ DEFINE_PER_CPU(struct vcpu_info *, xen_vcpu); /* * Per CPU pages used if hypervisor supports VCPUOP_register_vcpu_info * hypercall. This can be used both in PV and PVHVM mode. The structure * overrides the default per_cpu(xen_vcpu, cpu) value. */ DEFINE_PER_CPU(struct vcpu_info, xen_vcpu_info); enum xen_domain_type xen_domain_type = XEN_NATIVE; EXPORT_SYMBOL_GPL(xen_domain_type); unsigned long *machine_to_phys_mapping = (void *)MACH2PHYS_VIRT_START; EXPORT_SYMBOL(machine_to_phys_mapping); unsigned long machine_to_phys_nr; EXPORT_SYMBOL(machine_to_phys_nr); struct start_info *xen_start_info; EXPORT_SYMBOL_GPL(xen_start_info); struct shared_info xen_dummy_shared_info; void *xen_initial_gdt; RESERVE_BRK(shared_info_page_brk, PAGE_SIZE); __read_mostly int xen_have_vector_callback; EXPORT_SYMBOL_GPL(xen_have_vector_callback); /* * 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 = &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 = 1; struct tls_descs { struct desc_struct desc[3]; }; /* * Updating the 3 TLS descriptors in the GDT on every task switch is * surprisingly expensive so we avoid updating them if they haven't * changed. Since Xen writes different descriptors than the one * passed in the update_descriptor hypercall we keep shadow copies to * compare against. */ static DEFINE_PER_CPU(struct tls_descs, shadow_tls_desc); static void clamp_max_cpus(void) { #ifdef CONFIG_SMP if (setup_max_cpus > MAX_VIRT_CPUS) setup_max_cpus = MAX_VIRT_CPUS; #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); /* * This path is called twice on PVHVM - first during bootup via * smp_init -> xen_hvm_cpu_notify, and then if the VCPU is being * hotplugged: cpu_up -> xen_hvm_cpu_notify. * As we can only do the VCPUOP_register_vcpu_info once lets * not over-write its result. * * For PV it is called during restore (xen_vcpu_restore) and bootup * (xen_setup_vcpu_info_placement). The hotplug mechanism does not * use this function. */ if (xen_hvm_domain()) { if (per_cpu(xen_vcpu, cpu) == &per_cpu(xen_vcpu_info, cpu)) return; } if (cpu < MAX_VIRT_CPUS) per_cpu(xen_vcpu,cpu) = &HYPERVISOR_shared_info->vcpu_info[cpu]; if (!have_vcpu_info_placement) { if (cpu >= MAX_VIRT_CPUS) clamp_max_cpus(); return; } vcpup = &per_cpu(xen_vcpu_info, cpu); info.mfn = arbitrary_virt_to_mfn(vcpup); info.offset = offset_in_page(vcpup); /* Check to see if the hypervisor will put the vcpu_info structure where we want it, which allows direct access via a percpu-variable. N.B. This hypercall can _only_ be called once per CPU. Subsequent calls will error out with -EINVAL. This is due to the fact that hypervisor has no unregister variant and this hypercall does not allow to over-write info.mfn and info.offset. */ 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; clamp_max_cpus(); } else { /* This cpu is using the registered vcpu info, even if later ones fail to. */ per_cpu(xen_vcpu, 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) { int cpu; for_each_possible_cpu(cpu) { bool other_cpu = (cpu != smp_processor_id()); bool is_up = HYPERVISOR_vcpu_op(VCPUOP_is_up, cpu, NULL); if (other_cpu && is_up && HYPERVISOR_vcpu_op(VCPUOP_down, cpu, NULL)) BUG(); xen_setup_runstate_info(cpu); if (have_vcpu_info_placement) xen_vcpu_setup(cpu); if (other_cpu && is_up && HYPERVISOR_vcpu_op(VCPUOP_up, cpu, NULL)) BUG(); } } static void __init xen_banner(void) { unsigned version = HYPERVISOR_xen_version(XENVER_version, NULL); struct xen_extraversion extra; HYPERVISOR_xen_version(XENVER_extraversion, &extra); pr_info("Booting paravirtualized kernel %son %s\n", xen_feature(XENFEAT_auto_translated_physmap) ? "with PVH extensions " : "", 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)" : ""); } /* Check if running on Xen version (major, minor) or later */ bool xen_running_on_version_or_later(unsigned int major, unsigned int minor) { unsigned int version; if (!xen_domain()) return false; version = HYPERVISOR_xen_version(XENVER_version, NULL); if ((((version >> 16) == major) && ((version & 0xffff) >= minor)) || ((version >> 16) > major)) return true; return false; } #define CPUID_THERM_POWER_LEAF 6 #define APERFMPERF_PRESENT 0 static __read_mostly unsigned int cpuid_leaf1_edx_mask = ~0; static __read_mostly unsigned int cpuid_leaf1_ecx_mask = ~0; static __read_mostly unsigned int cpuid_leaf1_ecx_set_mask; static __read_mostly unsigned int cpuid_leaf5_ecx_val; static __read_mostly unsigned int cpuid_leaf5_edx_val; static void xen_cpuid(unsigned int *ax, unsigned int *bx, unsigned int *cx, unsigned int *dx) { unsigned maskebx = ~0; unsigned maskecx = ~0; unsigned maskedx = ~0; unsigned setecx = 0; /* * Mask out inconvenient features, to try and disable as many * unsupported kernel subsystems as possible. */ switch (*ax) { case 1: maskecx = cpuid_leaf1_ecx_mask; setecx = cpuid_leaf1_ecx_set_mask; maskedx = cpuid_leaf1_edx_mask; break; case CPUID_MWAIT_LEAF: /* Synthesize the values.. */ *ax = 0; *bx = 0; *cx = cpuid_leaf5_ecx_val; *dx = cpuid_leaf5_edx_val; return; case CPUID_THERM_POWER_LEAF: /* Disabling APERFMPERF for kernel usage */ maskecx = ~(1 << APERFMPERF_PRESENT); break; case 0xb: /* Suppress extended topology stuff */ maskebx = 0; break; } asm(XEN_EMULATE_PREFIX "cpuid" : "=a" (*ax), "=b" (*bx), "=c" (*cx), "=d" (*dx) : "0" (*ax), "2" (*cx)); *bx &= maskebx; *cx &= maskecx; *cx |= setecx; *dx &= maskedx; } static bool __init xen_check_mwait(void) { #ifdef CONFIG_ACPI struct xen_platform_op op = { .cmd = XENPF_set_processor_pminfo, .u.set_pminfo.id = -1, .u.set_pminfo.type = XEN_PM_PDC, }; uint32_t buf[3]; unsigned int ax, bx, cx, dx; unsigned int mwait_mask; /* We need to determine whether it is OK to expose the MWAIT * capability to the kernel to harvest deeper than C3 states from ACPI * _CST using the processor_harvest_xen.c module. For this to work, we * need to gather the MWAIT_LEAF values (which the cstate.c code * checks against). The hypervisor won't expose the MWAIT flag because * it would break backwards compatibility; so we will find out directly * from the hardware and hypercall. */ if (!xen_initial_domain()) return false; /* * When running under platform earlier than Xen4.2, do not expose * mwait, to avoid the risk of loading native acpi pad driver */ if (!xen_running_on_version_or_later(4, 2)) return false; ax = 1; cx = 0; native_cpuid(&ax, &bx, &cx, &dx); mwait_mask = (1 << (X86_FEATURE_EST % 32)) | (1 << (X86_FEATURE_MWAIT % 32)); if ((cx & mwait_mask) != mwait_mask) return false; /* We need to emulate the MWAIT_LEAF and for that we need both * ecx and edx. The hypercall provides only partial information. */ ax = CPUID_MWAIT_LEAF; bx = 0; cx = 0; dx = 0; native_cpuid(&ax, &bx, &cx, &dx); /* Ask the Hypervisor whether to clear ACPI_PDC_C_C2C3_FFH. If so, * don't expose MWAIT_LEAF and let ACPI pick the IOPORT version of C3. */ buf[0] = ACPI_PDC_REVISION_ID; buf[1] = 1; buf[2] = (ACPI_PDC_C_CAPABILITY_SMP | ACPI_PDC_EST_CAPABILITY_SWSMP); set_xen_guest_handle(op.u.set_pminfo.pdc, buf); if ((HYPERVISOR_dom0_op(&op) == 0) && (buf[2] & (ACPI_PDC_C_C1_FFH | ACPI_PDC_C_C2C3_FFH))) { cpuid_leaf5_ecx_val = cx; cpuid_leaf5_edx_val = dx; } return true; #else return false; #endif } static void __init xen_init_cpuid_mask(void) { unsigned int ax, bx, cx, dx; unsigned int xsave_mask; cpuid_leaf1_edx_mask = ~((1 << X86_FEATURE_MTRR) | /* disable MTRR */ (1 << X86_FEATURE_ACC)); /* thermal monitoring */ if (!xen_initial_domain()) cpuid_leaf1_edx_mask &= ~((1 << X86_FEATURE_ACPI)); /* disable ACPI */ cpuid_leaf1_ecx_mask &= ~(1 << (X86_FEATURE_X2APIC % 32)); ax = 1; cx = 0; cpuid(1, &ax, &bx, &cx, &dx); xsave_mask = (1 << (X86_FEATURE_XSAVE % 32)) | (1 << (X86_FEATURE_OSXSAVE % 32)); /* Xen will set CR4.OSXSAVE if supported and not disabled by force */ if ((cx & xsave_mask) != xsave_mask) cpuid_leaf1_ecx_mask &= ~xsave_mask; /* disable XSAVE & OSXSAVE */ if (xen_check_mwait()) cpuid_leaf1_ecx_set_mask = (1 << (X86_FEATURE_MWAIT % 32)); } 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_end_context_switch(struct task_struct *next) { xen_mc_flush(); paravirt_end_context_switch(next); } 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)); trace_xen_cpu_set_ldt(addr, entries); 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 va = dtr->address; unsigned int size = dtr->size + 1; unsigned pages = (size + PAGE_SIZE - 1) / PAGE_SIZE; unsigned long frames[pages]; int f; /* * 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); for (f = 0; va < dtr->address + size; va += PAGE_SIZE, f++) { int level; pte_t *ptep; unsigned long pfn, mfn; void *virt; /* * The GDT is per-cpu and is in the percpu data area. * That can be virtually mapped, so we need to do a * page-walk to get the underlying MFN for the * hypercall. The page can also be in the kernel's * linear range, so we need to RO that mapping too. */ ptep = lookup_address(va, &level); BUG_ON(ptep == NULL); pfn = pte_pfn(*ptep); mfn = pfn_to_mfn(pfn); virt = __va(PFN_PHYS(pfn)); frames[f] = mfn; make_lowmem_page_readonly((void *)va); make_lowmem_page_readonly(virt); } if (HYPERVISOR_set_gdt(frames, size / sizeof(struct desc_struct))) BUG(); } /* * load_gdt for early boot, when the gdt is only mapped once */ static void __init xen_load_gdt_boot(const struct desc_ptr *dtr) { unsigned long va = dtr->address; unsigned int size = dtr->size + 1; unsigned pages = (size + PAGE_SIZE - 1) / PAGE_SIZE; unsigned long frames[pages]; int f; /* * 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); for (f = 0; va < dtr->address + size; va += PAGE_SIZE, f++) { pte_t pte; unsigned long pfn, mfn; pfn = virt_to_pfn(va); mfn = pfn_to_mfn(pfn); pte = pfn_pte(pfn, PAGE_KERNEL_RO); if (HYPERVISOR_update_va_mapping((unsigned long)va, pte, 0)) BUG(); frames[f] = mfn; } if (HYPERVISOR_set_gdt(frames, size / sizeof(struct desc_struct))) BUG(); } static inline bool desc_equal(const struct desc_struct *d1, const struct desc_struct *d2) { return d1->a == d2->a && d1->b == d2->b; } static void load_TLS_descriptor(struct thread_struct *t, unsigned int cpu, unsigned int i) { struct desc_struct *shadow = &per_cpu(shadow_tls_desc, cpu).desc[i]; struct desc_struct *gdt; xmaddr_t maddr; struct multicall_space mc; if (desc_equal(shadow, &t->tls_array[i])) return; *shadow = t->tls_array[i]; gdt = get_cpu_gdt_table(cpu); maddr = arbitrary_virt_to_machine(&gdt[GDT_ENTRY_TLS_MIN+i]); 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 * and lazy gs handling is enabled, 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 lazy_load_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; trace_xen_cpu_write_ldt_entry(dt, entrynum, entry); 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) { unsigned long addr; if (val->type != GATE_TRAP && val->type != GATE_INTERRUPT) return 0; info->vector = vector; addr = gate_offset(*val); #ifdef CONFIG_X86_64 /* * Look for known traps using IST, and substitute them * appropriately. The debugger ones are the only ones we care * about. Xen will handle faults like double_fault, * so we should never see them. Warn if * there's an unexpected IST-using fault handler. */ if (addr == (unsigned long)debug) addr = (unsigned long)xen_debug; else if (addr == (unsigned long)int3) addr = (unsigned long)xen_int3; else if (addr == (unsigned long)stack_segment) addr = (unsigned long)xen_stack_segment; else if (addr == (unsigned long)double_fault) { /* Don't need to handle these */ return 0; #ifdef CONFIG_X86_MCE } else if (addr == (unsigned long)machine_check) { /* * when xen hypervisor inject vMCE to guest, * use native mce handler to handle it */ ; #endif } else if (addr == (unsigned long)nmi) /* * Use the native version as well. */ ; else { /* Some other trap using IST? */ if (WARN_ON(val->ist != 0)) return 0; } #endif /* CONFIG_X86_64 */ info->address = addr; info->cs = gate_segment(*val); info->flags = val->dpl; /* interrupt gates clear IF */ if (val->type == GATE_INTERRUPT) info->flags |= 1 << 2; 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; trace_xen_cpu_write_idt_entry(dt, entrynum, g); preempt_disable(); start = __this_cpu_read(idt_desc.address); end = start + __this_cpu_read(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]; trace_xen_cpu_load_idt(desc); 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) { trace_xen_cpu_write_gdt_entry(dt, entry, desc, type); preempt_disable(); switch (type) { case DESC_LDT: case DESC_TSS: /* ignore */ break; default: { xmaddr_t maddr = arbitrary_virt_to_machine(&dt[entry]); xen_mc_flush(); if (HYPERVISOR_update_descriptor(maddr.maddr, *(u64 *)desc)) BUG(); } } preempt_enable(); } /* * Version of write_gdt_entry for use at early boot-time needed to * update an entry as simply as possible. */ static void __init xen_write_gdt_entry_boot(struct desc_struct *dt, int entry, const void *desc, int type) { trace_xen_cpu_write_gdt_entry(dt, entry, desc, type); switch (type) { case DESC_LDT: case DESC_TSS: /* ignore */ break; default: { xmaddr_t maddr = virt_to_machine(&dt[entry]); if (HYPERVISOR_update_descriptor(maddr.maddr, *(u64 *)desc)) dt[entry] = *(struct desc_struct *)desc; } } } static void xen_load_sp0(struct tss_struct *tss, struct thread_struct *thread) { struct multicall_space mcs; 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 unsigned long xen_set_apic_id(unsigned int x) { WARN_ON(1); return x; } static unsigned int xen_get_apic_id(unsigned long x) { return ((x)>>24) & 0xFFu; } static u32 xen_apic_read(u32 reg) { struct xen_platform_op op = { .cmd = XENPF_get_cpuinfo, .interface_version = XENPF_INTERFACE_VERSION, .u.pcpu_info.xen_cpuid = 0, }; int ret = 0; /* Shouldn't need this as APIC is turned off for PV, and we only * get called on the bootup processor. But just in case. */ if (!xen_initial_domain() || smp_processor_id()) return 0; if (reg == APIC_LVR) return 0x10; if (reg != APIC_ID) return 0; ret = HYPERVISOR_dom0_op(&op); if (ret) return 0; return op.u.pcpu_info.apic_id << 24; } 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 void set_xen_basic_apic_ops(void) { apic->read = xen_apic_read; apic->write = xen_apic_write; apic->icr_read = xen_apic_icr_read; apic->icr_write = xen_apic_icr_write; apic->wait_icr_idle = xen_apic_wait_icr_idle; apic->safe_wait_icr_idle = xen_safe_apic_wait_icr_idle; apic->set_apic_id = xen_set_apic_id; apic->get_apic_id = xen_get_apic_id; #ifdef CONFIG_SMP apic->send_IPI_allbutself = xen_send_IPI_allbutself; apic->send_IPI_mask_allbutself = xen_send_IPI_mask_allbutself; apic->send_IPI_mask = xen_send_IPI_mask; apic->send_IPI_all = xen_send_IPI_all; apic->send_IPI_self = xen_send_IPI_self; #endif } #endif 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 DEFINE_PER_CPU(unsigned long, xen_cr0_value); static unsigned long xen_read_cr0(void) { unsigned long cr0 = this_cpu_read(xen_cr0_value); if (unlikely(cr0 == 0)) { cr0 = native_read_cr0(); this_cpu_write(xen_cr0_value, cr0); } return cr0; } static void xen_write_cr0(unsigned long cr0) { struct multicall_space mcs; this_cpu_write(xen_cr0_value, cr0); /* 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_cr4(unsigned long cr4) { cr4 &= ~X86_CR4_PGE; cr4 &= ~X86_CR4_PSE; native_write_cr4(cr4); } #ifdef CONFIG_X86_64 static inline unsigned long xen_read_cr8(void) { return 0; } static inline void xen_write_cr8(unsigned long val) { BUG_ON(val); } #endif 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 = -EIO; 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; case MSR_IA32_CR_PAT: if (smp_processor_id() == 0) xen_set_pat(((u64)high << 32) | low); break; default: ret = native_write_msr_safe(msr, low, high); } return ret; } 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(); } /* This is called once we have the cpu_possible_mask */ 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) { pv_irq_ops.save_fl = __PV_IS_CALLEE_SAVE(xen_save_fl_direct); pv_irq_ops.restore_fl = __PV_IS_CALLEE_SAVE(xen_restore_fl_direct); pv_irq_ops.irq_disable = __PV_IS_CALLEE_SAVE(xen_irq_disable_direct); pv_irq_ops.irq_enable = __PV_IS_CALLEE_SAVE(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 const struct pv_info xen_info __initconst = { .paravirt_enabled = 1, .shared_kernel_pmd = 0, #ifdef CONFIG_X86_64 .extra_user_64bit_cs = FLAT_USER_CS64, #endif .name = "Xen", }; static const struct pv_init_ops xen_init_ops __initconst = { .patch = xen_patch, }; static const struct pv_cpu_ops xen_cpu_ops __initconst = { .cpuid = xen_cpuid, .set_debugreg = xen_set_debugreg, .get_debugreg = xen_get_debugreg, .clts = xen_clts, .read_cr0 = xen_read_cr0, .write_cr0 = xen_write_cr0, .read_cr4 = native_read_cr4, .read_cr4_safe = native_read_cr4_safe, .write_cr4 = xen_write_cr4, #ifdef CONFIG_X86_64 .read_cr8 = xen_read_cr8, .write_cr8 = xen_write_cr8, #endif .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, .read_tscp = native_read_tscp, .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_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, .start_context_switch = paravirt_start_context_switch, .end_context_switch = xen_end_context_switch, }; static const struct pv_apic_ops xen_apic_ops __initconst = { #ifdef CONFIG_X86_LOCAL_APIC .startup_ipi_hook = paravirt_nop, #endif }; static void xen_reboot(int reason) { struct sched_shutdown r = { .reason = reason }; 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_machine_power_off(void) { if (pm_power_off) pm_power_off(); xen_reboot(SHUTDOWN_poweroff); } static void xen_crash_shutdown(struct pt_regs *regs) { xen_reboot(SHUTDOWN_crash); } static int xen_panic_event(struct notifier_block *this, unsigned long event, void *ptr) { xen_reboot(SHUTDOWN_crash); return NOTIFY_DONE; } static struct notifier_block xen_panic_block = { .notifier_call= xen_panic_event, }; int xen_panic_handler_init(void) { atomic_notifier_chain_register(&panic_notifier_list, &xen_panic_block); return 0; } static const struct machine_ops xen_machine_ops __initconst = { .restart = xen_restart, .halt = xen_machine_halt, .power_off = xen_machine_power_off, .shutdown = xen_machine_halt, .crash_shutdown = xen_crash_shutdown, .emergency_restart = xen_emergency_restart, }; static void __init xen_boot_params_init_edd(void) { #if IS_ENABLED(CONFIG_EDD) struct xen_platform_op op; struct edd_info *edd_info; u32 *mbr_signature; unsigned nr; int ret; edd_info = boot_params.eddbuf; mbr_signature = boot_params.edd_mbr_sig_buffer; op.cmd = XENPF_firmware_info; op.u.firmware_info.type = XEN_FW_DISK_INFO; for (nr = 0; nr < EDDMAXNR; nr++) { struct edd_info *info = edd_info + nr; op.u.firmware_info.index = nr; info->params.length = sizeof(info->params); set_xen_guest_handle(op.u.firmware_info.u.disk_info.edd_params, &info->params); ret = HYPERVISOR_dom0_op(&op); if (ret) break; #define C(x) info->x = op.u.firmware_info.u.disk_info.x C(device); C(version); C(interface_support); C(legacy_max_cylinder); C(legacy_max_head); C(legacy_sectors_per_track); #undef C } boot_params.eddbuf_entries = nr; op.u.firmware_info.type = XEN_FW_DISK_MBR_SIGNATURE; for (nr = 0; nr < EDD_MBR_SIG_MAX; nr++) { op.u.firmware_info.index = nr; ret = HYPERVISOR_dom0_op(&op); if (ret) break; mbr_signature[nr] = op.u.firmware_info.u.disk_mbr_signature.mbr_signature; } boot_params.edd_mbr_sig_buf_entries = nr; #endif } /* * Set up the GDT and segment registers for -fstack-protector. Until * we do this, we have to be careful not to call any stack-protected * function, which is most of the kernel. */ static void __init xen_setup_stackprotector(void) { pv_cpu_ops.write_gdt_entry = xen_write_gdt_entry_boot; pv_cpu_ops.load_gdt = xen_load_gdt_boot; setup_stack_canary_segment(0); switch_to_new_gdt(0); pv_cpu_ops.write_gdt_entry = xen_write_gdt_entry; pv_cpu_ops.load_gdt = xen_load_gdt; } static void __init xen_pvh_early_guest_init(void) { if (!xen_feature(XENFEAT_auto_translated_physmap)) return; if (xen_feature(XENFEAT_hvm_callback_vector)) xen_have_vector_callback = 1; #ifdef CONFIG_X86_32 BUG(); /* PVH: Implement proper support. */ #endif } /* First C function to be called on Xen boot */ asmlinkage void __init xen_start_kernel(void) { struct physdev_set_iopl set_iopl; int rc; if (!xen_start_info) return; xen_domain_type = XEN_PV_DOMAIN; xen_setup_features(); xen_pvh_early_guest_init(); xen_setup_machphys_mapping(); /* Install Xen paravirt ops */ pv_info = xen_info; pv_init_ops = xen_init_ops; pv_apic_ops = xen_apic_ops; if (!xen_pvh_domain()) pv_cpu_ops = xen_cpu_ops; x86_init.resources.memory_setup = xen_memory_setup; x86_init.oem.arch_setup = xen_arch_setup; x86_init.oem.banner = xen_banner; xen_init_time_ops(); /* * Set up some pagetable state before starting to set any ptes. */ xen_init_mmu_ops(); /* Prevent unwanted bits from being set in PTEs. */ __supported_pte_mask &= ~_PAGE_GLOBAL; #if 0 if (!xen_initial_domain()) #endif __supported_pte_mask &= ~(_PAGE_PWT | _PAGE_PCD); __supported_pte_mask |= _PAGE_IOMAP; /* * Prevent page tables from being allocated in highmem, even * if CONFIG_HIGHPTE is enabled. */ __userpte_alloc_gfp &= ~__GFP_HIGHMEM; /* Work out if we support NX */ x86_configure_nx(); /* Get mfn list */ xen_build_dynamic_phys_to_machine(); /* * Set up kernel GDT and segment registers, mainly so that * -fstack-protector code can be executed. */ xen_setup_stackprotector(); xen_init_irq_ops(); xen_init_cpuid_mask(); #ifdef CONFIG_X86_LOCAL_APIC /* * set up the basic apic ops. */ set_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; /* * The only reliable way to retain the initial address of the * percpu gdt_page is to remember it here, so we can go and * mark it RW later, when the initial percpu area is freed. */ xen_initial_gdt = &per_cpu(gdt_page, 0); xen_smp_init(); #ifdef CONFIG_ACPI_NUMA /* * The pages we from Xen are not related to machine pages, so * any NUMA information the kernel tries to get from ACPI will * be meaningless. Prevent it from trying. */ acpi_numa = -1; #endif #ifdef CONFIG_X86_PAT /* * For right now disable the PAT. We should remove this once * git commit 8eaffa67b43e99ae581622c5133e20b0f48bcef1 * (xen/pat: Disable PAT support for now) is reverted. */ pat_enabled = 0; #endif /* 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]; local_irq_disable(); early_boot_irqs_disabled = true; xen_raw_console_write("mapping kernel into physical memory\n"); xen_setup_kernel_pagetable((pgd_t *)xen_start_info->pt_base, xen_start_info->nr_pages); /* Allocate and initialize top and mid mfn levels for p2m structure */ xen_build_mfn_list_list(); /* keep using Xen gdt for now; no urgent need to change it */ #ifdef CONFIG_X86_32 pv_info.kernel_rpl = 1; if (xen_feature(XENFEAT_supervisor_mode_kernel)) pv_info.kernel_rpl = 0; #else pv_info.kernel_rpl = 0; #endif /* set the limit of our address space */ xen_reserve_top(); /* PVH: runs at default kernel iopl of 0 */ if (!xen_pvh_domain()) { /* * We used to do this in xen_arch_setup, but that is too late * on AMD were early_cpu_init (run before ->arch_setup()) calls * early_amd_init which pokes 0xcf8 port. */ set_iopl.iopl = 1; rc = HYPERVISOR_physdev_op(PHYSDEVOP_set_iopl, &set_iopl); if (rc != 0) xen_raw_printk("physdev_op failed %d\n", rc); } #ifdef CONFIG_X86_32 /* set up basic CPUID stuff */ cpu_detect(&new_cpu_data); set_cpu_cap(&new_cpu_data, X86_FEATURE_FPU); new_cpu_data.wp_works_ok = 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); if (pci_xen) x86_init.pci.arch_init = pci_xen_init; } else { const struct dom0_vga_console_info *info = (void *)((char *)xen_start_info + xen_start_info->console.dom0.info_off); struct xen_platform_op op = { .cmd = XENPF_firmware_info, .interface_version = XENPF_INTERFACE_VERSION, .u.firmware_info.type = XEN_FW_KBD_SHIFT_FLAGS, }; xen_init_vga(info, xen_start_info->console.dom0.info_size); xen_start_info->console.domU.mfn = 0; xen_start_info->console.domU.evtchn = 0; if (HYPERVISOR_dom0_op(&op) == 0) boot_params.kbd_status = op.u.firmware_info.u.kbd_shift_flags; xen_init_apic(); /* Make sure ACS will be enabled */ pci_request_acs(); xen_acpi_sleep_register(); /* Avoid searching for BIOS MP tables */ x86_init.mpparse.find_smp_config = x86_init_noop; x86_init.mpparse.get_smp_config = x86_init_uint_noop; xen_boot_params_init_edd(); } #ifdef CONFIG_PCI /* PCI BIOS service won't work from a PV guest. */ pci_probe &= ~PCI_PROBE_BIOS; #endif xen_raw_console_write("about to get started...\n"); xen_setup_runstate_info(0); /* Start the world */ #ifdef CONFIG_X86_32 i386_start_kernel(); #else x86_64_start_reservations((char *)__pa_symbol(&boot_params)); #endif } void __ref xen_hvm_init_shared_info(void) { int cpu; struct xen_add_to_physmap xatp; static struct shared_info *shared_info_page = 0; if (!shared_info_page) shared_info_page = (struct shared_info *) extend_brk(PAGE_SIZE, PAGE_SIZE); xatp.domid = DOMID_SELF; xatp.idx = 0; xatp.space = XENMAPSPACE_shared_info; xatp.gpfn = __pa(shared_info_page) >> PAGE_SHIFT; if (HYPERVISOR_memory_op(XENMEM_add_to_physmap, &xatp)) BUG(); HYPERVISOR_shared_info = (struct shared_info *)shared_info_page; /* xen_vcpu is a pointer to the vcpu_info struct in the shared_info * page, we use it in the event channel upcall and in some pvclock * related functions. We don't need the vcpu_info placement * optimizations because we don't use any pv_mmu or pv_irq op on * HVM. * When xen_hvm_init_shared_info is run at boot time only vcpu 0 is * online but xen_hvm_init_shared_info is run at resume time too and * in that case multiple vcpus might be online. */ for_each_online_cpu(cpu) { /* Leave it to be NULL. */ if (cpu >= MAX_VIRT_CPUS) continue; per_cpu(xen_vcpu, cpu) = &HYPERVISOR_shared_info->vcpu_info[cpu]; } } #ifdef CONFIG_XEN_PVHVM static void __init init_hvm_pv_info(void) { int major, minor; uint32_t eax, ebx, ecx, edx, pages, msr, base; u64 pfn; base = xen_cpuid_base(); cpuid(base + 1, &eax, &ebx, &ecx, &edx); major = eax >> 16; minor = eax & 0xffff; printk(KERN_INFO "Xen version %d.%d.\n", major, minor); cpuid(base + 2, &pages, &msr, &ecx, &edx); pfn = __pa(hypercall_page); wrmsr_safe(msr, (u32)pfn, (u32)(pfn >> 32)); xen_setup_features(); pv_info.name = "Xen HVM"; xen_domain_type = XEN_HVM_DOMAIN; } static int xen_hvm_cpu_notify(struct notifier_block *self, unsigned long action, void *hcpu) { int cpu = (long)hcpu; switch (action) { case CPU_UP_PREPARE: xen_vcpu_setup(cpu); if (xen_have_vector_callback) { if (xen_feature(XENFEAT_hvm_safe_pvclock)) xen_setup_timer(cpu); } break; default: break; } return NOTIFY_OK; } static struct notifier_block xen_hvm_cpu_notifier = { .notifier_call = xen_hvm_cpu_notify, }; static void __init xen_hvm_guest_init(void) { init_hvm_pv_info(); xen_hvm_init_shared_info(); xen_panic_handler_init(); if (xen_feature(XENFEAT_hvm_callback_vector)) xen_have_vector_callback = 1; xen_hvm_smp_init(); register_cpu_notifier(&xen_hvm_cpu_notifier); xen_unplug_emulated_devices(); x86_init.irqs.intr_init = xen_init_IRQ; xen_hvm_init_time_ops(); xen_hvm_init_mmu_ops(); } static uint32_t __init xen_hvm_platform(void) { if (xen_pv_domain()) return 0; return xen_cpuid_base(); } bool xen_hvm_need_lapic(void) { if (xen_pv_domain()) return false; if (!xen_hvm_domain()) return false; if (xen_feature(XENFEAT_hvm_pirqs) && xen_have_vector_callback) return false; return true; } EXPORT_SYMBOL_GPL(xen_hvm_need_lapic); const struct hypervisor_x86 x86_hyper_xen_hvm __refconst = { .name = "Xen HVM", .detect = xen_hvm_platform, .init_platform = xen_hvm_guest_init, .x2apic_available = xen_x2apic_para_available, }; EXPORT_SYMBOL(x86_hyper_xen_hvm); #endif