| /* |
| * 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 <jeremy@xensource.com>, XenSource Inc, 2007 |
| */ |
| |
| #include <linux/kernel.h> |
| #include <linux/init.h> |
| #include <linux/smp.h> |
| #include <linux/preempt.h> |
| #include <linux/hardirq.h> |
| #include <linux/percpu.h> |
| #include <linux/delay.h> |
| #include <linux/start_kernel.h> |
| #include <linux/sched.h> |
| #include <linux/kprobes.h> |
| #include <linux/bootmem.h> |
| #include <linux/module.h> |
| #include <linux/mm.h> |
| #include <linux/page-flags.h> |
| #include <linux/highmem.h> |
| #include <linux/console.h> |
| #include <linux/pci.h> |
| |
| #include <xen/xen.h> |
| #include <xen/interface/xen.h> |
| #include <xen/interface/version.h> |
| #include <xen/interface/physdev.h> |
| #include <xen/interface/vcpu.h> |
| #include <xen/features.h> |
| #include <xen/page.h> |
| #include <xen/hvc-console.h> |
| |
| #include <asm/paravirt.h> |
| #include <asm/apic.h> |
| #include <asm/page.h> |
| #include <asm/xen/hypercall.h> |
| #include <asm/xen/hypervisor.h> |
| #include <asm/fixmap.h> |
| #include <asm/processor.h> |
| #include <asm/proto.h> |
| #include <asm/msr-index.h> |
| #include <asm/traps.h> |
| #include <asm/setup.h> |
| #include <asm/desc.h> |
| #include <asm/pgtable.h> |
| #include <asm/tlbflush.h> |
| #include <asm/reboot.h> |
| #include <asm/stackprotector.h> |
| |
| #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); |
| |
| struct start_info *xen_start_info; |
| EXPORT_SYMBOL_GPL(xen_start_info); |
| |
| struct shared_info xen_dummy_shared_info; |
| |
| void *xen_initial_gdt; |
| |
| /* |
| * 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 = 1; |
| |
| 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 = arbitrary_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 __read_mostly unsigned int cpuid_leaf1_edx_mask = ~0; |
| static __read_mostly unsigned int cpuid_leaf1_ecx_mask = ~0; |
| |
| static void xen_cpuid(unsigned int *ax, unsigned int *bx, |
| unsigned int *cx, unsigned int *dx) |
| { |
| unsigned maskecx = ~0; |
| unsigned maskedx = ~0; |
| |
| /* |
| * Mask out inconvenient features, to try and disable as many |
| * unsupported kernel subsystems as possible. |
| */ |
| if (*ax == 1) { |
| maskecx = cpuid_leaf1_ecx_mask; |
| maskedx = cpuid_leaf1_edx_mask; |
| } |
| |
| asm(XEN_EMULATE_PREFIX "cpuid" |
| : "=a" (*ax), |
| "=b" (*bx), |
| "=c" (*cx), |
| "=d" (*dx) |
| : "0" (*ax), "2" (*cx)); |
| |
| *cx &= maskecx; |
| *dx &= maskedx; |
| } |
| |
| static __init void xen_init_cpuid_mask(void) |
| { |
| unsigned int ax, bx, cx, dx; |
| |
| cpuid_leaf1_edx_mask = |
| ~((1 << X86_FEATURE_MCE) | /* disable MCE */ |
| (1 << X86_FEATURE_MCA) | /* disable MCA */ |
| (1 << X86_FEATURE_ACC)); /* thermal monitoring */ |
| |
| if (!xen_initial_domain()) |
| cpuid_leaf1_edx_mask &= |
| ~((1 << X86_FEATURE_APIC) | /* disable local APIC */ |
| (1 << X86_FEATURE_ACPI)); /* disable ACPI */ |
| |
| ax = 1; |
| cx = 0; |
| xen_cpuid(&ax, &bx, &cx, &dx); |
| |
| /* cpuid claims we support xsave; try enabling it to see what happens */ |
| if (cx & (1 << (X86_FEATURE_XSAVE % 32))) { |
| unsigned long cr4; |
| |
| set_in_cr4(X86_CR4_OSXSAVE); |
| |
| cr4 = read_cr4(); |
| |
| if ((cr4 & X86_CR4_OSXSAVE) == 0) |
| cpuid_leaf1_ecx_mask &= ~(1 << (X86_FEATURE_XSAVE % 32)); |
| |
| clear_in_cr4(X86_CR4_OSXSAVE); |
| } |
| } |
| |
| 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)); |
| |
| 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 __init void 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 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 = arbitrary_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 |
| * 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; |
| |
| 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 and |
| * machine_check, 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 || |
| addr == (unsigned long)nmi) { |
| /* Don't need to handle these */ |
| return 0; |
| #ifdef CONFIG_X86_MCE |
| } else if (addr == (unsigned long)machine_check) { |
| return 0; |
| #endif |
| } 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; |
| |
| 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 = 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 __init void xen_write_gdt_entry_boot(struct desc_struct *dt, int entry, |
| const void *desc, int 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 = 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 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; |
| } |
| |
| #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 = percpu_read(xen_cr0_value); |
| |
| if (unlikely(cr0 == 0)) { |
| cr0 = native_read_cr0(); |
| percpu_write(xen_cr0_value, cr0); |
| } |
| |
| return cr0; |
| } |
| |
| static void xen_write_cr0(unsigned long cr0) |
| { |
| struct multicall_space mcs; |
| |
| percpu_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); |
| } |
| |
| 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; |
| |
| 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_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 = __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 __initdata = { |
| .paravirt_enabled = 1, |
| .shared_kernel_pmd = 0, |
| |
| .name = "Xen", |
| }; |
| |
| static const struct pv_init_ops xen_init_ops __initdata = { |
| .patch = xen_patch, |
| }; |
| |
| static const struct pv_time_ops xen_time_ops __initdata = { |
| .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 = 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, |
| |
| .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, |
| |
| .start_context_switch = paravirt_start_context_switch, |
| .end_context_switch = xen_end_context_switch, |
| }; |
| |
| static const struct pv_apic_ops xen_apic_ops __initdata = { |
| #ifdef CONFIG_X86_LOCAL_APIC |
| .startup_ipi_hook = paravirt_nop, |
| #endif |
| }; |
| |
| 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, |
| }; |
| |
| /* |
| * 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; |
| } |
| |
| /* 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; |
| |
| /* 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; |
| |
| x86_init.resources.memory_setup = xen_memory_setup; |
| x86_init.oem.arch_setup = xen_arch_setup; |
| x86_init.oem.banner = xen_banner; |
| |
| x86_init.timers.timer_init = xen_time_init; |
| x86_init.timers.setup_percpu_clockev = x86_init_noop; |
| x86_cpuinit.setup_percpu_clockev = x86_init_noop; |
| |
| x86_platform.calibrate_tsc = xen_tsc_khz; |
| x86_platform.get_wallclock = xen_get_wallclock; |
| x86_platform.set_wallclock = xen_set_wallclock; |
| |
| /* |
| * 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 (!xen_initial_domain()) |
| __supported_pte_mask &= ~(_PAGE_PWT | _PAGE_PCD); |
| |
| __supported_pte_mask |= _PAGE_IOMAP; |
| |
| #ifdef CONFIG_X86_64 |
| /* Work out if we support NX */ |
| check_efer(); |
| #endif |
| |
| xen_setup_features(); |
| |
| /* Get mfn list */ |
| if (!xen_feature(XENFEAT_auto_translated_physmap)) |
| 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(); |
| |
| pgd = (pgd_t *)xen_start_info->pt_base; |
| |
| /* 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_off(); |
| |
| 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.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); |
| } else { |
| /* Make sure ACS will be enabled */ |
| pci_request_acs(); |
| } |
| |
| |
| 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 |
| } |