示例#1
0
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 = lookup_address(va, &level);
		unsigned long pfn, mfn;
		void *virt;

		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();
}
示例#2
0
pte_t *pte_alloc_one_kernel(struct mm_struct *mm, unsigned long address)
{
	pte_t *pte = (pte_t *)__get_free_page(GFP_KERNEL|__GFP_REPEAT|__GFP_ZERO);
	if (pte)
		make_lowmem_page_readonly(pte, XENFEAT_writable_page_tables);
	return pte;
}
示例#3
0
static __cpuinit int
cpu_initialize_context(unsigned int cpu, struct task_struct *idle)
{
	struct vcpu_guest_context *ctxt;
	struct desc_struct *gdt;

	if (cpu_test_and_set(cpu, xen_cpu_initialized_map))
		return 0;

	ctxt = kzalloc(sizeof(*ctxt), GFP_KERNEL);
	if (ctxt == NULL)
		return -ENOMEM;

	gdt = get_cpu_gdt_table(cpu);

	ctxt->flags = VGCF_IN_KERNEL;
	ctxt->user_regs.ds = __KERNEL_DS;
	ctxt->user_regs.es = __KERNEL_DS;
	ctxt->user_regs.ss = __KERNEL_DS;
#ifdef CONFIG_X86_32
	ctxt->user_regs.fs = __KERNEL_PERCPU;
#endif
	ctxt->user_regs.eip = (unsigned long)cpu_bringup_and_idle;
	ctxt->user_regs.eflags = 0x1000; /* IOPL_RING1 */

	memset(&ctxt->fpu_ctxt, 0, sizeof(ctxt->fpu_ctxt));

	xen_copy_trap_info(ctxt->trap_ctxt);

	ctxt->ldt_ents = 0;

	BUG_ON((unsigned long)gdt & ~PAGE_MASK);
	make_lowmem_page_readonly(gdt);

	ctxt->gdt_frames[0] = virt_to_mfn(gdt);
	ctxt->gdt_ents      = GDT_ENTRIES;

	ctxt->user_regs.cs = __KERNEL_CS;
	ctxt->user_regs.esp = idle->thread.sp0 - sizeof(struct pt_regs);

	ctxt->kernel_ss = __KERNEL_DS;
	ctxt->kernel_sp = idle->thread.sp0;

#ifdef CONFIG_X86_32
	ctxt->event_callback_cs     = __KERNEL_CS;
	ctxt->failsafe_callback_cs  = __KERNEL_CS;
#endif
	ctxt->event_callback_eip    = (unsigned long)xen_hypervisor_callback;
	ctxt->failsafe_callback_eip = (unsigned long)xen_failsafe_callback;

	per_cpu(xen_cr3, cpu) = __pa(swapper_pg_dir);
	ctxt->ctrlreg[3] = xen_pfn_to_cr3(virt_to_mfn(swapper_pg_dir));

	if (HYPERVISOR_vcpu_op(VCPUOP_initialise, cpu, ctxt))
		BUG();

	kfree(ctxt);
	return 0;
}
示例#4
0
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();
}
示例#5
0
pgd_t *pgd_alloc(struct mm_struct *mm)
{
	int i;
	pgd_t *pgd = kmem_cache_alloc(pgd_cache, GFP_KERNEL);

	pgd_test_and_unpin(pgd);

	if (PTRS_PER_PMD == 1 || !pgd)
		return pgd;

	for (i = 0; i < USER_PTRS_PER_PGD; ++i) {
		pmd_t *pmd = kmem_cache_alloc(pmd_cache, GFP_KERNEL);
		if (!pmd)
			goto out_oom;
		set_pgd(&pgd[i], __pgd(1 + __pa(pmd)));
	}

	if (!HAVE_SHARED_KERNEL_PMD) {
		unsigned long flags;

		for (i = USER_PTRS_PER_PGD; i < PTRS_PER_PGD; i++) {
			pmd_t *pmd = kmem_cache_alloc(pmd_cache, GFP_KERNEL);
			if (!pmd)
				goto out_oom;
			set_pgd(&pgd[i], __pgd(1 + __pa(pmd)));
		}

		spin_lock_irqsave(&pgd_lock, flags);
		for (i = USER_PTRS_PER_PGD; i < PTRS_PER_PGD; i++) {
			unsigned long v = (unsigned long)i << PGDIR_SHIFT;
			pgd_t *kpgd = pgd_offset_k(v);
			pud_t *kpud = pud_offset(kpgd, v);
			pmd_t *kpmd = pmd_offset(kpud, v);
			pmd_t *pmd = (void *)__va(pgd_val(pgd[i])-1);
			memcpy(pmd, kpmd, PAGE_SIZE);
			make_lowmem_page_readonly(
				pmd, XENFEAT_writable_page_tables);
		}
		pgd_list_add(pgd);
		spin_unlock_irqrestore(&pgd_lock, flags);
	}

	return pgd;

out_oom:
	for (i--; i >= 0; i--)
		kmem_cache_free(pmd_cache, (void *)__va(pgd_val(pgd[i])-1));
	kmem_cache_free(pgd_cache, pgd);
	return NULL;
}
示例#6
0
void make_page_readonly(void *va, unsigned int feature)
{
	pte_t *pte;
	int rc;

	if (xen_feature(feature))
		return;

	pte = virt_to_ptep(va);
	rc = HYPERVISOR_update_va_mapping(
		(unsigned long)va, pte_wrprotect(*pte), 0);
	if (rc) /* fallback? */
		xen_l1_entry_update(pte, pte_wrprotect(*pte));
	if ((unsigned long)va >= (unsigned long)high_memory) {
		unsigned long pfn = pte_pfn(*pte);
#ifdef CONFIG_HIGHMEM
		if (pfn >= highstart_pfn)
			kmap_flush_unused(); /* flush stale writable kmaps */
		else
#endif
			make_lowmem_page_readonly(
				phys_to_virt(pfn << PAGE_SHIFT), feature); 
	}
}
示例#7
0
static int
cpu_initialize_context(unsigned int cpu, struct task_struct *idle)
{
	struct vcpu_guest_context *ctxt;
	struct desc_struct *gdt;
	unsigned long gdt_mfn;

	/* used to tell cpu_init() that it can proceed with initialization */
	cpumask_set_cpu(cpu, cpu_callout_mask);
	if (cpumask_test_and_set_cpu(cpu, xen_cpu_initialized_map))
		return 0;

	ctxt = kzalloc(sizeof(*ctxt), GFP_KERNEL);
	if (ctxt == NULL)
		return -ENOMEM;

	gdt = get_cpu_gdt_rw(cpu);

#ifdef CONFIG_X86_32
	ctxt->user_regs.fs = __KERNEL_PERCPU;
	ctxt->user_regs.gs = __KERNEL_STACK_CANARY;
#endif
	memset(&ctxt->fpu_ctxt, 0, sizeof(ctxt->fpu_ctxt));

	/*
	 * Bring up the CPU in cpu_bringup_and_idle() with the stack
	 * pointing just below where pt_regs would be if it were a normal
	 * kernel entry.
	 */
	ctxt->user_regs.eip = (unsigned long)cpu_bringup_and_idle;
	ctxt->flags = VGCF_IN_KERNEL;
	ctxt->user_regs.eflags = 0x1000; /* IOPL_RING1 */
	ctxt->user_regs.ds = __USER_DS;
	ctxt->user_regs.es = __USER_DS;
	ctxt->user_regs.ss = __KERNEL_DS;
	ctxt->user_regs.cs = __KERNEL_CS;
	ctxt->user_regs.esp = (unsigned long)task_pt_regs(idle);

	xen_copy_trap_info(ctxt->trap_ctxt);

	ctxt->ldt_ents = 0;

	BUG_ON((unsigned long)gdt & ~PAGE_MASK);

	gdt_mfn = arbitrary_virt_to_mfn(gdt);
	make_lowmem_page_readonly(gdt);
	make_lowmem_page_readonly(mfn_to_virt(gdt_mfn));

	ctxt->gdt_frames[0] = gdt_mfn;
	ctxt->gdt_ents      = GDT_ENTRIES;

	/*
	 * Set SS:SP that Xen will use when entering guest kernel mode
	 * from guest user mode.  Subsequent calls to load_sp0() can
	 * change this value.
	 */
	ctxt->kernel_ss = __KERNEL_DS;
	ctxt->kernel_sp = task_top_of_stack(idle);

#ifdef CONFIG_X86_32
	ctxt->event_callback_cs     = __KERNEL_CS;
	ctxt->failsafe_callback_cs  = __KERNEL_CS;
#else
	ctxt->gs_base_kernel = per_cpu_offset(cpu);
#endif
	ctxt->event_callback_eip    =
		(unsigned long)xen_hypervisor_callback;
	ctxt->failsafe_callback_eip =
		(unsigned long)xen_failsafe_callback;
	per_cpu(xen_cr3, cpu) = __pa(swapper_pg_dir);

	ctxt->ctrlreg[3] = xen_pfn_to_cr3(virt_to_gfn(swapper_pg_dir));
	if (HYPERVISOR_vcpu_op(VCPUOP_initialise, xen_vcpu_nr(cpu), ctxt))
		BUG();

	kfree(ctxt);
	return 0;
}
示例#8
0
文件: smp.c 项目: mbgg/linux
static int __cpuinit
cpu_initialize_context(unsigned int cpu, struct task_struct *idle)
{
	struct vcpu_guest_context *ctxt;
	struct desc_struct *gdt;
	unsigned long gdt_mfn;

	if (cpumask_test_and_set_cpu(cpu, xen_cpu_initialized_map))
		return 0;

	ctxt = kzalloc(sizeof(*ctxt), GFP_KERNEL);
	if (ctxt == NULL)
		return -ENOMEM;

	gdt = get_cpu_gdt_table(cpu);

	ctxt->flags = VGCF_IN_KERNEL;
	ctxt->user_regs.ss = __KERNEL_DS;
#ifdef CONFIG_X86_32
	ctxt->user_regs.fs = __KERNEL_PERCPU;
	ctxt->user_regs.gs = __KERNEL_STACK_CANARY;
#else
	ctxt->gs_base_kernel = per_cpu_offset(cpu);
#endif
	ctxt->user_regs.eip = (unsigned long)cpu_bringup_and_idle;

	memset(&ctxt->fpu_ctxt, 0, sizeof(ctxt->fpu_ctxt));

	if (xen_feature(XENFEAT_auto_translated_physmap) &&
	    xen_feature(XENFEAT_supervisor_mode_kernel)) {
		/* Note: PVH is not supported on x86_32. */
#ifdef CONFIG_X86_64
		ctxt->user_regs.ds = __KERNEL_DS;
		ctxt->user_regs.es = 0;
		ctxt->user_regs.gs = 0;

		/* GUEST_GDTR_BASE and */
		ctxt->u.pvh.gdtaddr = (unsigned long)gdt;
		/* GUEST_GDTR_LIMIT in the VMCS. */
		ctxt->u.pvh.gdtsz = (unsigned long)(GDT_SIZE - 1);

		ctxt->gs_base_user = (unsigned long)
					per_cpu(irq_stack_union.gs_base, cpu);
#endif
	} else {
		ctxt->user_regs.eflags = 0x1000; /* IOPL_RING1 */
		ctxt->user_regs.ds = __USER_DS;
		ctxt->user_regs.es = __USER_DS;

		xen_copy_trap_info(ctxt->trap_ctxt);

		ctxt->ldt_ents = 0;

		BUG_ON((unsigned long)gdt & ~PAGE_MASK);

		gdt_mfn = arbitrary_virt_to_mfn(gdt);
		make_lowmem_page_readonly(gdt);
		make_lowmem_page_readonly(mfn_to_virt(gdt_mfn));

		ctxt->u.pv.gdt_frames[0] = gdt_mfn;
		ctxt->u.pv.gdt_ents      = GDT_ENTRIES;

		ctxt->kernel_ss = __KERNEL_DS;
		ctxt->kernel_sp = idle->thread.sp0;

#ifdef CONFIG_X86_32
		ctxt->event_callback_cs     = __KERNEL_CS;
		ctxt->failsafe_callback_cs  = __KERNEL_CS;
#endif
		ctxt->event_callback_eip    =
					(unsigned long)xen_hypervisor_callback;
		ctxt->failsafe_callback_eip =
					(unsigned long)xen_failsafe_callback;
	}
	ctxt->user_regs.cs = __KERNEL_CS;
	ctxt->user_regs.esp = idle->thread.sp0 - sizeof(struct pt_regs);

	per_cpu(xen_cr3, cpu) = __pa(swapper_pg_dir);
	ctxt->ctrlreg[3] = xen_pfn_to_cr3(virt_to_mfn(swapper_pg_dir));

	if (HYPERVISOR_vcpu_op(VCPUOP_initialise, cpu, ctxt))
		BUG();

	kfree(ctxt);
	return 0;
}
示例#9
0
void __init xen_start_kernel(void)
{
	unsigned int i;
	struct xen_machphys_mapping mapping;
	unsigned long machine_to_phys_nr_ents;
#ifdef CONFIG_X86_32
	struct xen_platform_parameters pp;
	extern pte_t swapper_pg_fixmap[PTRS_PER_PTE];
	unsigned long addr;
#endif

	xen_setup_features();

	if (HYPERVISOR_memory_op(XENMEM_machphys_mapping, &mapping) == 0) {
		machine_to_phys_mapping = (unsigned long *)mapping.v_start;
		machine_to_phys_nr_ents = mapping.max_mfn + 1;
	} else
		machine_to_phys_nr_ents = MACH2PHYS_NR_ENTRIES;
	while ((1UL << machine_to_phys_order) < machine_to_phys_nr_ents )
		machine_to_phys_order++;

	if (!xen_feature(XENFEAT_auto_translated_physmap))
		phys_to_machine_mapping =
			(unsigned long *)xen_start_info->mfn_list;

	WARN_ON(HYPERVISOR_vm_assist(VMASST_CMD_enable,
				     VMASST_TYPE_writable_pagetables));

	reserve_early(ALIGN(__pa_symbol(&_end), PAGE_SIZE),
		      __pa(xen_start_info->pt_base)
		      + (xen_start_info->nr_pt_frames << PAGE_SHIFT),
		      "Xen provided");

#ifdef CONFIG_X86_32
	WARN_ON(HYPERVISOR_vm_assist(VMASST_CMD_enable,
				     VMASST_TYPE_4gb_segments));

	init_mm.pgd = swapper_pg_dir = (pgd_t *)xen_start_info->pt_base;

	if (HYPERVISOR_xen_version(XENVER_platform_parameters, &pp) == 0) {
		hypervisor_virt_start = pp.virt_start;
		reserve_top_address(0UL - pp.virt_start);
	}

	BUG_ON(pte_index(hypervisor_virt_start));

	/* Do an early initialization of the fixmap area */
	make_lowmem_page_readonly(swapper_pg_fixmap, XENFEAT_writable_page_tables);
	addr = __fix_to_virt(FIX_EARLYCON_MEM_BASE);
	set_pmd(pmd_offset(pud_offset(swapper_pg_dir + pgd_index(addr),
				      addr),
			   addr),
		__pmd(__pa_symbol(swapper_pg_fixmap) | _PAGE_TABLE));
#else
	check_efer();
	xen_init_pt();
#endif

#define __FIXADDR_TOP (-PAGE_SIZE)
#define pmd_index(addr) (((addr) >> PMD_SHIFT) & (PTRS_PER_PMD - 1))
#define FIX_BUG_ON(fix) BUILD_BUG_ON(pmd_index(__fix_to_virt(FIX_##fix)) \
			!= pmd_index(__fix_to_virt(FIX_EARLYCON_MEM_BASE)))
	FIX_BUG_ON(SHARED_INFO);
	FIX_BUG_ON(ISAMAP_BEGIN);
	FIX_BUG_ON(ISAMAP_END);
#undef pmd_index
#undef __FIXADDR_TOP

	/* Switch to the real shared_info page, and clear the dummy page. */
	set_fixmap(FIX_SHARED_INFO, xen_start_info->shared_info);
	HYPERVISOR_shared_info = (shared_info_t *)fix_to_virt(FIX_SHARED_INFO);
	memset(empty_zero_page, 0, sizeof(empty_zero_page));

	setup_vcpu_info(0);

	/* Set up mapping of lowest 1MB of physical memory. */
	for (i = 0; i < NR_FIX_ISAMAPS; i++)
		if (is_initial_xendomain())
			set_fixmap(FIX_ISAMAP_BEGIN - i, i * PAGE_SIZE);
		else
			__set_fixmap(FIX_ISAMAP_BEGIN - i,
				     virt_to_machine(empty_zero_page),
				     PAGE_KERNEL_RO);

}
示例#10
0
static int
cpu_initialize_context(unsigned int cpu, struct task_struct *idle)
{
	struct vcpu_guest_context *ctxt;
	struct desc_struct *gdt;
	unsigned long gdt_mfn;

	/* used to tell cpu_init() that it can proceed with initialization */
	cpumask_set_cpu(cpu, cpu_callout_mask);
	if (cpumask_test_and_set_cpu(cpu, xen_cpu_initialized_map))
		return 0;

	ctxt = kzalloc(sizeof(*ctxt), GFP_KERNEL);
	if (ctxt == NULL)
		return -ENOMEM;

	gdt = get_cpu_gdt_rw(cpu);

#ifdef CONFIG_X86_32
	ctxt->user_regs.fs = __KERNEL_PERCPU;
	ctxt->user_regs.gs = __KERNEL_STACK_CANARY;
#endif
	memset(&ctxt->fpu_ctxt, 0, sizeof(ctxt->fpu_ctxt));

	ctxt->user_regs.eip = (unsigned long)cpu_bringup_and_idle;
	ctxt->flags = VGCF_IN_KERNEL;
	ctxt->user_regs.eflags = 0x1000; /* IOPL_RING1 */
	ctxt->user_regs.ds = __USER_DS;
	ctxt->user_regs.es = __USER_DS;
	ctxt->user_regs.ss = __KERNEL_DS;

	xen_copy_trap_info(ctxt->trap_ctxt);

	ctxt->ldt_ents = 0;

	BUG_ON((unsigned long)gdt & ~PAGE_MASK);

	gdt_mfn = arbitrary_virt_to_mfn(gdt);
	make_lowmem_page_readonly(gdt);
	make_lowmem_page_readonly(mfn_to_virt(gdt_mfn));

	ctxt->gdt_frames[0] = gdt_mfn;
	ctxt->gdt_ents      = GDT_ENTRIES;

	ctxt->kernel_ss = __KERNEL_DS;
	ctxt->kernel_sp = idle->thread.sp0;

#ifdef CONFIG_X86_32
	ctxt->event_callback_cs     = __KERNEL_CS;
	ctxt->failsafe_callback_cs  = __KERNEL_CS;
#else
	ctxt->gs_base_kernel = per_cpu_offset(cpu);
#endif
	ctxt->event_callback_eip    =
		(unsigned long)xen_hypervisor_callback;
	ctxt->failsafe_callback_eip =
		(unsigned long)xen_failsafe_callback;
	ctxt->user_regs.cs = __KERNEL_CS;
	per_cpu(xen_cr3, cpu) = __pa(swapper_pg_dir);

	ctxt->user_regs.esp = idle->thread.sp0 - sizeof(struct pt_regs);
	ctxt->ctrlreg[3] = xen_pfn_to_cr3(virt_to_gfn(swapper_pg_dir));
	if (HYPERVISOR_vcpu_op(VCPUOP_initialise, xen_vcpu_nr(cpu), ctxt))
		BUG();

	kfree(ctxt);
	return 0;
}