5 #include <linux/types.h>
6 #include <linux/init.h>
7 #include <linux/stringify.h>
8 #include <linux/lguest.h>
9 #include <linux/lguest_launcher.h>
10 #include <linux/wait.h>
11 #include <linux/err.h>
12 #include <asm/semaphore.h>
14 #include <asm/lguest.h>
16 void free_pagetables(void);
17 int init_pagetables(struct page **switcher_page, unsigned int pages);
25 /* We have two pages shared with guests, per cpu. */
28 /* This is the stack page mapped rw in guest */
29 char spare[PAGE_SIZE - sizeof(struct lguest_regs)];
30 struct lguest_regs regs;
32 /* This is the host state & guest descriptor page, ro in guest */
33 struct lguest_ro_state state;
34 } __attribute__((aligned(PAGE_SIZE)));
38 #define CHANGED_GDT_TLS 4 /* Actually a subset of CHANGED_GDT */
46 struct task_struct *tsk;
47 struct mm_struct *mm; /* == tsk->mm, but that becomes NULL on exit */
54 /* At end of a page shared mapped over lguest_pages in guest. */
55 unsigned long regs_page;
56 struct lguest_regs *regs;
58 /* If a hypercall was asked for, this points to the arguments. */
59 struct hcall_args *hcall;
62 /* Virtual clock device */
65 /* Do we need to stop what we're doing and return to userspace? */
67 wait_queue_head_t break_wq;
70 /* Pending virtual interrupts */
71 DECLARE_BITMAP(irqs_pending, LGUEST_IRQS);
73 struct lg_cpu_arch arch;
76 /* The private info the thread maintains about the guest. */
79 struct lguest_data __user *lguest_data;
80 struct lg_cpu cpus[NR_CPUS];
84 /* This provides the offset to the base of guest-physical
85 * memory in the Launcher. */
86 void __user *mem_base;
87 unsigned long kernel_address;
89 /* Bitmap of what has changed: see CHANGED_* above. */
91 struct lguest_pages *last_pages;
93 /* We keep a small number of these. */
95 struct pgdir pgdirs[4];
97 unsigned long noirq_start, noirq_end;
98 unsigned long pending_notify; /* pfn from LHCALL_NOTIFY */
100 unsigned int stack_pages;
107 extern struct mutex lguest_lock;
110 int lguest_address_ok(const struct lguest *lg,
111 unsigned long addr, unsigned long len);
112 void __lgread(struct lguest *, void *, unsigned long, unsigned);
113 void __lgwrite(struct lguest *, unsigned long, const void *, unsigned);
115 /*H:035 Using memory-copy operations like that is usually inconvient, so we
116 * have the following helper macros which read and write a specific type (often
119 * This reads into a variable of the given type then returns that. */
120 #define lgread(lg, addr, type) \
121 ({ type _v; __lgread((lg), &_v, (addr), sizeof(_v)); _v; })
123 /* This checks that the variable is of the given type, then writes it out. */
124 #define lgwrite(lg, addr, type, val) \
126 typecheck(type, val); \
127 __lgwrite((lg), (addr), &(val), sizeof(val)); \
129 /* (end of memory access helper routines) :*/
131 int run_guest(struct lg_cpu *cpu, unsigned long __user *user);
133 /* Helper macros to obtain the first 12 or the last 20 bits, this is only the
134 * first step in the migration to the kernel types. pte_pfn is already defined
136 #define pgd_flags(x) (pgd_val(x) & ~PAGE_MASK)
137 #define pte_flags(x) (pte_val(x) & ~PAGE_MASK)
138 #define pgd_pfn(x) (pgd_val(x) >> PAGE_SHIFT)
140 /* interrupts_and_traps.c: */
141 void maybe_do_interrupt(struct lg_cpu *cpu);
142 int deliver_trap(struct lg_cpu *cpu, unsigned int num);
143 void load_guest_idt_entry(struct lg_cpu *cpu, unsigned int i,
145 void guest_set_stack(struct lg_cpu *cpu, u32 seg, u32 esp, unsigned int pages);
146 void pin_stack_pages(struct lg_cpu *cpu);
147 void setup_default_idt_entries(struct lguest_ro_state *state,
148 const unsigned long *def);
149 void copy_traps(const struct lg_cpu *cpu, struct desc_struct *idt,
150 const unsigned long *def);
151 void guest_set_clockevent(struct lg_cpu *cpu, unsigned long delta);
152 void init_clockdev(struct lg_cpu *cpu);
153 bool check_syscall_vector(struct lguest *lg);
154 int init_interrupts(void);
155 void free_interrupts(void);
158 void setup_default_gdt_entries(struct lguest_ro_state *state);
159 void setup_guest_gdt(struct lg_cpu *cpu);
160 void load_guest_gdt(struct lg_cpu *cpu, unsigned long table, u32 num);
161 void guest_load_tls(struct lg_cpu *cpu, unsigned long tls_array);
162 void copy_gdt(const struct lg_cpu *cpu, struct desc_struct *gdt);
163 void copy_gdt_tls(const struct lg_cpu *cpu, struct desc_struct *gdt);
166 int init_guest_pagetable(struct lguest *lg, unsigned long pgtable);
167 void free_guest_pagetable(struct lguest *lg);
168 void guest_new_pagetable(struct lg_cpu *cpu, unsigned long pgtable);
169 void guest_set_pmd(struct lguest *lg, unsigned long gpgdir, u32 i);
170 void guest_pagetable_clear_all(struct lg_cpu *cpu);
171 void guest_pagetable_flush_user(struct lguest *lg);
172 void guest_set_pte(struct lguest *lg, unsigned long gpgdir,
173 unsigned long vaddr, pte_t val);
174 void map_switcher_in_guest(struct lg_cpu *cpu, struct lguest_pages *pages);
175 int demand_page(struct lguest *info, unsigned long cr2, int errcode);
176 void pin_page(struct lguest *lg, unsigned long vaddr);
177 unsigned long guest_pa(struct lguest *lg, unsigned long vaddr);
178 void page_table_guest_data_init(struct lguest *lg);
181 void lguest_arch_host_init(void);
182 void lguest_arch_host_fini(void);
183 void lguest_arch_run_guest(struct lg_cpu *cpu);
184 void lguest_arch_handle_trap(struct lg_cpu *cpu);
185 int lguest_arch_init_hypercalls(struct lg_cpu *cpu);
186 int lguest_arch_do_hcall(struct lg_cpu *cpu, struct hcall_args *args);
187 void lguest_arch_setup_regs(struct lg_cpu *cpu, unsigned long start);
189 /* <arch>/switcher.S: */
190 extern char start_switcher_text[], end_switcher_text[], switch_to_guest[];
193 int lguest_device_init(void);
194 void lguest_device_remove(void);
197 void do_hypercalls(struct lg_cpu *cpu);
198 void write_timestamp(struct lguest *lg);
201 * Let's step aside for the moment, to study one important routine that's used
202 * widely in the Host code.
204 * There are many cases where the Guest can do something invalid, like pass crap
205 * to a hypercall. Since only the Guest kernel can make hypercalls, it's quite
206 * acceptable to simply terminate the Guest and give the Launcher a nicely
207 * formatted reason. It's also simpler for the Guest itself, which doesn't
208 * need to check most hypercalls for "success"; if you're still running, it
211 * Once this is called, the Guest will never run again, so most Host code can
212 * call this then continue as if nothing had happened. This means many
213 * functions don't have to explicitly return an error code, which keeps the
216 * It also means that this can be called more than once: only the first one is
217 * remembered. The only trick is that we still need to kill the Guest even if
218 * we can't allocate memory to store the reason. Linux has a neat way of
219 * packing error codes into invalid pointers, so we use that here.
221 * Like any macro which uses an "if", it is safely wrapped in a run-once "do {
224 #define kill_guest(lg, fmt...) \
227 (lg)->dead = kasprintf(GFP_ATOMIC, fmt); \
229 (lg)->dead = ERR_PTR(-ENOMEM); \
232 /* (End of aside) :*/
234 #endif /* __ASSEMBLY__ */
235 #endif /* _LGUEST_H */