1 #ifndef _LGUEST_H
2 #define _LGUEST_H
3
4 #ifndef __ASSEMBLY__
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/hrtimer.h>
12 #include <linux/err.h>
13
14 #include <asm/lguest.h>
15
16 void free_pagetables(void);
17 int init_pagetables(struct page **switcher_page, unsigned int pages);
18
19 struct pgdir {
20 unsigned long gpgdir;
21 pgd_t *pgdir;
22 };
23
24 /* We have two pages shared with guests, per cpu. */
25 struct lguest_pages {
26 /* This is the stack page mapped rw in guest */
27 char spare[PAGE_SIZE - sizeof(struct lguest_regs)];
28 struct lguest_regs regs;
29
30 /* This is the host state & guest descriptor page, ro in guest */
31 struct lguest_ro_state state;
32 } __attribute__((aligned(PAGE_SIZE)));
33
34 #define CHANGED_IDT 1
35 #define CHANGED_GDT 2
36 #define CHANGED_GDT_TLS 4 /* Actually a subset of CHANGED_GDT */
37 #define CHANGED_ALL 3
38
39 struct lg_cpu {
40 unsigned int id;
41 struct lguest *lg;
42 struct task_struct *tsk;
43 struct mm_struct *mm; /* == tsk->mm, but that becomes NULL on exit */
44
45 u32 cr2;
46 int ts;
47 u32 esp1;
48 u16 ss1;
49
50 /* Bitmap of what has changed: see CHANGED_* above. */
51 int changed;
52
53 unsigned long pending_notify; /* pfn from LHCALL_NOTIFY */
54
55 /* At end of a page shared mapped over lguest_pages in guest. */
56 unsigned long regs_page;
57 struct lguest_regs *regs;
58
59 struct lguest_pages *last_pages;
60
61 int cpu_pgd; /* Which pgd this cpu is currently using */
62
63 /* If a hypercall was asked for, this points to the arguments. */
64 struct hcall_args *hcall;
65 u32 next_hcall;
66
67 /* Virtual clock device */
68 struct hrtimer hrt;
69
70 /* Did the Guest tell us to halt? */
71 int halted;
72
73 /* Pending virtual interrupts */
74 DECLARE_BITMAP(irqs_pending, LGUEST_IRQS);
75
76 struct lg_cpu_arch arch;
77 };
78
79 struct lg_eventfd {
80 unsigned long addr;
81 struct eventfd_ctx *event;
82 };
83
84 struct lg_eventfd_map {
85 unsigned int num;
86 struct lg_eventfd map[];
87 };
88
89 /* The private info the thread maintains about the guest. */
90 struct lguest {
91 struct lguest_data __user *lguest_data;
92 struct lg_cpu cpus[NR_CPUS];
93 unsigned int nr_cpus;
94
95 u32 pfn_limit;
96
97 /*
98 * This provides the offset to the base of guest-physical memory in the
99 * Launcher.
100 */
101 void __user *mem_base;
102 unsigned long kernel_address;
103
104 struct pgdir pgdirs[4];
105
106 unsigned long noirq_start, noirq_end;
107
108 unsigned int stack_pages;
109 u32 tsc_khz;
110
111 struct lg_eventfd_map *eventfds;
112
113 /* Dead? */
114 const char *dead;
115 };
116
117 extern struct mutex lguest_lock;
118
119 /* core.c: */
120 bool lguest_address_ok(const struct lguest *lg,
121 unsigned long addr, unsigned long len);
122 void __lgread(struct lg_cpu *, void *, unsigned long, unsigned);
123 void __lgwrite(struct lg_cpu *, unsigned long, const void *, unsigned);
124
125 /*H:035
126 * Using memory-copy operations like that is usually inconvient, so we
127 * have the following helper macros which read and write a specific type (often
128 * an unsigned long).
129 *
130 * This reads into a variable of the given type then returns that.
131 */
132 #define lgread(cpu, addr, type) \
133 ({ type _v; __lgread((cpu), &_v, (addr), sizeof(_v)); _v; })
134
135 /* This checks that the variable is of the given type, then writes it out. */
136 #define lgwrite(cpu, addr, type, val) \
137 do { \
138 typecheck(type, val); \
139 __lgwrite((cpu), (addr), &(val), sizeof(val)); \
140 } while(0)
141 /* (end of memory access helper routines) :*/
142
143 int run_guest(struct lg_cpu *cpu, unsigned long __user *user);
144
145 /*
146 * Helper macros to obtain the first 12 or the last 20 bits, this is only the
147 * first step in the migration to the kernel types. pte_pfn is already defined
148 * in the kernel.
149 */
150 #define pgd_flags(x) (pgd_val(x) & ~PAGE_MASK)
151 #define pgd_pfn(x) (pgd_val(x) >> PAGE_SHIFT)
152 #define pmd_flags(x) (pmd_val(x) & ~PAGE_MASK)
153 #define pmd_pfn(x) (pmd_val(x) >> PAGE_SHIFT)
154
155 /* interrupts_and_traps.c: */
156 unsigned int interrupt_pending(struct lg_cpu *cpu, bool *more);
157 void try_deliver_interrupt(struct lg_cpu *cpu, unsigned int irq, bool more);
158 void set_interrupt(struct lg_cpu *cpu, unsigned int irq);
159 bool deliver_trap(struct lg_cpu *cpu, unsigned int num);
160 void load_guest_idt_entry(struct lg_cpu *cpu, unsigned int i,
161 u32 low, u32 hi);
162 void guest_set_stack(struct lg_cpu *cpu, u32 seg, u32 esp, unsigned int pages);
163 void pin_stack_pages(struct lg_cpu *cpu);
164 void setup_default_idt_entries(struct lguest_ro_state *state,
165 const unsigned long *def);
166 void copy_traps(const struct lg_cpu *cpu, struct desc_struct *idt,
167 const unsigned long *def);
168 void guest_set_clockevent(struct lg_cpu *cpu, unsigned long delta);
169 bool send_notify_to_eventfd(struct lg_cpu *cpu);
170 void init_clockdev(struct lg_cpu *cpu);
171 bool check_syscall_vector(struct lguest *lg);
172 int init_interrupts(void);
173 void free_interrupts(void);
174
175 /* segments.c: */
176 void setup_default_gdt_entries(struct lguest_ro_state *state);
177 void setup_guest_gdt(struct lg_cpu *cpu);
178 void load_guest_gdt_entry(struct lg_cpu *cpu, unsigned int i,
179 u32 low, u32 hi);
180 void guest_load_tls(struct lg_cpu *cpu, unsigned long tls_array);
181 void copy_gdt(const struct lg_cpu *cpu, struct desc_struct *gdt);
182 void copy_gdt_tls(const struct lg_cpu *cpu, struct desc_struct *gdt);
183
184 /* page_tables.c: */
185 int init_guest_pagetable(struct lguest *lg);
186 void free_guest_pagetable(struct lguest *lg);
187 void guest_new_pagetable(struct lg_cpu *cpu, unsigned long pgtable);
188 void guest_set_pgd(struct lguest *lg, unsigned long gpgdir, u32 i);
189 #ifdef CONFIG_X86_PAE
190 void guest_set_pmd(struct lguest *lg, unsigned long gpgdir, u32 i);
191 #endif
192 void guest_pagetable_clear_all(struct lg_cpu *cpu);
193 void guest_pagetable_flush_user(struct lg_cpu *cpu);
194 void guest_set_pte(struct lg_cpu *cpu, unsigned long gpgdir,
195 unsigned long vaddr, pte_t val);
196 void map_switcher_in_guest(struct lg_cpu *cpu, struct lguest_pages *pages);
197 bool demand_page(struct lg_cpu *cpu, unsigned long cr2, int errcode);
198 void pin_page(struct lg_cpu *cpu, unsigned long vaddr);
199 unsigned long guest_pa(struct lg_cpu *cpu, unsigned long vaddr);
200 void page_table_guest_data_init(struct lg_cpu *cpu);
201
202 /* <arch>/core.c: */
203 void lguest_arch_host_init(void);
204 void lguest_arch_host_fini(void);
205 void lguest_arch_run_guest(struct lg_cpu *cpu);
206 void lguest_arch_handle_trap(struct lg_cpu *cpu);
207 int lguest_arch_init_hypercalls(struct lg_cpu *cpu);
208 int lguest_arch_do_hcall(struct lg_cpu *cpu, struct hcall_args *args);
209 void lguest_arch_setup_regs(struct lg_cpu *cpu, unsigned long start);
210
211 /* <arch>/switcher.S: */
212 extern char start_switcher_text[], end_switcher_text[], switch_to_guest[];
213
214 /* lguest_user.c: */
215 int lguest_device_init(void);
216 void lguest_device_remove(void);
217
218 /* hypercalls.c: */
219 void do_hypercalls(struct lg_cpu *cpu);
220 void write_timestamp(struct lg_cpu *cpu);
221
222 /*L:035
223 * Let's step aside for the moment, to study one important routine that's used
224 * widely in the Host code.
225 *
226 * There are many cases where the Guest can do something invalid, like pass crap
227 * to a hypercall. Since only the Guest kernel can make hypercalls, it's quite
228 * acceptable to simply terminate the Guest and give the Launcher a nicely
229 * formatted reason. It's also simpler for the Guest itself, which doesn't
230 * need to check most hypercalls for "success"; if you're still running, it
231 * succeeded.
232 *
233 * Once this is called, the Guest will never run again, so most Host code can
234 * call this then continue as if nothing had happened. This means many
235 * functions don't have to explicitly return an error code, which keeps the
236 * code simple.
237 *
238 * It also means that this can be called more than once: only the first one is
239 * remembered. The only trick is that we still need to kill the Guest even if
240 * we can't allocate memory to store the reason. Linux has a neat way of
241 * packing error codes into invalid pointers, so we use that here.
242 *
243 * Like any macro which uses an "if", it is safely wrapped in a run-once "do {
244 * } while(0)".
245 */
246 #define kill_guest(cpu, fmt...) \
247 do { \
248 if (!(cpu)->lg->dead) { \
249 (cpu)->lg->dead = kasprintf(GFP_ATOMIC, fmt); \
250 if (!(cpu)->lg->dead) \
251 (cpu)->lg->dead = ERR_PTR(-ENOMEM); \
252 } \
253 } while(0)
254 /* (End of aside) :*/
255
256 #endif /* __ASSEMBLY__ */
257 #endif /* _LGUEST_H */
258
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