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 #include <asm/semaphore.h>
14
15 #include <asm/lguest.h>
16
17 void free_pagetables(void);
18 int init_pagetables(struct page **switcher_page, unsigned int pages);
19
20 struct pgdir
21 {
22 unsigned long gpgdir;
23 pgd_t *pgdir;
24 };
25
26 /* We have two pages shared with guests, per cpu. */
27 struct lguest_pages
28 {
29 /* This is the stack page mapped rw in guest */
30 char spare[PAGE_SIZE - sizeof(struct lguest_regs)];
31 struct lguest_regs regs;
32
33 /* This is the host state & guest descriptor page, ro in guest */
34 struct lguest_ro_state state;
35 } __attribute__((aligned(PAGE_SIZE)));
36
37 #define CHANGED_IDT 1
38 #define CHANGED_GDT 2
39 #define CHANGED_GDT_TLS 4 /* Actually a subset of CHANGED_GDT */
40 #define CHANGED_ALL 3
41
42 struct lguest;
43
44 struct lg_cpu {
45 unsigned int id;
46 struct lguest *lg;
47 struct task_struct *tsk;
48 struct mm_struct *mm; /* == tsk->mm, but that becomes NULL on exit */
49
50 u32 cr2;
51 int ts;
52 u32 esp1;
53 u8 ss1;
54
55 /* Bitmap of what has changed: see CHANGED_* above. */
56 int changed;
57
58 unsigned long pending_notify; /* pfn from LHCALL_NOTIFY */
59
60 /* At end of a page shared mapped over lguest_pages in guest. */
61 unsigned long regs_page;
62 struct lguest_regs *regs;
63
64 struct lguest_pages *last_pages;
65
66 int cpu_pgd; /* which pgd this cpu is currently using */
67
68 /* If a hypercall was asked for, this points to the arguments. */
69 struct hcall_args *hcall;
70 u32 next_hcall;
71
72 /* Virtual clock device */
73 struct hrtimer hrt;
74
75 /* Do we need to stop what we're doing and return to userspace? */
76 int break_out;
77 wait_queue_head_t break_wq;
78 int halted;
79
80 /* Pending virtual interrupts */
81 DECLARE_BITMAP(irqs_pending, LGUEST_IRQS);
82
83 struct lg_cpu_arch arch;
84 };
85
86 /* The private info the thread maintains about the guest. */
87 struct lguest
88 {
89 struct lguest_data __user *lguest_data;
90 struct lg_cpu cpus[NR_CPUS];
91 unsigned int nr_cpus;
92
93 u32 pfn_limit;
94 /* This provides the offset to the base of guest-physical
95 * memory in the Launcher. */
96 void __user *mem_base;
97 unsigned long kernel_address;
98
99 struct pgdir pgdirs[4];
100
101 unsigned long noirq_start, noirq_end;
102
103 unsigned int stack_pages;
104 u32 tsc_khz;
105
106 /* Dead? */
107 const char *dead;
108 };
109
110 extern struct mutex lguest_lock;
111
112 /* core.c: */
113 int lguest_address_ok(const struct lguest *lg,
114 unsigned long addr, unsigned long len);
115 void __lgread(struct lg_cpu *, void *, unsigned long, unsigned);
116 void __lgwrite(struct lg_cpu *, unsigned long, const void *, unsigned);
117
118 /*H:035 Using memory-copy operations like that is usually inconvient, so we
119 * have the following helper macros which read and write a specific type (often
120 * an unsigned long).
121 *
122 * This reads into a variable of the given type then returns that. */
123 #define lgread(cpu, addr, type) \
124 ({ type _v; __lgread((cpu), &_v, (addr), sizeof(_v)); _v; })
125
126 /* This checks that the variable is of the given type, then writes it out. */
127 #define lgwrite(cpu, addr, type, val) \
128 do { \
129 typecheck(type, val); \
130 __lgwrite((cpu), (addr), &(val), sizeof(val)); \
131 } while(0)
132 /* (end of memory access helper routines) :*/
133
134 int run_guest(struct lg_cpu *cpu, unsigned long __user *user);
135
136 /* Helper macros to obtain the first 12 or the last 20 bits, this is only the
137 * first step in the migration to the kernel types. pte_pfn is already defined
138 * in the kernel. */
139 #define pgd_flags(x) (pgd_val(x) & ~PAGE_MASK)
140 #define pte_flags(x) (pte_val(x) & ~PAGE_MASK)
141 #define pgd_pfn(x) (pgd_val(x) >> PAGE_SHIFT)
142
143 /* interrupts_and_traps.c: */
144 void maybe_do_interrupt(struct lg_cpu *cpu);
145 int deliver_trap(struct lg_cpu *cpu, unsigned int num);
146 void load_guest_idt_entry(struct lg_cpu *cpu, unsigned int i,
147 u32 low, u32 hi);
148 void guest_set_stack(struct lg_cpu *cpu, u32 seg, u32 esp, unsigned int pages);
149 void pin_stack_pages(struct lg_cpu *cpu);
150 void setup_default_idt_entries(struct lguest_ro_state *state,
151 const unsigned long *def);
152 void copy_traps(const struct lg_cpu *cpu, struct desc_struct *idt,
153 const unsigned long *def);
154 void guest_set_clockevent(struct lg_cpu *cpu, unsigned long delta);
155 void init_clockdev(struct lg_cpu *cpu);
156 bool check_syscall_vector(struct lguest *lg);
157 int init_interrupts(void);
158 void free_interrupts(void);
159
160 /* segments.c: */
161 void setup_default_gdt_entries(struct lguest_ro_state *state);
162 void setup_guest_gdt(struct lg_cpu *cpu);
163 void load_guest_gdt(struct lg_cpu *cpu, unsigned long table, u32 num);
164 void guest_load_tls(struct lg_cpu *cpu, unsigned long tls_array);
165 void copy_gdt(const struct lg_cpu *cpu, struct desc_struct *gdt);
166 void copy_gdt_tls(const struct lg_cpu *cpu, struct desc_struct *gdt);
167
168 /* page_tables.c: */
169 int init_guest_pagetable(struct lguest *lg, unsigned long pgtable);
170 void free_guest_pagetable(struct lguest *lg);
171 void guest_new_pagetable(struct lg_cpu *cpu, unsigned long pgtable);
172 void guest_set_pmd(struct lguest *lg, unsigned long gpgdir, u32 i);
173 void guest_pagetable_clear_all(struct lg_cpu *cpu);
174 void guest_pagetable_flush_user(struct lg_cpu *cpu);
175 void guest_set_pte(struct lg_cpu *cpu, unsigned long gpgdir,
176 unsigned long vaddr, pte_t val);
177 void map_switcher_in_guest(struct lg_cpu *cpu, struct lguest_pages *pages);
178 int demand_page(struct lg_cpu *cpu, unsigned long cr2, int errcode);
179 void pin_page(struct lg_cpu *cpu, unsigned long vaddr);
180 unsigned long guest_pa(struct lg_cpu *cpu, unsigned long vaddr);
181 void page_table_guest_data_init(struct lg_cpu *cpu);
182
183 /* <arch>/core.c: */
184 void lguest_arch_host_init(void);
185 void lguest_arch_host_fini(void);
186 void lguest_arch_run_guest(struct lg_cpu *cpu);
187 void lguest_arch_handle_trap(struct lg_cpu *cpu);
188 int lguest_arch_init_hypercalls(struct lg_cpu *cpu);
189 int lguest_arch_do_hcall(struct lg_cpu *cpu, struct hcall_args *args);
190 void lguest_arch_setup_regs(struct lg_cpu *cpu, unsigned long start);
191
192 /* <arch>/switcher.S: */
193 extern char start_switcher_text[], end_switcher_text[], switch_to_guest[];
194
195 /* lguest_user.c: */
196 int lguest_device_init(void);
197 void lguest_device_remove(void);
198
199 /* hypercalls.c: */
200 void do_hypercalls(struct lg_cpu *cpu);
201 void write_timestamp(struct lg_cpu *cpu);
202
203 /*L:035
204 * Let's step aside for the moment, to study one important routine that's used
205 * widely in the Host code.
206 *
207 * There are many cases where the Guest can do something invalid, like pass crap
208 * to a hypercall. Since only the Guest kernel can make hypercalls, it's quite
209 * acceptable to simply terminate the Guest and give the Launcher a nicely
210 * formatted reason. It's also simpler for the Guest itself, which doesn't
211 * need to check most hypercalls for "success"; if you're still running, it
212 * succeeded.
213 *
214 * Once this is called, the Guest will never run again, so most Host code can
215 * call this then continue as if nothing had happened. This means many
216 * functions don't have to explicitly return an error code, which keeps the
217 * code simple.
218 *
219 * It also means that this can be called more than once: only the first one is
220 * remembered. The only trick is that we still need to kill the Guest even if
221 * we can't allocate memory to store the reason. Linux has a neat way of
222 * packing error codes into invalid pointers, so we use that here.
223 *
224 * Like any macro which uses an "if", it is safely wrapped in a run-once "do {
225 * } while(0)".
226 */
227 #define kill_guest(cpu, fmt...) \
228 do { \
229 if (!(cpu)->lg->dead) { \
230 (cpu)->lg->dead = kasprintf(GFP_ATOMIC, fmt); \
231 if (!(cpu)->lg->dead) \
232 (cpu)->lg->dead = ERR_PTR(-ENOMEM); \
233 } \
234 } while(0)
235 /* (End of aside) :*/
236
237 #endif /* __ASSEMBLY__ */
238 #endif /* _LGUEST_H */
239
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