drivers/lguest/lg.h

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