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