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         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 */