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/futex.h>
   9 #include <linux/lguest.h>
  10 #include <linux/lguest_launcher.h>
  11 #include <linux/wait.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 lguest_dma_info
  21 {
  22         struct list_head list;
  23         union futex_key key;
  24         unsigned long dmas;
  25         struct lguest *owner;
  26         u16 next_dma;
  27         u16 num_dmas;
  28         u8 interrupt;   /* 0 when not registered */
  29 };
  30
  31 struct pgdir
  32 {
  33         unsigned long gpgdir;
  34         pgd_t *pgdir;
  35 };
  36
  37 /* We have two pages shared with guests, per cpu.  */
  38 struct lguest_pages
  39 {
  40         /* This is the stack page mapped rw in guest */
  41         char spare[PAGE_SIZE - sizeof(struct lguest_regs)];
  42         struct lguest_regs regs;
  43
  44         /* This is the host state & guest descriptor page, ro in guest */
  45         struct lguest_ro_state state;
  46 } __attribute__((aligned(PAGE_SIZE)));
  47
  48 #define CHANGED_IDT             1
  49 #define CHANGED_GDT             2
  50 #define CHANGED_GDT_TLS         4 /* Actually a subset of CHANGED_GDT */
  51 #define CHANGED_ALL             3
  52
  53 /* The private info the thread maintains about the guest. */
  54 struct lguest
  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         struct lguest_data __user *lguest_data;
  60         struct task_struct *tsk;
  61         struct mm_struct *mm;   /* == tsk->mm, but that becomes NULL on exit */
  62         u32 pfn_limit;
  63         /* This provides the offset to the base of guest-physical
  64          * memory in the Launcher. */
  65         void __user *mem_base;
  66         u32 page_offset;
  67         u32 cr2;
  68         int halted;
  69         int ts;
  70         u32 next_hcall;
  71         u32 esp1;
  72         u8 ss1;
  73
  74         /* If a hypercall was asked for, this points to the arguments. */
  75         struct hcall_args *hcall;
  76
  77         /* Do we need to stop what we're doing and return to userspace? */
  78         int break_out;
  79         wait_queue_head_t break_wq;
  80
  81         /* Bitmap of what has changed: see CHANGED_* above. */
  82         int changed;
  83         struct lguest_pages *last_pages;
  84
  85         /* We keep a small number of these. */
  86         u32 pgdidx;
  87         struct pgdir pgdirs[4];
  88
  89         /* Cached wakeup: we hold a reference to this task. */
  90         struct task_struct *wake;
  91
  92         unsigned long noirq_start, noirq_end;
  93         int dma_is_pending;
  94         unsigned long pending_dma; /* struct lguest_dma */
  95         unsigned long pending_key; /* address they're sending to */
  96
  97         unsigned int stack_pages;
  98         u32 tsc_khz;
  99
 100         struct lguest_dma_info dma[LGUEST_MAX_DMA];
 101
 102         /* Dead? */
 103         const char *dead;
 104
 105         struct lguest_arch arch;
 106
 107         /* Virtual clock device */
 108         struct hrtimer hrt;
 109
 110         /* Pending virtual interrupts */
 111         DECLARE_BITMAP(irqs_pending, LGUEST_IRQS);
 112 };
 113
 114 extern struct mutex lguest_lock;
 115
 116 /* core.c: */
 117 u32 lgread_u32(struct lguest *lg, unsigned long addr);
 118 void lgwrite_u32(struct lguest *lg, unsigned long addr, u32 val);
 119 void lgread(struct lguest *lg, void *buf, unsigned long addr, unsigned len);
 120 void lgwrite(struct lguest *lg, unsigned long, const void *buf, unsigned len);
 121 int lguest_address_ok(const struct lguest *lg,
 122                       unsigned long addr, unsigned long len);
 123 int run_guest(struct lguest *lg, unsigned long __user *user);
 124
 125 /* Helper macros to obtain the first 12 or the last 20 bits, this is only the
 126  * first step in the migration to the kernel types.  pte_pfn is already defined
 127  * in the kernel. */
 128 #define pgd_flags(x)    (pgd_val(x) & ~PAGE_MASK)
 129 #define pte_flags(x)    (pte_val(x) & ~PAGE_MASK)
 130 #define pgd_pfn(x)      (pgd_val(x) >> PAGE_SHIFT)
 131
 132 /* interrupts_and_traps.c: */
 133 void maybe_do_interrupt(struct lguest *lg);
 134 int deliver_trap(struct lguest *lg, unsigned int num);
 135 void load_guest_idt_entry(struct lguest *lg, unsigned int i, u32 low, u32 hi);
 136 void guest_set_stack(struct lguest *lg, u32 seg, u32 esp, unsigned int pages);
 137 void pin_stack_pages(struct lguest *lg);
 138 void setup_default_idt_entries(struct lguest_ro_state *state,
 139                                const unsigned long *def);
 140 void copy_traps(const struct lguest *lg, struct desc_struct *idt,
 141                 const unsigned long *def);
 142 void guest_set_clockevent(struct lguest *lg, unsigned long delta);
 143 void init_clockdev(struct lguest *lg);
 144 bool check_syscall_vector(struct lguest *lg);
 145 int init_interrupts(void);
 146 void free_interrupts(void);
 147
 148 /* segments.c: */
 149 void setup_default_gdt_entries(struct lguest_ro_state *state);
 150 void setup_guest_gdt(struct lguest *lg);
 151 void load_guest_gdt(struct lguest *lg, unsigned long table, u32 num);
 152 void guest_load_tls(struct lguest *lg, unsigned long tls_array);
 153 void copy_gdt(const struct lguest *lg, struct desc_struct *gdt);
 154 void copy_gdt_tls(const struct lguest *lg, struct desc_struct *gdt);
 155
 156 /* page_tables.c: */
 157 int init_guest_pagetable(struct lguest *lg, unsigned long pgtable);
 158 void free_guest_pagetable(struct lguest *lg);
 159 void guest_new_pagetable(struct lguest *lg, unsigned long pgtable);
 160 void guest_set_pmd(struct lguest *lg, unsigned long gpgdir, u32 i);
 161 void guest_pagetable_clear_all(struct lguest *lg);
 162 void guest_pagetable_flush_user(struct lguest *lg);
 163 void guest_set_pte(struct lguest *lg, unsigned long gpgdir,
 164                    unsigned long vaddr, pte_t val);
 165 void map_switcher_in_guest(struct lguest *lg, struct lguest_pages *pages);
 166 int demand_page(struct lguest *info, unsigned long cr2, int errcode);
 167 void pin_page(struct lguest *lg, unsigned long vaddr);
 168
 169 /* <arch>/core.c: */
 170 void lguest_arch_host_init(void);
 171 void lguest_arch_host_fini(void);
 172 void lguest_arch_run_guest(struct lguest *lg);
 173 void lguest_arch_handle_trap(struct lguest *lg);
 174 int lguest_arch_init_hypercalls(struct lguest *lg);
 175 int lguest_arch_do_hcall(struct lguest *lg, struct hcall_args *args);
 176 void lguest_arch_setup_regs(struct lguest *lg, unsigned long start);
 177
 178 /* <arch>/switcher.S: */
 179 extern char start_switcher_text[], end_switcher_text[], switch_to_guest[];
 180
 181 /* lguest_user.c: */
 182 int lguest_device_init(void);
 183 void lguest_device_remove(void);
 184
 185 /* io.c: */
 186 void lguest_io_init(void);
 187 int bind_dma(struct lguest *lg,
 188              unsigned long key, unsigned long udma, u16 numdmas, u8 interrupt);
 189 void send_dma(struct lguest *info, unsigned long key, unsigned long udma);
 190 void release_all_dma(struct lguest *lg);
 191 unsigned long get_dma_buffer(struct lguest *lg, unsigned long key,
 192                              unsigned long *interrupt);
 193
 194 /* hypercalls.c: */
 195 void do_hypercalls(struct lguest *lg);
 196 void write_timestamp(struct lguest *lg);
 197
 198 /*L:035
 199  * Let's step aside for the moment, to study one important routine that's used
 200  * widely in the Host code.
 201  *
 202  * There are many cases where the Guest does something invalid, like pass crap
 203  * to a hypercall.  Since only the Guest kernel can make hypercalls, it's quite
 204  * acceptable to simply terminate the Guest and give the Launcher a nicely
 205  * formatted reason.  It's also simpler for the Guest itself, which doesn't
 206  * need to check most hypercalls for "success"; if you're still running, it
 207  * succeeded.
 208  *
 209  * Once this is called, the Guest will never run again, so most Host code can
 210  * call this then continue as if nothing had happened.  This means many
 211  * functions don't have to explicitly return an error code, which keeps the
 212  * code simple.
 213  *
 214  * It also means that this can be called more than once: only the first one is
 215  * remembered.  The only trick is that we still need to kill the Guest even if
 216  * we can't allocate memory to store the reason.  Linux has a neat way of
 217  * packing error codes into invalid pointers, so we use that here.
 218  *
 219  * Like any macro which uses an "if", it is safely wrapped in a run-once "do {
 220  * } while(0)".
 221  */
 222 #define kill_guest(lg, fmt...)                                  \
 223 do {                                                            \
 224         if (!(lg)->dead) {                                      \
 225                 (lg)->dead = kasprintf(GFP_ATOMIC, fmt);        \
 226                 if (!(lg)->dead)                                \
 227                         (lg)->dead = ERR_PTR(-ENOMEM);          \
 228         }                                                       \
 229 } while(0)
 230 /* (End of aside) :*/
 231
 232 static inline unsigned long guest_pa(struct lguest *lg, unsigned long vaddr)
 233 {
 234         return vaddr - lg->page_offset;
 235 }
 236 #endif  /* __ASSEMBLY__ */
 237 #endif  /* _LGUEST_H */