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 /*H:310 The page-table code owes a great debt of gratitude to Andi Kleen.  He
  32  * reviewed the original code which used "u32" for all page table entries, and
  33  * insisted that it would be far clearer with explicit typing.  I thought it
  34  * was overkill, but he was right: it is much clearer than it was before.
  35  *
  36  * We have separate types for the Guest's ptes & pgds and the shadow ptes &
  37  * pgds.  There's already a Linux type for these (pte_t and pgd_t) but they
  38  * change depending on kernel config options (PAE). */
  39
  40 /* Each entry is identical: lower 12 bits of flags and upper 20 bits for the
  41  * "page frame number" (0 == first physical page, etc).  They are different
  42  * types so the compiler will warn us if we mix them improperly. */
  43 typedef union {
  44         struct { unsigned flags:12, pfn:20; };
  45         struct { unsigned long val; } raw;
  46 } spgd_t;
  47 typedef union {
  48         struct { unsigned flags:12, pfn:20; };
  49         struct { unsigned long val; } raw;
  50 } spte_t;
  51 typedef union {
  52         struct { unsigned flags:12, pfn:20; };
  53         struct { unsigned long val; } raw;
  54 } gpgd_t;
  55 typedef union {
  56         struct { unsigned flags:12, pfn:20; };
  57         struct { unsigned long val; } raw;
  58 } gpte_t;
  59
  60 /* We have two convenient macros to convert a "raw" value as handed to us by
  61  * the Guest into the correct Guest PGD or PTE type. */
  62 #define mkgpte(_val) ((gpte_t){.raw.val = _val})
  63 #define mkgpgd(_val) ((gpgd_t){.raw.val = _val})
  64 /*:*/
  65
  66 struct pgdir
  67 {
  68         unsigned long cr3;
  69         spgd_t *pgdir;
  70 };
  71
  72 /* We have two pages shared with guests, per cpu.  */
  73 struct lguest_pages
  74 {
  75         /* This is the stack page mapped rw in guest */
  76         char spare[PAGE_SIZE - sizeof(struct lguest_regs)];
  77         struct lguest_regs regs;
  78
  79         /* This is the host state & guest descriptor page, ro in guest */
  80         struct lguest_ro_state state;
  81 } __attribute__((aligned(PAGE_SIZE)));
  82
  83 #define CHANGED_IDT             1
  84 #define CHANGED_GDT             2
  85 #define CHANGED_GDT_TLS         4 /* Actually a subset of CHANGED_GDT */
  86 #define CHANGED_ALL             3
  87
  88 /* The private info the thread maintains about the guest. */
  89 struct lguest
  90 {
  91         /* At end of a page shared mapped over lguest_pages in guest.  */
  92         unsigned long regs_page;
  93         struct lguest_regs *regs;
  94         struct lguest_data __user *lguest_data;
  95         struct task_struct *tsk;
  96         struct mm_struct *mm;   /* == tsk->mm, but that becomes NULL on exit */
  97         u32 pfn_limit;
  98         /* This provides the offset to the base of guest-physical
  99          * memory in the Launcher. */
 100         void __user *mem_base;
 101         u32 page_offset;
 102         u32 cr2;
 103         int halted;
 104         int ts;
 105         u32 next_hcall;
 106         u32 esp1;
 107         u8 ss1;
 108
 109         /* If a hypercall was asked for, this points to the arguments. */
 110         struct hcall_args *hcall;
 111
 112         /* Do we need to stop what we're doing and return to userspace? */
 113         int break_out;
 114         wait_queue_head_t break_wq;
 115
 116         /* Bitmap of what has changed: see CHANGED_* above. */
 117         int changed;
 118         struct lguest_pages *last_pages;
 119
 120         /* We keep a small number of these. */
 121         u32 pgdidx;
 122         struct pgdir pgdirs[4];
 123
 124         /* Cached wakeup: we hold a reference to this task. */
 125         struct task_struct *wake;
 126
 127         unsigned long noirq_start, noirq_end;
 128         int dma_is_pending;
 129         unsigned long pending_dma; /* struct lguest_dma */
 130         unsigned long pending_key; /* address they're sending to */
 131
 132         unsigned int stack_pages;
 133         u32 tsc_khz;
 134
 135         struct lguest_dma_info dma[LGUEST_MAX_DMA];
 136
 137         /* Dead? */
 138         const char *dead;
 139
 140         struct lguest_arch arch;
 141
 142         /* Virtual clock device */
 143         struct hrtimer hrt;
 144
 145         /* Pending virtual interrupts */
 146         DECLARE_BITMAP(irqs_pending, LGUEST_IRQS);
 147 };
 148
 149 extern struct mutex lguest_lock;
 150
 151 /* core.c: */
 152 u32 lgread_u32(struct lguest *lg, unsigned long addr);
 153 void lgwrite_u32(struct lguest *lg, unsigned long addr, u32 val);
 154 void lgread(struct lguest *lg, void *buf, unsigned long addr, unsigned len);
 155 void lgwrite(struct lguest *lg, unsigned long, const void *buf, unsigned len);
 156 int lguest_address_ok(const struct lguest *lg,
 157                       unsigned long addr, unsigned long len);
 158 int run_guest(struct lguest *lg, unsigned long __user *user);
 159
 160
 161 /* interrupts_and_traps.c: */
 162 void maybe_do_interrupt(struct lguest *lg);
 163 int deliver_trap(struct lguest *lg, unsigned int num);
 164 void load_guest_idt_entry(struct lguest *lg, unsigned int i, u32 low, u32 hi);
 165 void guest_set_stack(struct lguest *lg, u32 seg, u32 esp, unsigned int pages);
 166 void pin_stack_pages(struct lguest *lg);
 167 void setup_default_idt_entries(struct lguest_ro_state *state,
 168                                const unsigned long *def);
 169 void copy_traps(const struct lguest *lg, struct desc_struct *idt,
 170                 const unsigned long *def);
 171 void guest_set_clockevent(struct lguest *lg, unsigned long delta);
 172 void init_clockdev(struct lguest *lg);
 173
 174 /* segments.c: */
 175 void setup_default_gdt_entries(struct lguest_ro_state *state);
 176 void setup_guest_gdt(struct lguest *lg);
 177 void load_guest_gdt(struct lguest *lg, unsigned long table, u32 num);
 178 void guest_load_tls(struct lguest *lg, unsigned long tls_array);
 179 void copy_gdt(const struct lguest *lg, struct desc_struct *gdt);
 180 void copy_gdt_tls(const struct lguest *lg, struct desc_struct *gdt);
 181
 182 /* page_tables.c: */
 183 int init_guest_pagetable(struct lguest *lg, unsigned long pgtable);
 184 void free_guest_pagetable(struct lguest *lg);
 185 void guest_new_pagetable(struct lguest *lg, unsigned long pgtable);
 186 void guest_set_pmd(struct lguest *lg, unsigned long cr3, u32 i);
 187 void guest_pagetable_clear_all(struct lguest *lg);
 188 void guest_pagetable_flush_user(struct lguest *lg);
 189 void guest_set_pte(struct lguest *lg, unsigned long cr3,
 190                    unsigned long vaddr, gpte_t val);
 191 void map_switcher_in_guest(struct lguest *lg, struct lguest_pages *pages);
 192 int demand_page(struct lguest *info, unsigned long cr2, int errcode);
 193 void pin_page(struct lguest *lg, unsigned long vaddr);
 194
 195 /* <arch>/core.c: */
 196 void lguest_arch_host_init(void);
 197 void lguest_arch_host_fini(void);
 198 void lguest_arch_run_guest(struct lguest *lg);
 199 void lguest_arch_handle_trap(struct lguest *lg);
 200 int lguest_arch_init_hypercalls(struct lguest *lg);
 201 int lguest_arch_do_hcall(struct lguest *lg, struct hcall_args *args);
 202
 203 /* <arch>/switcher.S: */
 204 extern char start_switcher_text[], end_switcher_text[], switch_to_guest[];
 205
 206 /* lguest_user.c: */
 207 int lguest_device_init(void);
 208 void lguest_device_remove(void);
 209
 210 /* io.c: */
 211 void lguest_io_init(void);
 212 int bind_dma(struct lguest *lg,
 213              unsigned long key, unsigned long udma, u16 numdmas, u8 interrupt);
 214 void send_dma(struct lguest *info, unsigned long key, unsigned long udma);
 215 void release_all_dma(struct lguest *lg);
 216 unsigned long get_dma_buffer(struct lguest *lg, unsigned long key,
 217                              unsigned long *interrupt);
 218
 219 /* hypercalls.c: */
 220 void do_hypercalls(struct lguest *lg);
 221 void write_timestamp(struct lguest *lg);
 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 does 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(lg, fmt...)                                  \
 248 do {                                                            \
 249         if (!(lg)->dead) {                                      \
 250                 (lg)->dead = kasprintf(GFP_ATOMIC, fmt);        \
 251                 if (!(lg)->dead)                                \
 252                         (lg)->dead = ERR_PTR(-ENOMEM);          \
 253         }                                                       \
 254 } while(0)
 255 /* (End of aside) :*/
 256
 257 static inline unsigned long guest_pa(struct lguest *lg, unsigned long vaddr)
 258 {
 259         return vaddr - lg->page_offset;
 260 }
 261 #endif  /* __ASSEMBLY__ */
 262 #endif  /* _LGUEST_H */