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 lg_cpu {
  42         unsigned int id;
  43         struct lguest *lg;
  44         struct task_struct *tsk;
  45         struct mm_struct *mm;   /* == tsk->mm, but that becomes NULL on exit */
  46
  47         u32 cr2;
  48         int ts;
  49         u32 esp1;
  50         u16 ss1;
  51
  52         /* Bitmap of what has changed: see CHANGED_* above. */
  53         int changed;
  54
  55         unsigned long pending_notify; /* pfn from LHCALL_NOTIFY */
  56
  57         /* At end of a page shared mapped over lguest_pages in guest.  */
  58         unsigned long regs_page;
  59         struct lguest_regs *regs;
  60
  61         struct lguest_pages *last_pages;
  62
  63         int cpu_pgd; /* which pgd this cpu is currently using */
  64
  65         /* If a hypercall was asked for, this points to the arguments. */
  66         struct hcall_args *hcall;
  67         u32 next_hcall;
  68
  69         /* Virtual clock device */
  70         struct hrtimer hrt;
  71
  72         /* Did the Guest tell us to halt? */
  73         int halted;
  74
  75         /* Pending virtual interrupts */
  76         DECLARE_BITMAP(irqs_pending, LGUEST_IRQS);
  77
  78         struct lg_cpu_arch arch;
  79 };
  80
  81 struct lg_eventfd {
  82         unsigned long addr;
  83         struct eventfd_ctx *event;
  84 };
  85
  86 struct lg_eventfd_map {
  87         unsigned int num;
  88         struct lg_eventfd map[];
  89 };
  90
  91 /* The private info the thread maintains about the guest. */
  92 struct lguest
  93 {
  94         struct lguest_data __user *lguest_data;
  95         struct lg_cpu cpus[NR_CPUS];
  96         unsigned int nr_cpus;
  97
  98         u32 pfn_limit;
  99         /* This provides the offset to the base of guest-physical
 100          * memory in the Launcher. */
 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 Using memory-copy operations like that is usually inconvient, so we
 126  * have the following helper macros which read and write a specific type (often
 127  * an unsigned long).
 128  *
 129  * This reads into a variable of the given type then returns that. */
 130 #define lgread(cpu, addr, type)                                         \
 131         ({ type _v; __lgread((cpu), &_v, (addr), sizeof(_v)); _v; })
 132
 133 /* This checks that the variable is of the given type, then writes it out. */
 134 #define lgwrite(cpu, addr, type, val)                           \
 135         do {                                                    \
 136                 typecheck(type, val);                           \
 137                 __lgwrite((cpu), (addr), &(val), sizeof(val));  \
 138         } while(0)
 139 /* (end of memory access helper routines) :*/
 140
 141 int run_guest(struct lg_cpu *cpu, unsigned long __user *user);
 142
 143 /* Helper macros to obtain the first 12 or the last 20 bits, this is only the
 144  * first step in the migration to the kernel types.  pte_pfn is already defined
 145  * in the kernel. */
 146 #define pgd_flags(x)    (pgd_val(x) & ~PAGE_MASK)
 147 #define pgd_pfn(x)      (pgd_val(x) >> PAGE_SHIFT)
 148 #define pmd_flags(x)    (pmd_val(x) & ~PAGE_MASK)
 149 #define pmd_pfn(x)      (pmd_val(x) >> PAGE_SHIFT)
 150
 151 /* interrupts_and_traps.c: */
 152 unsigned int interrupt_pending(struct lg_cpu *cpu, bool *more);
 153 void try_deliver_interrupt(struct lg_cpu *cpu, unsigned int irq, bool more);
 154 void set_interrupt(struct lg_cpu *cpu, unsigned int irq);
 155 bool deliver_trap(struct lg_cpu *cpu, unsigned int num);
 156 void load_guest_idt_entry(struct lg_cpu *cpu, unsigned int i,
 157                           u32 low, u32 hi);
 158 void guest_set_stack(struct lg_cpu *cpu, u32 seg, u32 esp, unsigned int pages);
 159 void pin_stack_pages(struct lg_cpu *cpu);
 160 void setup_default_idt_entries(struct lguest_ro_state *state,
 161                                const unsigned long *def);
 162 void copy_traps(const struct lg_cpu *cpu, struct desc_struct *idt,
 163                 const unsigned long *def);
 164 void guest_set_clockevent(struct lg_cpu *cpu, unsigned long delta);
 165 bool send_notify_to_eventfd(struct lg_cpu *cpu);
 166 void init_clockdev(struct lg_cpu *cpu);
 167 bool check_syscall_vector(struct lguest *lg);
 168 int init_interrupts(void);
 169 void free_interrupts(void);
 170
 171 /* segments.c: */
 172 void setup_default_gdt_entries(struct lguest_ro_state *state);
 173 void setup_guest_gdt(struct lg_cpu *cpu);
 174 void load_guest_gdt_entry(struct lg_cpu *cpu, unsigned int i,
 175                           u32 low, u32 hi);
 176 void guest_load_tls(struct lg_cpu *cpu, unsigned long tls_array);
 177 void copy_gdt(const struct lg_cpu *cpu, struct desc_struct *gdt);
 178 void copy_gdt_tls(const struct lg_cpu *cpu, struct desc_struct *gdt);
 179
 180 /* page_tables.c: */
 181 int init_guest_pagetable(struct lguest *lg);
 182 void free_guest_pagetable(struct lguest *lg);
 183 void guest_new_pagetable(struct lg_cpu *cpu, unsigned long pgtable);
 184 void guest_set_pgd(struct lguest *lg, unsigned long gpgdir, u32 i);
 185 #ifdef CONFIG_X86_PAE
 186 void guest_set_pmd(struct lguest *lg, unsigned long gpgdir, u32 i);
 187 #endif
 188 void guest_pagetable_clear_all(struct lg_cpu *cpu);
 189 void guest_pagetable_flush_user(struct lg_cpu *cpu);
 190 void guest_set_pte(struct lg_cpu *cpu, unsigned long gpgdir,
 191                    unsigned long vaddr, pte_t val);
 192 void map_switcher_in_guest(struct lg_cpu *cpu, struct lguest_pages *pages);
 193 bool demand_page(struct lg_cpu *cpu, unsigned long cr2, int errcode);
 194 void pin_page(struct lg_cpu *cpu, unsigned long vaddr);
 195 unsigned long guest_pa(struct lg_cpu *cpu, unsigned long vaddr);
 196 void page_table_guest_data_init(struct lg_cpu *cpu);
 197
 198 /* <arch>/core.c: */
 199 void lguest_arch_host_init(void);
 200 void lguest_arch_host_fini(void);
 201 void lguest_arch_run_guest(struct lg_cpu *cpu);
 202 void lguest_arch_handle_trap(struct lg_cpu *cpu);
 203 int lguest_arch_init_hypercalls(struct lg_cpu *cpu);
 204 int lguest_arch_do_hcall(struct lg_cpu *cpu, struct hcall_args *args);
 205 void lguest_arch_setup_regs(struct lg_cpu *cpu, unsigned long start);
 206
 207 /* <arch>/switcher.S: */
 208 extern char start_switcher_text[], end_switcher_text[], switch_to_guest[];
 209
 210 /* lguest_user.c: */
 211 int lguest_device_init(void);
 212 void lguest_device_remove(void);
 213
 214 /* hypercalls.c: */
 215 void do_hypercalls(struct lg_cpu *cpu);
 216 void write_timestamp(struct lg_cpu *cpu);
 217
 218 /*L:035
 219  * Let's step aside for the moment, to study one important routine that's used
 220  * widely in the Host code.
 221  *
 222  * There are many cases where the Guest can do something invalid, like pass crap
 223  * to a hypercall.  Since only the Guest kernel can make hypercalls, it's quite
 224  * acceptable to simply terminate the Guest and give the Launcher a nicely
 225  * formatted reason.  It's also simpler for the Guest itself, which doesn't
 226  * need to check most hypercalls for "success"; if you're still running, it
 227  * succeeded.
 228  *
 229  * Once this is called, the Guest will never run again, so most Host code can
 230  * call this then continue as if nothing had happened.  This means many
 231  * functions don't have to explicitly return an error code, which keeps the
 232  * code simple.
 233  *
 234  * It also means that this can be called more than once: only the first one is
 235  * remembered.  The only trick is that we still need to kill the Guest even if
 236  * we can't allocate memory to store the reason.  Linux has a neat way of
 237  * packing error codes into invalid pointers, so we use that here.
 238  *
 239  * Like any macro which uses an "if", it is safely wrapped in a run-once "do {
 240  * } while(0)".
 241  */
 242 #define kill_guest(cpu, fmt...)                                 \
 243 do {                                                            \
 244         if (!(cpu)->lg->dead) {                                 \
 245                 (cpu)->lg->dead = kasprintf(GFP_ATOMIC, fmt);   \
 246                 if (!(cpu)->lg->dead)                           \
 247                         (cpu)->lg->dead = ERR_PTR(-ENOMEM);     \
 248         }                                                       \
 249 } while(0)
 250 /* (End of aside) :*/
 251
 252 #endif  /* __ASSEMBLY__ */
 253 #endif  /* _LGUEST_H */