linux/drivers/lguest/lg.h
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   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
  17struct pgdir {
  18        unsigned long gpgdir;
  19        bool switcher_mapped;
  20        int last_host_cpu;
  21        pgd_t *pgdir;
  22};
  23
  24/* We have two pages shared with guests, per cpu.  */
  25struct 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
  39struct 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        /* Initialization mode: linear map everything. */
  62        bool linear_pages;
  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
  81struct lg_eventfd {
  82        unsigned long addr;
  83        struct eventfd_ctx *event;
  84};
  85
  86struct lg_eventfd_map {
  87        unsigned int num;
  88        struct lg_eventfd map[];
  89};
  90
  91/* The private info the thread maintains about the guest. */
  92struct lguest {
  93        struct lguest_data __user *lguest_data;
  94        struct lg_cpu cpus[NR_CPUS];
  95        unsigned int nr_cpus;
  96
  97        u32 pfn_limit;
  98
  99        /*
 100         * This provides the offset to the base of guest-physical memory in the
 101         * Launcher.
 102         */
 103        void __user *mem_base;
 104        unsigned long kernel_address;
 105
 106        struct pgdir pgdirs[4];
 107
 108        unsigned long noirq_start, noirq_end;
 109
 110        unsigned int stack_pages;
 111        u32 tsc_khz;
 112
 113        struct lg_eventfd_map *eventfds;
 114
 115        /* Dead? */
 116        const char *dead;
 117};
 118
 119extern struct mutex lguest_lock;
 120
 121/* core.c: */
 122bool lguest_address_ok(const struct lguest *lg,
 123                       unsigned long addr, unsigned long len);
 124void __lgread(struct lg_cpu *, void *, unsigned long, unsigned);
 125void __lgwrite(struct lg_cpu *, unsigned long, const void *, unsigned);
 126extern struct page **lg_switcher_pages;
 127
 128/*H:035
 129 * Using memory-copy operations like that is usually inconvient, so we
 130 * have the following helper macros which read and write a specific type (often
 131 * an unsigned long).
 132 *
 133 * This reads into a variable of the given type then returns that.
 134 */
 135#define lgread(cpu, addr, type)                                         \
 136        ({ type _v; __lgread((cpu), &_v, (addr), sizeof(_v)); _v; })
 137
 138/* This checks that the variable is of the given type, then writes it out. */
 139#define lgwrite(cpu, addr, type, val)                           \
 140        do {                                                    \
 141                typecheck(type, val);                           \
 142                __lgwrite((cpu), (addr), &(val), sizeof(val));  \
 143        } while(0)
 144/* (end of memory access helper routines) :*/
 145
 146int run_guest(struct lg_cpu *cpu, unsigned long __user *user);
 147
 148/*
 149 * Helper macros to obtain the first 12 or the last 20 bits, this is only the
 150 * first step in the migration to the kernel types.  pte_pfn is already defined
 151 * in the kernel.
 152 */
 153#define pgd_flags(x)    (pgd_val(x) & ~PAGE_MASK)
 154#define pgd_pfn(x)      (pgd_val(x) >> PAGE_SHIFT)
 155#define pmd_flags(x)    (pmd_val(x) & ~PAGE_MASK)
 156#define pmd_pfn(x)      (pmd_val(x) >> PAGE_SHIFT)
 157
 158/* interrupts_and_traps.c: */
 159unsigned int interrupt_pending(struct lg_cpu *cpu, bool *more);
 160void try_deliver_interrupt(struct lg_cpu *cpu, unsigned int irq, bool more);
 161void set_interrupt(struct lg_cpu *cpu, unsigned int irq);
 162bool deliver_trap(struct lg_cpu *cpu, unsigned int num);
 163void load_guest_idt_entry(struct lg_cpu *cpu, unsigned int i,
 164                          u32 low, u32 hi);
 165void guest_set_stack(struct lg_cpu *cpu, u32 seg, u32 esp, unsigned int pages);
 166void pin_stack_pages(struct lg_cpu *cpu);
 167void setup_default_idt_entries(struct lguest_ro_state *state,
 168                               const unsigned long *def);
 169void copy_traps(const struct lg_cpu *cpu, struct desc_struct *idt,
 170                const unsigned long *def);
 171void guest_set_clockevent(struct lg_cpu *cpu, unsigned long delta);
 172bool send_notify_to_eventfd(struct lg_cpu *cpu);
 173void init_clockdev(struct lg_cpu *cpu);
 174bool check_syscall_vector(struct lguest *lg);
 175int init_interrupts(void);
 176void free_interrupts(void);
 177
 178/* segments.c: */
 179void setup_default_gdt_entries(struct lguest_ro_state *state);
 180void setup_guest_gdt(struct lg_cpu *cpu);
 181void load_guest_gdt_entry(struct lg_cpu *cpu, unsigned int i,
 182                          u32 low, u32 hi);
 183void guest_load_tls(struct lg_cpu *cpu, unsigned long tls_array);
 184void copy_gdt(const struct lg_cpu *cpu, struct desc_struct *gdt);
 185void copy_gdt_tls(const struct lg_cpu *cpu, struct desc_struct *gdt);
 186
 187/* page_tables.c: */
 188int init_guest_pagetable(struct lguest *lg);
 189void free_guest_pagetable(struct lguest *lg);
 190void guest_new_pagetable(struct lg_cpu *cpu, unsigned long pgtable);
 191void guest_set_pgd(struct lguest *lg, unsigned long gpgdir, u32 i);
 192#ifdef CONFIG_X86_PAE
 193void guest_set_pmd(struct lguest *lg, unsigned long gpgdir, u32 i);
 194#endif
 195void guest_pagetable_clear_all(struct lg_cpu *cpu);
 196void guest_pagetable_flush_user(struct lg_cpu *cpu);
 197void guest_set_pte(struct lg_cpu *cpu, unsigned long gpgdir,
 198                   unsigned long vaddr, pte_t val);
 199void map_switcher_in_guest(struct lg_cpu *cpu, struct lguest_pages *pages);
 200bool demand_page(struct lg_cpu *cpu, unsigned long cr2, int errcode);
 201void pin_page(struct lg_cpu *cpu, unsigned long vaddr);
 202unsigned long guest_pa(struct lg_cpu *cpu, unsigned long vaddr);
 203void page_table_guest_data_init(struct lg_cpu *cpu);
 204
 205/* <arch>/core.c: */
 206void lguest_arch_host_init(void);
 207void lguest_arch_host_fini(void);
 208void lguest_arch_run_guest(struct lg_cpu *cpu);
 209void lguest_arch_handle_trap(struct lg_cpu *cpu);
 210int lguest_arch_init_hypercalls(struct lg_cpu *cpu);
 211int lguest_arch_do_hcall(struct lg_cpu *cpu, struct hcall_args *args);
 212void lguest_arch_setup_regs(struct lg_cpu *cpu, unsigned long start);
 213
 214/* <arch>/switcher.S: */
 215extern char start_switcher_text[], end_switcher_text[], switch_to_guest[];
 216
 217/* lguest_user.c: */
 218int lguest_device_init(void);
 219void lguest_device_remove(void);
 220
 221/* hypercalls.c: */
 222void do_hypercalls(struct lg_cpu *cpu);
 223void write_timestamp(struct lg_cpu *cpu);
 224
 225/*L:035
 226 * Let's step aside for the moment, to study one important routine that's used
 227 * widely in the Host code.
 228 *
 229 * There are many cases where the Guest can do something invalid, like pass crap
 230 * to a hypercall.  Since only the Guest kernel can make hypercalls, it's quite
 231 * acceptable to simply terminate the Guest and give the Launcher a nicely
 232 * formatted reason.  It's also simpler for the Guest itself, which doesn't
 233 * need to check most hypercalls for "success"; if you're still running, it
 234 * succeeded.
 235 *
 236 * Once this is called, the Guest will never run again, so most Host code can
 237 * call this then continue as if nothing had happened.  This means many
 238 * functions don't have to explicitly return an error code, which keeps the
 239 * code simple.
 240 *
 241 * It also means that this can be called more than once: only the first one is
 242 * remembered.  The only trick is that we still need to kill the Guest even if
 243 * we can't allocate memory to store the reason.  Linux has a neat way of
 244 * packing error codes into invalid pointers, so we use that here.
 245 *
 246 * Like any macro which uses an "if", it is safely wrapped in a run-once "do {
 247 * } while(0)".
 248 */
 249#define kill_guest(cpu, fmt...)                                 \
 250do {                                                            \
 251        if (!(cpu)->lg->dead) {                                 \
 252                (cpu)->lg->dead = kasprintf(GFP_ATOMIC, fmt);   \
 253                if (!(cpu)->lg->dead)                           \
 254                        (cpu)->lg->dead = ERR_PTR(-ENOMEM);     \
 255        }                                                       \
 256} while(0)
 257/* (End of aside) :*/
 258
 259#endif  /* __ASSEMBLY__ */
 260#endif  /* _LGUEST_H */
 261
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