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 lguest; 42 43 struct lg_cpu { 44 unsigned int id; 45 struct lguest *lg; 46 struct task_struct *tsk; 47 struct mm_struct *mm; /* == tsk->mm, but that becomes NULL on exit */ 48 49 u32 cr2; 50 int ts; 51 u32 esp1; 52 u8 ss1; 53 54 /* Bitmap of what has changed: see CHANGED_* above. */ 55 int changed; 56 57 unsigned long pending_notify; /* pfn from LHCALL_NOTIFY */ 58 59 /* At end of a page shared mapped over lguest_pages in guest. */ 60 unsigned long regs_page; 61 struct lguest_regs *regs; 62 63 struct lguest_pages *last_pages; 64 65 int cpu_pgd; /* which pgd this cpu is currently using */ 66 67 /* If a hypercall was asked for, this points to the arguments. */ 68 struct hcall_args *hcall; 69 u32 next_hcall; 70 71 /* Virtual clock device */ 72 struct hrtimer hrt; 73 74 /* Do we need to stop what we're doing and return to userspace? */ 75 int break_out; 76 wait_queue_head_t break_wq; 77 int halted; 78 79 /* Pending virtual interrupts */ 80 DECLARE_BITMAP(irqs_pending, LGUEST_IRQS); 81 82 struct lg_cpu_arch arch; 83 }; 84 85 /* The private info the thread maintains about the guest. */ 86 struct lguest 87 { 88 struct lguest_data __user *lguest_data; 89 struct lg_cpu cpus[NR_CPUS]; 90 unsigned int nr_cpus; 91 92 u32 pfn_limit; 93 /* This provides the offset to the base of guest-physical 94 * memory in the Launcher. */ 95 void __user *mem_base; 96 unsigned long kernel_address; 97 98 struct pgdir pgdirs[4]; 99 100 unsigned long noirq_start, noirq_end; 101 102 unsigned int stack_pages; 103 u32 tsc_khz; 104 105 /* Dead? */ 106 const char *dead; 107 }; 108 109 extern struct mutex lguest_lock; 110 111 /* core.c: */ 112 int lguest_address_ok(const struct lguest *lg, 113 unsigned long addr, unsigned long len); 114 void __lgread(struct lg_cpu *, void *, unsigned long, unsigned); 115 void __lgwrite(struct lg_cpu *, unsigned long, const void *, unsigned); 116 117 /*H:035 Using memory-copy operations like that is usually inconvient, so we 118 * have the following helper macros which read and write a specific type (often 119 * an unsigned long). 120 * 121 * This reads into a variable of the given type then returns that. */ 122 #define lgread(cpu, addr, type) \ 123 ({ type _v; __lgread((cpu), &_v, (addr), sizeof(_v)); _v; }) 124 125 /* This checks that the variable is of the given type, then writes it out. */ 126 #define lgwrite(cpu, addr, type, val) \ 127 do { \ 128 typecheck(type, val); \ 129 __lgwrite((cpu), (addr), &(val), sizeof(val)); \ 130 } while(0) 131 /* (end of memory access helper routines) :*/ 132 133 int run_guest(struct lg_cpu *cpu, unsigned long __user *user); 134 135 /* Helper macros to obtain the first 12 or the last 20 bits, this is only the 136 * first step in the migration to the kernel types. pte_pfn is already defined 137 * in the kernel. */ 138 #define pgd_flags(x) (pgd_val(x) & ~PAGE_MASK) 139 #define pgd_pfn(x) (pgd_val(x) >> PAGE_SHIFT) 140 141 /* interrupts_and_traps.c: */ 142 void maybe_do_interrupt(struct lg_cpu *cpu); 143 int deliver_trap(struct lg_cpu *cpu, unsigned int num); 144 void load_guest_idt_entry(struct lg_cpu *cpu, unsigned int i, 145 u32 low, u32 hi); 146 void guest_set_stack(struct lg_cpu *cpu, u32 seg, u32 esp, unsigned int pages); 147 void pin_stack_pages(struct lg_cpu *cpu); 148 void setup_default_idt_entries(struct lguest_ro_state *state, 149 const unsigned long *def); 150 void copy_traps(const struct lg_cpu *cpu, struct desc_struct *idt, 151 const unsigned long *def); 152 void guest_set_clockevent(struct lg_cpu *cpu, unsigned long delta); 153 void init_clockdev(struct lg_cpu *cpu); 154 bool check_syscall_vector(struct lguest *lg); 155 int init_interrupts(void); 156 void free_interrupts(void); 157 158 /* segments.c: */ 159 void setup_default_gdt_entries(struct lguest_ro_state *state); 160 void setup_guest_gdt(struct lg_cpu *cpu); 161 void load_guest_gdt(struct lg_cpu *cpu, unsigned long table, u32 num); 162 void guest_load_tls(struct lg_cpu *cpu, unsigned long tls_array); 163 void copy_gdt(const struct lg_cpu *cpu, struct desc_struct *gdt); 164 void copy_gdt_tls(const struct lg_cpu *cpu, struct desc_struct *gdt); 165 166 /* page_tables.c: */ 167 int init_guest_pagetable(struct lguest *lg); 168 void free_guest_pagetable(struct lguest *lg); 169 void guest_new_pagetable(struct lg_cpu *cpu, unsigned long pgtable); 170 void guest_set_pmd(struct lguest *lg, unsigned long gpgdir, u32 i); 171 void guest_pagetable_clear_all(struct lg_cpu *cpu); 172 void guest_pagetable_flush_user(struct lg_cpu *cpu); 173 void guest_set_pte(struct lg_cpu *cpu, unsigned long gpgdir, 174 unsigned long vaddr, pte_t val); 175 void map_switcher_in_guest(struct lg_cpu *cpu, struct lguest_pages *pages); 176 int demand_page(struct lg_cpu *cpu, unsigned long cr2, int errcode); 177 void pin_page(struct lg_cpu *cpu, unsigned long vaddr); 178 unsigned long guest_pa(struct lg_cpu *cpu, unsigned long vaddr); 179 void page_table_guest_data_init(struct lg_cpu *cpu); 180 181 /* <arch>/core.c: */ 182 void lguest_arch_host_init(void); 183 void lguest_arch_host_fini(void); 184 void lguest_arch_run_guest(struct lg_cpu *cpu); 185 void lguest_arch_handle_trap(struct lg_cpu *cpu); 186 int lguest_arch_init_hypercalls(struct lg_cpu *cpu); 187 int lguest_arch_do_hcall(struct lg_cpu *cpu, struct hcall_args *args); 188 void lguest_arch_setup_regs(struct lg_cpu *cpu, unsigned long start); 189 190 /* <arch>/switcher.S: */ 191 extern char start_switcher_text[], end_switcher_text[], switch_to_guest[]; 192 193 /* lguest_user.c: */ 194 int lguest_device_init(void); 195 void lguest_device_remove(void); 196 197 /* hypercalls.c: */ 198 void do_hypercalls(struct lg_cpu *cpu); 199 void write_timestamp(struct lg_cpu *cpu); 200 201 /*L:035 202 * Let's step aside for the moment, to study one important routine that's used 203 * widely in the Host code. 204 * 205 * There are many cases where the Guest can do something invalid, like pass crap 206 * to a hypercall. Since only the Guest kernel can make hypercalls, it's quite 207 * acceptable to simply terminate the Guest and give the Launcher a nicely 208 * formatted reason. It's also simpler for the Guest itself, which doesn't 209 * need to check most hypercalls for "success"; if you're still running, it 210 * succeeded. 211 * 212 * Once this is called, the Guest will never run again, so most Host code can 213 * call this then continue as if nothing had happened. This means many 214 * functions don't have to explicitly return an error code, which keeps the 215 * code simple. 216 * 217 * It also means that this can be called more than once: only the first one is 218 * remembered. The only trick is that we still need to kill the Guest even if 219 * we can't allocate memory to store the reason. Linux has a neat way of 220 * packing error codes into invalid pointers, so we use that here. 221 * 222 * Like any macro which uses an "if", it is safely wrapped in a run-once "do { 223 * } while(0)". 224 */ 225 #define kill_guest(cpu, fmt...) \ 226 do { \ 227 if (!(cpu)->lg->dead) { \ 228 (cpu)->lg->dead = kasprintf(GFP_ATOMIC, fmt); \ 229 if (!(cpu)->lg->dead) \ 230 (cpu)->lg->dead = ERR_PTR(-ENOMEM); \ 231 } \ 232 } while(0) 233 /* (End of aside) :*/ 234 235 #endif /* __ASSEMBLY__ */ 236 #endif /* _LGUEST_H */ 237