#ifndef _LGUEST_H #define _LGUEST_H #ifndef __ASSEMBLY__ #include #include #include #include #include #include #include #include #include void free_pagetables(void); int init_pagetables(struct page **switcher_page, unsigned int pages); struct pgdir { unsigned long gpgdir; pgd_t *pgdir; }; /* We have two pages shared with guests, per cpu. */ struct lguest_pages { /* This is the stack page mapped rw in guest */ char spare[PAGE_SIZE - sizeof(struct lguest_regs)]; struct lguest_regs regs; /* This is the host state & guest descriptor page, ro in guest */ struct lguest_ro_state state; } __attribute__((aligned(PAGE_SIZE))); #define CHANGED_IDT 1 #define CHANGED_GDT 2 #define CHANGED_GDT_TLS 4 /* Actually a subset of CHANGED_GDT */ #define CHANGED_ALL 3 struct lguest; struct lg_cpu { unsigned int id; struct lguest *lg; /* At end of a page shared mapped over lguest_pages in guest. */ unsigned long regs_page; struct lguest_regs *regs; /* If a hypercall was asked for, this points to the arguments. */ struct hcall_args *hcall; u32 next_hcall; /* Virtual clock device */ struct hrtimer hrt; /* Pending virtual interrupts */ DECLARE_BITMAP(irqs_pending, LGUEST_IRQS); struct lg_cpu_arch arch; }; /* The private info the thread maintains about the guest. */ struct lguest { struct lguest_data __user *lguest_data; struct task_struct *tsk; struct mm_struct *mm; /* == tsk->mm, but that becomes NULL on exit */ struct lg_cpu cpus[NR_CPUS]; unsigned int nr_cpus; u32 pfn_limit; /* This provides the offset to the base of guest-physical * memory in the Launcher. */ void __user *mem_base; unsigned long kernel_address; u32 cr2; int halted; int ts; u32 esp1; u8 ss1; /* Do we need to stop what we're doing and return to userspace? */ int break_out; wait_queue_head_t break_wq; /* Bitmap of what has changed: see CHANGED_* above. */ int changed; struct lguest_pages *last_pages; /* We keep a small number of these. */ u32 pgdidx; struct pgdir pgdirs[4]; unsigned long noirq_start, noirq_end; unsigned long pending_notify; /* pfn from LHCALL_NOTIFY */ unsigned int stack_pages; u32 tsc_khz; /* Dead? */ const char *dead; }; extern struct mutex lguest_lock; /* core.c: */ int lguest_address_ok(const struct lguest *lg, unsigned long addr, unsigned long len); void __lgread(struct lguest *, void *, unsigned long, unsigned); void __lgwrite(struct lguest *, unsigned long, const void *, unsigned); /*H:035 Using memory-copy operations like that is usually inconvient, so we * have the following helper macros which read and write a specific type (often * an unsigned long). * * This reads into a variable of the given type then returns that. */ #define lgread(lg, addr, type) \ ({ type _v; __lgread((lg), &_v, (addr), sizeof(_v)); _v; }) /* This checks that the variable is of the given type, then writes it out. */ #define lgwrite(lg, addr, type, val) \ do { \ typecheck(type, val); \ __lgwrite((lg), (addr), &(val), sizeof(val)); \ } while(0) /* (end of memory access helper routines) :*/ int run_guest(struct lg_cpu *cpu, unsigned long __user *user); /* Helper macros to obtain the first 12 or the last 20 bits, this is only the * first step in the migration to the kernel types. pte_pfn is already defined * in the kernel. */ #define pgd_flags(x) (pgd_val(x) & ~PAGE_MASK) #define pte_flags(x) (pte_val(x) & ~PAGE_MASK) #define pgd_pfn(x) (pgd_val(x) >> PAGE_SHIFT) /* interrupts_and_traps.c: */ void maybe_do_interrupt(struct lg_cpu *cpu); int deliver_trap(struct lg_cpu *cpu, unsigned int num); void load_guest_idt_entry(struct lg_cpu *cpu, unsigned int i, u32 low, u32 hi); void guest_set_stack(struct lguest *lg, u32 seg, u32 esp, unsigned int pages); void pin_stack_pages(struct lguest *lg); void setup_default_idt_entries(struct lguest_ro_state *state, const unsigned long *def); void copy_traps(const struct lg_cpu *cpu, struct desc_struct *idt, const unsigned long *def); void guest_set_clockevent(struct lg_cpu *cpu, unsigned long delta); void init_clockdev(struct lg_cpu *cpu); bool check_syscall_vector(struct lguest *lg); int init_interrupts(void); void free_interrupts(void); /* segments.c: */ void setup_default_gdt_entries(struct lguest_ro_state *state); void setup_guest_gdt(struct lg_cpu *cpu); void load_guest_gdt(struct lg_cpu *cpu, unsigned long table, u32 num); void guest_load_tls(struct lg_cpu *cpu, unsigned long tls_array); void copy_gdt(const struct lg_cpu *cpu, struct desc_struct *gdt); void copy_gdt_tls(const struct lg_cpu *cpu, struct desc_struct *gdt); /* page_tables.c: */ int init_guest_pagetable(struct lguest *lg, unsigned long pgtable); void free_guest_pagetable(struct lguest *lg); void guest_new_pagetable(struct lguest *lg, unsigned long pgtable); void guest_set_pmd(struct lguest *lg, unsigned long gpgdir, u32 i); void guest_pagetable_clear_all(struct lguest *lg); void guest_pagetable_flush_user(struct lguest *lg); void guest_set_pte(struct lguest *lg, unsigned long gpgdir, unsigned long vaddr, pte_t val); void map_switcher_in_guest(struct lg_cpu *cpu, struct lguest_pages *pages); int demand_page(struct lguest *info, unsigned long cr2, int errcode); void pin_page(struct lguest *lg, unsigned long vaddr); unsigned long guest_pa(struct lguest *lg, unsigned long vaddr); void page_table_guest_data_init(struct lguest *lg); /* /core.c: */ void lguest_arch_host_init(void); void lguest_arch_host_fini(void); void lguest_arch_run_guest(struct lg_cpu *cpu); void lguest_arch_handle_trap(struct lg_cpu *cpu); int lguest_arch_init_hypercalls(struct lg_cpu *cpu); int lguest_arch_do_hcall(struct lg_cpu *cpu, struct hcall_args *args); void lguest_arch_setup_regs(struct lg_cpu *cpu, unsigned long start); /* /switcher.S: */ extern char start_switcher_text[], end_switcher_text[], switch_to_guest[]; /* lguest_user.c: */ int lguest_device_init(void); void lguest_device_remove(void); /* hypercalls.c: */ void do_hypercalls(struct lg_cpu *cpu); void write_timestamp(struct lguest *lg); /*L:035 * Let's step aside for the moment, to study one important routine that's used * widely in the Host code. * * There are many cases where the Guest can do something invalid, like pass crap * to a hypercall. Since only the Guest kernel can make hypercalls, it's quite * acceptable to simply terminate the Guest and give the Launcher a nicely * formatted reason. It's also simpler for the Guest itself, which doesn't * need to check most hypercalls for "success"; if you're still running, it * succeeded. * * Once this is called, the Guest will never run again, so most Host code can * call this then continue as if nothing had happened. This means many * functions don't have to explicitly return an error code, which keeps the * code simple. * * It also means that this can be called more than once: only the first one is * remembered. The only trick is that we still need to kill the Guest even if * we can't allocate memory to store the reason. Linux has a neat way of * packing error codes into invalid pointers, so we use that here. * * Like any macro which uses an "if", it is safely wrapped in a run-once "do { * } while(0)". */ #define kill_guest(lg, fmt...) \ do { \ if (!(lg)->dead) { \ (lg)->dead = kasprintf(GFP_ATOMIC, fmt); \ if (!(lg)->dead) \ (lg)->dead = ERR_PTR(-ENOMEM); \ } \ } while(0) /* (End of aside) :*/ #endif /* __ASSEMBLY__ */ #endif /* _LGUEST_H */