diff options
Diffstat (limited to 'drivers/lguest/lg.h')
| -rw-r--r-- | drivers/lguest/lg.h | 300 |
1 files changed, 300 insertions, 0 deletions
diff --git a/drivers/lguest/lg.h b/drivers/lguest/lg.h new file mode 100644 index 000000000000..64f0abed317c --- /dev/null +++ b/drivers/lguest/lg.h @@ -0,0 +1,300 @@ +#ifndef _LGUEST_H +#define _LGUEST_H + +#include <asm/desc.h> + +#define GDT_ENTRY_LGUEST_CS 10 +#define GDT_ENTRY_LGUEST_DS 11 +#define LGUEST_CS (GDT_ENTRY_LGUEST_CS * 8) +#define LGUEST_DS (GDT_ENTRY_LGUEST_DS * 8) + +#ifndef __ASSEMBLY__ +#include <linux/types.h> +#include <linux/init.h> +#include <linux/stringify.h> +#include <linux/binfmts.h> +#include <linux/futex.h> +#include <linux/lguest.h> +#include <linux/lguest_launcher.h> +#include <linux/wait.h> +#include <linux/err.h> +#include <asm/semaphore.h> +#include "irq_vectors.h" + +#define GUEST_PL 1 + +struct lguest_regs +{ + /* Manually saved part. */ + unsigned long ebx, ecx, edx; + unsigned long esi, edi, ebp; + unsigned long gs; + unsigned long eax; + unsigned long fs, ds, es; + unsigned long trapnum, errcode; + /* Trap pushed part */ + unsigned long eip; + unsigned long cs; + unsigned long eflags; + unsigned long esp; + unsigned long ss; +}; + +void free_pagetables(void); +int init_pagetables(struct page **switcher_page, unsigned int pages); + +/* Full 4G segment descriptors, suitable for CS and DS. */ +#define FULL_EXEC_SEGMENT ((struct desc_struct){0x0000ffff, 0x00cf9b00}) +#define FULL_SEGMENT ((struct desc_struct){0x0000ffff, 0x00cf9300}) + +struct lguest_dma_info +{ + struct list_head list; + union futex_key key; + unsigned long dmas; + u16 next_dma; + u16 num_dmas; + u16 guestid; + u8 interrupt; /* 0 when not registered */ +}; + +/*H:310 The page-table code owes a great debt of gratitude to Andi Kleen. He + * reviewed the original code which used "u32" for all page table entries, and + * insisted that it would be far clearer with explicit typing. I thought it + * was overkill, but he was right: it is much clearer than it was before. + * + * We have separate types for the Guest's ptes & pgds and the shadow ptes & + * pgds. There's already a Linux type for these (pte_t and pgd_t) but they + * change depending on kernel config options (PAE). */ + +/* Each entry is identical: lower 12 bits of flags and upper 20 bits for the + * "page frame number" (0 == first physical page, etc). They are different + * types so the compiler will warn us if we mix them improperly. */ +typedef union { + struct { unsigned flags:12, pfn:20; }; + struct { unsigned long val; } raw; +} spgd_t; +typedef union { + struct { unsigned flags:12, pfn:20; }; + struct { unsigned long val; } raw; +} spte_t; +typedef union { + struct { unsigned flags:12, pfn:20; }; + struct { unsigned long val; } raw; +} gpgd_t; +typedef union { + struct { unsigned flags:12, pfn:20; }; + struct { unsigned long val; } raw; +} gpte_t; + +/* We have two convenient macros to convert a "raw" value as handed to us by + * the Guest into the correct Guest PGD or PTE type. */ +#define mkgpte(_val) ((gpte_t){.raw.val = _val}) +#define mkgpgd(_val) ((gpgd_t){.raw.val = _val}) +/*:*/ + +struct pgdir +{ + unsigned long cr3; + spgd_t *pgdir; +}; + +/* This is a guest-specific page (mapped ro) into the guest. */ +struct lguest_ro_state +{ + /* Host information we need to restore when we switch back. */ + u32 host_cr3; + struct Xgt_desc_struct host_idt_desc; + struct Xgt_desc_struct host_gdt_desc; + u32 host_sp; + + /* Fields which are used when guest is running. */ + struct Xgt_desc_struct guest_idt_desc; + struct Xgt_desc_struct guest_gdt_desc; + struct i386_hw_tss guest_tss; + struct desc_struct guest_idt[IDT_ENTRIES]; + struct desc_struct guest_gdt[GDT_ENTRIES]; +}; + +/* 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 + +/* The private info the thread maintains about the guest. */ +struct lguest +{ + /* At end of a page shared mapped over lguest_pages in guest. */ + unsigned long regs_page; + struct lguest_regs *regs; + struct lguest_data __user *lguest_data; + struct task_struct *tsk; + struct mm_struct *mm; /* == tsk->mm, but that becomes NULL on exit */ + u16 guestid; + u32 pfn_limit; + u32 page_offset; + u32 cr2; + int halted; + int ts; + u32 next_hcall; + 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]; + + /* Cached wakeup: we hold a reference to this task. */ + struct task_struct *wake; + + unsigned long noirq_start, noirq_end; + int dma_is_pending; + unsigned long pending_dma; /* struct lguest_dma */ + unsigned long pending_key; /* address they're sending to */ + + unsigned int stack_pages; + u32 tsc_khz; + + struct lguest_dma_info dma[LGUEST_MAX_DMA]; + + /* Dead? */ + const char *dead; + + /* The GDT entries copied into lguest_ro_state when running. */ + struct desc_struct gdt[GDT_ENTRIES]; + + /* The IDT entries: some copied into lguest_ro_state when running. */ + struct desc_struct idt[FIRST_EXTERNAL_VECTOR+LGUEST_IRQS]; + struct desc_struct syscall_idt; + + /* Virtual clock device */ + struct hrtimer hrt; + + /* Pending virtual interrupts */ + DECLARE_BITMAP(irqs_pending, LGUEST_IRQS); +}; + +extern struct lguest lguests[]; +extern struct mutex lguest_lock; + +/* core.c: */ +u32 lgread_u32(struct lguest *lg, unsigned long addr); +void lgwrite_u32(struct lguest *lg, unsigned long addr, u32 val); +void lgread(struct lguest *lg, void *buf, unsigned long addr, unsigned len); +void lgwrite(struct lguest *lg, unsigned long, const void *buf, unsigned len); +int find_free_guest(void); +int lguest_address_ok(const struct lguest *lg, + unsigned long addr, unsigned long len); +int run_guest(struct lguest *lg, unsigned long __user *user); + + +/* interrupts_and_traps.c: */ +void maybe_do_interrupt(struct lguest *lg); +int deliver_trap(struct lguest *lg, unsigned int num); +void load_guest_idt_entry(struct lguest *lg, 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 lguest *lg, struct desc_struct *idt, + const unsigned long *def); +void guest_set_clockevent(struct lguest *lg, unsigned long delta); +void init_clockdev(struct lguest *lg); + +/* segments.c: */ +void setup_default_gdt_entries(struct lguest_ro_state *state); +void setup_guest_gdt(struct lguest *lg); +void load_guest_gdt(struct lguest *lg, unsigned long table, u32 num); +void guest_load_tls(struct lguest *lg, unsigned long tls_array); +void copy_gdt(const struct lguest *lg, struct desc_struct *gdt); +void copy_gdt_tls(const struct lguest *lg, 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 cr3, 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 cr3, + unsigned long vaddr, gpte_t val); +void map_switcher_in_guest(struct lguest *lg, struct lguest_pages *pages); +int demand_page(struct lguest *info, unsigned long cr2, int errcode); +void pin_page(struct lguest *lg, unsigned long vaddr); + +/* lguest_user.c: */ +int lguest_device_init(void); +void lguest_device_remove(void); + +/* io.c: */ +void lguest_io_init(void); +int bind_dma(struct lguest *lg, + unsigned long key, unsigned long udma, u16 numdmas, u8 interrupt); +void send_dma(struct lguest *info, unsigned long key, unsigned long udma); +void release_all_dma(struct lguest *lg); +unsigned long get_dma_buffer(struct lguest *lg, unsigned long key, + unsigned long *interrupt); + +/* hypercalls.c: */ +void do_hypercalls(struct lguest *lg); +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 does 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) :*/ + +static inline unsigned long guest_pa(struct lguest *lg, unsigned long vaddr) +{ + return vaddr - lg->page_offset; +} +#endif /* __ASSEMBLY__ */ +#endif /* _LGUEST_H */ |