drivers/lguest/lg.h - kernel/prism - Git at Google

 #ifndef _LGUEST_H
 #define _LGUEST_H

 #ifndef __ASSEMBLY__
 #include <linux/types.h>
 #include <linux/init.h>
 #include <linux/stringify.h>
 #include <linux/lguest.h>
 #include <linux/lguest_launcher.h>
 #include <linux/wait.h>
 #include <linux/hrtimer.h>
 #include <linux/err.h>

 #include <asm/lguest.h>

 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 lg_cpu {
 	unsigned int id;
 	struct lguest *lg;
 	struct task_struct *tsk;
 	struct mm_struct *mm; 	/* == tsk->mm, but that becomes NULL on exit */

 	u32 cr2;
 	int ts;
 	u32 esp1;
 	u16 ss1;

 	/* Bitmap of what has changed: see CHANGED_* above. */
 	int changed;

 	unsigned long pending_notify; /* pfn from LHCALL_NOTIFY */

 	/* At end of a page shared mapped over lguest_pages in guest. */
 	unsigned long regs_page;
 	struct lguest_regs *regs;

 	struct lguest_pages *last_pages;

 	int cpu_pgd; /* Which pgd this cpu is currently using */

 	/* If a hypercall was asked for, this points to the arguments. */
 	struct hcall_args *hcall;
 	u32 next_hcall;

 	/* Virtual clock device */
 	struct hrtimer hrt;

 	/* Did the Guest tell us to halt? */
 	int halted;

 	/* Pending virtual interrupts */
 	DECLARE_BITMAP(irqs_pending, LGUEST_IRQS);

 	struct lg_cpu_arch arch;
 };

 struct lg_eventfd {
 	unsigned long addr;
 	struct eventfd_ctx *event;
 };

 struct lg_eventfd_map {
 	unsigned int num;
 	struct lg_eventfd map[];
 };

 /* The private info the thread maintains about the guest. */
 struct lguest {
 	struct lguest_data __user *lguest_data;
 	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;

 	struct pgdir pgdirs[4];

 	unsigned long noirq_start, noirq_end;

 	unsigned int stack_pages;
 	u32 tsc_khz;

 	struct lg_eventfd_map *eventfds;

 	/* Dead? */
 	const char *dead;
 };

 extern struct mutex lguest_lock;

 /* core.c: */
 bool lguest_address_ok(const struct lguest *lg,
 		       unsigned long addr, unsigned long len);
 void __lgread(struct lg_cpu *, void *, unsigned long, unsigned);
 void __lgwrite(struct lg_cpu *, 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(cpu, addr, type)						\
 	({ type _v; __lgread((cpu), &_v, (addr), sizeof(_v)); _v; })

 /* This checks that the variable is of the given type, then writes it out. */
 #define lgwrite(cpu, addr, type, val)				\
 	do {							\
 		typecheck(type, val);				\
 		__lgwrite((cpu), (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 pgd_pfn(x)	(pgd_val(x) >> PAGE_SHIFT)
 #define pmd_flags(x)    (pmd_val(x) & ~PAGE_MASK)
 #define pmd_pfn(x)	(pmd_val(x) >> PAGE_SHIFT)

 /* interrupts_and_traps.c: */
 unsigned int interrupt_pending(struct lg_cpu *cpu, bool *more);
 void try_deliver_interrupt(struct lg_cpu *cpu, unsigned int irq, bool more);
 void set_interrupt(struct lg_cpu *cpu, unsigned int irq);
 bool 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 lg_cpu *cpu, u32 seg, u32 esp, unsigned int pages);
 void pin_stack_pages(struct lg_cpu *cpu);
 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);
 bool send_notify_to_eventfd(struct lg_cpu *cpu);
 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_entry(struct lg_cpu *cpu, unsigned int i,
 			  u32 low, u32 hi);
 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);
 void free_guest_pagetable(struct lguest *lg);
 void guest_new_pagetable(struct lg_cpu *cpu, unsigned long pgtable);
 void guest_set_pgd(struct lguest *lg, unsigned long gpgdir, u32 i);
 #ifdef CONFIG_X86_PAE
 void guest_set_pmd(struct lguest *lg, unsigned long gpgdir, u32 i);
 #endif
 void guest_pagetable_clear_all(struct lg_cpu *cpu);
 void guest_pagetable_flush_user(struct lg_cpu *cpu);
 void guest_set_pte(struct lg_cpu *cpu, unsigned long gpgdir,
 		   unsigned long vaddr, pte_t val);
 void map_switcher_in_guest(struct lg_cpu *cpu, struct lguest_pages *pages);
 bool demand_page(struct lg_cpu *cpu, unsigned long cr2, int errcode);
 void pin_page(struct lg_cpu *cpu, unsigned long vaddr);
 unsigned long guest_pa(struct lg_cpu *cpu, unsigned long vaddr);
 void page_table_guest_data_init(struct lg_cpu *cpu);

 /* <arch>/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);

 /* <arch>/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 lg_cpu *cpu);

 /*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(cpu, fmt...)					\
 do {								\
 	if (!(cpu)->lg->dead) {					\
 		(cpu)->lg->dead = kasprintf(GFP_ATOMIC, fmt);	\
 		if (!(cpu)->lg->dead)				\
 			(cpu)->lg->dead = ERR_PTR(-ENOMEM);	\
 	}							\
 } while(0)
 /* (End of aside) :*/

 #endif	/* __ASSEMBLY__ */
 #endif	/* _LGUEST_H */
	#ifndef _LGUEST_H
	#define _LGUEST_H

	#ifndef __ASSEMBLY__
	#include <linux/types.h>
	#include <linux/init.h>
	#include <linux/stringify.h>
	#include <linux/lguest.h>
	#include <linux/lguest_launcher.h>
	#include <linux/wait.h>
	#include <linux/hrtimer.h>
	#include <linux/err.h>

	#include <asm/lguest.h>

	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 lg_cpu {
	unsigned int id;
	struct lguest *lg;
	struct task_struct *tsk;
	struct mm_struct mm; / == tsk->mm, but that becomes NULL on exit */

	u32 cr2;
	int ts;
	u32 esp1;
	u16 ss1;

	/* Bitmap of what has changed: see CHANGED_* above. */
	int changed;

	unsigned long pending_notify; /* pfn from LHCALL_NOTIFY */

	/* At end of a page shared mapped over lguest_pages in guest. */
	unsigned long regs_page;
	struct lguest_regs *regs;

	struct lguest_pages *last_pages;

	int cpu_pgd; /* Which pgd this cpu is currently using */

	/* If a hypercall was asked for, this points to the arguments. */
	struct hcall_args *hcall;
	u32 next_hcall;

	/* Virtual clock device */
	struct hrtimer hrt;

	/* Did the Guest tell us to halt? */
	int halted;

	/* Pending virtual interrupts */
	DECLARE_BITMAP(irqs_pending, LGUEST_IRQS);

	struct lg_cpu_arch arch;
	};

	struct lg_eventfd {
	unsigned long addr;
	struct eventfd_ctx *event;
	};

	struct lg_eventfd_map {
	unsigned int num;
	struct lg_eventfd map[];
	};

	/* The private info the thread maintains about the guest. */
	struct lguest {
	struct lguest_data __user *lguest_data;
	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;

	struct pgdir pgdirs[4];

	unsigned long noirq_start, noirq_end;

	unsigned int stack_pages;
	u32 tsc_khz;

	struct lg_eventfd_map *eventfds;

	/* Dead? */
	const char *dead;
	};

	extern struct mutex lguest_lock;

	/* core.c: */
	bool lguest_address_ok(const struct lguest *lg,
	unsigned long addr, unsigned long len);
	void __lgread(struct lg_cpu , void , unsigned long, unsigned);
	void __lgwrite(struct lg_cpu , 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(cpu, addr, type) \
	({ type _v; __lgread((cpu), &_v, (addr), sizeof(_v)); _v; })

	/* This checks that the variable is of the given type, then writes it out. */
	#define lgwrite(cpu, addr, type, val) \
	do { \
	typecheck(type, val); \
	__lgwrite((cpu), (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 pgd_pfn(x) (pgd_val(x) >> PAGE_SHIFT)
	#define pmd_flags(x) (pmd_val(x) & ~PAGE_MASK)
	#define pmd_pfn(x) (pmd_val(x) >> PAGE_SHIFT)

	/* interrupts_and_traps.c: */
	unsigned int interrupt_pending(struct lg_cpu cpu, bool more);
	void try_deliver_interrupt(struct lg_cpu *cpu, unsigned int irq, bool more);
	void set_interrupt(struct lg_cpu *cpu, unsigned int irq);
	bool 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 lg_cpu *cpu, u32 seg, u32 esp, unsigned int pages);
	void pin_stack_pages(struct lg_cpu *cpu);
	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);
	bool send_notify_to_eventfd(struct lg_cpu *cpu);
	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_entry(struct lg_cpu *cpu, unsigned int i,
	u32 low, u32 hi);
	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);
	void free_guest_pagetable(struct lguest *lg);
	void guest_new_pagetable(struct lg_cpu *cpu, unsigned long pgtable);
	void guest_set_pgd(struct lguest *lg, unsigned long gpgdir, u32 i);
	#ifdef CONFIG_X86_PAE
	void guest_set_pmd(struct lguest *lg, unsigned long gpgdir, u32 i);
	#endif
	void guest_pagetable_clear_all(struct lg_cpu *cpu);
	void guest_pagetable_flush_user(struct lg_cpu *cpu);
	void guest_set_pte(struct lg_cpu *cpu, unsigned long gpgdir,
	unsigned long vaddr, pte_t val);
	void map_switcher_in_guest(struct lg_cpu cpu, struct lguest_pages pages);
	bool demand_page(struct lg_cpu *cpu, unsigned long cr2, int errcode);
	void pin_page(struct lg_cpu *cpu, unsigned long vaddr);
	unsigned long guest_pa(struct lg_cpu *cpu, unsigned long vaddr);
	void page_table_guest_data_init(struct lg_cpu *cpu);

	/* <arch>/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);

	/* <arch>/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 lg_cpu *cpu);

	/*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(cpu, fmt...) \
	do { \
	if (!(cpu)->lg->dead) { \
	(cpu)->lg->dead = kasprintf(GFP_ATOMIC, fmt); \
	if (!(cpu)->lg->dead) \
	(cpu)->lg->dead = ERR_PTR(-ENOMEM); \
	} \
	} while(0)
	/* (End of aside) :*/

	#endif /* __ASSEMBLY__ */
	#endif /* _LGUEST_H */