47436aa4ad
1) This allows us to get alot closer to booting bzImages. 2) It means we don't have to know page_offset. 3) The Guest needs to modify the boot pagetables to create the PAGE_OFFSET mapping before jumping to C code. 4) guest_pa() walks the page tables rather than using page_offset. 5) We don't use page_offset to figure out whether to emulate: it was always kinda quesationable, and won't work for instructions done before remapping (bzImage unpacking in particular). 6) We still want the kernel address for tlb flushing: have the initial hypercall give us that, too. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
235 lines
7.7 KiB
C
235 lines
7.7 KiB
C
#ifndef _LGUEST_H
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#define _LGUEST_H
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#ifndef __ASSEMBLY__
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#include <linux/types.h>
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#include <linux/init.h>
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#include <linux/stringify.h>
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#include <linux/futex.h>
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#include <linux/lguest.h>
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#include <linux/lguest_launcher.h>
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#include <linux/wait.h>
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#include <linux/err.h>
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#include <asm/semaphore.h>
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#include <asm/lguest.h>
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void free_pagetables(void);
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int init_pagetables(struct page **switcher_page, unsigned int pages);
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struct lguest_dma_info
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{
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struct list_head list;
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union futex_key key;
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unsigned long dmas;
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struct lguest *owner;
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u16 next_dma;
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u16 num_dmas;
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u8 interrupt; /* 0 when not registered */
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};
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struct pgdir
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{
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unsigned long gpgdir;
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pgd_t *pgdir;
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};
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/* We have two pages shared with guests, per cpu. */
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struct lguest_pages
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{
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/* This is the stack page mapped rw in guest */
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char spare[PAGE_SIZE - sizeof(struct lguest_regs)];
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struct lguest_regs regs;
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/* This is the host state & guest descriptor page, ro in guest */
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struct lguest_ro_state state;
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} __attribute__((aligned(PAGE_SIZE)));
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#define CHANGED_IDT 1
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#define CHANGED_GDT 2
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#define CHANGED_GDT_TLS 4 /* Actually a subset of CHANGED_GDT */
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#define CHANGED_ALL 3
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/* The private info the thread maintains about the guest. */
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struct lguest
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{
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/* At end of a page shared mapped over lguest_pages in guest. */
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unsigned long regs_page;
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struct lguest_regs *regs;
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struct lguest_data __user *lguest_data;
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struct task_struct *tsk;
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struct mm_struct *mm; /* == tsk->mm, but that becomes NULL on exit */
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u32 pfn_limit;
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/* This provides the offset to the base of guest-physical
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* memory in the Launcher. */
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void __user *mem_base;
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unsigned long kernel_address;
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u32 cr2;
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int halted;
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int ts;
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u32 next_hcall;
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u32 esp1;
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u8 ss1;
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/* If a hypercall was asked for, this points to the arguments. */
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struct hcall_args *hcall;
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/* Do we need to stop what we're doing and return to userspace? */
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int break_out;
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wait_queue_head_t break_wq;
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/* Bitmap of what has changed: see CHANGED_* above. */
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int changed;
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struct lguest_pages *last_pages;
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/* We keep a small number of these. */
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u32 pgdidx;
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struct pgdir pgdirs[4];
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/* Cached wakeup: we hold a reference to this task. */
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struct task_struct *wake;
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unsigned long noirq_start, noirq_end;
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int dma_is_pending;
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unsigned long pending_dma; /* struct lguest_dma */
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unsigned long pending_key; /* address they're sending to */
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unsigned int stack_pages;
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u32 tsc_khz;
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struct lguest_dma_info dma[LGUEST_MAX_DMA];
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/* Dead? */
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const char *dead;
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struct lguest_arch arch;
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/* Virtual clock device */
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struct hrtimer hrt;
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/* Pending virtual interrupts */
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DECLARE_BITMAP(irqs_pending, LGUEST_IRQS);
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};
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extern struct mutex lguest_lock;
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/* core.c: */
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u32 lgread_u32(struct lguest *lg, unsigned long addr);
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void lgwrite_u32(struct lguest *lg, unsigned long addr, u32 val);
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void lgread(struct lguest *lg, void *buf, unsigned long addr, unsigned len);
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void lgwrite(struct lguest *lg, unsigned long, const void *buf, unsigned len);
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int lguest_address_ok(const struct lguest *lg,
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unsigned long addr, unsigned long len);
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int run_guest(struct lguest *lg, unsigned long __user *user);
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/* Helper macros to obtain the first 12 or the last 20 bits, this is only the
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* first step in the migration to the kernel types. pte_pfn is already defined
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* in the kernel. */
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#define pgd_flags(x) (pgd_val(x) & ~PAGE_MASK)
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#define pte_flags(x) (pte_val(x) & ~PAGE_MASK)
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#define pgd_pfn(x) (pgd_val(x) >> PAGE_SHIFT)
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/* interrupts_and_traps.c: */
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void maybe_do_interrupt(struct lguest *lg);
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int deliver_trap(struct lguest *lg, unsigned int num);
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void load_guest_idt_entry(struct lguest *lg, unsigned int i, u32 low, u32 hi);
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void guest_set_stack(struct lguest *lg, u32 seg, u32 esp, unsigned int pages);
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void pin_stack_pages(struct lguest *lg);
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void setup_default_idt_entries(struct lguest_ro_state *state,
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const unsigned long *def);
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void copy_traps(const struct lguest *lg, struct desc_struct *idt,
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const unsigned long *def);
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void guest_set_clockevent(struct lguest *lg, unsigned long delta);
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void init_clockdev(struct lguest *lg);
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bool check_syscall_vector(struct lguest *lg);
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int init_interrupts(void);
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void free_interrupts(void);
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/* segments.c: */
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void setup_default_gdt_entries(struct lguest_ro_state *state);
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void setup_guest_gdt(struct lguest *lg);
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void load_guest_gdt(struct lguest *lg, unsigned long table, u32 num);
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void guest_load_tls(struct lguest *lg, unsigned long tls_array);
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void copy_gdt(const struct lguest *lg, struct desc_struct *gdt);
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void copy_gdt_tls(const struct lguest *lg, struct desc_struct *gdt);
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/* page_tables.c: */
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int init_guest_pagetable(struct lguest *lg, unsigned long pgtable);
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void free_guest_pagetable(struct lguest *lg);
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void guest_new_pagetable(struct lguest *lg, unsigned long pgtable);
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void guest_set_pmd(struct lguest *lg, unsigned long gpgdir, u32 i);
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void guest_pagetable_clear_all(struct lguest *lg);
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void guest_pagetable_flush_user(struct lguest *lg);
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void guest_set_pte(struct lguest *lg, unsigned long gpgdir,
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unsigned long vaddr, pte_t val);
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void map_switcher_in_guest(struct lguest *lg, struct lguest_pages *pages);
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int demand_page(struct lguest *info, unsigned long cr2, int errcode);
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void pin_page(struct lguest *lg, unsigned long vaddr);
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unsigned long guest_pa(struct lguest *lg, unsigned long vaddr);
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void page_table_guest_data_init(struct lguest *lg);
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/* <arch>/core.c: */
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void lguest_arch_host_init(void);
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void lguest_arch_host_fini(void);
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void lguest_arch_run_guest(struct lguest *lg);
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void lguest_arch_handle_trap(struct lguest *lg);
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int lguest_arch_init_hypercalls(struct lguest *lg);
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int lguest_arch_do_hcall(struct lguest *lg, struct hcall_args *args);
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void lguest_arch_setup_regs(struct lguest *lg, unsigned long start);
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/* <arch>/switcher.S: */
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extern char start_switcher_text[], end_switcher_text[], switch_to_guest[];
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/* lguest_user.c: */
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int lguest_device_init(void);
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void lguest_device_remove(void);
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/* io.c: */
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void lguest_io_init(void);
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int bind_dma(struct lguest *lg,
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unsigned long key, unsigned long udma, u16 numdmas, u8 interrupt);
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void send_dma(struct lguest *info, unsigned long key, unsigned long udma);
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void release_all_dma(struct lguest *lg);
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unsigned long get_dma_buffer(struct lguest *lg, unsigned long key,
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unsigned long *interrupt);
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/* hypercalls.c: */
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void do_hypercalls(struct lguest *lg);
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void write_timestamp(struct lguest *lg);
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/*L:035
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* Let's step aside for the moment, to study one important routine that's used
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* widely in the Host code.
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*
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* There are many cases where the Guest does something invalid, like pass crap
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* to a hypercall. Since only the Guest kernel can make hypercalls, it's quite
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* acceptable to simply terminate the Guest and give the Launcher a nicely
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* formatted reason. It's also simpler for the Guest itself, which doesn't
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* need to check most hypercalls for "success"; if you're still running, it
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* succeeded.
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*
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* Once this is called, the Guest will never run again, so most Host code can
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* call this then continue as if nothing had happened. This means many
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* functions don't have to explicitly return an error code, which keeps the
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* code simple.
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*
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* It also means that this can be called more than once: only the first one is
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* remembered. The only trick is that we still need to kill the Guest even if
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* we can't allocate memory to store the reason. Linux has a neat way of
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* packing error codes into invalid pointers, so we use that here.
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*
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* Like any macro which uses an "if", it is safely wrapped in a run-once "do {
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* } while(0)".
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*/
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#define kill_guest(lg, fmt...) \
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do { \
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if (!(lg)->dead) { \
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(lg)->dead = kasprintf(GFP_ATOMIC, fmt); \
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if (!(lg)->dead) \
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(lg)->dead = ERR_PTR(-ENOMEM); \
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} \
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} while(0)
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/* (End of aside) :*/
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#endif /* __ASSEMBLY__ */
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#endif /* _LGUEST_H */
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