diff options
| -rw-r--r-- | include/asm-i386/paravirt.h | 131 |
1 files changed, 121 insertions, 10 deletions
diff --git a/include/asm-i386/paravirt.h b/include/asm-i386/paravirt.h index 837457b42db..8bfaf10d996 100644 --- a/include/asm-i386/paravirt.h +++ b/include/asm-i386/paravirt.h @@ -21,6 +21,14 @@ struct Xgt_desc_struct; struct tss_struct; struct mm_struct; struct desc_struct; + +/* Lazy mode for batching updates / context switch */ +enum paravirt_lazy_mode { + PARAVIRT_LAZY_NONE = 0, + PARAVIRT_LAZY_MMU = 1, + PARAVIRT_LAZY_CPU = 2, +}; + struct paravirt_ops { unsigned int kernel_rpl; @@ -37,22 +45,33 @@ struct paravirt_ops */ unsigned (*patch)(u8 type, u16 clobber, void *firstinsn, unsigned len); + /* Basic arch-specific setup */ void (*arch_setup)(void); char *(*memory_setup)(void); void (*init_IRQ)(void); + void (*time_init)(void); + /* + * Called before/after init_mm pagetable setup. setup_start + * may reset %cr3, and may pre-install parts of the pagetable; + * pagetable setup is expected to preserve any existing + * mapping. + */ void (*pagetable_setup_start)(pgd_t *pgd_base); void (*pagetable_setup_done)(pgd_t *pgd_base); + /* Print a banner to identify the environment */ void (*banner)(void); + /* Set and set time of day */ unsigned long (*get_wallclock)(void); int (*set_wallclock)(unsigned long); - void (*time_init)(void); + /* cpuid emulation, mostly so that caps bits can be disabled */ void (*cpuid)(unsigned int *eax, unsigned int *ebx, unsigned int *ecx, unsigned int *edx); + /* hooks for various privileged instructions */ unsigned long (*get_debugreg)(int regno); void (*set_debugreg)(int regno, unsigned long value); @@ -71,15 +90,23 @@ struct paravirt_ops unsigned long (*read_cr4)(void); void (*write_cr4)(unsigned long); + /* + * Get/set interrupt state. save_fl and restore_fl are only + * expected to use X86_EFLAGS_IF; all other bits + * returned from save_fl are undefined, and may be ignored by + * restore_fl. + */ unsigned long (*save_fl)(void); void (*restore_fl)(unsigned long); void (*irq_disable)(void); void (*irq_enable)(void); void (*safe_halt)(void); void (*halt)(void); + void (*wbinvd)(void); - /* err = 0/-EFAULT. wrmsr returns 0/-EFAULT. */ + /* MSR, PMC and TSR operations. + err = 0/-EFAULT. wrmsr returns 0/-EFAULT. */ u64 (*read_msr)(unsigned int msr, int *err); int (*write_msr)(unsigned int msr, u64 val); @@ -88,6 +115,7 @@ struct paravirt_ops u64 (*get_scheduled_cycles)(void); unsigned long (*get_cpu_khz)(void); + /* Segment descriptor handling */ void (*load_tr_desc)(void); void (*load_gdt)(const struct Xgt_desc_struct *); void (*load_idt)(const struct Xgt_desc_struct *); @@ -105,9 +133,12 @@ struct paravirt_ops void (*load_esp0)(struct tss_struct *tss, struct thread_struct *t); void (*set_iopl_mask)(unsigned mask); - void (*io_delay)(void); + /* + * Hooks for intercepting the creation/use/destruction of an + * mm_struct. + */ void (*activate_mm)(struct mm_struct *prev, struct mm_struct *next); void (*dup_mmap)(struct mm_struct *oldmm, @@ -115,30 +146,43 @@ struct paravirt_ops void (*exit_mmap)(struct mm_struct *mm); #ifdef CONFIG_X86_LOCAL_APIC + /* + * Direct APIC operations, principally for VMI. Ideally + * these shouldn't be in this interface. + */ void (*apic_write)(unsigned long reg, unsigned long v); void (*apic_write_atomic)(unsigned long reg, unsigned long v); unsigned long (*apic_read)(unsigned long reg); void (*setup_boot_clock)(void); void (*setup_secondary_clock)(void); + + void (*startup_ipi_hook)(int phys_apicid, + unsigned long start_eip, + unsigned long start_esp); #endif + /* TLB operations */ void (*flush_tlb_user)(void); void (*flush_tlb_kernel)(void); void (*flush_tlb_single)(unsigned long addr); void (*map_pt_hook)(int type, pte_t *va, u32 pfn); + /* Hooks for allocating/releasing pagetable pages */ void (*alloc_pt)(u32 pfn); void (*alloc_pd)(u32 pfn); void (*alloc_pd_clone)(u32 pfn, u32 clonepfn, u32 start, u32 count); void (*release_pt)(u32 pfn); void (*release_pd)(u32 pfn); + /* Pagetable manipulation functions */ void (*set_pte)(pte_t *ptep, pte_t pteval); - void (*set_pte_at)(struct mm_struct *mm, unsigned long addr, pte_t *ptep, pte_t pteval); + void (*set_pte_at)(struct mm_struct *mm, unsigned long addr, + pte_t *ptep, pte_t pteval); void (*set_pmd)(pmd_t *pmdp, pmd_t pmdval); void (*pte_update)(struct mm_struct *mm, unsigned long addr, pte_t *ptep); - void (*pte_update_defer)(struct mm_struct *mm, unsigned long addr, pte_t *ptep); + void (*pte_update_defer)(struct mm_struct *mm, + unsigned long addr, pte_t *ptep); pte_t (*ptep_get_and_clear)(pte_t *ptep); @@ -164,13 +208,12 @@ struct paravirt_ops pgd_t (*make_pgd)(unsigned long pgd); #endif - void (*set_lazy_mode)(int mode); + /* Set deferred update mode, used for batching operations. */ + void (*set_lazy_mode)(enum paravirt_lazy_mode mode); /* These two are jmp to, not actually called. */ void (*irq_enable_sysexit)(void); void (*iret)(void); - - void (*startup_ipi_hook)(int phys_apicid, unsigned long start_eip, unsigned long start_esp); }; /* Mark a paravirt probe function. */ @@ -188,8 +231,10 @@ extern struct paravirt_ops paravirt_ops; #define paravirt_clobber(clobber) \ [paravirt_clobber] "i" (clobber) -#define PARAVIRT_CALL "call *(paravirt_ops+%c[paravirt_typenum]*4);" - +/* + * Generate some code, and mark it as patchable by the + * apply_paravirt() alternate instruction patcher. + */ #define _paravirt_alt(insn_string, type, clobber) \ "771:\n\t" insn_string "\n" "772:\n" \ ".pushsection .parainstructions,\"a\"\n" \ @@ -199,9 +244,74 @@ extern struct paravirt_ops paravirt_ops; " .short " clobber "\n" \ ".popsection\n" +/* Generate patchable code, with the default asm parameters. */ #define paravirt_alt(insn_string) \ _paravirt_alt(insn_string, "%c[paravirt_typenum]", "%c[paravirt_clobber]") +/* + * This generates an indirect call based on the operation type number. + * The type number, computed in PARAVIRT_PATCH, is derived from the + * offset into the paravirt_ops structure, and can therefore be freely + * converted back into a structure offset. + */ +#define PARAVIRT_CALL "call *(paravirt_ops+%c[paravirt_typenum]*4);" + +/* + * These macros are intended to wrap calls into a paravirt_ops + * operation, so that they can be later identified and patched at + * runtime. + * + * Normally, a call to a pv_op function is a simple indirect call: + * (paravirt_ops.operations)(args...). + * + * Unfortunately, this is a relatively slow operation for modern CPUs, + * because it cannot necessarily determine what the destination + * address is. In this case, the address is a runtime constant, so at + * the very least we can patch the call to e a simple direct call, or + * ideally, patch an inline implementation into the callsite. (Direct + * calls are essentially free, because the call and return addresses + * are completely predictable.) + * + * These macros rely on the standard gcc "regparm(3)" calling + * convention, in which the first three arguments are placed in %eax, + * %edx, %ecx (in that order), and the remaining arguments are placed + * on the stack. All caller-save registers (eax,edx,ecx) are expected + * to be modified (either clobbered or used for return values). + * + * The call instruction itself is marked by placing its start address + * and size into the .parainstructions section, so that + * apply_paravirt() in arch/i386/kernel/alternative.c can do the + * appropriate patching under the control of the backend paravirt_ops + * implementation. + * + * Unfortunately there's no way to get gcc to generate the args setup + * for the call, and then allow the call itself to be generated by an + * inline asm. Because of this, we must do the complete arg setup and + * return value handling from within these macros. This is fairly + * cumbersome. + * + * There are 5 sets of PVOP_* macros for dealing with 0-4 arguments. + * It could be extended to more arguments, but there would be little + * to be gained from that. For each number of arguments, there are + * the two VCALL and CALL variants for void and non-void functions. + * + * When there is a return value, the invoker of the macro must specify + * the return type. The macro then uses sizeof() on that type to + * determine whether its a 32 or 64 bit value, and places the return + * in the right register(s) (just %eax for 32-bit, and %edx:%eax for + * 64-bit). + * + * 64-bit arguments are passed as a pair of adjacent 32-bit arguments + * in low,high order. + * + * Small structures are passed and returned in registers. The macro + * calling convention can't directly deal with this, so the wrapper + * functions must do this. + * + * These PVOP_* macros are only defined within this header. This + * means that all uses must be wrapped in inline functions. This also + * makes sure the incoming and outgoing types are always correct. + */ #define PVOP_CALL0(__rettype, __op) \ ({ \ __rettype __ret; \ @@ -1026,6 +1136,7 @@ static inline unsigned long __raw_local_irq_save(void) [paravirt_sti_type] "i" (PARAVIRT_PATCH(irq_enable)), \ paravirt_clobber(CLBR_EAX) +/* Make sure as little as possible of this mess escapes. */ #undef PARAVIRT_CALL #undef PVOP_VCALL0 #undef PVOP_CALL0 |