#ifndef _ASM_X86_XEN_PAGE_H #define _ASM_X86_XEN_PAGE_H #include #include #include #include #include #include #include #include #include #include #include /* Xen machine address */ typedef struct xmaddr { phys_addr_t maddr; } xmaddr_t; /* Xen pseudo-physical address */ typedef struct xpaddr { phys_addr_t paddr; } xpaddr_t; #define XMADDR(x) ((xmaddr_t) { .maddr = (x) }) #define XPADDR(x) ((xpaddr_t) { .paddr = (x) }) /**** MACHINE <-> PHYSICAL CONVERSION MACROS ****/ #define INVALID_P2M_ENTRY (~0UL) #define FOREIGN_FRAME_BIT (1UL<<(BITS_PER_LONG-1)) #define IDENTITY_FRAME_BIT (1UL<<(BITS_PER_LONG-2)) #define FOREIGN_FRAME(m) ((m) | FOREIGN_FRAME_BIT) #define IDENTITY_FRAME(m) ((m) | IDENTITY_FRAME_BIT) /* Maximum amount of memory we can handle in a domain in pages */ #define MAX_DOMAIN_PAGES \ ((unsigned long)((u64)CONFIG_XEN_MAX_DOMAIN_MEMORY * 1024 * 1024 * 1024 / PAGE_SIZE)) extern unsigned long *machine_to_phys_mapping; extern unsigned long machine_to_phys_nr; extern unsigned long get_phys_to_machine(unsigned long pfn); extern bool set_phys_to_machine(unsigned long pfn, unsigned long mfn); extern bool __set_phys_to_machine(unsigned long pfn, unsigned long mfn); extern unsigned long set_phys_range_identity(unsigned long pfn_s, unsigned long pfn_e); extern int m2p_add_override(unsigned long mfn, struct page *page, struct gnttab_map_grant_ref *kmap_op); extern int m2p_remove_override(struct page *page, struct gnttab_map_grant_ref *kmap_op); extern struct page *m2p_find_override(unsigned long mfn); extern unsigned long m2p_find_override_pfn(unsigned long mfn, unsigned long pfn); static inline unsigned long pfn_to_mfn(unsigned long pfn) { unsigned long mfn; if (xen_feature(XENFEAT_auto_translated_physmap)) return pfn; mfn = get_phys_to_machine(pfn); if (mfn != INVALID_P2M_ENTRY) mfn &= ~(FOREIGN_FRAME_BIT | IDENTITY_FRAME_BIT); return mfn; } static inline int phys_to_machine_mapping_valid(unsigned long pfn) { if (xen_feature(XENFEAT_auto_translated_physmap)) return 1; return get_phys_to_machine(pfn) != INVALID_P2M_ENTRY; } static inline unsigned long mfn_to_pfn(unsigned long mfn) { unsigned long pfn; int ret = 0; if (xen_feature(XENFEAT_auto_translated_physmap)) return mfn; if (unlikely(mfn >= machine_to_phys_nr)) { pfn = ~0; goto try_override; } pfn = 0; /* * The array access can fail (e.g., device space beyond end of RAM). * In such cases it doesn't matter what we return (we return garbage), * but we must handle the fault without crashing! */ ret = __get_user(pfn, &machine_to_phys_mapping[mfn]); try_override: /* ret might be < 0 if there are no entries in the m2p for mfn */ if (ret < 0) pfn = ~0; else if (get_phys_to_machine(pfn) != mfn) /* * If this appears to be a foreign mfn (because the pfn * doesn't map back to the mfn), then check the local override * table to see if there's a better pfn to use. * * m2p_find_override_pfn returns ~0 if it doesn't find anything. */ pfn = m2p_find_override_pfn(mfn, ~0); /* * pfn is ~0 if there are no entries in the m2p for mfn or if the * entry doesn't map back to the mfn and m2p_override doesn't have a * valid entry for it. */ if (pfn == ~0 && get_phys_to_machine(mfn) == IDENTITY_FRAME(mfn)) pfn = mfn; return pfn; } static inline xmaddr_t phys_to_machine(xpaddr_t phys) { unsigned offset = phys.paddr & ~PAGE_MASK; return XMADDR(PFN_PHYS(pfn_to_mfn(PFN_DOWN(phys.paddr))) | offset); } static inline xpaddr_t machine_to_phys(xmaddr_t machine) { unsigned offset = machine.maddr & ~PAGE_MASK; return XPADDR(PFN_PHYS(mfn_to_pfn(PFN_DOWN(machine.maddr))) | offset); } /* * We detect special mappings in one of two ways: * 1. If the MFN is an I/O page then Xen will set the m2p entry * to be outside our maximum possible pseudophys range. * 2. If the MFN belongs to a different domain then we will certainly * not have MFN in our p2m table. Conversely, if the page is ours, * then we'll have p2m(m2p(MFN))==MFN. * If we detect a special mapping then it doesn't have a 'struct page'. * We force !pfn_valid() by returning an out-of-range pointer. * * NB. These checks require that, for any MFN that is not in our reservation, * there is no PFN such that p2m(PFN) == MFN. Otherwise we can get confused if * we are foreign-mapping the MFN, and the other domain as m2p(MFN) == PFN. * Yikes! Various places must poke in INVALID_P2M_ENTRY for safety. * * NB2. When deliberately mapping foreign pages into the p2m table, you *must* * use FOREIGN_FRAME(). This will cause pte_pfn() to choke on it, as we * require. In all the cases we care about, the FOREIGN_FRAME bit is * masked (e.g., pfn_to_mfn()) so behaviour there is correct. */ static inline unsigned long mfn_to_local_pfn(unsigned long mfn) { unsigned long pfn = mfn_to_pfn(mfn); if (get_phys_to_machine(pfn) != mfn) return -1; /* force !pfn_valid() */ return pfn; } /* VIRT <-> MACHINE conversion */ #define virt_to_machine(v) (phys_to_machine(XPADDR(__pa(v)))) #define virt_to_pfn(v) (PFN_DOWN(__pa(v))) #define virt_to_mfn(v) (pfn_to_mfn(virt_to_pfn(v))) #define mfn_to_virt(m) (__va(mfn_to_pfn(m) << PAGE_SHIFT)) static inline unsigned long pte_mfn(pte_t pte) { return (pte.pte & PTE_PFN_MASK) >> PAGE_SHIFT; } static inline pte_t mfn_pte(unsigned long page_nr, pgprot_t pgprot) { pte_t pte; pte.pte = ((phys_addr_t)page_nr << PAGE_SHIFT) | massage_pgprot(pgprot); return pte; } static inline pteval_t pte_val_ma(pte_t pte) { return pte.pte; } static inline pte_t __pte_ma(pteval_t x) { return (pte_t) { .pte = x }; } #define pmd_val_ma(v) ((v).pmd) #ifdef __PAGETABLE_PUD_FOLDED #define pud_val_ma(v) ((v).pgd.pgd) #else #define pud_val_ma(v) ((v).pud) #endif #define __pmd_ma(x) ((pmd_t) { (x) } ) #define pgd_val_ma(x) ((x).pgd) void xen_set_domain_pte(pte_t *ptep, pte_t pteval, unsigned domid); xmaddr_t arbitrary_virt_to_machine(void *address); unsigned long arbitrary_virt_to_mfn(void *vaddr); void make_lowmem_page_readonly(void *vaddr); void make_lowmem_page_readwrite(void *vaddr); #endif /* _ASM_X86_XEN_PAGE_H */