diff options
Diffstat (limited to 'arch/x86/include/asm/xen/page.h')
| -rw-r--r-- | arch/x86/include/asm/xen/page.h | 357 |
1 files changed, 357 insertions, 0 deletions
diff --git a/arch/x86/include/asm/xen/page.h b/arch/x86/include/asm/xen/page.h new file mode 100644 index 000000000..fa9ec2078 --- /dev/null +++ b/arch/x86/include/asm/xen/page.h @@ -0,0 +1,357 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _ASM_X86_XEN_PAGE_H +#define _ASM_X86_XEN_PAGE_H + +#include <linux/kernel.h> +#include <linux/types.h> +#include <linux/spinlock.h> +#include <linux/pfn.h> +#include <linux/mm.h> +#include <linux/device.h> + +#include <asm/extable.h> +#include <asm/page.h> + +#include <xen/interface/xen.h> +#include <xen/interface/grant_table.h> +#include <xen/features.h> + +/* 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; + +#ifdef CONFIG_X86_64 +#define XEN_PHYSICAL_MASK __sme_clr((1UL << 52) - 1) +#else +#define XEN_PHYSICAL_MASK __PHYSICAL_MASK +#endif + +#define XEN_PTE_MFN_MASK ((pteval_t)(((signed long)PAGE_MASK) & \ + XEN_PHYSICAL_MASK)) + +#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) + +#define P2M_PER_PAGE (PAGE_SIZE / sizeof(unsigned long)) + +extern unsigned long *machine_to_phys_mapping; +extern unsigned long machine_to_phys_nr; +extern unsigned long *xen_p2m_addr; +extern unsigned long xen_p2m_size; +extern unsigned long xen_max_p2m_pfn; + +extern int xen_alloc_p2m_entry(unsigned long pfn); + +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 __init set_phys_range_identity(unsigned long pfn_s, + unsigned long pfn_e); + +#ifdef CONFIG_XEN_PV +extern int set_foreign_p2m_mapping(struct gnttab_map_grant_ref *map_ops, + struct gnttab_map_grant_ref *kmap_ops, + struct page **pages, unsigned int count); +extern int clear_foreign_p2m_mapping(struct gnttab_unmap_grant_ref *unmap_ops, + struct gnttab_unmap_grant_ref *kunmap_ops, + struct page **pages, unsigned int count); +#else +static inline int +set_foreign_p2m_mapping(struct gnttab_map_grant_ref *map_ops, + struct gnttab_map_grant_ref *kmap_ops, + struct page **pages, unsigned int count) +{ + return 0; +} + +static inline int +clear_foreign_p2m_mapping(struct gnttab_unmap_grant_ref *unmap_ops, + struct gnttab_unmap_grant_ref *kunmap_ops, + struct page **pages, unsigned int count) +{ + return 0; +} +#endif + +/* + * Helper functions to write or read unsigned long values to/from + * memory, when the access may fault. + */ +static inline int xen_safe_write_ulong(unsigned long *addr, unsigned long val) +{ + int ret = 0; + + asm volatile("1: mov %[val], %[ptr]\n" + "2:\n" + _ASM_EXTABLE_TYPE_REG(1b, 2b, EX_TYPE_EFAULT_REG, %[ret]) + : [ret] "+r" (ret), [ptr] "=m" (*addr) + : [val] "r" (val)); + + return ret; +} + +static inline int xen_safe_read_ulong(const unsigned long *addr, + unsigned long *val) +{ + unsigned long rval = ~0ul; + int ret = 0; + + asm volatile("1: mov %[ptr], %[rval]\n" + "2:\n" + _ASM_EXTABLE_TYPE_REG(1b, 2b, EX_TYPE_EFAULT_REG, %[ret]) + : [ret] "+r" (ret), [rval] "+r" (rval) + : [ptr] "m" (*addr)); + *val = rval; + + return ret; +} + +#ifdef CONFIG_XEN_PV +/* + * When to use pfn_to_mfn(), __pfn_to_mfn() or get_phys_to_machine(): + * - pfn_to_mfn() returns either INVALID_P2M_ENTRY or the mfn. No indicator + * bits (identity or foreign) are set. + * - __pfn_to_mfn() returns the found entry of the p2m table. A possibly set + * identity or foreign indicator will be still set. __pfn_to_mfn() is + * encapsulating get_phys_to_machine() which is called in special cases only. + * - get_phys_to_machine() is to be called by __pfn_to_mfn() only in special + * cases needing an extended handling. + */ +static inline unsigned long __pfn_to_mfn(unsigned long pfn) +{ + unsigned long mfn; + + if (pfn < xen_p2m_size) + mfn = xen_p2m_addr[pfn]; + else if (unlikely(pfn < xen_max_p2m_pfn)) + return get_phys_to_machine(pfn); + else + return IDENTITY_FRAME(pfn); + + if (unlikely(mfn == INVALID_P2M_ENTRY)) + return get_phys_to_machine(pfn); + + return mfn; +} +#else +static inline unsigned long __pfn_to_mfn(unsigned long pfn) +{ + return pfn; +} +#endif + +static inline unsigned long pfn_to_mfn(unsigned long pfn) +{ + unsigned long mfn; + + /* + * Some x86 code are still using pfn_to_mfn instead of + * pfn_to_mfn. This will have to be removed when we figured + * out which call. + */ + if (xen_feature(XENFEAT_auto_translated_physmap)) + return pfn; + + mfn = __pfn_to_mfn(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 __pfn_to_mfn(pfn) != INVALID_P2M_ENTRY; +} + +static inline unsigned long mfn_to_pfn_no_overrides(unsigned long mfn) +{ + unsigned long pfn; + int ret; + + if (unlikely(mfn >= machine_to_phys_nr)) + return ~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 = xen_safe_read_ulong(&machine_to_phys_mapping[mfn], &pfn); + if (ret < 0) + return ~0; + + return pfn; +} + +static inline unsigned long mfn_to_pfn(unsigned long mfn) +{ + unsigned long pfn; + + /* + * Some x86 code are still using mfn_to_pfn instead of + * gfn_to_pfn. This will have to be removed when we figure + * out which call. + */ + if (xen_feature(XENFEAT_auto_translated_physmap)) + return mfn; + + pfn = mfn_to_pfn_no_overrides(mfn); + if (__pfn_to_mfn(pfn) != mfn) + pfn = ~0; + + /* + * pfn is ~0 if there are no entries in the m2p for mfn or the + * entry doesn't map back to the mfn. + */ + if (pfn == ~0 && __pfn_to_mfn(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); +} + +/* Pseudo-physical <-> Guest conversion */ +static inline unsigned long pfn_to_gfn(unsigned long pfn) +{ + if (xen_feature(XENFEAT_auto_translated_physmap)) + return pfn; + else + return pfn_to_mfn(pfn); +} + +static inline unsigned long gfn_to_pfn(unsigned long gfn) +{ + if (xen_feature(XENFEAT_auto_translated_physmap)) + return gfn; + else + return mfn_to_pfn(gfn); +} + +/* Pseudo-physical <-> Bus conversion */ +#define pfn_to_bfn(pfn) pfn_to_gfn(pfn) +#define bfn_to_pfn(bfn) gfn_to_pfn(bfn) + +/* + * 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 bfn_to_local_pfn(unsigned long mfn) +{ + unsigned long pfn; + + if (xen_feature(XENFEAT_auto_translated_physmap)) + return mfn; + + pfn = mfn_to_pfn(mfn); + if (__pfn_to_mfn(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)) + +/* VIRT <-> GUEST conversion */ +#define virt_to_gfn(v) (pfn_to_gfn(virt_to_pfn(v))) +#define gfn_to_virt(g) (__va(gfn_to_pfn(g) << PAGE_SHIFT)) + +static inline unsigned long pte_mfn(pte_t pte) +{ + return (pte.pte & XEN_PTE_MFN_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).p4d.pgd.pgd) +#else +#define pud_val_ma(v) ((v).pud) +#endif +#define __pmd_ma(x) ((pmd_t) { (x) } ) + +#ifdef __PAGETABLE_P4D_FOLDED +#define p4d_val_ma(x) ((x).pgd.pgd) +#else +#define p4d_val_ma(x) ((x).p4d) +#endif + +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); + +static inline bool xen_arch_need_swiotlb(struct device *dev, + phys_addr_t phys, + dma_addr_t dev_addr) +{ + return false; +} + +#endif /* _ASM_X86_XEN_PAGE_H */ |