Add page table management functions to be used for KVM guest (gmap) page tables. This patch adds functions related to storage key handling. Signed-off-by: Claudio Imbrenda --- arch/s390/kvm/dat.c | 212 ++++++++++++++++++++++++++++++++++++++++++++ arch/s390/kvm/dat.h | 6 ++ 2 files changed, 218 insertions(+) diff --git a/arch/s390/kvm/dat.c b/arch/s390/kvm/dat.c index fe93e1c07158..f626e8c37770 100644 --- a/arch/s390/kvm/dat.c +++ b/arch/s390/kvm/dat.c @@ -560,3 +560,215 @@ long _dat_walk_gfn_range(gfn_t start, gfn_t end, union asce asce, return dat_crste_walk_range(start, min(end, asce_end(asce)), table, &walk); } + +int dat_get_storage_key(union asce asce, gfn_t gfn, union skey *skey) +{ + union crste *crstep; + union pgste pgste; + union pte *ptep; + int rc; + + skey->skey = 0; + rc = dat_entry_walk(gfn, asce, DAT_WALK_ANY, LEVEL_PTE, &crstep, &ptep); + if (rc) + return rc; + + if (!ptep) { + union crste crste; + + crste = READ_ONCE(*crstep); + if (!crste.h.fc || !crste.s.fc1.pr) + return 0; + skey->skey = page_get_storage_key(large_crste_to_phys(crste, gfn)); + return 0; + } + pgste = pgste_get_lock(ptep); + if (ptep->h.i) { + skey->acc = pgste.acc; + skey->fp = pgste.fp; + } else { + skey->skey = page_get_storage_key(pte_origin(*ptep)); + } + skey->r |= pgste.gr; + skey->c |= pgste.gc; + pgste_set_unlock(ptep, pgste); + return 0; +} + +static void dat_update_ptep_sd(union pgste old, union pgste pgste, union pte *ptep) +{ + if (pgste.acc != old.acc || pgste.fp != old.fp || pgste.gr != old.gr || pgste.gc != old.gc) + __atomic64_or(_PAGE_SD, &ptep->val); +} + +int dat_set_storage_key(union asce asce, gfn_t gfn, union skey skey, bool nq) +{ + union pgste pgste, old; + union crste *crstep; + union pte *ptep; + int rc; + + rc = dat_entry_walk(gfn, asce, DAT_WALK_LEAF_ALLOC, LEVEL_PTE, &crstep, &ptep); + if (rc) + return rc; + + if (!ptep) { + page_set_storage_key(large_crste_to_phys(*crstep, gfn), skey.skey, !nq); + return 0; + } + + old = pgste_get_lock(ptep); + pgste = old; + + pgste.acc = skey.acc; + pgste.fp = skey.fp; + pgste.gc = skey.c; + pgste.gr = skey.r; + + if (!ptep->h.i) { + union skey old_skey; + + old_skey.skey = page_get_storage_key(pte_origin(*ptep)); + pgste.hc |= old_skey.c; + pgste.hr |= old_skey.r; + skey.r = 0; + skey.c = 0; + page_set_storage_key(pte_origin(*ptep), skey.skey, !nq); + } + + dat_update_ptep_sd(old, pgste, ptep); + pgste_set_unlock(ptep, pgste); + return 0; +} + +static bool page_cond_set_storage_key(phys_addr_t paddr, union skey skey, union skey *oldkey, + bool nq, bool mr, bool mc) +{ + oldkey->skey = page_get_storage_key(paddr); + if (oldkey->acc == skey.acc && oldkey->fp == skey.fp && + (oldkey->r == skey.r || mr) && (oldkey->c == skey.c || mc)) + return false; + page_set_storage_key(paddr, skey.skey, !nq); + return true; +} + +int dat_cond_set_storage_key(union asce asce, gfn_t gfn, union skey skey, union skey *oldkey, + bool nq, bool mr, bool mc) +{ + union pgste pgste, old; + union crste *crstep; + union pte *ptep; + int rc; + + rc = dat_entry_walk(gfn, asce, DAT_WALK_LEAF_ALLOC, LEVEL_PTE, &crstep, &ptep); + if (rc) + return rc; + + if (!ptep) + return page_cond_set_storage_key(large_crste_to_phys(*crstep, gfn), skey, oldkey, + nq, mr, mc); + + old = pgste_get_lock(ptep); + pgste = old; + + rc = 1; + pgste.acc = skey.acc; + pgste.fp = skey.fp; + pgste.gc = skey.c; + pgste.gr = skey.r; + + if (!ptep->h.i) { + union skey prev; + + rc = page_cond_set_storage_key(pte_origin(*ptep), skey, &prev, nq, mr, mc); + pgste.hc |= prev.c; + pgste.hr |= prev.r; + if (oldkey) + *oldkey = prev; + } + + dat_update_ptep_sd(old, pgste, ptep); + pgste_set_unlock(ptep, pgste); + return rc; +} + +int dat_reset_reference_bit(union asce asce, gfn_t gfn) +{ + union pgste pgste, old; + union crste *crstep; + union pte *ptep; + int rc; + + rc = dat_entry_walk(gfn, asce, DAT_WALK_ANY, LEVEL_PTE, &crstep, &ptep); + if (rc) + return rc; + + if (!ptep) { + union crste crste = READ_ONCE(*crstep); + + if (!crste.h.fc || !crste.s.fc1.pr) + return 0; + return page_reset_referenced(large_crste_to_phys(*crstep, gfn)); + } + old = pgste_get_lock(ptep); + pgste = old; + + if (!ptep->h.i) { + rc = page_reset_referenced(pte_origin(*ptep)); + pgste.hr = rc >> 1; + } + rc |= (pgste.gr << 1) | pgste.gc; + pgste.gr = 0; + + dat_update_ptep_sd(old, pgste, ptep); + pgste_set_unlock(ptep, pgste); + return rc; +} + +static long dat_reset_skeys_pte(union pte *ptep, gfn_t gfn, gfn_t next, struct dat_walk *walk) +{ + union pgste pgste; + + pgste = pgste_get_lock(ptep); + pgste.acc = 0; + pgste.fp = 0; + pgste.gr = 0; + pgste.gc = 0; + if (ptep->s.pr) + page_set_storage_key(pte_origin(*ptep), PAGE_DEFAULT_KEY, 1); + pgste_set_unlock(ptep, pgste); + + if (need_resched()) + return next; + return 0; +} + +static long dat_reset_skeys_crste(union crste *crstep, gfn_t gfn, gfn_t next, struct dat_walk *walk) +{ + phys_addr_t addr, end, origin = crste_origin_large(*crstep); + + if (!crstep->h.fc || !crstep->s.fc1.pr) + return 0; + + addr = ((max(gfn, walk->start) - gfn) << PAGE_SHIFT) + origin; + end = ((min(next, walk->end) - gfn) << PAGE_SHIFT) + origin; + while (ALIGN(addr + 1, _SEGMENT_SIZE) <= end) + addr = sske_frame(addr, PAGE_DEFAULT_KEY); + for ( ; addr < end; addr += PAGE_SIZE) + page_set_storage_key(addr, PAGE_DEFAULT_KEY, 1); + + if (need_resched()) + return next; + return 0; +} + +long dat_reset_skeys(union asce asce, gfn_t start) +{ + const struct dat_walk_ops ops = { + .pte_entry = dat_reset_skeys_pte, + .pmd_entry = dat_reset_skeys_crste, + .pud_entry = dat_reset_skeys_crste, + }; + + return _dat_walk_gfn_range(start, asce_end(asce), asce, &ops, DAT_WALK_IGN_HOLES, NULL); +} diff --git a/arch/s390/kvm/dat.h b/arch/s390/kvm/dat.h index de4bd2298945..40f5c1371ef3 100644 --- a/arch/s390/kvm/dat.h +++ b/arch/s390/kvm/dat.h @@ -427,6 +427,12 @@ int dat_entry_walk(gfn_t gfn, union asce asce, int flags, int walk_level, void dat_free_level(struct crst_table *table, bool owns_ptes); struct page_table *dat_alloc_pt(unsigned long pte_bits, unsigned long pgste_bits); struct crst_table *dat_alloc_crst(unsigned long init); +int dat_get_storage_key(union asce asce, gfn_t gfn, union skey *skey); +int dat_set_storage_key(union asce asce, gfn_t gfn, union skey skey, bool nq); +int dat_cond_set_storage_key(union asce asce, gfn_t gfn, union skey skey, union skey *oldkey, + bool nq, bool mr, bool mc); +int dat_reset_reference_bit(union asce asce, gfn_t gfn); +long dat_reset_skeys(union asce asce, gfn_t start); static inline struct crst_table *crste_table_start(union crste *crstep) { -- 2.51.0