return pgste;
}
-static inline pgste_t pgste_ipte_notify(struct mm_struct *mm,
- unsigned long addr,
- pte_t *ptep, pgste_t pgste)
+static inline pgste_t pgste_pte_notify(struct mm_struct *mm,
+ unsigned long addr,
+ pte_t *ptep, pgste_t pgste)
{
#ifdef CONFIG_PGSTE
- if (pgste_val(pgste) & PGSTE_IN_BIT) {
- pgste_val(pgste) &= ~PGSTE_IN_BIT;
- ptep_notify(mm, addr, ptep);
+ unsigned long bits;
+
+ bits = pgste_val(pgste) & (PGSTE_IN_BIT | PGSTE_VSIE_BIT);
+ if (bits) {
+ pgste_val(pgste) ^= bits;
+ ptep_notify(mm, addr, ptep, bits);
}
#endif
return pgste;
if (mm_has_pgste(mm)) {
pgste = pgste_get_lock(ptep);
- pgste = pgste_ipte_notify(mm, addr, ptep, pgste);
+ pgste = pgste_pte_notify(mm, addr, ptep, pgste);
}
return pgste;
}
preempt_enable();
}
+/**
+ * ptep_force_prot - change access rights of a locked pte
+ * @mm: pointer to the process mm_struct
+ * @addr: virtual address in the guest address space
+ * @ptep: pointer to the page table entry
+ * @prot: indicates guest access rights: PROT_NONE, PROT_READ or PROT_WRITE
+ * @bit: pgste bit to set (e.g. for notification)
+ *
+ * Returns 0 if the access rights were changed and -EAGAIN if the current
+ * and requested access rights are incompatible.
+ */
+int ptep_force_prot(struct mm_struct *mm, unsigned long addr,
+ pte_t *ptep, int prot, unsigned long bit)
+{
+ pte_t entry;
+ pgste_t pgste;
+ int pte_i, pte_p;
+
+ pgste = pgste_get_lock(ptep);
+ entry = *ptep;
+ /* Check pte entry after all locks have been acquired */
+ pte_i = pte_val(entry) & _PAGE_INVALID;
+ pte_p = pte_val(entry) & _PAGE_PROTECT;
+ if ((pte_i && (prot != PROT_NONE)) ||
+ (pte_p && (prot & PROT_WRITE))) {
+ pgste_set_unlock(ptep, pgste);
+ return -EAGAIN;
+ }
+ /* Change access rights and set pgste bit */
+ if (prot == PROT_NONE && !pte_i) {
+ ptep_flush_direct(mm, addr, ptep);
+ pgste = pgste_update_all(entry, pgste, mm);
+ pte_val(entry) |= _PAGE_INVALID;
+ }
+ if (prot == PROT_READ && !pte_p) {
+ ptep_flush_direct(mm, addr, ptep);
+ pte_val(entry) &= ~_PAGE_INVALID;
+ pte_val(entry) |= _PAGE_PROTECT;
+ }
+ pgste_val(pgste) |= bit;
+ pgste = pgste_set_pte(ptep, pgste, entry);
+ pgste_set_unlock(ptep, pgste);
+ return 0;
+}
+
+int ptep_shadow_pte(struct mm_struct *mm, unsigned long saddr,
+ pte_t *sptep, pte_t *tptep, pte_t pte)
+{
+ pgste_t spgste, tpgste;
+ pte_t spte, tpte;
+ int rc = -EAGAIN;
+
+ if (!(pte_val(*tptep) & _PAGE_INVALID))
+ return 0; /* already shadowed */
+ spgste = pgste_get_lock(sptep);
+ spte = *sptep;
+ if (!(pte_val(spte) & _PAGE_INVALID) &&
+ !((pte_val(spte) & _PAGE_PROTECT) &&
+ !(pte_val(pte) & _PAGE_PROTECT))) {
+ pgste_val(spgste) |= PGSTE_VSIE_BIT;
+ tpgste = pgste_get_lock(tptep);
+ pte_val(tpte) = (pte_val(spte) & PAGE_MASK) |
+ (pte_val(pte) & _PAGE_PROTECT);
+ /* don't touch the storage key - it belongs to parent pgste */
+ tpgste = pgste_set_pte(tptep, tpgste, tpte);
+ pgste_set_unlock(tptep, tpgste);
+ rc = 1;
+ }
+ pgste_set_unlock(sptep, spgste);
+ return rc;
+}
+
+void ptep_unshadow_pte(struct mm_struct *mm, unsigned long saddr, pte_t *ptep)
+{
+ pgste_t pgste;
+
+ pgste = pgste_get_lock(ptep);
+ /* notifier is called by the caller */
+ ptep_flush_direct(mm, saddr, ptep);
+ /* don't touch the storage key - it belongs to parent pgste */
+ pgste = pgste_set_pte(ptep, pgste, __pte(_PAGE_INVALID));
+ pgste_set_unlock(ptep, pgste);
+}
+
static void ptep_zap_swap_entry(struct mm_struct *mm, swp_entry_t entry)
{
if (!non_swap_entry(entry))
pgste_val(pgste) &= ~PGSTE_UC_BIT;
pte = *ptep;
if (dirty && (pte_val(pte) & _PAGE_PRESENT)) {
- pgste = pgste_ipte_notify(mm, addr, ptep, pgste);
+ pgste = pgste_pte_notify(mm, addr, ptep, pgste);
__ptep_ipte(addr, ptep);
if (MACHINE_HAS_ESOP || !(pte_val(pte) & _PAGE_WRITE))
pte_val(pte) |= _PAGE_PROTECT;
pgste_t old, new;
pte_t *ptep;
- down_read(&mm->mmap_sem);
ptep = get_locked_pte(mm, addr, &ptl);
- if (unlikely(!ptep)) {
- up_read(&mm->mmap_sem);
+ if (unlikely(!ptep))
return -EFAULT;
- }
new = old = pgste_get_lock(ptep);
pgste_val(new) &= ~(PGSTE_GR_BIT | PGSTE_GC_BIT |
pgste_set_unlock(ptep, new);
pte_unmap_unlock(ptep, ptl);
- up_read(&mm->mmap_sem);
return 0;
}
EXPORT_SYMBOL(set_guest_storage_key);
-unsigned char get_guest_storage_key(struct mm_struct *mm, unsigned long addr)
+/**
+ * Conditionally set a guest storage key (handling csske).
+ * oldkey will be updated when either mr or mc is set and a pointer is given.
+ *
+ * Returns 0 if a guests storage key update wasn't necessary, 1 if the guest
+ * storage key was updated and -EFAULT on access errors.
+ */
+int cond_set_guest_storage_key(struct mm_struct *mm, unsigned long addr,
+ unsigned char key, unsigned char *oldkey,
+ bool nq, bool mr, bool mc)
+{
+ unsigned char tmp, mask = _PAGE_ACC_BITS | _PAGE_FP_BIT;
+ int rc;
+
+ /* we can drop the pgste lock between getting and setting the key */
+ if (mr | mc) {
+ rc = get_guest_storage_key(current->mm, addr, &tmp);
+ if (rc)
+ return rc;
+ if (oldkey)
+ *oldkey = tmp;
+ if (!mr)
+ mask |= _PAGE_REFERENCED;
+ if (!mc)
+ mask |= _PAGE_CHANGED;
+ if (!((tmp ^ key) & mask))
+ return 0;
+ }
+ rc = set_guest_storage_key(current->mm, addr, key, nq);
+ return rc < 0 ? rc : 1;
+}
+EXPORT_SYMBOL(cond_set_guest_storage_key);
+
+/**
+ * Reset a guest reference bit (rrbe), returning the reference and changed bit.
+ *
+ * Returns < 0 in case of error, otherwise the cc to be reported to the guest.
+ */
+int reset_guest_reference_bit(struct mm_struct *mm, unsigned long addr)
{
- unsigned char key;
spinlock_t *ptl;
- pgste_t pgste;
+ pgste_t old, new;
pte_t *ptep;
+ int cc = 0;
- down_read(&mm->mmap_sem);
ptep = get_locked_pte(mm, addr, &ptl);
- if (unlikely(!ptep)) {
- up_read(&mm->mmap_sem);
+ if (unlikely(!ptep))
return -EFAULT;
- }
- pgste = pgste_get_lock(ptep);
- if (pte_val(*ptep) & _PAGE_INVALID) {
- key = (pgste_val(pgste) & PGSTE_ACC_BITS) >> 56;
- key |= (pgste_val(pgste) & PGSTE_FP_BIT) >> 56;
- key |= (pgste_val(pgste) & PGSTE_GR_BIT) >> 48;
- key |= (pgste_val(pgste) & PGSTE_GC_BIT) >> 48;
- } else {
- key = page_get_storage_key(pte_val(*ptep) & PAGE_MASK);
+ new = old = pgste_get_lock(ptep);
+ /* Reset guest reference bit only */
+ pgste_val(new) &= ~PGSTE_GR_BIT;
- /* Reflect guest's logical view, not physical */
- if (pgste_val(pgste) & PGSTE_GR_BIT)
- key |= _PAGE_REFERENCED;
- if (pgste_val(pgste) & PGSTE_GC_BIT)
- key |= _PAGE_CHANGED;
+ if (!(pte_val(*ptep) & _PAGE_INVALID)) {
+ cc = page_reset_referenced(pte_val(*ptep) & PAGE_MASK);
+ /* Merge real referenced bit into host-set */
+ pgste_val(new) |= ((unsigned long) cc << 53) & PGSTE_HR_BIT;
}
+ /* Reflect guest's logical view, not physical */
+ cc |= (pgste_val(old) & (PGSTE_GR_BIT | PGSTE_GC_BIT)) >> 49;
+ /* Changing the guest storage key is considered a change of the page */
+ if ((pgste_val(new) ^ pgste_val(old)) & PGSTE_GR_BIT)
+ pgste_val(new) |= PGSTE_UC_BIT;
+
+ pgste_set_unlock(ptep, new);
+ pte_unmap_unlock(ptep, ptl);
+ return 0;
+}
+EXPORT_SYMBOL(reset_guest_reference_bit);
+
+int get_guest_storage_key(struct mm_struct *mm, unsigned long addr,
+ unsigned char *key)
+{
+ spinlock_t *ptl;
+ pgste_t pgste;
+ pte_t *ptep;
+ ptep = get_locked_pte(mm, addr, &ptl);
+ if (unlikely(!ptep))
+ return -EFAULT;
+
+ pgste = pgste_get_lock(ptep);
+ *key = (pgste_val(pgste) & (PGSTE_ACC_BITS | PGSTE_FP_BIT)) >> 56;
+ if (!(pte_val(*ptep) & _PAGE_INVALID))
+ *key = page_get_storage_key(pte_val(*ptep) & PAGE_MASK);
+ /* Reflect guest's logical view, not physical */
+ *key |= (pgste_val(pgste) & (PGSTE_GR_BIT | PGSTE_GC_BIT)) >> 48;
pgste_set_unlock(ptep, pgste);
pte_unmap_unlock(ptep, ptl);
- up_read(&mm->mmap_sem);
- return key;
+ return 0;
}
EXPORT_SYMBOL(get_guest_storage_key);
#endif
projects / cascardo / linux.git / blobdiff