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-rw-r--r--arch/s390/mm/gmap.c454
1 files changed, 431 insertions, 23 deletions
diff --git a/arch/s390/mm/gmap.c b/arch/s390/mm/gmap.c
index bc56ec8abcf7..bb44990c8212 100644
--- a/arch/s390/mm/gmap.c
+++ b/arch/s390/mm/gmap.c
@@ -2,8 +2,10 @@
/*
* KVM guest address space mapping code
*
- * Copyright IBM Corp. 2007, 2016
+ * Copyright IBM Corp. 2007, 2016, 2018
* Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com>
+ * David Hildenbrand <david@redhat.com>
+ * Janosch Frank <frankja@linux.vnet.ibm.com>
*/
#include <linux/kernel.h>
@@ -521,6 +523,9 @@ void gmap_unlink(struct mm_struct *mm, unsigned long *table,
rcu_read_unlock();
}
+static void gmap_pmdp_xchg(struct gmap *gmap, pmd_t *old, pmd_t new,
+ unsigned long gaddr);
+
/**
* gmap_link - set up shadow page tables to connect a host to a guest address
* @gmap: pointer to guest mapping meta data structure
@@ -541,6 +546,7 @@ int __gmap_link(struct gmap *gmap, unsigned long gaddr, unsigned long vmaddr)
p4d_t *p4d;
pud_t *pud;
pmd_t *pmd;
+ u64 unprot;
int rc;
BUG_ON(gmap_is_shadow(gmap));
@@ -584,8 +590,8 @@ int __gmap_link(struct gmap *gmap, unsigned long gaddr, unsigned long vmaddr)
return -EFAULT;
pmd = pmd_offset(pud, vmaddr);
VM_BUG_ON(pmd_none(*pmd));
- /* large pmds cannot yet be handled */
- if (pmd_large(*pmd))
+ /* Are we allowed to use huge pages? */
+ if (pmd_large(*pmd) && !gmap->mm->context.allow_gmap_hpage_1m)
return -EFAULT;
/* Link gmap segment table entry location to page table. */
rc = radix_tree_preload(GFP_KERNEL);
@@ -596,10 +602,22 @@ int __gmap_link(struct gmap *gmap, unsigned long gaddr, unsigned long vmaddr)
if (*table == _SEGMENT_ENTRY_EMPTY) {
rc = radix_tree_insert(&gmap->host_to_guest,
vmaddr >> PMD_SHIFT, table);
- if (!rc)
- *table = pmd_val(*pmd);
- } else
- rc = 0;
+ if (!rc) {
+ if (pmd_large(*pmd)) {
+ *table = (pmd_val(*pmd) &
+ _SEGMENT_ENTRY_HARDWARE_BITS_LARGE)
+ | _SEGMENT_ENTRY_GMAP_UC;
+ } else
+ *table = pmd_val(*pmd) &
+ _SEGMENT_ENTRY_HARDWARE_BITS;
+ }
+ } else if (*table & _SEGMENT_ENTRY_PROTECT &&
+ !(pmd_val(*pmd) & _SEGMENT_ENTRY_PROTECT)) {
+ unprot = (u64)*table;
+ unprot &= ~_SEGMENT_ENTRY_PROTECT;
+ unprot |= _SEGMENT_ENTRY_GMAP_UC;
+ gmap_pmdp_xchg(gmap, (pmd_t *)table, __pmd(unprot), gaddr);
+ }
spin_unlock(&gmap->guest_table_lock);
spin_unlock(ptl);
radix_tree_preload_end();
@@ -690,6 +708,12 @@ void gmap_discard(struct gmap *gmap, unsigned long from, unsigned long to)
vmaddr |= gaddr & ~PMD_MASK;
/* Find vma in the parent mm */
vma = find_vma(gmap->mm, vmaddr);
+ /*
+ * We do not discard pages that are backed by
+ * hugetlbfs, so we don't have to refault them.
+ */
+ if (vma && is_vm_hugetlb_page(vma))
+ continue;
size = min(to - gaddr, PMD_SIZE - (gaddr & ~PMD_MASK));
zap_page_range(vma, vmaddr, size);
}
@@ -864,7 +888,128 @@ static int gmap_pte_op_fixup(struct gmap *gmap, unsigned long gaddr,
*/
static void gmap_pte_op_end(spinlock_t *ptl)
{
- spin_unlock(ptl);
+ if (ptl)
+ spin_unlock(ptl);
+}
+
+/**
+ * gmap_pmd_op_walk - walk the gmap tables, get the guest table lock
+ * and return the pmd pointer
+ * @gmap: pointer to guest mapping meta data structure
+ * @gaddr: virtual address in the guest address space
+ *
+ * Returns a pointer to the pmd for a guest address, or NULL
+ */
+static inline pmd_t *gmap_pmd_op_walk(struct gmap *gmap, unsigned long gaddr)
+{
+ pmd_t *pmdp;
+
+ BUG_ON(gmap_is_shadow(gmap));
+ spin_lock(&gmap->guest_table_lock);
+ pmdp = (pmd_t *) gmap_table_walk(gmap, gaddr, 1);
+
+ if (!pmdp || pmd_none(*pmdp)) {
+ spin_unlock(&gmap->guest_table_lock);
+ return NULL;
+ }
+
+ /* 4k page table entries are locked via the pte (pte_alloc_map_lock). */
+ if (!pmd_large(*pmdp))
+ spin_unlock(&gmap->guest_table_lock);
+ return pmdp;
+}
+
+/**
+ * gmap_pmd_op_end - release the guest_table_lock if needed
+ * @gmap: pointer to the guest mapping meta data structure
+ * @pmdp: pointer to the pmd
+ */
+static inline void gmap_pmd_op_end(struct gmap *gmap, pmd_t *pmdp)
+{
+ if (pmd_large(*pmdp))
+ spin_unlock(&gmap->guest_table_lock);
+}
+
+/*
+ * gmap_protect_pmd - remove access rights to memory and set pmd notification bits
+ * @pmdp: pointer to the pmd to be protected
+ * @prot: indicates access rights: PROT_NONE, PROT_READ or PROT_WRITE
+ * @bits: notification bits to set
+ *
+ * Returns:
+ * 0 if successfully protected
+ * -EAGAIN if a fixup is needed
+ * -EINVAL if unsupported notifier bits have been specified
+ *
+ * Expected to be called with sg->mm->mmap_sem in read and
+ * guest_table_lock held.
+ */
+static int gmap_protect_pmd(struct gmap *gmap, unsigned long gaddr,
+ pmd_t *pmdp, int prot, unsigned long bits)
+{
+ int pmd_i = pmd_val(*pmdp) & _SEGMENT_ENTRY_INVALID;
+ int pmd_p = pmd_val(*pmdp) & _SEGMENT_ENTRY_PROTECT;
+ pmd_t new = *pmdp;
+
+ /* Fixup needed */
+ if ((pmd_i && (prot != PROT_NONE)) || (pmd_p && (prot == PROT_WRITE)))
+ return -EAGAIN;
+
+ if (prot == PROT_NONE && !pmd_i) {
+ pmd_val(new) |= _SEGMENT_ENTRY_INVALID;
+ gmap_pmdp_xchg(gmap, pmdp, new, gaddr);
+ }
+
+ if (prot == PROT_READ && !pmd_p) {
+ pmd_val(new) &= ~_SEGMENT_ENTRY_INVALID;
+ pmd_val(new) |= _SEGMENT_ENTRY_PROTECT;
+ gmap_pmdp_xchg(gmap, pmdp, new, gaddr);
+ }
+
+ if (bits & GMAP_NOTIFY_MPROT)
+ pmd_val(*pmdp) |= _SEGMENT_ENTRY_GMAP_IN;
+
+ /* Shadow GMAP protection needs split PMDs */
+ if (bits & GMAP_NOTIFY_SHADOW)
+ return -EINVAL;
+
+ return 0;
+}
+
+/*
+ * gmap_protect_pte - remove access rights to memory and set pgste bits
+ * @gmap: pointer to guest mapping meta data structure
+ * @gaddr: virtual address in the guest address space
+ * @pmdp: pointer to the pmd associated with the pte
+ * @prot: indicates access rights: PROT_NONE, PROT_READ or PROT_WRITE
+ * @bits: notification bits to set
+ *
+ * Returns 0 if successfully protected, -ENOMEM if out of memory and
+ * -EAGAIN if a fixup is needed.
+ *
+ * Expected to be called with sg->mm->mmap_sem in read
+ */
+static int gmap_protect_pte(struct gmap *gmap, unsigned long gaddr,
+ pmd_t *pmdp, int prot, unsigned long bits)
+{
+ int rc;
+ pte_t *ptep;
+ spinlock_t *ptl = NULL;
+ unsigned long pbits = 0;
+
+ if (pmd_val(*pmdp) & _SEGMENT_ENTRY_INVALID)
+ return -EAGAIN;
+
+ ptep = pte_alloc_map_lock(gmap->mm, pmdp, gaddr, &ptl);
+ if (!ptep)
+ return -ENOMEM;
+
+ pbits |= (bits & GMAP_NOTIFY_MPROT) ? PGSTE_IN_BIT : 0;
+ pbits |= (bits & GMAP_NOTIFY_SHADOW) ? PGSTE_VSIE_BIT : 0;
+ /* Protect and unlock. */
+ rc = ptep_force_prot(gmap->mm, gaddr, ptep, prot, pbits);
+ gmap_pte_op_end(ptl);
+ return rc;
}
/*
@@ -883,30 +1028,45 @@ static void gmap_pte_op_end(spinlock_t *ptl)
static int gmap_protect_range(struct gmap *gmap, unsigned long gaddr,
unsigned long len, int prot, unsigned long bits)
{
- unsigned long vmaddr;
- spinlock_t *ptl;
- pte_t *ptep;
+ unsigned long vmaddr, dist;
+ pmd_t *pmdp;
int rc;
BUG_ON(gmap_is_shadow(gmap));
while (len) {
rc = -EAGAIN;
- ptep = gmap_pte_op_walk(gmap, gaddr, &ptl);
- if (ptep) {
- rc = ptep_force_prot(gmap->mm, gaddr, ptep, prot, bits);
- gmap_pte_op_end(ptl);
+ pmdp = gmap_pmd_op_walk(gmap, gaddr);
+ if (pmdp) {
+ if (!pmd_large(*pmdp)) {
+ rc = gmap_protect_pte(gmap, gaddr, pmdp, prot,
+ bits);
+ if (!rc) {
+ len -= PAGE_SIZE;
+ gaddr += PAGE_SIZE;
+ }
+ } else {
+ rc = gmap_protect_pmd(gmap, gaddr, pmdp, prot,
+ bits);
+ if (!rc) {
+ dist = HPAGE_SIZE - (gaddr & ~HPAGE_MASK);
+ len = len < dist ? 0 : len - dist;
+ gaddr = (gaddr & HPAGE_MASK) + HPAGE_SIZE;
+ }
+ }
+ gmap_pmd_op_end(gmap, pmdp);
}
if (rc) {
+ if (rc == -EINVAL)
+ return rc;
+
+ /* -EAGAIN, fixup of userspace mm and gmap */
vmaddr = __gmap_translate(gmap, gaddr);
if (IS_ERR_VALUE(vmaddr))
return vmaddr;
rc = gmap_pte_op_fixup(gmap, gaddr, vmaddr, prot);
if (rc)
return rc;
- continue;
}
- gaddr += PAGE_SIZE;
- len -= PAGE_SIZE;
}
return 0;
}
@@ -935,7 +1095,7 @@ int gmap_mprotect_notify(struct gmap *gmap, unsigned long gaddr,
if (!MACHINE_HAS_ESOP && prot == PROT_READ)
return -EINVAL;
down_read(&gmap->mm->mmap_sem);
- rc = gmap_protect_range(gmap, gaddr, len, prot, PGSTE_IN_BIT);
+ rc = gmap_protect_range(gmap, gaddr, len, prot, GMAP_NOTIFY_MPROT);
up_read(&gmap->mm->mmap_sem);
return rc;
}
@@ -1474,6 +1634,7 @@ struct gmap *gmap_shadow(struct gmap *parent, unsigned long asce,
unsigned long limit;
int rc;
+ BUG_ON(parent->mm->context.allow_gmap_hpage_1m);
BUG_ON(gmap_is_shadow(parent));
spin_lock(&parent->shadow_lock);
sg = gmap_find_shadow(parent, asce, edat_level);
@@ -1526,7 +1687,7 @@ struct gmap *gmap_shadow(struct gmap *parent, unsigned long asce,
down_read(&parent->mm->mmap_sem);
rc = gmap_protect_range(parent, asce & _ASCE_ORIGIN,
((asce & _ASCE_TABLE_LENGTH) + 1) * PAGE_SIZE,
- PROT_READ, PGSTE_VSIE_BIT);
+ PROT_READ, GMAP_NOTIFY_SHADOW);
up_read(&parent->mm->mmap_sem);
spin_lock(&parent->shadow_lock);
new->initialized = true;
@@ -2092,6 +2253,225 @@ void ptep_notify(struct mm_struct *mm, unsigned long vmaddr,
}
EXPORT_SYMBOL_GPL(ptep_notify);
+static void pmdp_notify_gmap(struct gmap *gmap, pmd_t *pmdp,
+ unsigned long gaddr)
+{
+ pmd_val(*pmdp) &= ~_SEGMENT_ENTRY_GMAP_IN;
+ gmap_call_notifier(gmap, gaddr, gaddr + HPAGE_SIZE - 1);
+}
+
+/**
+ * gmap_pmdp_xchg - exchange a gmap pmd with another
+ * @gmap: pointer to the guest address space structure
+ * @pmdp: pointer to the pmd entry
+ * @new: replacement entry
+ * @gaddr: the affected guest address
+ *
+ * This function is assumed to be called with the guest_table_lock
+ * held.
+ */
+static void gmap_pmdp_xchg(struct gmap *gmap, pmd_t *pmdp, pmd_t new,
+ unsigned long gaddr)
+{
+ gaddr &= HPAGE_MASK;
+ pmdp_notify_gmap(gmap, pmdp, gaddr);
+ pmd_val(new) &= ~_SEGMENT_ENTRY_GMAP_IN;
+ if (MACHINE_HAS_TLB_GUEST)
+ __pmdp_idte(gaddr, (pmd_t *)pmdp, IDTE_GUEST_ASCE, gmap->asce,
+ IDTE_GLOBAL);
+ else if (MACHINE_HAS_IDTE)
+ __pmdp_idte(gaddr, (pmd_t *)pmdp, 0, 0, IDTE_GLOBAL);
+ else
+ __pmdp_csp(pmdp);
+ *pmdp = new;
+}
+
+static void gmap_pmdp_clear(struct mm_struct *mm, unsigned long vmaddr,
+ int purge)
+{
+ pmd_t *pmdp;
+ struct gmap *gmap;
+ unsigned long gaddr;
+
+ rcu_read_lock();
+ list_for_each_entry_rcu(gmap, &mm->context.gmap_list, list) {
+ spin_lock(&gmap->guest_table_lock);
+ pmdp = (pmd_t *)radix_tree_delete(&gmap->host_to_guest,
+ vmaddr >> PMD_SHIFT);
+ if (pmdp) {
+ gaddr = __gmap_segment_gaddr((unsigned long *)pmdp);
+ pmdp_notify_gmap(gmap, pmdp, gaddr);
+ WARN_ON(pmd_val(*pmdp) & ~(_SEGMENT_ENTRY_HARDWARE_BITS_LARGE |
+ _SEGMENT_ENTRY_GMAP_UC));
+ if (purge)
+ __pmdp_csp(pmdp);
+ pmd_val(*pmdp) = _SEGMENT_ENTRY_EMPTY;
+ }
+ spin_unlock(&gmap->guest_table_lock);
+ }
+ rcu_read_unlock();
+}
+
+/**
+ * gmap_pmdp_invalidate - invalidate all affected guest pmd entries without
+ * flushing
+ * @mm: pointer to the process mm_struct
+ * @vmaddr: virtual address in the process address space
+ */
+void gmap_pmdp_invalidate(struct mm_struct *mm, unsigned long vmaddr)
+{
+ gmap_pmdp_clear(mm, vmaddr, 0);
+}
+EXPORT_SYMBOL_GPL(gmap_pmdp_invalidate);
+
+/**
+ * gmap_pmdp_csp - csp all affected guest pmd entries
+ * @mm: pointer to the process mm_struct
+ * @vmaddr: virtual address in the process address space
+ */
+void gmap_pmdp_csp(struct mm_struct *mm, unsigned long vmaddr)
+{
+ gmap_pmdp_clear(mm, vmaddr, 1);
+}
+EXPORT_SYMBOL_GPL(gmap_pmdp_csp);
+
+/**
+ * gmap_pmdp_idte_local - invalidate and clear a guest pmd entry
+ * @mm: pointer to the process mm_struct
+ * @vmaddr: virtual address in the process address space
+ */
+void gmap_pmdp_idte_local(struct mm_struct *mm, unsigned long vmaddr)
+{
+ unsigned long *entry, gaddr;
+ struct gmap *gmap;
+ pmd_t *pmdp;
+
+ rcu_read_lock();
+ list_for_each_entry_rcu(gmap, &mm->context.gmap_list, list) {
+ spin_lock(&gmap->guest_table_lock);
+ entry = radix_tree_delete(&gmap->host_to_guest,
+ vmaddr >> PMD_SHIFT);
+ if (entry) {
+ pmdp = (pmd_t *)entry;
+ gaddr = __gmap_segment_gaddr(entry);
+ pmdp_notify_gmap(gmap, pmdp, gaddr);
+ WARN_ON(*entry & ~(_SEGMENT_ENTRY_HARDWARE_BITS_LARGE |
+ _SEGMENT_ENTRY_GMAP_UC));
+ if (MACHINE_HAS_TLB_GUEST)
+ __pmdp_idte(gaddr, pmdp, IDTE_GUEST_ASCE,
+ gmap->asce, IDTE_LOCAL);
+ else if (MACHINE_HAS_IDTE)
+ __pmdp_idte(gaddr, pmdp, 0, 0, IDTE_LOCAL);
+ *entry = _SEGMENT_ENTRY_EMPTY;
+ }
+ spin_unlock(&gmap->guest_table_lock);
+ }
+ rcu_read_unlock();
+}
+EXPORT_SYMBOL_GPL(gmap_pmdp_idte_local);
+
+/**
+ * gmap_pmdp_idte_global - invalidate and clear a guest pmd entry
+ * @mm: pointer to the process mm_struct
+ * @vmaddr: virtual address in the process address space
+ */
+void gmap_pmdp_idte_global(struct mm_struct *mm, unsigned long vmaddr)
+{
+ unsigned long *entry, gaddr;
+ struct gmap *gmap;
+ pmd_t *pmdp;
+
+ rcu_read_lock();
+ list_for_each_entry_rcu(gmap, &mm->context.gmap_list, list) {
+ spin_lock(&gmap->guest_table_lock);
+ entry = radix_tree_delete(&gmap->host_to_guest,
+ vmaddr >> PMD_SHIFT);
+ if (entry) {
+ pmdp = (pmd_t *)entry;
+ gaddr = __gmap_segment_gaddr(entry);
+ pmdp_notify_gmap(gmap, pmdp, gaddr);
+ WARN_ON(*entry & ~(_SEGMENT_ENTRY_HARDWARE_BITS_LARGE |
+ _SEGMENT_ENTRY_GMAP_UC));
+ if (MACHINE_HAS_TLB_GUEST)
+ __pmdp_idte(gaddr, pmdp, IDTE_GUEST_ASCE,
+ gmap->asce, IDTE_GLOBAL);
+ else if (MACHINE_HAS_IDTE)
+ __pmdp_idte(gaddr, pmdp, 0, 0, IDTE_GLOBAL);
+ else
+ __pmdp_csp(pmdp);
+ *entry = _SEGMENT_ENTRY_EMPTY;
+ }
+ spin_unlock(&gmap->guest_table_lock);
+ }
+ rcu_read_unlock();
+}
+EXPORT_SYMBOL_GPL(gmap_pmdp_idte_global);
+
+/**
+ * gmap_test_and_clear_dirty_pmd - test and reset segment dirty status
+ * @gmap: pointer to guest address space
+ * @pmdp: pointer to the pmd to be tested
+ * @gaddr: virtual address in the guest address space
+ *
+ * This function is assumed to be called with the guest_table_lock
+ * held.
+ */
+bool gmap_test_and_clear_dirty_pmd(struct gmap *gmap, pmd_t *pmdp,
+ unsigned long gaddr)
+{
+ if (pmd_val(*pmdp) & _SEGMENT_ENTRY_INVALID)
+ return false;
+
+ /* Already protected memory, which did not change is clean */
+ if (pmd_val(*pmdp) & _SEGMENT_ENTRY_PROTECT &&
+ !(pmd_val(*pmdp) & _SEGMENT_ENTRY_GMAP_UC))
+ return false;
+
+ /* Clear UC indication and reset protection */
+ pmd_val(*pmdp) &= ~_SEGMENT_ENTRY_GMAP_UC;
+ gmap_protect_pmd(gmap, gaddr, pmdp, PROT_READ, 0);
+ return true;
+}
+
+/**
+ * gmap_sync_dirty_log_pmd - set bitmap based on dirty status of segment
+ * @gmap: pointer to guest address space
+ * @bitmap: dirty bitmap for this pmd
+ * @gaddr: virtual address in the guest address space
+ * @vmaddr: virtual address in the host address space
+ *
+ * This function is assumed to be called with the guest_table_lock
+ * held.
+ */
+void gmap_sync_dirty_log_pmd(struct gmap *gmap, unsigned long bitmap[4],
+ unsigned long gaddr, unsigned long vmaddr)
+{
+ int i;
+ pmd_t *pmdp;
+ pte_t *ptep;
+ spinlock_t *ptl;
+
+ pmdp = gmap_pmd_op_walk(gmap, gaddr);
+ if (!pmdp)
+ return;
+
+ if (pmd_large(*pmdp)) {
+ if (gmap_test_and_clear_dirty_pmd(gmap, pmdp, gaddr))
+ bitmap_fill(bitmap, _PAGE_ENTRIES);
+ } else {
+ for (i = 0; i < _PAGE_ENTRIES; i++, vmaddr += PAGE_SIZE) {
+ ptep = pte_alloc_map_lock(gmap->mm, pmdp, vmaddr, &ptl);
+ if (!ptep)
+ continue;
+ if (ptep_test_and_clear_uc(gmap->mm, vmaddr, ptep))
+ set_bit(i, bitmap);
+ spin_unlock(ptl);
+ }
+ }
+ gmap_pmd_op_end(gmap, pmdp);
+}
+EXPORT_SYMBOL_GPL(gmap_sync_dirty_log_pmd);
+
static inline void thp_split_mm(struct mm_struct *mm)
{
#ifdef CONFIG_TRANSPARENT_HUGEPAGE
@@ -2168,17 +2548,45 @@ EXPORT_SYMBOL_GPL(s390_enable_sie);
* Enable storage key handling from now on and initialize the storage
* keys with the default key.
*/
-static int __s390_enable_skey(pte_t *pte, unsigned long addr,
- unsigned long next, struct mm_walk *walk)
+static int __s390_enable_skey_pte(pte_t *pte, unsigned long addr,
+ unsigned long next, struct mm_walk *walk)
{
/* Clear storage key */
ptep_zap_key(walk->mm, addr, pte);
return 0;
}
+static int __s390_enable_skey_hugetlb(pte_t *pte, unsigned long addr,
+ unsigned long hmask, unsigned long next,
+ struct mm_walk *walk)
+{
+ pmd_t *pmd = (pmd_t *)pte;
+ unsigned long start, end;
+ struct page *page = pmd_page(*pmd);
+
+ /*
+ * The write check makes sure we do not set a key on shared
+ * memory. This is needed as the walker does not differentiate
+ * between actual guest memory and the process executable or
+ * shared libraries.
+ */
+ if (pmd_val(*pmd) & _SEGMENT_ENTRY_INVALID ||
+ !(pmd_val(*pmd) & _SEGMENT_ENTRY_WRITE))
+ return 0;
+
+ start = pmd_val(*pmd) & HPAGE_MASK;
+ end = start + HPAGE_SIZE - 1;
+ __storage_key_init_range(start, end);
+ set_bit(PG_arch_1, &page->flags);
+ return 0;
+}
+
int s390_enable_skey(void)
{
- struct mm_walk walk = { .pte_entry = __s390_enable_skey };
+ struct mm_walk walk = {
+ .hugetlb_entry = __s390_enable_skey_hugetlb,
+ .pte_entry = __s390_enable_skey_pte,
+ };
struct mm_struct *mm = current->mm;
struct vm_area_struct *vma;
int rc = 0;