+ * given mm, but stop when a fatal signal is received.
+ * @mm the mm on which to operate on
+ * @start the start of the range
+ * @end the end of the range
+ *
+ * This call will call cond_sched, so it should not generate stalls. It
+ * will return -EINTR if a fatal signal is received, or 0 if the whole range
+ * has been destroyed.
+ */
+static inline int s390_uv_destroy_range_interruptible(struct mm_struct *mm, unsigned long start,
+ unsigned long end)
+{
+ return __s390_uv_destroy_range(mm, start, end, 1);
+}
#endif /* _ASM_S390_GMAP_H */
diff --git a/arch/s390/kvm/pv.c b/arch/s390/kvm/pv.c
index 3c59ef763dde..2ab22500e092 100644
--- a/arch/s390/kvm/pv.c
+++ b/arch/s390/kvm/pv.c
@@ -12,6 +12,8 @@
#include <asm/gmap.h>
#include <asm/uv.h>
#include <asm/mman.h>
+#include <linux/pagewalk.h>
+#include <linux/sched/mm.h>
#include "kvm-s390.h"
int kvm_s390_pv_destroy_cpu(struct kvm_vcpu *vcpu, u16 *rc, u16 *rrc)
@@ -157,8 +159,14 @@ int kvm_s390_pv_deinit_vm(struct kvm *kvm, u16 *rc, u16 *rrc)
{
int cc;
- /* make all pages accessible before destroying the guest */
- s390_reset_acc(kvm->mm);
+ /*
+ * if the mm still has a mapping, make all its pages accessible
+ * before destroying the guest
+ */
+ if (mmget_not_zero(kvm->mm)) {
+ s390_uv_destroy_range(kvm->mm, 0, TASK_SIZE);
+ mmput(kvm->mm);
+ }
cc = uv_cmd_nodata(kvm_s390_pv_get_handle(kvm),
UVC_CMD_DESTROY_SEC_CONF, rc, rrc);
diff --git a/arch/s390/mm/gmap.c b/arch/s390/mm/gmap.c
index ce6cac4463f2..6eb5acb4be3d 100644
--- a/arch/s390/mm/gmap.c
+++ b/arch/s390/mm/gmap.c
@@ -2676,44 +2676,81 @@ void s390_reset_cmma(struct mm_struct *mm)
}
EXPORT_SYMBOL_GPL(s390_reset_cmma);
-/*
- * make inaccessible pages accessible again
- */
-static int __s390_reset_acc(pte_t *ptep, unsigned long addr,
- unsigned long next, struct mm_walk *walk)
+#define DESTROY_LOOP_THRESHOLD 32
+
+struct reset_walk_state {
+ unsigned long next;
+ unsigned long count;
+ unsigned long pfns[DESTROY_LOOP_THRESHOLD];
+};
+
+static int s390_gather_pages(pte_t *ptep, unsigned long addr,
+ unsigned long next, struct mm_walk *walk)
{
+ struct reset_walk_state *p = walk->private;
pte_t pte = READ_ONCE(*ptep);
- /* There is a reference through the mapping */
- if (pte_present(pte))
- WARN_ON_ONCE(uv_destroy_owned_page(pte_val(pte) & PAGE_MASK));
-
- return 0;
+ if (pte_present(pte)) {
+ /* we have a reference from the mapping, take an extra one */
+ get_page(phys_to_page(pte_val(pte)));
+ p->pfns[p->count] = phys_to_pfn(pte_val(pte));
+ p->next = next;
+ p->count++;
+ }
+ return p->count >= DESTROY_LOOP_THRESHOLD;
}
-static const struct mm_walk_ops reset_acc_walk_ops = {
- .pte_entry = __s390_reset_acc,
+static const struct mm_walk_ops gather_pages_ops = {
+ .pte_entry = s390_gather_pages,
};
-#include <linux/sched/mm.h>
-void s390_reset_acc(struct mm_struct *mm)
+/*
+ * Call the Destroy secure page UVC on each page in the given array of PFNs.
+ * Each page needs to have an extra reference, which will be released here.
+ */
+void s390_uv_destroy_pfns(unsigned long count, unsigned long *pfns)
{
- if (!mm_is_protected(mm))
- return;
- /*
- * we might be called during
- * reset: we walk the pages and clear
- * close of all kvm file descriptors: we walk the pages and clear
- * exit of process on fd closure: vma already gone, do nothing
- */
- if (!mmget_not_zero(mm))
- return;
- mmap_read_lock(mm);
- walk_page_range(mm, 0, TASK_SIZE, &reset_acc_walk_ops, NULL);
- mmap_read_unlock(mm);
- mmput(mm);
+ unsigned long i;
+
+ for (i = 0; i < count; i++) {
+ /* we always have an extra reference */
+ uv_destroy_owned_page(pfn_to_phys(pfns[i]));
+ /* get rid of the extra reference */
+ put_page(pfn_to_page(pfns[i]));
+ cond_resched();
+ }
+}
+EXPORT_SYMBOL_GPL(s390_uv_destroy_pfns);
+
+/**
+ * __s390_uv_destroy_range - Walk the given range of the given address
+ * space, and call the destroy secure page UVC on each page.
+ * Optionally exit early if a fatal signal is pending.
+ * @mm the mm to operate on
+ * @start the start of the range
+ * @end the end of the range
+ * @interruptible if not 0, stop when a fatal signal is received
+ * Return: 0 on success, -EINTR if the function stopped before completing
+ */
+int __s390_uv_destroy_range(struct mm_struct *mm, unsigned long start,
+ unsigned long end, int interruptible)
+{
+ struct reset_walk_state state = { .next = start };
+ int r = 1;
+
+ while (r > 0) {
+ state.count = 0;
+ mmap_read_lock(mm);
+ r = walk_page_range(mm, state.next, end, &gather_pages_ops, &state);
+ mmap_read_unlock(mm);
+ cond_resched();
+ s390_uv_destroy_pfns(state.count, state.pfns);
+ if (interruptible && fatal_signal_pending(current))
+ return -EINTR;
+ }
+ return 0;
}
-EXPORT_SYMBOL_GPL(s390_reset_acc);
+EXPORT_SYMBOL_GPL(__s390_uv_destroy_range);
/**
* s390_remove_old_asce - Remove the topmost level of page tables from the
