A shadow gmap and its parent are locked right after each other when
doing VSIE management. Lockdep can't differentiate between the two
classes without some help.
Signed-off-by: Janosch Frank <frankja@xxxxxxxxxxxxx>
---
arch/s390/include/asm/gmap.h | 6 ++++++
arch/s390/mm/gmap.c | 40 +++++++++++++++++++-----------------
2 files changed, 27 insertions(+), 19 deletions(-)
diff --git a/arch/s390/include/asm/gmap.h b/arch/s390/include/asm/gmap.h
index 4133d09597a5..4edbeb012e2a 100644
--- a/arch/s390/include/asm/gmap.h
+++ b/arch/s390/include/asm/gmap.h
@@ -26,6 +26,12 @@
#define GMAP_SEGMENT_STATUS_BITS (_SEGMENT_ENTRY_GMAP_UC | _SEGMENT_ENTRY_GMAP_SPLIT)
#define GMAP_SEGMENT_NOTIFY_BITS (_SEGMENT_ENTRY_GMAP_IN | _SEGMENT_ENTRY_GMAP_VSIE)
+
+enum gmap_lock_class {
+ GMAP_LOCK_PARENT,
+ GMAP_LOCK_SHADOW
+};
+
/**
* struct gmap_struct - guest address space
* @list: list head for the mm->context gmap list
diff --git a/arch/s390/mm/gmap.c b/arch/s390/mm/gmap.c
index 50dd95946d32..bc89fb974367 100644
--- a/arch/s390/mm/gmap.c
+++ b/arch/s390/mm/gmap.c
@@ -1339,7 +1339,7 @@ static int gmap_protect_rmap_pte(struct gmap *sg, struct gmap_rmap *rmap,
{
int rc = 0;
- spin_lock(&sg->guest_table_lock);
+ spin_lock_nested(&sg->guest_table_lock, GMAP_LOCK_SHADOW);
rc = gmap_protect_pte(sg->parent, paddr, vmaddr, ptep,
prot, GMAP_NOTIFY_SHADOW);
if (!rc)
@@ -1874,7 +1874,7 @@ struct gmap *gmap_shadow(struct gmap *parent, unsigned long asce,
/* only allow one real-space gmap shadow */
list_for_each_entry(sg, &parent->children, list) {
if (sg->orig_asce & _ASCE_REAL_SPACE) {
- spin_lock(&sg->guest_table_lock);
+ spin_lock_nested(&sg->guest_table_lock, GMAP_LOCK_SHADOW);
gmap_unshadow(sg);
spin_unlock(&sg->guest_table_lock);
list_del(&sg->list);
@@ -1946,7 +1946,7 @@ int gmap_shadow_r2t(struct gmap *sg, unsigned long saddr, unsigned long r2t,
page->index |= GMAP_SHADOW_FAKE_TABLE;
s_r2t = (unsigned long *) page_to_phys(page);
/* Install shadow region second table */
- spin_lock(&sg->guest_table_lock);
+ spin_lock_nested(&sg->guest_table_lock, GMAP_LOCK_SHADOW);
table = gmap_table_walk(sg, saddr, 4); /* get region-1 pointer */
if (!table) {
rc = -EAGAIN; /* Race with unshadow */
@@ -1979,7 +1979,7 @@ int gmap_shadow_r2t(struct gmap *sg, unsigned long saddr, unsigned long r2t,
offset = ((r2t & _REGION_ENTRY_OFFSET) >> 6) * PAGE_SIZE;
len = ((r2t & _REGION_ENTRY_LENGTH) + 1) * PAGE_SIZE - offset;
rc = gmap_protect_rmap(sg, raddr, origin + offset, len);
- spin_lock(&sg->guest_table_lock);
+ spin_lock_nested(&sg->guest_table_lock, GMAP_LOCK_SHADOW);
if (!rc) {
table = gmap_table_walk(sg, saddr, 4);
if (!table || (*table & _REGION_ENTRY_ORIGIN) !=
@@ -2030,7 +2030,7 @@ int gmap_shadow_r3t(struct gmap *sg, unsigned long saddr, unsigned long r3t,
page->index |= GMAP_SHADOW_FAKE_TABLE;
s_r3t = (unsigned long *) page_to_phys(page);
/* Install shadow region second table */
- spin_lock(&sg->guest_table_lock);
+ spin_lock_nested(&sg->guest_table_lock, GMAP_LOCK_SHADOW);
table = gmap_table_walk(sg, saddr, 3); /* get region-2 pointer */
if (!table) {
rc = -EAGAIN; /* Race with unshadow */
@@ -2063,7 +2063,7 @@ int gmap_shadow_r3t(struct gmap *sg, unsigned long saddr, unsigned long r3t,
offset = ((r3t & _REGION_ENTRY_OFFSET) >> 6) * PAGE_SIZE;
len = ((r3t & _REGION_ENTRY_LENGTH) + 1) * PAGE_SIZE - offset;
rc = gmap_protect_rmap(sg, raddr, origin + offset, len);
- spin_lock(&sg->guest_table_lock);
+ spin_lock_nested(&sg->guest_table_lock, GMAP_LOCK_SHADOW);
if (!rc) {
table = gmap_table_walk(sg, saddr, 3);
if (!table || (*table & _REGION_ENTRY_ORIGIN) !=
@@ -2114,7 +2114,7 @@ int gmap_shadow_sgt(struct gmap *sg, unsigned long saddr, unsigned long sgt,
page->index |= GMAP_SHADOW_FAKE_TABLE;
s_sgt = (unsigned long *) page_to_phys(page);
/* Install shadow region second table */
- spin_lock(&sg->guest_table_lock);
+ spin_lock_nested(&sg->guest_table_lock, GMAP_LOCK_SHADOW);
table = gmap_table_walk(sg, saddr, 2); /* get region-3 pointer */
if (!table) {
rc = -EAGAIN; /* Race with unshadow */
@@ -2147,7 +2147,7 @@ int gmap_shadow_sgt(struct gmap *sg, unsigned long saddr, unsigned long sgt,
offset = ((sgt & _REGION_ENTRY_OFFSET) >> 6) * PAGE_SIZE;
len = ((sgt & _REGION_ENTRY_LENGTH) + 1) * PAGE_SIZE - offset;
rc = gmap_protect_rmap(sg, raddr, origin + offset, len);
- spin_lock(&sg->guest_table_lock);
+ spin_lock_nested(&sg->guest_table_lock, GMAP_LOCK_SHADOW);
if (!rc) {
table = gmap_table_walk(sg, saddr, 2);
if (!table || (*table & _REGION_ENTRY_ORIGIN) !=
@@ -2203,7 +2203,7 @@ int gmap_shadow_sgt_lookup(struct gmap *sg, unsigned long saddr,
int rc = -EAGAIN;
BUG_ON(!gmap_is_shadow(sg));
- spin_lock(&sg->guest_table_lock);
+ spin_lock_nested(&sg->guest_table_lock, GMAP_LOCK_SHADOW);
if (sg->asce & _ASCE_TYPE_MASK) {
/* >2 GB guest */
r3e = (unsigned long *) gmap_table_walk(sg, saddr, 2);
@@ -2270,7 +2270,7 @@ int gmap_shadow_pgt(struct gmap *sg, unsigned long saddr, unsigned long pgt,
page->index |= GMAP_SHADOW_FAKE_TABLE;
s_pgt = (unsigned long *) page_to_phys(page);
/* Install shadow page table */
- spin_lock(&sg->guest_table_lock);
+ spin_lock_nested(&sg->guest_table_lock, GMAP_LOCK_SHADOW);
table = gmap_table_walk(sg, saddr, 1); /* get segment pointer */
if (!table) {
rc = -EAGAIN; /* Race with unshadow */
@@ -2298,7 +2298,7 @@ int gmap_shadow_pgt(struct gmap *sg, unsigned long saddr, unsigned long pgt,
raddr = (saddr & _SEGMENT_MASK) | _SHADOW_RMAP_SEGMENT;
origin = pgt & _SEGMENT_ENTRY_ORIGIN & PAGE_MASK;
rc = gmap_protect_rmap(sg, raddr, origin, PAGE_SIZE);
- spin_lock(&sg->guest_table_lock);
+ spin_lock_nested(&sg->guest_table_lock, GMAP_LOCK_SHADOW);
if (!rc) {
table = gmap_table_walk(sg, saddr, 1);
if (!table || (*table & _SEGMENT_ENTRY_ORIGIN) !=
@@ -2359,7 +2359,7 @@ int gmap_shadow_segment(struct gmap *sg, unsigned long saddr, pmd_t pmd)
rc = -EISDIR;
break;
}
- spin_lock(&sg->guest_table_lock);
+ spin_lock_nested(&sg->guest_table_lock, GMAP_LOCK_SHADOW);
/* Get shadow segment table pointer */
tpmdp = (pmd_t *) gmap_table_walk(sg, saddr, 1);
if (!tpmdp) {
@@ -2464,7 +2464,8 @@ int gmap_shadow_page(struct gmap *sg, unsigned long saddr, pte_t pte)
if (pmd_large(*spmdp)) {
pte_t spte;
if (!(pmd_val(*spmdp) & _SEGMENT_ENTRY_PROTECT)) {
- spin_lock(&sg->guest_table_lock);
+ spin_lock_nested(&sg->guest_table_lock,
+ GMAP_LOCK_SHADOW);
spte = __pte((pmd_val(*spmdp) &
_SEGMENT_ENTRY_ORIGIN_LARGE)
+ (pte_index(paddr) << 12));
@@ -2477,7 +2478,8 @@ int gmap_shadow_page(struct gmap *sg, unsigned long saddr, pte_t pte)
}
} else {
sptep = gmap_pte_from_pmd(parent, spmdp, paddr, &ptl_pte);
- spin_lock(&sg->guest_table_lock);
+ spin_lock_nested(&sg->guest_table_lock,
+ GMAP_LOCK_SHADOW);
if (sptep) {
rc = ptep_shadow_pte(sg->mm, saddr, sptep, tptep, pte);
if (rc > 0) {
@@ -2535,7 +2537,7 @@ static void gmap_shadow_notify_pmd(struct gmap *sg, unsigned long vmaddr,
BUG_ON(!gmap_is_shadow(sg));
- spin_lock(&sg->guest_table_lock);
+ spin_lock_nested(&sg->guest_table_lock, GMAP_LOCK_SHADOW);
if (sg->removed) {
spin_unlock(&sg->guest_table_lock);
return;
@@ -2586,7 +2588,7 @@ static void gmap_shadow_notify(struct gmap *sg, unsigned long vmaddr,
BUG_ON(!gmap_is_shadow(sg));
- spin_lock(&sg->guest_table_lock);
+ spin_lock_nested(&sg->guest_table_lock, GMAP_LOCK_SHADOW);
if (sg->removed) {
spin_unlock(&sg->guest_table_lock);
return;
@@ -2761,7 +2763,7 @@ static void gmap_pmdp_clear(struct mm_struct *mm, unsigned long vmaddr,
rcu_read_lock();
list_for_each_entry_rcu(gmap, &mm->context.gmap_list, list) {
- spin_lock(&gmap->guest_table_lock);
+ spin_lock_nested(&gmap->guest_table_lock, GMAP_LOCK_PARENT);
pmdp = (pmd_t *)radix_tree_delete(&gmap->host_to_guest,
vmaddr >> PMD_SHIFT);
if (pmdp) {
@@ -2816,7 +2818,7 @@ void gmap_pmdp_idte_local(struct mm_struct *mm, unsigned long vmaddr)
rcu_read_lock();
list_for_each_entry_rcu(gmap, &mm->context.gmap_list, list) {
- spin_lock(&gmap->guest_table_lock);
+ spin_lock_nested(&gmap->guest_table_lock, GMAP_LOCK_PARENT);
entry = radix_tree_delete(&gmap->host_to_guest,
vmaddr >> PMD_SHIFT);
if (entry) {
@@ -2852,7 +2854,7 @@ void gmap_pmdp_idte_global(struct mm_struct *mm, unsigned long vmaddr)
rcu_read_lock();
list_for_each_entry_rcu(gmap, &mm->context.gmap_list, list) {
- spin_lock(&gmap->guest_table_lock);
+ spin_lock_nested(&gmap->guest_table_lock, GMAP_LOCK_PARENT);
entry = radix_tree_delete(&gmap->host_to_guest,
vmaddr >> PMD_SHIFT);
if (entry) {
--
2.27.0
