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.
TODO: Not sure yet if I have to annotate all and if gmap_pmd_walk will
be used by both shadow and parent
Signed-off-by: Janosch Frank <frankja@xxxxxxxxxxxxxxxxxx>
---
arch/s390/include/asm/gmap.h | 6 ++++++
arch/s390/mm/gmap.c | 40 +++++++++++++++++++---------------------
2 files changed, 25 insertions(+), 21 deletions(-)
diff --git a/arch/s390/include/asm/gmap.h b/arch/s390/include/asm/gmap.h
index a187033..6287aca 100644
--- a/arch/s390/include/asm/gmap.h
+++ b/arch/s390/include/asm/gmap.h
@@ -20,6 +20,12 @@
#define _SEGMENT_ENTRY_GMAP_UC 0x4000 /* user dirty (migration) */
#define _SEGMENT_ENTRY_GMAP_VSIE 0x8000 /* vsie bit */
+
+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 cb03646..86a12f3 100644
--- a/arch/s390/mm/gmap.c
+++ b/arch/s390/mm/gmap.c
@@ -199,10 +199,8 @@ static void gmap_free(struct gmap *gmap)
gmap_radix_tree_free(&gmap->host_to_guest);
/* Free split pmd page tables */
- spin_lock(&gmap->guest_table_lock);
list_for_each_entry_safe(page, next, &gmap->split_list, lru)
page_table_free_pgste(page);
- spin_unlock(&gmap->guest_table_lock);
/* Free additional data for a shadow gmap */
if (gmap_is_shadow(gmap)) {
@@ -1373,7 +1371,7 @@ static int gmap_protect_rmap_pmd(struct gmap *sg, struct gmap_rmap *rmap,
if (pmd_val(*pmdp) & _SEGMENT_ENTRY_INVALID)
return -EAGAIN;
- spin_lock(&sg->guest_table_lock);
+ spin_lock_nested(&sg->guest_table_lock, GMAP_LOCK_SHADOW);
rc = gmap_protect_pmd(sg->parent, paddr, vmaddr, pmdp, hpmdp,
prot, GMAP_NOTIFY_SHADOW);
if (!rc)
@@ -1397,7 +1395,7 @@ static int gmap_protect_rmap_pte(struct gmap *sg, struct gmap_rmap *rmap,
ptep = gmap_pte_from_pmd(sg->parent, pmdp, paddr, &ptl);
if (ptep) {
- spin_lock(&sg->guest_table_lock);
+ spin_lock_nested(&sg->guest_table_lock, GMAP_LOCK_SHADOW);
rc = ptep_force_prot(sg->parent->mm, paddr, ptep, prot,
PGSTE_VSIE_BIT);
if (!rc)
@@ -1913,7 +1911,7 @@ 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);
@@ -1985,7 +1983,7 @@ 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 */
@@ -2018,7 +2016,7 @@ 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, PROT_READ);
- 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) !=
@@ -2069,7 +2067,7 @@ 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 */
@@ -2101,7 +2099,7 @@ 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, PROT_READ);
- 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) !=
@@ -2152,7 +2150,7 @@ 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 */
@@ -2185,7 +2183,7 @@ 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, PROT_READ);
- 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) !=
@@ -2241,7 +2239,7 @@ 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);
@@ -2308,7 +2306,7 @@ 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 */
@@ -2336,7 +2334,7 @@ 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, PROT_READ);
- 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) !=
@@ -2398,7 +2396,7 @@ int gmap_shadow_segment(struct gmap *sg, unsigned long saddr, pmd_t pmd)
if (spmdp) {
if (!pmd_large(*spmdp))
BUG();
- 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) {
@@ -2496,7 +2494,7 @@ int gmap_shadow_page(struct gmap *sg, unsigned long saddr, pte_t pte)
rc = -EAGAIN;
spmdp = gmap_pmd_op_walk(parent, paddr);
if (spmdp && !(pmd_val(*spmdp) & _SEGMENT_ENTRY_INVALID)) {
- spin_lock(&sg->guest_table_lock);
+ spin_lock_nested(&sg->guest_table_lock, GMAP_LOCK_SHADOW);
/* Get page table pointer */
tptep = (pte_t *) gmap_table_walk(sg, saddr, 0);
if (!tptep) {
@@ -2574,7 +2572,7 @@ 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;
@@ -2635,7 +2633,7 @@ 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;
@@ -2876,7 +2874,7 @@ 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) {
@@ -2926,7 +2924,7 @@ 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) {
@@ -2961,7 +2959,7 @@ 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) {
--
2.7.4
--
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