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, 26 insertions(+), 20 deletions(-) diff --git a/arch/s390/include/asm/gmap.h b/arch/s390/include/asm/gmap.h index 15a7834..31fad98 100644 --- a/arch/s390/include/asm/gmap.h +++ b/arch/s390/include/asm/gmap.h @@ -19,6 +19,12 @@ #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 3cc2765..b17f424 100644 --- a/arch/s390/mm/gmap.c +++ b/arch/s390/mm/gmap.c @@ -198,7 +198,7 @@ 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); + spin_lock_nested(&gmap->guest_table_lock, GMAP_LOCK_PARENT); list_for_each_entry_safe(page, next, &gmap->split_list, lru) page_table_free_pgste(page); spin_unlock(&gmap->guest_table_lock); @@ -1385,7 +1385,7 @@ static int gmap_protect_rmap_large(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_large(sg->parent, paddr, vmaddr, pmdp, hpmdp, prot, GMAP_ENTRY_VSIE); if (!rc) @@ -1413,7 +1413,7 @@ static int gmap_protect_rmap_pte(struct gmap *sg, struct gmap_rmap *rmap, ptep = pte_alloc_map_lock(sg->parent->mm, 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) @@ -1932,7 +1932,7 @@ 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); @@ -2004,7 +2004,7 @@ 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 */ @@ -2037,7 +2037,7 @@ 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) != @@ -2088,7 +2088,7 @@ 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 */ @@ -2120,7 +2120,7 @@ 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) != @@ -2171,7 +2171,7 @@ 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 */ @@ -2204,7 +2204,7 @@ 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) != @@ -2260,7 +2260,7 @@ 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); @@ -2327,7 +2327,7 @@ 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 */ @@ -2355,7 +2355,7 @@ 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) != @@ -2417,7 +2417,7 @@ 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) { @@ -2513,7 +2513,7 @@ 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) { @@ -2597,7 +2597,7 @@ 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; @@ -2658,7 +2658,7 @@ 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; @@ -2899,7 +2899,7 @@ 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) { @@ -2949,7 +2949,7 @@ 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) { @@ -2984,7 +2984,7 @@ 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 -- To unsubscribe from this list: send the line "unsubscribe linux-s390" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html