From 0d0dafc1e48fd254c22f75738def870a7ffd2c3e Mon Sep 17 00:00:00 2001 From: Martin Schwidefsky Date: Fri, 17 May 2013 14:41:33 +0200 Subject: s390/kvm: rename RCP_xxx defines to PGSTE_xxx The RCP byte is a part of the PGSTE value, the existing RCP_xxx names are inaccurate. As the defines describe bits and pieces of the PGSTE, the names should start with PGSTE_. The KVM_UR_BIT and KVM_UC_BIT are part of the PGSTE as well, give them better names as well. Signed-off-by: Martin Schwidefsky Signed-off-by: Christian Borntraeger Signed-off-by: Gleb Natapov --- arch/s390/mm/pgtable.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'arch/s390/mm/pgtable.c') diff --git a/arch/s390/mm/pgtable.c b/arch/s390/mm/pgtable.c index 7805ddca833..5ca75683c65 100644 --- a/arch/s390/mm/pgtable.c +++ b/arch/s390/mm/pgtable.c @@ -690,7 +690,7 @@ int gmap_ipte_notify(struct gmap *gmap, unsigned long start, unsigned long len) entry = *ptep; if ((pte_val(entry) & (_PAGE_INVALID | _PAGE_RO)) == 0) { pgste = pgste_get_lock(ptep); - pgste_val(pgste) |= RCP_IN_BIT; + pgste_val(pgste) |= PGSTE_IN_BIT; pgste_set_unlock(ptep, pgste); start += PAGE_SIZE; len -= PAGE_SIZE; -- cgit v1.2.3-70-g09d2 From f8b5ff2cff232df052955ef975f7219e1faa217f Mon Sep 17 00:00:00 2001 From: Christian Borntraeger Date: Fri, 17 May 2013 14:41:38 +0200 Subject: s390: fix gmap_ipte_notifier vs. software dirty pages On heavy paging load some guest cpus started to loop in gmap_ipte_notify. This was visible as stalled cpus inside the guest. The gmap_ipte_notifier tries to map a user page and then made sure that the pte is valid and writable. Turns out that with the software change bit tracking the pte can become read-only (and only software writable) if the page is clean. Since we loop in this code, the page would stay clean and, therefore, be never writable again. Let us just use fixup_user_fault, that guarantees to call handle_mm_fault. Signed-off-by: Christian Borntraeger Acked-by: Martin Schwidefsky Signed-off-by: Gleb Natapov --- arch/s390/mm/pgtable.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) (limited to 'arch/s390/mm/pgtable.c') diff --git a/arch/s390/mm/pgtable.c b/arch/s390/mm/pgtable.c index 5ca75683c65..1e0c438dbd6 100644 --- a/arch/s390/mm/pgtable.c +++ b/arch/s390/mm/pgtable.c @@ -677,8 +677,7 @@ int gmap_ipte_notify(struct gmap *gmap, unsigned long start, unsigned long len) break; } /* Get the page mapped */ - if (get_user_pages(current, gmap->mm, addr, 1, 1, 0, - NULL, NULL) != 1) { + if (fixup_user_fault(current, gmap->mm, addr, FAULT_FLAG_WRITE)) { rc = -EFAULT; break; } -- cgit v1.2.3-70-g09d2 From db70ccdfb9953b984f5b95d98c50d8da335bab59 Mon Sep 17 00:00:00 2001 From: Christian Borntraeger Date: Wed, 12 Jun 2013 13:54:52 +0200 Subject: KVM: s390: Provide function for setting the guest storage key From time to time we need to set the guest storage key. Lets provide a helper function that handles the changes with all the right locking and checking. Signed-off-by: Christian Borntraeger Signed-off-by: Cornelia Huck Signed-off-by: Paolo Bonzini --- arch/s390/include/asm/pgalloc.h | 3 +++ arch/s390/mm/pgtable.c | 48 +++++++++++++++++++++++++++++++++++++++++ 2 files changed, 51 insertions(+) (limited to 'arch/s390/mm/pgtable.c') diff --git a/arch/s390/include/asm/pgalloc.h b/arch/s390/include/asm/pgalloc.h index 590c3219c63..e1408ddb94f 100644 --- a/arch/s390/include/asm/pgalloc.h +++ b/arch/s390/include/asm/pgalloc.h @@ -22,6 +22,9 @@ unsigned long *page_table_alloc(struct mm_struct *, unsigned long); void page_table_free(struct mm_struct *, unsigned long *); void page_table_free_rcu(struct mmu_gather *, unsigned long *); +int set_guest_storage_key(struct mm_struct *mm, unsigned long addr, + unsigned long key, bool nq); + static inline void clear_table(unsigned long *s, unsigned long val, size_t n) { typedef struct { char _[n]; } addrtype; diff --git a/arch/s390/mm/pgtable.c b/arch/s390/mm/pgtable.c index 1e0c438dbd6..44b145055f3 100644 --- a/arch/s390/mm/pgtable.c +++ b/arch/s390/mm/pgtable.c @@ -771,6 +771,54 @@ static inline void page_table_free_pgste(unsigned long *table) __free_page(page); } +int set_guest_storage_key(struct mm_struct *mm, unsigned long addr, + unsigned long key, bool nq) +{ + spinlock_t *ptl; + pgste_t old, new; + pte_t *ptep; + + down_read(&mm->mmap_sem); + ptep = get_locked_pte(current->mm, addr, &ptl); + if (unlikely(!ptep)) { + up_read(&mm->mmap_sem); + return -EFAULT; + } + + new = old = pgste_get_lock(ptep); + pgste_val(new) &= ~(PGSTE_GR_BIT | PGSTE_GC_BIT | + PGSTE_ACC_BITS | PGSTE_FP_BIT); + pgste_val(new) |= (key & (_PAGE_CHANGED | _PAGE_REFERENCED)) << 48; + pgste_val(new) |= (key & (_PAGE_ACC_BITS | _PAGE_FP_BIT)) << 56; + if (!(pte_val(*ptep) & _PAGE_INVALID)) { + unsigned long address, bits; + unsigned char skey; + + address = pte_val(*ptep) & PAGE_MASK; + skey = page_get_storage_key(address); + bits = skey & (_PAGE_CHANGED | _PAGE_REFERENCED); + /* Set storage key ACC and FP */ + page_set_storage_key(address, + (key & (_PAGE_ACC_BITS | _PAGE_FP_BIT)), + !nq); + + /* Merge host changed & referenced into pgste */ + pgste_val(new) |= bits << 52; + /* Transfer skey changed & referenced bit to kvm user bits */ + pgste_val(new) |= bits << 45; /* PGSTE_UR_BIT & PGSTE_UC_BIT */ + } + /* changing the guest storage key is considered a change of the page */ + if ((pgste_val(new) ^ pgste_val(old)) & + (PGSTE_ACC_BITS | PGSTE_FP_BIT | PGSTE_GR_BIT | PGSTE_GC_BIT)) + pgste_val(new) |= PGSTE_UC_BIT; + + pgste_set_unlock(ptep, new); + pte_unmap_unlock(*ptep, ptl); + up_read(&mm->mmap_sem); + return 0; +} +EXPORT_SYMBOL(set_guest_storage_key); + #else /* CONFIG_PGSTE */ static inline unsigned long *page_table_alloc_pgste(struct mm_struct *mm, -- cgit v1.2.3-70-g09d2