From d3ed1ceeace311af9973d17a07a114bfaf0ca1b1 Mon Sep 17 00:00:00 2001 From: Martin Schwidefsky Date: Tue, 8 Mar 2016 11:53:35 +0100 Subject: s390/mm: set and get guest storage key mmap locking Move the mmap semaphore locking out of set_guest_storage_key and get_guest_storage_key. This makes the two functions more like the other ptep_xxx operations and allows to avoid repeated semaphore operations if multiple keys are read or written. Reviewed-by: David Hildenbrand Reviewed-by: Christian Borntraeger Signed-off-by: Martin Schwidefsky Signed-off-by: Christian Borntraeger --- arch/s390/kvm/kvm-s390.c | 26 ++++++++++++++++---------- arch/s390/kvm/priv.c | 7 +++++-- arch/s390/mm/pgtable.c | 15 +++------------ 3 files changed, 24 insertions(+), 24 deletions(-) (limited to 'arch/s390') diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c index 9d0e4d0..d0156d7 100644 --- a/arch/s390/kvm/kvm-s390.c +++ b/arch/s390/kvm/kvm-s390.c @@ -1050,26 +1050,30 @@ static long kvm_s390_get_skeys(struct kvm *kvm, struct kvm_s390_skeys *args) if (!keys) return -ENOMEM; + down_read(¤t->mm->mmap_sem); for (i = 0; i < args->count; i++) { hva = gfn_to_hva(kvm, args->start_gfn + i); if (kvm_is_error_hva(hva)) { r = -EFAULT; - goto out; + break; } curkey = get_guest_storage_key(current->mm, hva); if (IS_ERR_VALUE(curkey)) { r = curkey; - goto out; + break; } keys[i] = curkey; } + up_read(¤t->mm->mmap_sem); + + if (!r) { + r = copy_to_user((uint8_t __user *)args->skeydata_addr, keys, + sizeof(uint8_t) * args->count); + if (r) + r = -EFAULT; + } - r = copy_to_user((uint8_t __user *)args->skeydata_addr, keys, - sizeof(uint8_t) * args->count); - if (r) - r = -EFAULT; -out: kvfree(keys); return r; } @@ -1106,24 +1110,26 @@ static long kvm_s390_set_skeys(struct kvm *kvm, struct kvm_s390_skeys *args) if (r) goto out; + down_read(¤t->mm->mmap_sem); for (i = 0; i < args->count; i++) { hva = gfn_to_hva(kvm, args->start_gfn + i); if (kvm_is_error_hva(hva)) { r = -EFAULT; - goto out; + break; } /* Lowest order bit is reserved */ if (keys[i] & 0x01) { r = -EINVAL; - goto out; + break; } r = set_guest_storage_key(current->mm, hva, (unsigned long)keys[i], 0); if (r) - goto out; + break; } + up_read(¤t->mm->mmap_sem); out: kvfree(keys); return r; diff --git a/arch/s390/kvm/priv.c b/arch/s390/kvm/priv.c index 95916fa..c6deed7 100644 --- a/arch/s390/kvm/priv.c +++ b/arch/s390/kvm/priv.c @@ -728,9 +728,12 @@ static int handle_pfmf(struct kvm_vcpu *vcpu) if (rc) return rc; - if (set_guest_storage_key(current->mm, useraddr, + down_read(¤t->mm->mmap_sem); + rc = set_guest_storage_key(current->mm, useraddr, vcpu->run->s.regs.gprs[reg1] & PFMF_KEY, - vcpu->run->s.regs.gprs[reg1] & PFMF_NQ)) + vcpu->run->s.regs.gprs[reg1] & PFMF_NQ); + up_read(¤t->mm->mmap_sem); + if (rc) return kvm_s390_inject_program_int(vcpu, PGM_ADDRESSING); } diff --git a/arch/s390/mm/pgtable.c b/arch/s390/mm/pgtable.c index 2a23ca9..7612a7c 100644 --- a/arch/s390/mm/pgtable.c +++ b/arch/s390/mm/pgtable.c @@ -506,12 +506,9 @@ int set_guest_storage_key(struct mm_struct *mm, unsigned long addr, pgste_t old, new; pte_t *ptep; - down_read(&mm->mmap_sem); ptep = get_locked_pte(mm, addr, &ptl); - if (unlikely(!ptep)) { - up_read(&mm->mmap_sem); + if (unlikely(!ptep)) return -EFAULT; - } new = old = pgste_get_lock(ptep); pgste_val(new) &= ~(PGSTE_GR_BIT | PGSTE_GC_BIT | @@ -538,7 +535,6 @@ int set_guest_storage_key(struct mm_struct *mm, unsigned long addr, pgste_set_unlock(ptep, new); pte_unmap_unlock(ptep, ptl); - up_read(&mm->mmap_sem); return 0; } EXPORT_SYMBOL(set_guest_storage_key); @@ -550,14 +546,11 @@ unsigned long get_guest_storage_key(struct mm_struct *mm, unsigned long addr) pgste_t pgste; pte_t *ptep; - down_read(&mm->mmap_sem); ptep = get_locked_pte(mm, addr, &ptl); - if (unlikely(!ptep)) { - up_read(&mm->mmap_sem); + if (unlikely(!ptep)) return -EFAULT; - } - pgste = pgste_get_lock(ptep); + pgste = pgste_get_lock(ptep); if (pte_val(*ptep) & _PAGE_INVALID) { key = (pgste_val(pgste) & PGSTE_ACC_BITS) >> 56; key |= (pgste_val(pgste) & PGSTE_FP_BIT) >> 56; @@ -572,10 +565,8 @@ unsigned long get_guest_storage_key(struct mm_struct *mm, unsigned long addr) if (pgste_val(pgste) & PGSTE_GC_BIT) key |= _PAGE_CHANGED; } - pgste_set_unlock(ptep, pgste); pte_unmap_unlock(ptep, ptl); - up_read(&mm->mmap_sem); return key; } EXPORT_SYMBOL(get_guest_storage_key); -- cgit v1.1