From 3ac8e38015d4fd1c12e4e048a01a9f059a2053a2 Mon Sep 17 00:00:00 2001 From: Dominik Dingel Date: Thu, 23 Oct 2014 12:09:17 +0200 Subject: [PATCH] s390/mm: disable KSM for storage key enabled pages When storage keys are enabled unmerge already merged pages and prevent new pages from being merged. Signed-off-by: Dominik Dingel Acked-by: Christian Borntraeger Reviewed-by: Paolo Bonzini Signed-off-by: Martin Schwidefsky --- arch/s390/include/asm/pgtable.h | 2 +- arch/s390/kvm/priv.c | 17 ++++++++++++----- arch/s390/mm/pgtable.c | 16 +++++++++++++++- 3 files changed, 28 insertions(+), 7 deletions(-) diff --git a/arch/s390/include/asm/pgtable.h b/arch/s390/include/asm/pgtable.h index df2e7f14ffb7..00d460742e1e 100644 --- a/arch/s390/include/asm/pgtable.h +++ b/arch/s390/include/asm/pgtable.h @@ -1751,7 +1751,7 @@ static inline pte_t mk_swap_pte(unsigned long type, unsigned long offset) extern int vmem_add_mapping(unsigned long start, unsigned long size); extern int vmem_remove_mapping(unsigned long start, unsigned long size); extern int s390_enable_sie(void); -extern void s390_enable_skey(void); +extern int s390_enable_skey(void); extern void s390_reset_cmma(struct mm_struct *mm); /* diff --git a/arch/s390/kvm/priv.c b/arch/s390/kvm/priv.c index 72bb2dd8b9cd..f47cb0c6d906 100644 --- a/arch/s390/kvm/priv.c +++ b/arch/s390/kvm/priv.c @@ -156,21 +156,25 @@ static int handle_store_cpu_address(struct kvm_vcpu *vcpu) return 0; } -static void __skey_check_enable(struct kvm_vcpu *vcpu) +static int __skey_check_enable(struct kvm_vcpu *vcpu) { + int rc = 0; if (!(vcpu->arch.sie_block->ictl & (ICTL_ISKE | ICTL_SSKE | ICTL_RRBE))) - return; + return rc; - s390_enable_skey(); + rc = s390_enable_skey(); trace_kvm_s390_skey_related_inst(vcpu); vcpu->arch.sie_block->ictl &= ~(ICTL_ISKE | ICTL_SSKE | ICTL_RRBE); + return rc; } static int handle_skey(struct kvm_vcpu *vcpu) { - __skey_check_enable(vcpu); + int rc = __skey_check_enable(vcpu); + if (rc) + return rc; vcpu->stat.instruction_storage_key++; if (vcpu->arch.sie_block->gpsw.mask & PSW_MASK_PSTATE) @@ -683,7 +687,10 @@ static int handle_pfmf(struct kvm_vcpu *vcpu) } if (vcpu->run->s.regs.gprs[reg1] & PFMF_SK) { - __skey_check_enable(vcpu); + int rc = __skey_check_enable(vcpu); + + if (rc) + return rc; if (set_guest_storage_key(current->mm, useraddr, vcpu->run->s.regs.gprs[reg1] & PFMF_KEY, vcpu->run->s.regs.gprs[reg1] & PFMF_NQ)) diff --git a/arch/s390/mm/pgtable.c b/arch/s390/mm/pgtable.c index 0f1e9ff6bc12..b1871d39e46e 100644 --- a/arch/s390/mm/pgtable.c +++ b/arch/s390/mm/pgtable.c @@ -18,6 +18,8 @@ #include #include #include +#include +#include #include #include @@ -1275,22 +1277,34 @@ static int __s390_enable_skey(pte_t *pte, unsigned long addr, return 0; } -void s390_enable_skey(void) +int s390_enable_skey(void) { struct mm_walk walk = { .pte_entry = __s390_enable_skey }; struct mm_struct *mm = current->mm; + struct vm_area_struct *vma; + int rc = 0; down_write(&mm->mmap_sem); if (mm_use_skey(mm)) goto out_up; mm->context.use_skey = 1; + for (vma = mm->mmap; vma; vma = vma->vm_next) { + if (ksm_madvise(vma, vma->vm_start, vma->vm_end, + MADV_UNMERGEABLE, &vma->vm_flags)) { + mm->context.use_skey = 0; + rc = -ENOMEM; + goto out_up; + } + } + mm->def_flags &= ~VM_MERGEABLE; walk.mm = mm; walk_page_range(0, TASK_SIZE, &walk); out_up: up_write(&mm->mmap_sem); + return rc; } EXPORT_SYMBOL_GPL(s390_enable_skey); -- 2.20.1