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authorDominik Dingel <dingel@linux.vnet.ibm.com>2014-10-23 12:09:17 +0200
committerMartin Schwidefsky <schwidefsky@de.ibm.com>2014-10-27 13:27:26 +0100
commit3ac8e38015d4fd1c12e4e048a01a9f059a2053a2 (patch)
treeca076c3bc2009ee77f2a312673c934601d767287 /arch/s390
parent2faee8ff9dc6f4bfe46f6d2d110add858140fb20 (diff)
downloadlinux-3ac8e38015d4fd1c12e4e048a01a9f059a2053a2.tar.bz2
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 <dingel@linux.vnet.ibm.com> Acked-by: Christian Borntraeger <borntraeger@de.ibm.com> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Diffstat (limited to 'arch/s390')
-rw-r--r--arch/s390/include/asm/pgtable.h2
-rw-r--r--arch/s390/kvm/priv.c17
-rw-r--r--arch/s390/mm/pgtable.c16
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 <linux/rcupdate.h>
#include <linux/slab.h>
#include <linux/swapops.h>
+#include <linux/ksm.h>
+#include <linux/mman.h>
#include <asm/pgtable.h>
#include <asm/pgalloc.h>
@@ -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);