Reviewed-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>
(missing R-b on patch 1 is _not_ a mistake :))
Paolo
On 10/22/2014 01:09 PM, Dominik Dingel wrote:
> When storage keys are enabled unmerge already merged pages and prevent
> new pages from being merged.
>
> Signed-off-by: Dominik Dingel <dingel@xxxxxxxxxxxxxxxxxx>
> Acked-by: Christian Borntraeger <borntraeger@xxxxxxxxxx>
> ---
> 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 0da98d6..dfb38af 100644
> --- a/arch/s390/include/asm/pgtable.h
> +++ b/arch/s390/include/asm/pgtable.h
> @@ -1754,7 +1754,7 @@ 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 f89c1cd..e0967fd 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)
> @@ -692,7 +696,10 @@ 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 58d7eb2..82aa528 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>
> @@ -1328,22 +1330,34 @@ 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);
>
>
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