Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 3ac8e380 authored by Dominik Dingel's avatar Dominik Dingel Committed by Martin Schwidefsky
Browse files

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: default avatarDominik Dingel <dingel@linux.vnet.ibm.com>
Acked-by: default avatarChristian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: default avatarMartin Schwidefsky <schwidefsky@de.ibm.com>
parent 2faee8ff

arch/s390/include/asm/pgtable.h

+1 −1
Original line number Diff line number Diff line
@@ -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);



/*

arch/s390/kvm/priv.c

+12 −5
Original line number Diff line number Diff line
@@ -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))

arch/s390/mm/pgtable.c

+15 −1
Original line number Diff line number Diff line
@@ -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);