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

Commit d3ed1cee authored by Martin Schwidefsky's avatar Martin Schwidefsky Committed by Christian Borntraeger
Browse files

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: default avatarDavid Hildenbrand <dahi@linux.vnet.ibm.com>
Reviewed-by: default avatarChristian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: default avatarMartin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: default avatarChristian Borntraeger <borntraeger@de.ibm.com>
parent c427c42c

arch/s390/kvm/kvm-s390.c

+16 −10
Original line number Diff line number Diff line
@@ -1050,26 +1050,30 @@ static long kvm_s390_get_skeys(struct kvm *kvm, struct kvm_s390_skeys *args) 
	if (!keys)

		return -ENOMEM;



	down_read(&current->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(&current->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;

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(&current->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(&current->mm->mmap_sem);

out:

	kvfree(keys);

	return r;

arch/s390/kvm/priv.c

+5 −2
Original line number Diff line number Diff line
@@ -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(&current->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(&current->mm->mmap_sem);

			if (rc)

				return kvm_s390_inject_program_int(vcpu, PGM_ADDRESSING);

		}

arch/s390/mm/pgtable.c

+3 −12
Original line number Diff line number Diff line
@@ -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);