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Commit d4cb1134 authored by Dominik Dingel's avatar Dominik Dingel Committed by Christian Borntraeger
Browse files

KVM: s390: Clear storage keys 



page_table_reset_pgste() already does a complete page table walk to
reset the pgste. Enhance it to initialize the storage keys to
PAGE_DEFAULT_KEY if requested by the caller. This will be used
for lazy storage key handling. Also provide an empty stub for
!CONFIG_PGSTE

Lets adopt the current code (diag 308) to not clear the keys.

Signed-off-by: default avatarDominik Dingel <dingel@linux.vnet.ibm.com>
Acked-by: default avatarMartin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: default avatarChristian Borntraeger <borntraeger@de.ibm.com>
parent 65eef335

arch/s390/include/asm/pgalloc.h

+2 −1
Original line number Diff line number Diff line
@@ -22,7 +22,8 @@ unsigned long *page_table_alloc(struct mm_struct *, unsigned long); 
void page_table_free(struct mm_struct *, unsigned long *);

void page_table_free_rcu(struct mmu_gather *, unsigned long *);



void page_table_reset_pgste(struct mm_struct *, unsigned long, unsigned long);

void page_table_reset_pgste(struct mm_struct *, unsigned long, unsigned long,

			    bool init_skey);

int set_guest_storage_key(struct mm_struct *mm, unsigned long addr,

			  unsigned long key, bool nq);

arch/s390/kvm/diag.c

+3 −3
Original line number Diff line number Diff line
@@ -169,15 +169,15 @@ static int __diag_ipl_functions(struct kvm_vcpu *vcpu) 
	switch (subcode) {

	case 0:

	case 1:

		page_table_reset_pgste(current->mm, 0, TASK_SIZE);

		page_table_reset_pgste(current->mm, 0, TASK_SIZE, false);

		return -EOPNOTSUPP;

	case 3:

		vcpu->run->s390_reset_flags = KVM_S390_RESET_CLEAR;

		page_table_reset_pgste(current->mm, 0, TASK_SIZE);

		page_table_reset_pgste(current->mm, 0, TASK_SIZE, false);

		break;

	case 4:

		vcpu->run->s390_reset_flags = 0;

		page_table_reset_pgste(current->mm, 0, TASK_SIZE);

		page_table_reset_pgste(current->mm, 0, TASK_SIZE, false);

		break;

	default:

		return -EOPNOTSUPP;

arch/s390/mm/pgtable.c

+32 −11
Original line number Diff line number Diff line
@@ -883,8 +883,8 @@ static inline void page_table_free_pgste(unsigned long *table) 
	__free_page(page);

}



static inline unsigned long page_table_reset_pte(struct mm_struct *mm,

			pmd_t *pmd, unsigned long addr, unsigned long end)

static inline unsigned long page_table_reset_pte(struct mm_struct *mm, pmd_t *pmd,

			unsigned long addr, unsigned long end, bool init_skey)

{

	pte_t *start_pte, *pte;

	spinlock_t *ptl;
@@ -895,6 +895,22 @@ static inline unsigned long page_table_reset_pte(struct mm_struct *mm, 
	do {

		pgste = pgste_get_lock(pte);

		pgste_val(pgste) &= ~_PGSTE_GPS_USAGE_MASK;

		if (init_skey) {

			unsigned long address;



			pgste_val(pgste) &= ~(PGSTE_ACC_BITS | PGSTE_FP_BIT |

					      PGSTE_GR_BIT | PGSTE_GC_BIT);



			/* skip invalid and not writable pages */

			if (pte_val(*pte) & _PAGE_INVALID ||

			    !(pte_val(*pte) & _PAGE_WRITE)) {

				pgste_set_unlock(pte, pgste);

				continue;

			}



			address = pte_val(*pte) & PAGE_MASK;

			page_set_storage_key(address, PAGE_DEFAULT_KEY, 1);

		}

		pgste_set_unlock(pte, pgste);

	} while (pte++, addr += PAGE_SIZE, addr != end);

	pte_unmap_unlock(start_pte, ptl);
@@ -902,8 +918,8 @@ static inline unsigned long page_table_reset_pte(struct mm_struct *mm, 
	return addr;

}



static inline unsigned long page_table_reset_pmd(struct mm_struct *mm,

			pud_t *pud, unsigned long addr, unsigned long end)

static inline unsigned long page_table_reset_pmd(struct mm_struct *mm, pud_t *pud,

			unsigned long addr, unsigned long end, bool init_skey)

{

	unsigned long next;

	pmd_t *pmd;
@@ -913,14 +929,14 @@ static inline unsigned long page_table_reset_pmd(struct mm_struct *mm, 
		next = pmd_addr_end(addr, end);

		if (pmd_none_or_clear_bad(pmd))

			continue;

		next = page_table_reset_pte(mm, pmd, addr, next);

		next = page_table_reset_pte(mm, pmd, addr, next, init_skey);

	} while (pmd++, addr = next, addr != end);



	return addr;

}



static inline unsigned long page_table_reset_pud(struct mm_struct *mm,

			pgd_t *pgd, unsigned long addr, unsigned long end)

static inline unsigned long page_table_reset_pud(struct mm_struct *mm, pgd_t *pgd,

			unsigned long addr, unsigned long end, bool init_skey)

{

	unsigned long next;

	pud_t *pud;
@@ -930,14 +946,14 @@ static inline unsigned long page_table_reset_pud(struct mm_struct *mm, 
		next = pud_addr_end(addr, end);

		if (pud_none_or_clear_bad(pud))

			continue;

		next = page_table_reset_pmd(mm, pud, addr, next);

		next = page_table_reset_pmd(mm, pud, addr, next, init_skey);

	} while (pud++, addr = next, addr != end);



	return addr;

}



void page_table_reset_pgste(struct mm_struct *mm,

			unsigned long start, unsigned long end)

void page_table_reset_pgste(struct mm_struct *mm, unsigned long start,

			    unsigned long end, bool init_skey)

{

	unsigned long addr, next;

	pgd_t *pgd;
@@ -949,7 +965,7 @@ void page_table_reset_pgste(struct mm_struct *mm, 
		next = pgd_addr_end(addr, end);

		if (pgd_none_or_clear_bad(pgd))

			continue;

		next = page_table_reset_pud(mm, pgd, addr, next);

		next = page_table_reset_pud(mm, pgd, addr, next, init_skey);

	} while (pgd++, addr = next, addr != end);

	up_read(&mm->mmap_sem);

}
@@ -1011,6 +1027,11 @@ static inline unsigned long *page_table_alloc_pgste(struct mm_struct *mm, 
	return NULL;

}



void page_table_reset_pgste(struct mm_struct *mm, unsigned long start,

			    unsigned long end, bool init_skey)

{

}



static inline void page_table_free_pgste(unsigned long *table)

{

}