From 3e03d4c46daa849880837d802e41c14132a03ef9 Mon Sep 17 00:00:00 2001 From: Christian Borntraeger Date: Thu, 28 Aug 2014 21:21:41 +0200 Subject: KVM: s390/mm: Fix storage key corruption during swapping Since 3.12 or more precisely commit 0944fe3f4a32 ("s390/mm: implement software referenced bits") guest storage keys get corrupted during paging. This commit added another valid->invalid translation for page tables - namely ptep_test_and_clear_young. We have to transfer the storage key into the pgste in that case. Signed-off-by: Christian Borntraeger Acked-by: Martin Schwidefsky Cc: stable@vger.kernel.org # v3.12+ --- arch/s390/include/asm/pgtable.h | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) (limited to 'arch/s390/include/asm/pgtable.h') diff --git a/arch/s390/include/asm/pgtable.h b/arch/s390/include/asm/pgtable.h index b76317c1f3eb..32686e891313 100644 --- a/arch/s390/include/asm/pgtable.h +++ b/arch/s390/include/asm/pgtable.h @@ -1127,7 +1127,7 @@ static inline int ptep_test_and_clear_young(struct vm_area_struct *vma, unsigned long addr, pte_t *ptep) { pgste_t pgste; - pte_t pte; + pte_t pte, oldpte; int young; if (mm_has_pgste(vma->vm_mm)) { @@ -1135,12 +1135,13 @@ static inline int ptep_test_and_clear_young(struct vm_area_struct *vma, pgste = pgste_ipte_notify(vma->vm_mm, ptep, pgste); } - pte = *ptep; + oldpte = pte = *ptep; ptep_flush_direct(vma->vm_mm, addr, ptep); young = pte_young(pte); pte = pte_mkold(pte); if (mm_has_pgste(vma->vm_mm)) { + pgste = pgste_update_all(&oldpte, pgste, vma->vm_mm); pgste = pgste_set_pte(ptep, pgste, pte); pgste_set_unlock(ptep, pgste); } else -- cgit v1.2.3 From 1951497d90d6754201af3e65241a06f9ef6755cd Mon Sep 17 00:00:00 2001 From: Christian Borntraeger Date: Thu, 28 Aug 2014 23:44:57 +0200 Subject: KVM: s390/mm: Fix guest storage key corruption in ptep_set_access_flags commit 0944fe3f4a32 ("s390/mm: implement software referenced bits") triggered another paging/storage key corruption. There is an unhandled invalid->valid pte change where we have to set the real storage key from the pgste. When doing paging a guest page might be swapcache or swap and when faulted in it might be read-only and due to a parallel scan old. An do_wp_page will make it writeable and young. Due to software reference tracking this page was invalid and now becomes valid. Signed-off-by: Christian Borntraeger Acked-by: Martin Schwidefsky Cc: stable@vger.kernel.org # v3.12+ --- arch/s390/include/asm/pgtable.h | 1 + 1 file changed, 1 insertion(+) (limited to 'arch/s390/include/asm/pgtable.h') diff --git a/arch/s390/include/asm/pgtable.h b/arch/s390/include/asm/pgtable.h index 32686e891313..5efb2fe186e7 100644 --- a/arch/s390/include/asm/pgtable.h +++ b/arch/s390/include/asm/pgtable.h @@ -1331,6 +1331,7 @@ static inline int ptep_set_access_flags(struct vm_area_struct *vma, ptep_flush_direct(vma->vm_mm, address, ptep); if (mm_has_pgste(vma->vm_mm)) { + pgste_set_key(ptep, pgste, entry, vma->vm_mm); pgste = pgste_set_pte(ptep, pgste, entry); pgste_set_unlock(ptep, pgste); } else -- cgit v1.2.3