From 964c2c05c9f3095a18387a57b289cf06de637521 Mon Sep 17 00:00:00 2001 From: Dominik Dingel Date: Fri, 13 Jul 2018 11:28:25 +0100 Subject: s390/mm: Clear huge page storage keys on enable_skey When a guest starts using storage keys, we trap and set a default one for its whole valid address space. With this patch we are now able to do that for large pages. To speed up the storage key insertion, we use __storage_key_init_range, which in-turn will use sske_frame to set multiple storage keys with one instruction. As it has been previously used for debuging we have to get rid of the default key check and make it quiescing. Signed-off-by: Dominik Dingel Signed-off-by: Janosch Frank [replaced page_set_storage_key loop with __storage_key_init_range] Reviewed-by: Martin Schwidefsky Reviewed-by: David Hildenbrand --- arch/s390/mm/gmap.c | 32 +++++++++++++++++++++++++++++--- arch/s390/mm/pageattr.c | 6 ++---- 2 files changed, 31 insertions(+), 7 deletions(-) (limited to 'arch') diff --git a/arch/s390/mm/gmap.c b/arch/s390/mm/gmap.c index 3807de25a706..a8e32e60226b 100644 --- a/arch/s390/mm/gmap.c +++ b/arch/s390/mm/gmap.c @@ -2539,17 +2539,43 @@ EXPORT_SYMBOL_GPL(s390_enable_sie); * Enable storage key handling from now on and initialize the storage * keys with the default key. */ -static int __s390_enable_skey(pte_t *pte, unsigned long addr, - unsigned long next, struct mm_walk *walk) +static int __s390_enable_skey_pte(pte_t *pte, unsigned long addr, + unsigned long next, struct mm_walk *walk) { /* Clear storage key */ ptep_zap_key(walk->mm, addr, pte); return 0; } +static int __s390_enable_skey_hugetlb(pte_t *pte, unsigned long addr, + unsigned long hmask, unsigned long next, + struct mm_walk *walk) +{ + pmd_t *pmd = (pmd_t *)pte; + unsigned long start, end; + + /* + * The write check makes sure we do not set a key on shared + * memory. This is needed as the walker does not differentiate + * between actual guest memory and the process executable or + * shared libraries. + */ + if (pmd_val(*pmd) & _SEGMENT_ENTRY_INVALID || + !(pmd_val(*pmd) & _SEGMENT_ENTRY_WRITE)) + return 0; + + start = pmd_val(*pmd) & HPAGE_MASK; + end = start + HPAGE_SIZE - 1; + __storage_key_init_range(start, end); + return 0; +} + int s390_enable_skey(void) { - struct mm_walk walk = { .pte_entry = __s390_enable_skey }; + struct mm_walk walk = { + .hugetlb_entry = __s390_enable_skey_hugetlb, + .pte_entry = __s390_enable_skey_pte, + }; struct mm_struct *mm = current->mm; struct vm_area_struct *vma; int rc = 0; diff --git a/arch/s390/mm/pageattr.c b/arch/s390/mm/pageattr.c index c44171588d08..f8c6faab41f4 100644 --- a/arch/s390/mm/pageattr.c +++ b/arch/s390/mm/pageattr.c @@ -14,7 +14,7 @@ static inline unsigned long sske_frame(unsigned long addr, unsigned char skey) { - asm volatile(".insn rrf,0xb22b0000,%[skey],%[addr],9,0" + asm volatile(".insn rrf,0xb22b0000,%[skey],%[addr],1,0" : [addr] "+a" (addr) : [skey] "d" (skey)); return addr; } @@ -23,8 +23,6 @@ void __storage_key_init_range(unsigned long start, unsigned long end) { unsigned long boundary, size; - if (!PAGE_DEFAULT_KEY) - return; while (start < end) { if (MACHINE_HAS_EDAT1) { /* set storage keys for a 1MB frame */ @@ -37,7 +35,7 @@ void __storage_key_init_range(unsigned long start, unsigned long end) continue; } } - page_set_storage_key(start, PAGE_DEFAULT_KEY, 0); + page_set_storage_key(start, PAGE_DEFAULT_KEY, 1); start += PAGE_SIZE; } } -- cgit v1.2.3