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| author | Dominik Dingel <dingel@linux.vnet.ibm.com> | 2014-12-01 19:24:42 +0300 |
|---|---|---|
| committer | Christian Borntraeger <borntraeger@de.ibm.com> | 2015-12-15 19:08:21 +0300 |
| commit | a3a92c31bf0b57ad0ca7f092a6f3a57168ba9ae2 (patch) | |
| tree | 1e8fd0810ebeb5331a8cb3ec700b023a17162aaa /arch/s390/mm | |
| parent | 8335713ad08caf2c3dfcb5bc2c93d7e0276142d4 (diff) | |
| download | linux-a3a92c31bf0b57ad0ca7f092a6f3a57168ba9ae2.tar.xz | |
KVM: s390: fix mismatch between user and in-kernel guest limit
While the userspace interface requests the maximum size the gmap code
expects to get a maximum address.
This error resulted in bigger page tables than necessary for some guest
sizes, e.g. a 2GB guest used 3 levels instead of 2.
At the same time we introduce KVM_S390_NO_MEM_LIMIT, which allows in a
bright future that a guest spans the complete 64 bit address space.
We also switch to TASK_MAX_SIZE for the initial memory size, this is a
cosmetic change as the previous size also resulted in a 4 level pagetable
creation.
Reported-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Dominik Dingel <dingel@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Diffstat (limited to 'arch/s390/mm')
| -rw-r--r-- | arch/s390/mm/pgtable.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/arch/s390/mm/pgtable.c b/arch/s390/mm/pgtable.c index 54ef3bc01b43..63b039899a5e 100644 --- a/arch/s390/mm/pgtable.c +++ b/arch/s390/mm/pgtable.c @@ -133,7 +133,7 @@ void crst_table_downgrade(struct mm_struct *mm, unsigned long limit) /** * gmap_alloc - allocate a guest address space * @mm: pointer to the parent mm_struct - * @limit: maximum size of the gmap address space + * @limit: maximum address of the gmap address space * * Returns a guest address space structure. */ @@ -402,7 +402,7 @@ int gmap_map_segment(struct gmap *gmap, unsigned long from, if ((from | to | len) & (PMD_SIZE - 1)) return -EINVAL; if (len == 0 || from + len < from || to + len < to || - from + len > TASK_MAX_SIZE || to + len > gmap->asce_end) + from + len - 1 > TASK_MAX_SIZE || to + len - 1 > gmap->asce_end) return -EINVAL; flush = 0; |