[PATCH 0/1] KVM: s390/mm: fix for 4.6

[PATCH 0/1] KVM: s390/mm: fix for 4.6

[Christian Borntraeger]

Paolo,

here is a fix of a "merge issue" breaking some 
kvm configurations on s390.

since Martin is away this week, lets push this fix via your
tree. (this has the additional advantage that this fix will
probably be part of kvm/next, making 4.7 patch handling
easier). Ok?

Heiko, can you ack this fix?


Christian Borntraeger (1):
  s390/mm/kvm: fix mis-merge in gmap handling

 arch/s390/mm/gmap.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

-- 
2.5.5

[PATCH 1/1] s390/mm/kvm: fix mis-merge in gmap handling

[Christian Borntraeger]

commit 1e133ab296f3 ("s390/mm: split arch/s390/mm/pgtable.c") dropped
some changes from commit a3a92c31bf0b ("KVM: s390: fix mismatch
between user and in-kernel guest limit") - this breaks KVM for some
memory sizes (kvm-s390: failed to commit memory region) like
exactly 2GB.

Cc: Dominik Dingel <dingel@linux.vnet.ibm.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
---
 arch/s390/mm/gmap.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/s390/mm/gmap.c b/arch/s390/mm/gmap.c
index 69247b4..cace818 100644
--- a/arch/s390/mm/gmap.c
+++ b/arch/s390/mm/gmap.c
@@ -23,7 +23,7 @@
 /**
  * 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.
  */
@@ -292,7 +292,7 @@ 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;
-- 
2.5.5

Re: [PATCH 1/1] s390/mm/kvm: fix mis-merge in gmap handling

[Heiko Carstens]

On Mon, Apr 04, 2016 at 09:41:32AM +0200, Christian Borntraeger wrote:
> commit 1e133ab296f3 ("s390/mm: split arch/s390/mm/pgtable.c") dropped
> some changes from commit a3a92c31bf0b ("KVM: s390: fix mismatch
> between user and in-kernel guest limit") - this breaks KVM for some
> memory sizes (kvm-s390: failed to commit memory region) like
> exactly 2GB.
> 
> Cc: Dominik Dingel <dingel@linux.vnet.ibm.com>
> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
> Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
> ---
>  arch/s390/mm/gmap.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/arch/s390/mm/gmap.c b/arch/s390/mm/gmap.c
> index 69247b4..cace818 100644
> --- a/arch/s390/mm/gmap.c
> +++ b/arch/s390/mm/gmap.c
> @@ -23,7 +23,7 @@
>  /**
>   * 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.
>   */
> @@ -292,7 +292,7 @@ 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;

Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com>

Re: [PATCH 1/1] s390/mm/kvm: fix mis-merge in gmap handling

[Paolo Bonzini]

On 04/04/2016 09:41, Christian Borntraeger wrote:
> commit 1e133ab296f3 ("s390/mm: split arch/s390/mm/pgtable.c") dropped
> some changes from commit a3a92c31bf0b ("KVM: s390: fix mismatch
> between user and in-kernel guest limit") - this breaks KVM for some
> memory sizes (kvm-s390: failed to commit memory region) like
> exactly 2GB.
> 
> Cc: Dominik Dingel <dingel@linux.vnet.ibm.com>
> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
> Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
> ---
>  arch/s390/mm/gmap.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/arch/s390/mm/gmap.c b/arch/s390/mm/gmap.c
> index 69247b4..cace818 100644
> --- a/arch/s390/mm/gmap.c
> +++ b/arch/s390/mm/gmap.c
> @@ -23,7 +23,7 @@
>  /**
>   * 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.
>   */
> @@ -292,7 +292,7 @@ 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;
> 

Applied, thanks.  Pull request going out in a few hours.

Paolo

Re: [PATCH 0/1] KVM: s390/mm: fix for 4.6

[Paolo Bonzini]

On 04/04/2016 09:41, Christian Borntraeger wrote:
> Paolo,
> 
> here is a fix of a "merge issue" breaking some 
> kvm configurations on s390.
> 
> since Martin is away this week, lets push this fix via your
> tree. (this has the additional advantage that this fix will
> probably be part of kvm/next, making 4.7 patch handling
> easier). Ok?

Sure.

Paolo

> Heiko, can you ack this fix?