2020-04-03 15:48:21

by David Hildenbrand

Subject: [PATCH v2 5/5] KVM: s390: vsie: gmap_table_walk() simplifications

Let's use asce_type where applicable. Also, simplify our sanity check for
valid table levels and convert it into a WARN_ON_ONCE(). Check if we even
have a valid gmap shadow as the very first step.

Signed-off-by: David Hildenbrand <[email protected]>
---
arch/s390/mm/gmap.c | 10 +++++-----
1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/arch/s390/mm/gmap.c b/arch/s390/mm/gmap.c
index 24ef30fb0833..a2bd8d7792e9 100644
--- a/arch/s390/mm/gmap.c
+++ b/arch/s390/mm/gmap.c
@@ -788,19 +788,19 @@ static inline unsigned long *gmap_table_walk(struct gmap *gmap,
unsigned long gaddr, int level)
{
const int asce_type = gmap->asce & _ASCE_TYPE_MASK;
- unsigned long *table;
+ unsigned long *table = gmap->table;

- if ((gmap->asce & _ASCE_TYPE_MASK) + 4 < (level * 4))
- return NULL;
if (gmap_is_shadow(gmap) && gmap->removed)
return NULL;

+ if (WARN_ON_ONCE(level > (asce_type >> 2) + 1))
+ return NULL;
+
if (WARN_ON_ONCE(asce_type != _ASCE_TYPE_REGION1 &&
gaddr & (-1UL << (31 + (asce_type >> 2) * 11))))
return NULL;

- table = gmap->table;
- switch (gmap->asce & _ASCE_TYPE_MASK) {
+ switch (asce_type) {
case _ASCE_TYPE_REGION1:
table += (gaddr & _REGION1_INDEX) >> _REGION1_SHIFT;
if (level == 4)
--
2.25.1

2020-04-06 16:07:42

by Christian Borntraeger

Subject: Re: [PATCH v2 5/5] KVM: s390: vsie: gmap_table_walk() simplifications

On 03.04.20 17:30, David Hildenbrand wrote:
> Let's use asce_type where applicable. Also, simplify our sanity check for
> valid table levels and convert it into a WARN_ON_ONCE(). Check if we even
> have a valid gmap shadow as the very first step.
>
> Signed-off-by: David Hildenbrand <[email protected]>

Reviewed-by: Christian Borntraeger <[email protected]>
> ---
> arch/s390/mm/gmap.c | 10 +++++-----
> 1 file changed, 5 insertions(+), 5 deletions(-)
>
> diff --git a/arch/s390/mm/gmap.c b/arch/s390/mm/gmap.c
> index 24ef30fb0833..a2bd8d7792e9 100644
> --- a/arch/s390/mm/gmap.c
> +++ b/arch/s390/mm/gmap.c
> @@ -788,19 +788,19 @@ static inline unsigned long *gmap_table_walk(struct gmap *gmap,
> unsigned long gaddr, int level)
> {
> const int asce_type = gmap->asce & _ASCE_TYPE_MASK;
> - unsigned long *table;
> + unsigned long *table = gmap->table;
>
> - if ((gmap->asce & _ASCE_TYPE_MASK) + 4 < (level * 4))
> - return NULL;
> if (gmap_is_shadow(gmap) && gmap->removed)
> return NULL;
>
> + if (WARN_ON_ONCE(level > (asce_type >> 2) + 1))
> + return NULL;
> +
> if (WARN_ON_ONCE(asce_type != _ASCE_TYPE_REGION1 &&
> gaddr & (-1UL << (31 + (asce_type >> 2) * 11))))
> return NULL;
>
> - table = gmap->table;
> - switch (gmap->asce & _ASCE_TYPE_MASK) {
> + switch (asce_type) {
> case _ASCE_TYPE_REGION1:
> table += (gaddr & _REGION1_INDEX) >> _REGION1_SHIFT;
> if (level == 4)
>

2020-04-07 11:12:36

by Claudio Imbrenda

Subject: Re: [PATCH v2 5/5] KVM: s390: vsie: gmap_table_walk() simplifications

On Fri, 3 Apr 2020 17:30:50 +0200
David Hildenbrand <[email protected]> wrote:

> Let's use asce_type where applicable. Also, simplify our sanity check
> for valid table levels and convert it into a WARN_ON_ONCE(). Check if
> we even have a valid gmap shadow as the very first step.
>
> Signed-off-by: David Hildenbrand <[email protected]>
> ---
> arch/s390/mm/gmap.c | 10 +++++-----
> 1 file changed, 5 insertions(+), 5 deletions(-)
>
> diff --git a/arch/s390/mm/gmap.c b/arch/s390/mm/gmap.c
> index 24ef30fb0833..a2bd8d7792e9 100644
> --- a/arch/s390/mm/gmap.c
> +++ b/arch/s390/mm/gmap.c
> @@ -788,19 +788,19 @@ static inline unsigned long
> *gmap_table_walk(struct gmap *gmap, unsigned long gaddr, int level)
> {
> const int asce_type = gmap->asce & _ASCE_TYPE_MASK;
> - unsigned long *table;
> + unsigned long *table = gmap->table;
>
> - if ((gmap->asce & _ASCE_TYPE_MASK) + 4 < (level * 4))
> - return NULL;
> if (gmap_is_shadow(gmap) && gmap->removed)
> return NULL;
>
> + if (WARN_ON_ONCE(level > (asce_type >> 2) + 1))
> + return NULL;
> +
> if (WARN_ON_ONCE(asce_type != _ASCE_TYPE_REGION1 &&
> gaddr & (-1UL << (31 + (asce_type >> 2) *
> 11)))) return NULL;
>
> - table = gmap->table;
> - switch (gmap->asce & _ASCE_TYPE_MASK) {
> + switch (asce_type) {
> case _ASCE_TYPE_REGION1:
> table += (gaddr & _REGION1_INDEX) >> _REGION1_SHIFT;
> if (level == 4)

Reviewed-by: Claudio Imbrenda <[email protected]>