| Message ID | 20221201084642.3747014-3-nrb@linux.ibm.com (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | s390x: test storage keys during migration | expand |
On Thu, 1 Dec 2022 09:46:41 +0100 Nico Boehr <nrb@linux.ibm.com> wrote: > Upcoming changes will change storage keys in a loop. To make sure each > iteration of the loops sets different keys, add variants of the storage > key library functions which allow to specify a seed. > > Signed-off-by: Nico Boehr <nrb@linux.ibm.com> I wonder if you can simply merge this patch with the previous one > --- > lib/s390x/skey.c | 12 +++++++----- > lib/s390x/skey.h | 14 ++++++++++++-- > 2 files changed, 19 insertions(+), 7 deletions(-) > > diff --git a/lib/s390x/skey.c b/lib/s390x/skey.c > index 100f0949a244..4ab0828ee98f 100644 > --- a/lib/s390x/skey.c > +++ b/lib/s390x/skey.c > @@ -14,10 +14,11 @@ > #include <skey.h> > > /* > - * Set storage keys on pagebuf. > + * Set storage keys on pagebuf with a seed for the storage keys. > * pagebuf must point to page_count consecutive pages. > + * Only the lower seven bits of the seed are considered. > */ > -void skey_set_keys(uint8_t *pagebuf, unsigned long page_count) > +void skey_set_keys_with_seed(uint8_t *pagebuf, unsigned long page_count, unsigned char seed) > { > unsigned char key_to_set; > unsigned long i; > @@ -30,7 +31,7 @@ void skey_set_keys(uint8_t *pagebuf, unsigned long page_count) > * protection as well as reference and change indication for > * some keys. > */ > - key_to_set = i * 2; > + key_to_set = (i ^ seed) * 2; > set_storage_key(pagebuf + i * PAGE_SIZE, key_to_set, 1); > } > } > @@ -38,13 +39,14 @@ void skey_set_keys(uint8_t *pagebuf, unsigned long page_count) > /* > * Verify storage keys on pagebuf. > * Storage keys must have been set by skey_set_keys on pagebuf before. > + * skey_set_keys must have been called with the same seed value. > * > * If storage keys match the expected result, will return a skey_verify_result > * with verify_failed false. All other fields are then invalid. > * If there is a mismatch, returned struct will have verify_failed true and will > * be filled with the details on the first mismatch encountered. > */ > -struct skey_verify_result skey_verify_keys(uint8_t *pagebuf, unsigned long page_count) > +struct skey_verify_result skey_verify_keys_with_seed(uint8_t *pagebuf, unsigned long page_count, unsigned char seed) > { > union skey expected_key, actual_key; > struct skey_verify_result result = { > @@ -56,7 +58,7 @@ struct skey_verify_result skey_verify_keys(uint8_t *pagebuf, unsigned long page_ > for (i = 0; i < page_count; i++) { > cur_page = pagebuf + i * PAGE_SIZE; > actual_key.val = get_storage_key(cur_page); > - expected_key.val = i * 2; > + expected_key.val = (i ^ seed) * 2; > > /* > * The PoP neither gives a guarantee that the reference bit is > diff --git a/lib/s390x/skey.h b/lib/s390x/skey.h > index a0f8caa1270b..bba1c131276d 100644 > --- a/lib/s390x/skey.h > +++ b/lib/s390x/skey.h > @@ -23,9 +23,19 @@ struct skey_verify_result { > unsigned long page_mismatch_addr; > }; > > -void skey_set_keys(uint8_t *pagebuf, unsigned long page_count); > +void skey_set_keys_with_seed(uint8_t *pagebuf, unsigned long page_count, unsigned char seed); > > -struct skey_verify_result skey_verify_keys(uint8_t *pagebuf, unsigned long page_count); > +static inline void skey_set_keys(uint8_t *pagebuf, unsigned long page_count) > +{ > + skey_set_keys_with_seed(pagebuf, page_count, 0); > +} > + > +struct skey_verify_result skey_verify_keys_with_seed(uint8_t *pagebuf, unsigned long page_count, unsigned char seed); > + > +static inline struct skey_verify_result skey_verify_keys(uint8_t *pagebuf, unsigned long page_count) > +{ > + return skey_verify_keys_with_seed(pagebuf, page_count, 0); > +} > > void skey_report_verify(struct skey_verify_result * const result); >
Quoting Claudio Imbrenda (2022-12-01 14:27:58) > On Thu, 1 Dec 2022 09:46:41 +0100 > Nico Boehr <nrb@linux.ibm.com> wrote: > > > Upcoming changes will change storage keys in a loop. To make sure each > > iteration of the loops sets different keys, add variants of the storage > > key library functions which allow to specify a seed. > > > > Signed-off-by: Nico Boehr <nrb@linux.ibm.com> > > I wonder if you can simply merge this patch with the previous one Yes, I thought about that too, but I was not sure whether people will like this approach, so I kept it as a seperate patch so I can undo it easily and it stands out a bit :) I will merge with the previous commit if nobody complains.
diff --git a/lib/s390x/skey.c b/lib/s390x/skey.c index 100f0949a244..4ab0828ee98f 100644 --- a/lib/s390x/skey.c +++ b/lib/s390x/skey.c @@ -14,10 +14,11 @@ #include <skey.h> /* - * Set storage keys on pagebuf. + * Set storage keys on pagebuf with a seed for the storage keys. * pagebuf must point to page_count consecutive pages. + * Only the lower seven bits of the seed are considered. */ -void skey_set_keys(uint8_t *pagebuf, unsigned long page_count) +void skey_set_keys_with_seed(uint8_t *pagebuf, unsigned long page_count, unsigned char seed) { unsigned char key_to_set; unsigned long i; @@ -30,7 +31,7 @@ void skey_set_keys(uint8_t *pagebuf, unsigned long page_count) * protection as well as reference and change indication for * some keys. */ - key_to_set = i * 2; + key_to_set = (i ^ seed) * 2; set_storage_key(pagebuf + i * PAGE_SIZE, key_to_set, 1); } } @@ -38,13 +39,14 @@ void skey_set_keys(uint8_t *pagebuf, unsigned long page_count) /* * Verify storage keys on pagebuf. * Storage keys must have been set by skey_set_keys on pagebuf before. + * skey_set_keys must have been called with the same seed value. * * If storage keys match the expected result, will return a skey_verify_result * with verify_failed false. All other fields are then invalid. * If there is a mismatch, returned struct will have verify_failed true and will * be filled with the details on the first mismatch encountered. */ -struct skey_verify_result skey_verify_keys(uint8_t *pagebuf, unsigned long page_count) +struct skey_verify_result skey_verify_keys_with_seed(uint8_t *pagebuf, unsigned long page_count, unsigned char seed) { union skey expected_key, actual_key; struct skey_verify_result result = { @@ -56,7 +58,7 @@ struct skey_verify_result skey_verify_keys(uint8_t *pagebuf, unsigned long page_ for (i = 0; i < page_count; i++) { cur_page = pagebuf + i * PAGE_SIZE; actual_key.val = get_storage_key(cur_page); - expected_key.val = i * 2; + expected_key.val = (i ^ seed) * 2; /* * The PoP neither gives a guarantee that the reference bit is diff --git a/lib/s390x/skey.h b/lib/s390x/skey.h index a0f8caa1270b..bba1c131276d 100644 --- a/lib/s390x/skey.h +++ b/lib/s390x/skey.h @@ -23,9 +23,19 @@ struct skey_verify_result { unsigned long page_mismatch_addr; }; -void skey_set_keys(uint8_t *pagebuf, unsigned long page_count); +void skey_set_keys_with_seed(uint8_t *pagebuf, unsigned long page_count, unsigned char seed); -struct skey_verify_result skey_verify_keys(uint8_t *pagebuf, unsigned long page_count); +static inline void skey_set_keys(uint8_t *pagebuf, unsigned long page_count) +{ + skey_set_keys_with_seed(pagebuf, page_count, 0); +} + +struct skey_verify_result skey_verify_keys_with_seed(uint8_t *pagebuf, unsigned long page_count, unsigned char seed); + +static inline struct skey_verify_result skey_verify_keys(uint8_t *pagebuf, unsigned long page_count) +{ + return skey_verify_keys_with_seed(pagebuf, page_count, 0); +} void skey_report_verify(struct skey_verify_result * const result);
Upcoming changes will change storage keys in a loop. To make sure each iteration of the loops sets different keys, add variants of the storage key library functions which allow to specify a seed. Signed-off-by: Nico Boehr <nrb@linux.ibm.com> --- lib/s390x/skey.c | 12 +++++++----- lib/s390x/skey.h | 14 ++++++++++++-- 2 files changed, 19 insertions(+), 7 deletions(-)