| Message ID | 20181206045300.32387-1-ebiggers@kernel.org (mailing list archive) |
|---|---|
| State | Not Applicable |
| Delegated to: | Herbert Xu |
| Headers | show |
| Series | dm crypt: log the encryption algorithm implementation | expand |
On Thu, 6 Dec 2018 at 05:54, Eric Biggers <ebiggers@kernel.org> wrote: > > From: Eric Biggers <ebiggers@google.com> > > Log the encryption algorithm's driver name when a dm-crypt target is > created. This will help people determine whether the expected > implementation is being used. In some cases we've seen people do > benchmarks and reject using encryption for performance reasons, when in > fact they used a much slower implementation than was possible on the > hardware. It can make an enormous difference; e.g., AES-XTS on ARM can > be over 10x faster with the crypto extensions than without. It can also > be useful to know if an implementation using an external crypto > accelerator is being used instead of a software implementation. > > Example message: > > [ 29.307629] device-mapper: crypt: xts(aes) using implementation "xts-aes-ce" > > We've already found the similar message in fs/crypto/keyinfo.c to be > very useful. > > Signed-off-by: Eric Biggers <ebiggers@google.com> Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> > --- > drivers/md/dm-crypt.c | 9 +++++++++ > 1 file changed, 9 insertions(+) > > diff --git a/drivers/md/dm-crypt.c b/drivers/md/dm-crypt.c > index b8eec515a003..7646135487be 100644 > --- a/drivers/md/dm-crypt.c > +++ b/drivers/md/dm-crypt.c > @@ -1885,6 +1885,13 @@ static int crypt_alloc_tfms_skcipher(struct crypt_config *cc, char *ciphermode) > } > } > > + /* > + * dm-crypt performance can vary greatly depending on which crypto > + * algorithm implementation is used. Help people debug performance > + * problems by logging the ->cra_driver_name. > + */ > + DMINFO("%s using implementation \"%s\"", ciphermode, > + crypto_skcipher_alg(any_tfm(cc))->base.cra_driver_name); > return 0; > } > > @@ -1903,6 +1910,8 @@ static int crypt_alloc_tfms_aead(struct crypt_config *cc, char *ciphermode) > return err; > } > > + DMINFO("%s using implementation \"%s\"", ciphermode, > + crypto_aead_alg(any_tfm_aead(cc))->base.cra_driver_name); > return 0; > } > > -- > 2.19.2 >
diff --git a/drivers/md/dm-crypt.c b/drivers/md/dm-crypt.c index b8eec515a003..7646135487be 100644 --- a/drivers/md/dm-crypt.c +++ b/drivers/md/dm-crypt.c @@ -1885,6 +1885,13 @@ static int crypt_alloc_tfms_skcipher(struct crypt_config *cc, char *ciphermode) } } + /* + * dm-crypt performance can vary greatly depending on which crypto + * algorithm implementation is used. Help people debug performance + * problems by logging the ->cra_driver_name. + */ + DMINFO("%s using implementation \"%s\"", ciphermode, + crypto_skcipher_alg(any_tfm(cc))->base.cra_driver_name); return 0; } @@ -1903,6 +1910,8 @@ static int crypt_alloc_tfms_aead(struct crypt_config *cc, char *ciphermode) return err; } + DMINFO("%s using implementation \"%s\"", ciphermode, + crypto_aead_alg(any_tfm_aead(cc))->base.cra_driver_name); return 0; }