On Tue, 2021-11-23 at 13:31 +0100, Olivier Matz wrote:
> On Tue, Nov 23, 2021 at 11:25:22AM +0000, Xueming(Steven) Li wrote:
> > On Tue, 2021-11-23 at 11:25 +0100, Olivier Matz wrote:
> > > Hi Xueming,
> > >
> > > On Mon, Nov 22, 2021 at 02:12:50PM +0800, Xueming Li wrote:
> > > > Device iterator RTE_DEV_FOREACH() failed to return devices from
> > > > classifier like "class=vdpa", because matching name from empty kvargs
> > > > returns no result. If device name not specified in kvargs, the function
> > > > should iterate all devices.
> > > >
> > > > This patch allows empty devargs or devargs without name specified.
> > > >
> > > > Fixes: 6aebb942907d ("kvargs: add function to get from key and value")
> > > > Cc: olivier.m...@6wind.com
> > > >
> > > > Signed-off-by: Xueming Li <xuemi...@nvidia.com>
> > > > ---
> > > > 21.11 specific bug, no copy to stable.org
> > > > ---
> > > > drivers/bus/auxiliary/auxiliary_params.c | 3 +++
> > > > drivers/bus/vdev/vdev_params.c | 3 +++
> > > > 2 files changed, 6 insertions(+)
> > > >
> > > > diff --git a/drivers/bus/auxiliary/auxiliary_params.c
> > > > b/drivers/bus/auxiliary/auxiliary_params.c
> > > > index a9c7853ed1d..6a6382961ea 100644
> > > > --- a/drivers/bus/auxiliary/auxiliary_params.c
> > > > +++ b/drivers/bus/auxiliary/auxiliary_params.c
> > > > @@ -27,6 +27,9 @@ auxiliary_dev_match(const struct rte_device *dev,
> > > > const struct rte_kvargs *kvlist = _kvlist;
> > > > const char *key =
> > > > auxiliary_params_keys[RTE_AUXILIARY_PARAM_NAME];
> > > >
> > > > + /* Iterate all devices if name not specified. */
> > > > + if (kvlist == NULL || rte_kvargs_get(kvlist, key) == NULL)
> > > > + return 0;
> > > > if (rte_kvargs_get_with_value(kvlist, key, dev->name) == NULL)
> > > > return -1;
> > > >
> > > > diff --git a/drivers/bus/vdev/vdev_params.c
> > > > b/drivers/bus/vdev/vdev_params.c
> > > > index 37d95395e7a..bab4c0d1d08 100644
> > > > --- a/drivers/bus/vdev/vdev_params.c
> > > > +++ b/drivers/bus/vdev/vdev_params.c
> > > > @@ -29,6 +29,9 @@ vdev_dev_match(const struct rte_device *dev,
> > > > const struct rte_kvargs *kvlist = _kvlist;
> > > > const char *key = vdev_params_keys[RTE_VDEV_PARAM_NAME];
> > > >
> > > > + /* Iterate all devices if name not specified. */
> > > > + if (kvlist == NULL || rte_kvargs_get(kvlist, key) == NULL)
> > > > + return 0;
> > > > if (rte_kvargs_get_with_value(kvlist, key, dev->name) == NULL)
> > > > return -1;
> > > >
> > >
> > >
> > > Thank you for spotting and fixing this issue. The patch looks good to
> > > me, but may I suggest an alternative that would avoid to browse the
> > > kvlist twice? It is not yes tested, just for discussion. The idea
> > > is to add an errno for error cases of rte_kvargs_get_with_value()
> > > to identify the different cases.
> >
> > Yes, the code walk the kvlist twice. An alternative complex code could
> > be this:
> >
> > if (kvlist == NULL)
> > return 0;
> > name = rte_kvargs_get(kvlist, key);
> > if (name == NULL)
> > /* Iterate all devices if name not specified. */
> > return 0;
> > if (strcmp(name, dev->name) != 0)
> > return -1;
>
> Maybe it is equivalent for common usages, but a difference is that
> rte_kvargs_get_with_value(kvlist, "key", "value2") also matches
> a kvlist="key=value1,key=value2" (i.e. the case where the key appears
> several times with different values).
>
>
> > >
> > > --- a/drivers/bus/auxiliary/auxiliary_params.c
> > > +++ b/drivers/bus/auxiliary/auxiliary_params.c
> > > @@ -27,7 +27,9 @@ auxiliary_dev_match(const struct rte_device *dev,
> > > const struct rte_kvargs *kvlist = _kvlist;
> > > const char *key =
> > > auxiliary_params_keys[RTE_AUXILIARY_PARAM_NAME];
> > >
> > > - if (rte_kvargs_get_with_value(kvlist, key, dev->name) == NULL)
> > > + /* if kvlist is valid and contains the key, filter matching
> > > devices */
> > > + if (rte_kvargs_get_with_value(kvlist, key, dev->name) == NULL &&
> > > + rte_errno == ENOENT)
> >
> > rte_errno == ENODEV? we should allow ENOENT - name not specified.
> >
> > > return -1;
>
> I think the patch is correct: the item is filtered only if there is no
> matching key/value tuple, but the key is found.
For "class=vdpa", name key not specified, all devices should be walked.
the kvargs is "" in such case.
>
> If kvlist is NULL (rte_errno=EINVAL), or if the key does not exist
> (rte_errno=ENODEV), we return 0.
>
> As a side note, there is an errno ENOKEY, which would be much better
> than ENODEV... but it seems it is not POSIX, so it may not exist on
> FreeBSD or Windows.
>
> > >
> > > return 0;
> > > diff --git a/drivers/bus/vdev/vdev_params.c
> > > b/drivers/bus/vdev/vdev_params.c
> > > index 37d95395e7..0a5a8a9f58 100644
> > > --- a/drivers/bus/vdev/vdev_params.c
> > > +++ b/drivers/bus/vdev/vdev_params.c
> > > @@ -29,7 +29,9 @@ vdev_dev_match(const struct rte_device *dev,
> > > const struct rte_kvargs *kvlist = _kvlist;
> > > const char *key = vdev_params_keys[RTE_VDEV_PARAM_NAME];
> > >
> > > - if (rte_kvargs_get_with_value(kvlist, key, dev->name) == NULL)
> > > + /* if kvlist is valid and contains the key, filter matching
> > > devices */
> > > + if (rte_kvargs_get_with_value(kvlist, key, dev->name) == NULL &&
> > > + rte_errno == ENOENT)
> >
> > Same, ENODEV? which means name specified but not match.
> >
> > > return -1;
> > >
> > > return 0;
> > > diff --git a/lib/kvargs/rte_kvargs.c b/lib/kvargs/rte_kvargs.c
> > > index 11f624ef14..f1491715bf 100644
> > > --- a/lib/kvargs/rte_kvargs.c
> > > +++ b/lib/kvargs/rte_kvargs.c
> > > @@ -209,17 +209,28 @@ const char *
> > > rte_kvargs_get_with_value(const struct rte_kvargs *kvlist, const char
> > > *key,
> > > const char *value)
> > > {
> > > + int key_found = 0;
> > > unsigned int i;
> > >
> > > - if (kvlist == NULL)
> > > + if (kvlist == NULL) {
> > > + rte_errno = EINVAL;
> > > return NULL;
> > > + }
> > > +
> > > for (i = 0; i < kvlist->count; ++i) {
> > > if (key != NULL && strcmp(kvlist->pairs[i].key, key) !=
> > > 0)
> > > continue;
> > > + key_found = 1;
> > > if (value != NULL && strcmp(kvlist->pairs[i].value,
> > > value) != 0)
> > > continue;
> > > return kvlist->pairs[i].value;
> > > }
> > > +
> > > + if (key_found)
> > > + rte_errno = ENODEV;
> > > + else
> > > + rte_errno = ENOENT;
> > > +
> > > return NULL;
> > > }
> > >
> > > diff --git a/lib/kvargs/rte_kvargs.h b/lib/kvargs/rte_kvargs.h
> > > index 359a9f5b09..3cb22ece48 100644
> > > --- a/lib/kvargs/rte_kvargs.h
> > > +++ b/lib/kvargs/rte_kvargs.h
> > > @@ -152,8 +152,12 @@ const char *rte_kvargs_get(const struct rte_kvargs
> > > *kvlist, const char *key);
> > > * The matching value. If NULL, any value will match.
> > > *
> > > * @return
> > > - * NULL if no key matches the input,
> > > - * a value associated with a matching key otherwise.
> > > + * The value associated with a matching key/value on success.
> > > + * On error, return NULL and rte_errno is set:
> > > + * - EINVAL - kvlist is NULL
> > > + * - ENOENT - no matching key/value tuple, but the key matches with
> > > + * a different value
> > > + * - ENODEV - key is not found in the kvlist
> > > */
> > > __rte_experimental
> > > const char *rte_kvargs_get_with_value(const struct rte_kvargs *kvlist,
> > >
> > >
> > > Let me know if it would work for you. I can submit a patch if you want.
> >
> >
> > LGTM, let's use your patch.
>
> OK, I'll submit this patch then. Thanks for the feedback.
>
> > >
> > > I can add a unit test for kvargs, but do you know where we could add a
> > > unit test for the dev iterate?
> >
> > Good idea, how about test_devargs.c?
>
> Thanks, I'll have a look.
>
> > >
> > > Thanks,
> > > Olivier
> >
