On Fri, Oct 4, 2019 at 6:25 PM Gaetan Rivet <gaetan.ri...@6wind.com> wrote:
>
> Add a new EAL option enabling manual probing in the EAL.
> This command line option will configure the EAL so that buses
> will not trigger their probe step on their own.
>
> Applications are then expected to hotplug devices as they see fit.
>
> Devices declared on the command line by the user (using -w and --vdev),
> will be probed using the hotplug API, in the order they are declared.
>
> This has the effect of offering a way for users to control probe order
> of their devices, for drivers requiring it.
>
> Signed-off-by: Gaetan Rivet <gaetan.ri...@6wind.com>
> ---
>
> I haven't heard many opinions on the matter, please shout if you see an issue
> with this approach.
>
> @Slava: I have tested rather quickly that it does not break anything,
> and that it works as intended for basic cases.
> Can you test it further for your use-case and tell me if it works
> fine?
>
> Beyond the obvious difference between both probe mode, something to keep in
> mind:
> while using -w on invalid devices would not block (PCI) bus probing, it will
> stop manual
> probing in its track. All devices need to exist and be valid device IDs.
>
> v2: fixed a few typos, map file (and used Travis to validate).
>
> Slava, are you able to test this patch?
>
> v3: properly fixed the map file (herited 19.08 instead of 19.05).
>
> Added a function to set the probe manual from the application,
> without having the user do it from the command line.
>
> Stopped spamming Slava about it, Vamsi was actually the one interested in
> it!
>
> Standing issue worth chiming in:
>
> Currently manual-probe will cut off probing from all buses.
> It could be interesting to be able to only cut buses supporting hotplug,
> given that they are the one able to probe devices afterward.
>
> No real use-case for this right now, so leaving as-is. Might be worth
> considering in the future.
>
> doc/guides/rel_notes/release_19_11.rst | 9 +++++++
> lib/librte_eal/common/eal_common_bus.c | 6 +++++
> lib/librte_eal/common/eal_common_dev.c | 41
> ++++++++++++++++++++++++++++++
> lib/librte_eal/common/eal_common_options.c | 8 ++++++
> lib/librte_eal/common/eal_internal_cfg.h | 1 +
> lib/librte_eal/common/eal_options.h | 2 ++
> lib/librte_eal/common/eal_private.h | 9 +++++++
> lib/librte_eal/common/include/rte_eal.h | 34 +++++++++++++++++++++++++
> lib/librte_eal/freebsd/eal/eal.c | 10 ++++++++
> lib/librte_eal/linux/eal/eal.c | 10 ++++++++
> lib/librte_eal/rte_eal_version.map | 8 ++++++
> 11 files changed, 138 insertions(+)
>
> diff --git a/doc/guides/rel_notes/release_19_11.rst
> b/doc/guides/rel_notes/release_19_11.rst
> index 27cfbd9e3..700f9a726 100644
> --- a/doc/guides/rel_notes/release_19_11.rst
> +++ b/doc/guides/rel_notes/release_19_11.rst
> @@ -56,6 +56,15 @@ New Features
> Also, make sure to start the actual text at the margin.
> =========================================================
>
> +* **EAL will now allow manual probing devices.**
> +
> + Previously, a user could not force an order when probing declared devices.
> + This could cause issues for drivers depending on another device being
> present.
> + A new option ``--manual-probe`` is now available to do just that.
> + This new option relies on the device bus supporting hotplug. It can
> + also be used to disable automatic probing from the ``PCI`` bus without
> + having to disable the whole bus.
> +
>
> Removed Items
> -------------
> diff --git a/lib/librte_eal/common/eal_common_bus.c
> b/lib/librte_eal/common/eal_common_bus.c
> index baa5b532a..145a96812 100644
> --- a/lib/librte_eal/common/eal_common_bus.c
> +++ b/lib/librte_eal/common/eal_common_bus.c
> @@ -6,6 +6,7 @@
> #include <string.h>
> #include <sys/queue.h>
>
> +#include <rte_eal.h>
> #include <rte_bus.h>
> #include <rte_debug.h>
> #include <rte_string_fns.h>
> @@ -63,6 +64,11 @@ rte_bus_probe(void)
> int ret;
> struct rte_bus *bus, *vbus = NULL;
>
> + if (rte_eal_manual_probe()) {
See below,
> int rte_vfio_setup_device(__rte_unused const char *sysfs_base,
> __rte_unused const char *dev_addr,
> __rte_unused int *vfio_dev_fd,
> diff --git a/lib/librte_eal/linux/eal/eal.c b/lib/librte_eal/linux/eal/eal.c
> index 946222ccd..da00eb14d 100644
> --- a/lib/librte_eal/linux/eal/eal.c
> +++ b/lib/librte_eal/linux/eal/eal.c
> @@ -1382,6 +1382,16 @@ rte_eal_vfio_intr_mode(void)
> return internal_config.vfio_intr_mode;
> }
>
> +int rte_eal_manual_probe(void)
> +{
> + return internal_config.manual_probe;
> +}
> +
> +void rte_eal_manual_probe_set(int enabled)
> +{
> + internal_config.manual_probe = !!enabled;
> +}
I don't think FreeBSD and Linux specific implementation is NOT required
as internal_config accessible in eal/common. example diff.
[master][dpdk.org] $ git diff
diff --git a/lib/librte_eal/common/eal_common_bus.c
b/lib/librte_eal/common/eal_common_bus.c
index 145a96812..db4257cf1 100644
--- a/lib/librte_eal/common/eal_common_bus.c
+++ b/lib/librte_eal/common/eal_common_bus.c
@@ -13,6 +13,7 @@
#include <rte_errno.h>
#include "eal_private.h"
+#include "eal_internal_cfg.h"
static struct rte_bus_list rte_bus_list =
TAILQ_HEAD_INITIALIZER(rte_bus_list);
@@ -64,7 +65,7 @@ rte_bus_probe(void)
int ret;
struct rte_bus *bus, *vbus = NULL;
- if (rte_eal_manual_probe()) {
+ if (internal_config.manual_probe) {
RTE_LOG(DEBUG, EAL, "Manual probing enabled.\n");
return rte_dev_probe_devargs_list();
}
> int
> rte_eal_check_module(const char *module_name)
> {
> diff --git a/lib/librte_eal/rte_eal_version.map
> b/lib/librte_eal/rte_eal_version.map
> index 7cbf82d37..ccc4ffb21 100644
> --- a/lib/librte_eal/rte_eal_version.map
> +++ b/lib/librte_eal/rte_eal_version.map
> @@ -312,6 +312,14 @@ DPDK_19.08 {
>
> } DPDK_19.05;
>
> +DPDK_19.11 {
> + global:
> +
> + rte_eal_manual_probe;
> + rte_eal_manual_probe_set;
Do we need public API for this? it is only used by eal lib.
checkpatch complains the following too.
ERROR: symbol rte_eal_manual_probe_set is added in the DPDK_19.11
section, but is expected to be added in the EXPERIMENTAL section of
the version map
