Gaetan Rivet <gaetan.ri...@6wind.com> writes:
> 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.
>
> 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 | 17 +++++++++++++
> lib/librte_eal/freebsd/eal/eal.c | 5 ++++
> lib/librte_eal/linux/eal/eal.c | 5 ++++
> lib/librte_eal/rte_eal_version.map | 7 +++++
> 11 files changed, 110 insertions(+)
>
> diff --git a/doc/guides/rel_notes/release_19_11.rst
> b/doc/guides/rel_notes/release_19_11.rst
> index 27cfbd9e3..3996e429d 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 wil now propose to enforce manual probing of 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()) {
> + RTE_LOG(DEBUG, EAL, "Manual probing enabled.\n");
> + return rte_dev_probe_devargs_list();
> + }
> +
> TAILQ_FOREACH(bus, &rte_bus_list, next) {
> if (!strcmp(bus->name, "vdev")) {
> vbus = bus;
> diff --git a/lib/librte_eal/common/eal_common_dev.c
> b/lib/librte_eal/common/eal_common_dev.c
> index 9e4f09d83..3b7769a3c 100644
> --- a/lib/librte_eal/common/eal_common_dev.c
> +++ b/lib/librte_eal/common/eal_common_dev.c
> @@ -109,6 +109,47 @@ build_devargs(const char *busname, const char *devname,
> }
>
> int
> +rte_dev_probe_devargs_list(void)
> +{
> + struct rte_device *dev;
> + struct rte_devargs *da;
> + int ret;
> +
> + RTE_EAL_DEVARGS_FOREACH(NULL, da) {
> + dev = da->bus->find_device(NULL, cmp_dev_name, da->name);
> + if (dev == NULL) {
> + RTE_LOG(ERR, EAL, "Unable to find device %s on bus
> %s\n",
> + da->name, da->bus->name);
> + continue;
> + }
> +
> + if (rte_dev_is_probed(dev))
> + continue;
> +
> + if (dev->bus->plug == NULL) {
> + RTE_LOG(ERR, EAL, "Manual probing (hotplug) not
> supported by bus %s, "
> + "required by device %s\n",
> + dev->bus->name, dev->name);
> + continue;
> + }
> +
> + ret = dev->bus->plug(dev);
> + /* Ignore positive return values, they are possibly
> + * triggered by blacklisted devices on the PCI bus. Probing
> + * should then continue.
> + */
> + if (ret < 0 || !rte_dev_is_probed(dev)) {
> + RTE_LOG(ERR, EAL, "Driver cannot attach device %s\n",
> + dev->name);
> + /* Fail on first real probe error. */
> + return ret;
> + }
> + }
> +
> + return 0;
> +}
> +
> +int
> rte_eal_hotplug_add(const char *busname, const char *devname,
> const char *drvargs)
> {
> diff --git a/lib/librte_eal/common/eal_common_options.c
> b/lib/librte_eal/common/eal_common_options.c
> index 05cae5f75..66c232b14 100644
> --- a/lib/librte_eal/common/eal_common_options.c
> +++ b/lib/librte_eal/common/eal_common_options.c
> @@ -81,6 +81,7 @@ eal_long_options[] = {
> {OPT_LEGACY_MEM, 0, NULL, OPT_LEGACY_MEM_NUM },
> {OPT_SINGLE_FILE_SEGMENTS, 0, NULL, OPT_SINGLE_FILE_SEGMENTS_NUM},
> {OPT_MATCH_ALLOCATIONS, 0, NULL, OPT_MATCH_ALLOCATIONS_NUM},
> + {OPT_MANUAL_PROBE, 0, NULL, OPT_MANUAL_PROBE_NUM },
> {0, 0, NULL, 0 }
> };
>
> @@ -1408,6 +1409,9 @@ eal_parse_common_option(int opt, const char *optarg,
> return -1;
> }
> break;
> + case OPT_MANUAL_PROBE_NUM:
> + conf->manual_probe = 1;
> + break;
>
> /* don't know what to do, leave this to caller */
> default:
> @@ -1634,6 +1638,10 @@ eal_common_usage(void)
> " --"OPT_VDEV" Add a virtual device.\n"
> " The argument format is
> <driver><id>[,key=val,...]\n"
> " (ex: --vdev=net_pcap0,iface=eth2).\n"
> + " --"OPT_MANUAL_PROBE" Enable manual probing.\n"
> + " Disable probe step for all buses.\n"
> + " Devices will need to be probed using the
> hotplug API.\n"
> + " PCI and vdev declarations will be treated
> in order as hotplug commands.\n"
> " --"OPT_IOVA_MODE" Set IOVA mode. 'pa' for IOVA_PA\n"
> " 'va' for IOVA_VA\n"
> " -d LIB.so|DIR Add a driver or driver directory\n"
> diff --git a/lib/librte_eal/common/eal_internal_cfg.h
> b/lib/librte_eal/common/eal_internal_cfg.h
> index a42f34923..0006f903f 100644
> --- a/lib/librte_eal/common/eal_internal_cfg.h
> +++ b/lib/librte_eal/common/eal_internal_cfg.h
> @@ -44,6 +44,7 @@ struct internal_config {
> unsigned hugepage_unlink; /**< true to unlink backing files */
> volatile unsigned no_pci; /**< true to disable PCI */
> volatile unsigned no_hpet; /**< true to disable HPET */
> + volatile unsigned manual_probe; /**< true to enable manual device
> probing. */
> volatile unsigned vmware_tsc_map; /**< true to use VMware TSC mapping
>
> * instead of native TSC */
> volatile unsigned no_shconf; /**< true if there is no shared
> config */
> diff --git a/lib/librte_eal/common/eal_options.h
> b/lib/librte_eal/common/eal_options.h
> index 9855429e5..588fa32a6 100644
> --- a/lib/librte_eal/common/eal_options.h
> +++ b/lib/librte_eal/common/eal_options.h
> @@ -69,6 +69,8 @@ enum {
> OPT_IOVA_MODE_NUM,
> #define OPT_MATCH_ALLOCATIONS "match-allocations"
> OPT_MATCH_ALLOCATIONS_NUM,
> +#define OPT_MANUAL_PROBE "manual-probe"
> + OPT_MANUAL_PROBE_NUM,
> OPT_LONG_MAX_NUM
> };
>
> diff --git a/lib/librte_eal/common/eal_private.h
> b/lib/librte_eal/common/eal_private.h
> index 798ede553..fd7ac8e37 100644
> --- a/lib/librte_eal/common/eal_private.h
> +++ b/lib/librte_eal/common/eal_private.h
> @@ -381,4 +381,13 @@ rte_option_init(void);
> void
> rte_option_usage(void);
>
> +/**
> + * Go through the devargs list and probe everything in order.
> + *
> + * @return
> + * 0 on success, negative on error.
> + */
> +int
> +rte_dev_probe_devargs_list(void);
> +
> #endif /* _EAL_PRIVATE_H_ */
> diff --git a/lib/librte_eal/common/include/rte_eal.h
> b/lib/librte_eal/common/include/rte_eal.h
> index b7cf91214..bd9087bcc 100644
> --- a/lib/librte_eal/common/include/rte_eal.h
> +++ b/lib/librte_eal/common/include/rte_eal.h
> @@ -465,6 +465,23 @@ int rte_eal_has_hugepages(void);
> int rte_eal_has_pci(void);
>
> /**
> + * Whether EAL probe is manual.
> + * Enabled by the --manual-probe option.
> + *
> + * When manual probing is enabled, batched bus probe of
> + * their devices is disabled. All devices need to be probed
> + * using the proper rte_dev API.
> + *
> + * In this mode, devices declared on the command line will
> + * be probed using the bus hotplug API. It is used to enforce
> + * a specific probe order.
> + *
> + * @return
> + * Nonzero if manual device probing is enabled.
> + */
> +int rte_eal_manual_probe(void);
> +
> +/**
> * Whether the EAL was asked to create UIO device.
> *
> * @return
> diff --git a/lib/librte_eal/freebsd/eal/eal.c
> b/lib/librte_eal/freebsd/eal/eal.c
> index d53f0fe69..2daa63b23 100644
> --- a/lib/librte_eal/freebsd/eal/eal.c
> +++ b/lib/librte_eal/freebsd/eal/eal.c
> @@ -961,6 +961,11 @@ int rte_eal_has_pci(void)
> return !internal_config.no_pci;
> }
>
> +int rte_eal_manual_probe(void)
> +{
> + return internal_config.manual_probe;
> +}
> +
> int rte_eal_create_uio_dev(void)
> {
> return internal_config.create_uio_dev;
> diff --git a/lib/librte_eal/linux/eal/eal.c b/lib/librte_eal/linux/eal/eal.c
> index 946222ccd..476fc2e4a 100644
> --- a/lib/librte_eal/linux/eal/eal.c
> +++ b/lib/librte_eal/linux/eal/eal.c
> @@ -1376,6 +1376,11 @@ int rte_eal_create_uio_dev(void)
> return internal_config.create_uio_dev;
> }
>
> +int rte_eal_manual_probe(void)
> +{
> + return internal_config.manual_probe;
> +}
> +
> enum rte_intr_mode
> rte_eal_vfio_intr_mode(void)
> {
> diff --git a/lib/librte_eal/rte_eal_version.map
> b/lib/librte_eal/rte_eal_version.map
> index 7cbf82d37..fe5395c24 100644
> --- a/lib/librte_eal/rte_eal_version.map
> +++ b/lib/librte_eal/rte_eal_version.map
> @@ -312,6 +312,13 @@ DPDK_19.08 {
>
> } DPDK_19.05;
>
> +DPDK_19.05 {
> + global:
> +
> + rte_eal_manual_probe
Syntax error - needs a ';' at the end of this symbol.
> +
> +} DPDK_19.11;
> +
> EXPERIMENTAL {
> global:
