vfio: support VF token

The Linux kernel module vfio-pci introduces the VF token to enable
SR-IOV support since 5.7.

The VF token can be set by a vfio-pci based PF driver and must be known
by the vfio-pci based VF driver in order to gain access to the device.

Since the vfio-pci module uses the VF token as internal data to provide
the collaboration between SR-IOV PF and VFs, so DPDK can use the same
VF token for all PF devices by specifying the related EAL option.

Signed-off-by: Haiyue Wang <haiyue.wang@intel.com>
Acked-by: Anatoly Burakov <anatoly.burakov@intel.com>
Acked-by: Andrew Rybchenko <arybchenko@solarflare.com>
Tested-by: Harman Kalra <hkalra@marvell.com>

doc/guides/linux_gsg/linux_drivers.rst

@@ -78,11 +78,44 @@ Note that in order to use VFIO, your kernel must support it.
 VFIO kernel modules have been included in the Linux kernel since version 3.6.0 and are usually present by default,
 however please consult your distributions documentation to make sure that is the case.
 
+The ``vfio-pci`` module since Linux version 5.7 supports the creation of virtual
+functions. After the PF is bound to vfio-pci module, the user can create the VFs
+by sysfs interface, and these VFs are bound to vfio-pci module automatically.
+
+When the PF is bound to vfio-pci, it has initial VF token generated by random. For
+security reason, this token is write only, the user can't read it from the kernel
+directly. To access the VF, the user needs to start the PF with token parameter to
+setup a VF token in UUID format, then the VF can be accessed with this new token.
+
+Since the ``vfio-pci`` module uses the VF token as internal data to provide the
+collaboration between SR-IOV PF and VFs, so DPDK can use the same VF token for all
+PF devices which bound to one application. This VF token can be specified by the EAL
+parameter ``--vfio-vf-token``.
+
+.. code-block:: console
+
+    1. Generate the VF token by uuid command
+        14d63f20-8445-11ea-8900-1f9ce7d5650d
+
+    2. sudo modprobe vfio-pci enable_sriov=1
+
+    2. ./usertools/dpdk-devbind.py -b vfio-pci 0000:86:00.0
+
+    3. echo 2 > /sys/bus/pci/devices/0000:86:00.0/sriov_numvfs
+
+    4. Start the PF:
+        ./x86_64-native-linux-gcc/app/testpmd -l 22-25 -n 4 -w 86:00.0 \
+         --vfio-vf-token=14d63f20-8445-11ea-8900-1f9ce7d5650d --file-prefix=pf -- -i
+
+    5. Start the VF:
+        ./x86_64-native-linux-gcc/app/testpmd -l 26-29 -n 4 -w 86:02.0 \
+         --vfio-vf-token=14d63f20-8445-11ea-8900-1f9ce7d5650d --file-prefix=vf0 -- -i
+
 Also, to use VFIO, both kernel and BIOS must support and be configured to use IO virtualization (such as Intel® VT-d).
 
 .. note::
 
-    ``vfio-pci`` module doesn't support the creation of virtual functions.
+    ``vfio-pci`` module doesn't support the creation of virtual functions before Linux version 5.7.
 
 For proper operation of VFIO when running DPDK applications as a non-privileged user, correct permissions should also be set up.
 This can be done by using the DPDK setup script (called dpdk-setup.sh and located in the usertools directory).

doc/guides/linux_gsg/linux_eal_parameters.rst

@@ -40,6 +40,10 @@ Device-related options
 
     Use specified interrupt mode for devices bound to VFIO kernel driver.
 
+*   ``--vfio-vf-token <uuid>``
+
+    Use specified VF token for devices bound to VFIO kernel driver.
+
 Multiprocessing-related options
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 

doc/guides/rel_notes/release_20_08.rst

@@ -56,6 +56,13 @@ New Features
      Also, make sure to start the actual text at the margin.
      =========================================================
 
+* **Added the support for vfio-pci new VF token interface.**
+
+  From Linux 5.7, vfio-pci supports to bind both SR-IOV PF and the created VFs,
+  it uses a shared VF token (UUID) to represent the collaboration between PF
+  and VFs. Update DPDK PCI driver to gain the access to the PF and VFs devices
+  by appending the VF token parameter.
+
 * **Added the RegEx Library, a generic RegEx service library.**
 
   Added the RegEx library which provides an API for offload of regular

lib/librte_eal/common/eal_common_options.c

@@ -95,6 +95,7 @@ eal_long_options[] = {
 	{OPT_SYSLOG,            1, NULL, OPT_SYSLOG_NUM           },
 	{OPT_VDEV,              1, NULL, OPT_VDEV_NUM             },
 	{OPT_VFIO_INTR,         1, NULL, OPT_VFIO_INTR_NUM        },
+	{OPT_VFIO_VF_TOKEN,     1, NULL, OPT_VFIO_VF_TOKEN_NUM    },
 	{OPT_VMWARE_TSC_MAP,    0, NULL, OPT_VMWARE_TSC_MAP_NUM   },
 	{OPT_LEGACY_MEM,        0, NULL, OPT_LEGACY_MEM_NUM       },
 	{OPT_SINGLE_FILE_SEGMENTS, 0, NULL, OPT_SINGLE_FILE_SEGMENTS_NUM},
@@ -328,6 +329,8 @@ eal_reset_internal_config(struct internal_config *internal_cfg)
 
 	/* if set to NONE, interrupt mode is determined automatically */
 	internal_cfg->vfio_intr_mode = RTE_INTR_MODE_NONE;
+	memset(internal_cfg->vfio_vf_token, 0,
+			sizeof(internal_cfg->vfio_vf_token));
 
 #ifdef RTE_LIBEAL_USE_HPET
 	internal_cfg->no_hpet = 0;

lib/librte_eal/common/eal_internal_cfg.h

@@ -72,6 +72,8 @@ struct internal_config {
 	volatile int syslog_facility;	  /**< facility passed to openlog() */
 	/** default interrupt mode for VFIO */
 	volatile enum rte_intr_mode vfio_intr_mode;
+	/** the shared VF token for VFIO-PCI bound PF and VFs devices */
+	rte_uuid_t vfio_vf_token;
 	char *hugefile_prefix;      /**< the base filename of hugetlbfs files */
 	char *hugepage_dir;         /**< specific hugetlbfs directory to use */
 	char *user_mbuf_pool_ops_name;

lib/librte_eal/common/eal_options.h

@@ -69,6 +69,8 @@ enum {
 	OPT_VDEV_NUM,
 #define OPT_VFIO_INTR         "vfio-intr"
 	OPT_VFIO_INTR_NUM,
+#define OPT_VFIO_VF_TOKEN     "vfio-vf-token"
+	OPT_VFIO_VF_TOKEN_NUM,
 #define OPT_VMWARE_TSC_MAP    "vmware-tsc-map"
 	OPT_VMWARE_TSC_MAP_NUM,
 #define OPT_LEGACY_MEM    "legacy-mem"

lib/librte_eal/freebsd/eal.c

@@ -966,6 +966,11 @@ rte_eal_vfio_intr_mode(void)
 	return RTE_INTR_MODE_NONE;
 }
 
+void
+rte_eal_vfio_get_vf_token(__rte_unused rte_uuid_t vf_token)
+{
+}
+
 int rte_vfio_setup_device(__rte_unused const char *sysfs_base,
 		      __rte_unused const char *dev_addr,
 		      __rte_unused int *vfio_dev_fd,

lib/librte_eal/include/rte_eal.h

@@ -19,6 +19,7 @@
 #include <rte_compat.h>
 #include <rte_per_lcore.h>
 #include <rte_bus.h>
+#include <rte_uuid.h>
 
 #include <rte_pci_dev_feature_defs.h>
 
@@ -438,6 +439,19 @@ int rte_eal_create_uio_dev(void);
  */
 enum rte_intr_mode rte_eal_vfio_intr_mode(void);
 
+/**
+ * @warning
+ * @b EXPERIMENTAL: this API may change without prior notice
+ *
+ * Copy the user-configured vfio VF token.
+ *
+ * @param vf_token
+ *   vfio VF token configured with the command line is copied
+ *   into this parameter, zero uuid by default.
+ */
+__rte_experimental
+void rte_eal_vfio_get_vf_token(rte_uuid_t vf_token);
+
 /**
  * A wrap API for syscall gettid.
  *

lib/librte_eal/linux/eal.c

@@ -540,6 +540,7 @@ eal_usage(const char *prgname)
 	       "  --"OPT_FILE_PREFIX"       Prefix for hugepage filenames\n"
 	       "  --"OPT_CREATE_UIO_DEV"    Create /dev/uioX (usually done by hotplug)\n"
 	       "  --"OPT_VFIO_INTR"         Interrupt mode for VFIO (legacy|msi|msix)\n"
+	       "  --"OPT_VFIO_VF_TOKEN"     VF token (UUID) shared between SR-IOV PF and VFs\n"
 	       "  --"OPT_LEGACY_MEM"        Legacy memory mode (no dynamic allocation, contiguous segments)\n"
 	       "  --"OPT_SINGLE_FILE_SEGMENTS" Put all hugepage memory in single files\n"
 	       "  --"OPT_MATCH_ALLOCATIONS" Free hugepages exactly as allocated\n"
@@ -620,6 +621,20 @@ eal_parse_vfio_intr(const char *mode)
 	return -1;
 }
 
+static int
+eal_parse_vfio_vf_token(const char *vf_token)
+{
+	struct internal_config *cfg = eal_get_internal_configuration();
+	rte_uuid_t uuid;
+
+	if (!rte_uuid_parse(vf_token, uuid)) {
+		rte_uuid_copy(cfg->vfio_vf_token, uuid);
+		return 0;
+	}
+
+	return -1;
+}
+
 /* Parse the arguments for --log-level only */
 static void
 eal_log_level_parse(int argc, char **argv)
@@ -762,6 +777,16 @@ eal_parse_args(int argc, char **argv)
 			}
 			break;
 
+		case OPT_VFIO_VF_TOKEN_NUM:
+			if (eal_parse_vfio_vf_token(optarg) < 0) {
+				RTE_LOG(ERR, EAL, "invalid parameters for --"
+						OPT_VFIO_VF_TOKEN "\n");
+				eal_usage(prgname);
+				ret = -1;
+				goto out;
+			}
+			break;
+
 		case OPT_CREATE_UIO_DEV_NUM:
 			internal_conf->create_uio_dev = 1;
 			break;
@@ -1342,6 +1367,14 @@ rte_eal_vfio_intr_mode(void)
 	return internal_conf->vfio_intr_mode;
 }
 
+void
+rte_eal_vfio_get_vf_token(rte_uuid_t vf_token)
+{
+	struct internal_config *cfg = eal_get_internal_configuration();
+
+	rte_uuid_copy(vf_token, cfg->vfio_vf_token);
+}
+
 int
 rte_eal_check_module(const char *module_name)
 {

lib/librte_eal/linux/eal_vfio.c

@@ -714,6 +714,7 @@ rte_vfio_setup_device(const char *sysfs_base, const char *dev_addr,
 	int vfio_container_fd;
 	int vfio_group_fd;
 	int iommu_group_num;
+	rte_uuid_t vf_token;
 	int i, ret;
 	const struct internal_config *internal_conf =
 		eal_get_internal_configuration();
@@ -899,6 +900,23 @@ rte_vfio_setup_device(const char *sysfs_base, const char *dev_addr,
 				t->type_id, t->name);
 	}
 
+	rte_eal_vfio_get_vf_token(vf_token);
+
+	/* get a file descriptor for the device with VF token firstly */
+	if (!rte_uuid_is_null(vf_token)) {
+		char vf_token_str[RTE_UUID_STRLEN];
+		char dev[PATH_MAX];
+
+		rte_uuid_unparse(vf_token, vf_token_str, sizeof(vf_token_str));
+		snprintf(dev, sizeof(dev),
+			 "%s vf_token=%s", dev_addr, vf_token_str);
+
+		*vfio_dev_fd = ioctl(vfio_group_fd, VFIO_GROUP_GET_DEVICE_FD,
+				     dev);
+		if (*vfio_dev_fd >= 0)
+			goto dev_get_info;
+	}
+
 	/* get a file descriptor for the device */
 	*vfio_dev_fd = ioctl(vfio_group_fd, VFIO_GROUP_GET_DEVICE_FD, dev_addr);
 	if (*vfio_dev_fd < 0) {
@@ -914,6 +932,7 @@ rte_vfio_setup_device(const char *sysfs_base, const char *dev_addr,
 	}
 
 	/* test and setup the device */
+dev_get_info:
 	ret = ioctl(*vfio_dev_fd, VFIO_DEVICE_GET_INFO, device_info);
 	if (ret) {
 		RTE_LOG(ERR, EAL, "  %s cannot get device info, "

lib/librte_eal/rte_eal_version.map

@@ -386,6 +386,9 @@ EXPERIMENTAL {
 	rte_trace_point_lookup;
 	rte_trace_regexp;
 	rte_trace_save;
+
+	# added in 20.08
+	rte_eal_vfio_get_vf_token;
 };
 
 INTERNAL {