platform: detect SR-IOV support and allow changing the number of VFs

(cherry picked from commit 0a7694cf81)

src/platform/nm-fake-platform.c

@@ -573,6 +573,12 @@ link_set_mtu (NMPlatform *platform, int ifindex, guint32 mtu)
 	return !!device;
 }
 
+static gboolean
+link_set_sriov_num_vfs (NMPlatform *platform, int ifindex, guint num_vfs)
+{
+	return TRUE;
+}
+
 static const char *
 link_get_udi (NMPlatform *platform, int ifindex)
 {
@@ -632,6 +638,22 @@ link_supports_vlans (NMPlatform *platform, int ifindex)
 	}
 }
 
+static gboolean
+link_supports_sriov (NMPlatform *platform, int ifindex)
+{
+	NMFakePlatformLink *device = link_get (platform, ifindex);
+
+	if (!device)
+		return FALSE;
+
+	switch (device->link.type) {
+	case NM_LINK_TYPE_LOOPBACK:
+		return FALSE;
+	default:
+		return TRUE;
+	}
+}
+
 static gboolean
 link_enslave (NMPlatform *platform, int master, int slave)
 {
@@ -1470,11 +1492,13 @@ nm_fake_platform_class_init (NMFakePlatformClass *klass)
 
 	platform_class->link_set_address = link_set_address;
 	platform_class->link_set_mtu = link_set_mtu;
+	platform_class->link_set_sriov_num_vfs = link_set_sriov_num_vfs;
 
 	platform_class->link_get_driver_info = link_get_driver_info;
 
 	platform_class->link_supports_carrier_detect = link_supports_carrier_detect;
 	platform_class->link_supports_vlans = link_supports_vlans;
+	platform_class->link_supports_sriov = link_supports_sriov;
 
 	platform_class->link_enslave = link_enslave;
 	platform_class->link_release = link_release;

src/platform/nm-linux-platform.c

@@ -4604,6 +4604,30 @@ link_supports_vlans (NMPlatform *platform, int ifindex)
 	return nmp_utils_ethtool_supports_vlans (ifindex);
 }
 
+static gboolean
+link_supports_sriov (NMPlatform *platform, int ifindex)
+{
+	nm_auto_pop_netns NMPNetns *netns = NULL;
+	nm_auto_close int dirfd = -1;
+	char ifname[IFNAMSIZ];
+	int total = -1;
+
+	if (!nm_platform_netns_push (platform, &netns))
+		return FALSE;
+
+	dirfd = nm_platform_sysctl_open_netdir (platform, ifindex, ifname);
+	if (dirfd < 0)
+		return FALSE;
+
+	total = nm_platform_sysctl_get_int32 (platform,
+	                                      NMP_SYSCTL_PATHID_NETDIR (dirfd,
+	                                                                ifname,
+	                                                                "device/sriov_totalvfs"),
+	                                      -1);
+
+	return total > 0;
+}
+
 static NMPlatformError
 link_set_address (NMPlatform *platform, int ifindex, gconstpointer address, size_t length)
 {
@@ -4695,6 +4719,71 @@ nla_put_failure:
 	g_return_val_if_reached (FALSE);
 }
 
+static gboolean
+link_set_sriov_num_vfs (NMPlatform *platform, int ifindex, guint num_vfs)
+{
+	nm_auto_pop_netns NMPNetns *netns = NULL;
+	nm_auto_close int dirfd = -1;
+	int total, current;
+	char ifname[IFNAMSIZ];
+	char buf[64];
+
+	_LOGD ("link: change %d: num VFs: %u", ifindex, num_vfs);
+
+	if (!nm_platform_netns_push (platform, &netns))
+		return FALSE;
+
+	dirfd = nm_platform_sysctl_open_netdir (platform, ifindex, ifname);
+	if (!dirfd)
+		return FALSE;
+
+	total = nm_platform_sysctl_get_int32 (platform,
+	                                      NMP_SYSCTL_PATHID_NETDIR (dirfd,
+	                                                                ifname,
+	                                                                "device/sriov_totalvfs"),
+	                                      -1);
+	if (total < 1)
+		return FALSE;
+	if (num_vfs > total) {
+		_LOGW ("link: %d only supports %u VFs (requested %u)", ifindex, total, num_vfs);
+		num_vfs = total;
+	}
+
+	current = nm_platform_sysctl_get_int32 (platform,
+	                                        NMP_SYSCTL_PATHID_NETDIR (dirfd,
+	                                                                  ifname,
+	                                                                  "device/sriov_numvfs"),
+	                                        -1);
+	if (current == num_vfs)
+		return TRUE;
+
+	if (current != 0) {
+		/* We need to destroy all other VFs before changing the value */
+		if (!nm_platform_sysctl_set (NM_PLATFORM_GET,
+		                             NMP_SYSCTL_PATHID_NETDIR (dirfd,
+		                                                       ifname,
+		                                                      "device/sriov_numvfs"),
+		                             "0")) {
+			_LOGW ("link: couldn't set SR-IOV num_vfs to %d: %s", 0, strerror (errno));
+			return FALSE;
+		}
+		if (num_vfs == 0)
+			return TRUE;
+	}
+
+	/* Finally, set the desired value */
+	if (!nm_platform_sysctl_set (NM_PLATFORM_GET,
+	                             NMP_SYSCTL_PATHID_NETDIR (dirfd,
+	                                                       ifname,
+	                                                       "device/sriov_numvfs"),
+	                             nm_sprintf_buf (buf, "%d", num_vfs))) {
+		_LOGW ("link: couldn't set SR-IOV num_vfs to %d: %s", num_vfs, strerror (errno));
+		return FALSE;
+	}
+
+	return TRUE;
+}
+
 static char *
 link_get_physical_port_id (NMPlatform *platform, int ifindex)
 {
@@ -6845,6 +6934,7 @@ nm_linux_platform_class_init (NMLinuxPlatformClass *klass)
 	platform_class->link_set_address = link_set_address;
 	platform_class->link_get_permanent_address = link_get_permanent_address;
 	platform_class->link_set_mtu = link_set_mtu;
+	platform_class->link_set_sriov_num_vfs = link_set_sriov_num_vfs;
 
 	platform_class->link_get_physical_port_id = link_get_physical_port_id;
 	platform_class->link_get_dev_id = link_get_dev_id;
@@ -6853,6 +6943,7 @@ nm_linux_platform_class_init (NMLinuxPlatformClass *klass)
 
 	platform_class->link_supports_carrier_detect = link_supports_carrier_detect;
 	platform_class->link_supports_vlans = link_supports_vlans;
+	platform_class->link_supports_sriov = link_supports_sriov;
 
 	platform_class->link_enslave = link_enslave;
 	platform_class->link_release = link_release;

src/platform/nm-platform.c

@@ -1179,6 +1179,30 @@ nm_platform_link_supports_vlans (NMPlatform *self, int ifindex)
 	return klass->link_supports_vlans (self, ifindex);
 }
 
+gboolean
+nm_platform_link_supports_sriov (NMPlatform *self, int ifindex)
+{
+	_CHECK_SELF (self, klass, FALSE);
+
+	g_return_val_if_fail (ifindex >= 0, FALSE);
+
+	return klass->link_supports_sriov (self, ifindex);
+}
+
+gboolean
+nm_platform_link_set_sriov_num_vfs (NMPlatform *self, int ifindex, guint num_vfs)
+{
+	_CHECK_SELF (self, klass, FALSE);
+
+	g_return_val_if_fail (ifindex > 0, FALSE);
+
+	_LOGD ("link: setting %u VFs for %s (%d)",
+	       num_vfs,
+	       nm_strquote_a (25, nm_platform_link_get_name (self, ifindex)),
+	       ifindex);
+	return klass->link_set_sriov_num_vfs (self, ifindex, num_vfs);
+}
+
 /**
  * nm_platform_link_set_up:
  * @self: platform instance

src/platform/nm-platform.h

@@ -575,6 +575,7 @@ typedef struct {
 	                                        size_t *length);
 	NMPlatformError (*link_set_address) (NMPlatform *, int ifindex, gconstpointer address, size_t length);
 	gboolean (*link_set_mtu) (NMPlatform *, int ifindex, guint32 mtu);
+	gboolean (*link_set_sriov_num_vfs) (NMPlatform *, int ifindex, guint num_vfs);
 
 	char *   (*link_get_physical_port_id) (NMPlatform *, int ifindex);
 	guint    (*link_get_dev_id) (NMPlatform *, int ifindex);
@@ -587,6 +588,7 @@ typedef struct {
 
 	gboolean (*link_supports_carrier_detect) (NMPlatform *, int ifindex);
 	gboolean (*link_supports_vlans) (NMPlatform *, int ifindex);
+	gboolean (*link_supports_sriov) (NMPlatform *, int ifindex);
 
 	gboolean (*link_enslave) (NMPlatform *, int master, int slave);
 	gboolean (*link_release) (NMPlatform *, int master, int slave);
@@ -825,6 +827,7 @@ gboolean nm_platform_link_set_ipv6_token (NMPlatform *self, int ifindex, NMUtils
 gboolean nm_platform_link_get_permanent_address (NMPlatform *self, int ifindex, guint8 *buf, size_t *length);
 NMPlatformError nm_platform_link_set_address (NMPlatform *self, int ifindex, const void *address, size_t length);
 gboolean nm_platform_link_set_mtu (NMPlatform *self, int ifindex, guint32 mtu);
+gboolean nm_platform_link_set_sriov_num_vfs (NMPlatform *self, int ifindex, guint num_vfs);
 
 char    *nm_platform_link_get_physical_port_id (NMPlatform *self, int ifindex);
 guint    nm_platform_link_get_dev_id (NMPlatform *self, int ifindex);
@@ -837,6 +840,7 @@ gboolean nm_platform_link_get_driver_info (NMPlatform *self,
 
 gboolean nm_platform_link_supports_carrier_detect (NMPlatform *self, int ifindex);
 gboolean nm_platform_link_supports_vlans (NMPlatform *self, int ifindex);
+gboolean nm_platform_link_supports_sriov (NMPlatform *self, int ifindex);
 
 gboolean nm_platform_link_enslave (NMPlatform *self, int master, int slave);
 gboolean nm_platform_link_release (NMPlatform *self, int master, int slave);