[PATCH 4.14 018/165] hv_netvsc: preserve hw_features on mtu/channels/ringparam changes

From: Greg Kroah-Hartman
Date: Thu May 24 2018 - 06:31:23 EST


4.14-stable review patch. If anyone has any objections, please let me know.

------------------

From: Vitaly Kuznetsov <vkuznets@xxxxxxxxxx>

[ Commit aefd80e874e98a864915df5b7d90824a4340b450 upstream. ]

rndis_filter_device_add() is called both from netvsc_probe() when we
initially create the device and from set channels/mtu/ringparam
routines where we basically remove the device and add it back.

hw_features is reset in rndis_filter_device_add() and filled with
host data. However, we lose all additional flags which are set outside
of the driver, e.g. register_netdevice() adds NETIF_F_SOFT_FEATURES and
many others.

Unfortunately, calls to rndis_{query_hwcaps(), _set_offload_params()}
calls cannot be avoided on every RNDIS reset: host expects us to set
required features explicitly. Moreover, in theory hardware capabilities
can change and we need to reflect the change in hw_features.

Reset net->hw_features bits according to host data in
rndis_netdev_set_hwcaps(), clear corresponding feature bits
from net->features in case some features went missing (will never happen
in real life I guess but let's be consistent).

Signed-off-by: Vitaly Kuznetsov <vkuznets@xxxxxxxxxx>
Reviewed-by: Haiyang Zhang <haiyangz@xxxxxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/net/hyperv/hyperv_net.h | 4 +
drivers/net/hyperv/netvsc_drv.c | 2
drivers/net/hyperv/rndis_filter.c | 136 +++++++++++++++++++++-----------------
3 files changed, 83 insertions(+), 59 deletions(-)

--- a/drivers/net/hyperv/hyperv_net.h
+++ b/drivers/net/hyperv/hyperv_net.h
@@ -659,6 +659,10 @@ struct nvsp_message {
#define NETVSC_RECEIVE_BUFFER_ID 0xcafe
#define NETVSC_SEND_BUFFER_ID 0

+#define NETVSC_SUPPORTED_HW_FEATURES (NETIF_F_RXCSUM | NETIF_F_IP_CSUM | \
+ NETIF_F_TSO | NETIF_F_IPV6_CSUM | \
+ NETIF_F_TSO6)
+
#define VRSS_SEND_TAB_SIZE 16 /* must be power of 2 */
#define VRSS_CHANNEL_MAX 64
#define VRSS_CHANNEL_DEFAULT 8
--- a/drivers/net/hyperv/netvsc_drv.c
+++ b/drivers/net/hyperv/netvsc_drv.c
@@ -1956,7 +1956,7 @@ static int netvsc_probe(struct hv_device

memcpy(net->dev_addr, device_info.mac_adr, ETH_ALEN);

- /* hw_features computed in rndis_filter_device_add */
+ /* hw_features computed in rndis_netdev_set_hwcaps() */
net->features = net->hw_features |
NETIF_F_HIGHDMA | NETIF_F_SG |
NETIF_F_HW_VLAN_CTAG_TX | NETIF_F_HW_VLAN_CTAG_RX;
--- a/drivers/net/hyperv/rndis_filter.c
+++ b/drivers/net/hyperv/rndis_filter.c
@@ -1131,69 +1131,20 @@ unlock:
rtnl_unlock();
}

-struct netvsc_device *rndis_filter_device_add(struct hv_device *dev,
- struct netvsc_device_info *device_info)
+static int rndis_netdev_set_hwcaps(struct rndis_device *rndis_device,
+ struct netvsc_device *nvdev)
{
- struct net_device *net = hv_get_drvdata(dev);
+ struct net_device *net = rndis_device->ndev;
struct net_device_context *net_device_ctx = netdev_priv(net);
- struct netvsc_device *net_device;
- struct rndis_device *rndis_device;
struct ndis_offload hwcaps;
struct ndis_offload_params offloads;
- struct ndis_recv_scale_cap rsscap;
- u32 rsscap_size = sizeof(struct ndis_recv_scale_cap);
unsigned int gso_max_size = GSO_MAX_SIZE;
- u32 mtu, size;
- const struct cpumask *node_cpu_mask;
- u32 num_possible_rss_qs;
- int i, ret;
-
- rndis_device = get_rndis_device();
- if (!rndis_device)
- return ERR_PTR(-ENODEV);
-
- /*
- * Let the inner driver handle this first to create the netvsc channel
- * NOTE! Once the channel is created, we may get a receive callback
- * (RndisFilterOnReceive()) before this call is completed
- */
- net_device = netvsc_device_add(dev, device_info);
- if (IS_ERR(net_device)) {
- kfree(rndis_device);
- return net_device;
- }
-
- /* Initialize the rndis device */
- net_device->max_chn = 1;
- net_device->num_chn = 1;
-
- net_device->extension = rndis_device;
- rndis_device->ndev = net;
-
- /* Send the rndis initialization message */
- ret = rndis_filter_init_device(rndis_device, net_device);
- if (ret != 0)
- goto err_dev_remv;
-
- /* Get the MTU from the host */
- size = sizeof(u32);
- ret = rndis_filter_query_device(rndis_device, net_device,
- RNDIS_OID_GEN_MAXIMUM_FRAME_SIZE,
- &mtu, &size);
- if (ret == 0 && size == sizeof(u32) && mtu < net->mtu)
- net->mtu = mtu;
-
- /* Get the mac address */
- ret = rndis_filter_query_device_mac(rndis_device, net_device);
- if (ret != 0)
- goto err_dev_remv;
-
- memcpy(device_info->mac_adr, rndis_device->hw_mac_adr, ETH_ALEN);
+ int ret;

/* Find HW offload capabilities */
- ret = rndis_query_hwcaps(rndis_device, net_device, &hwcaps);
+ ret = rndis_query_hwcaps(rndis_device, nvdev, &hwcaps);
if (ret != 0)
- goto err_dev_remv;
+ return ret;

/* A value of zero means "no change"; now turn on what we want. */
memset(&offloads, 0, sizeof(struct ndis_offload_params));
@@ -1201,8 +1152,12 @@ struct netvsc_device *rndis_filter_devic
/* Linux does not care about IP checksum, always does in kernel */
offloads.ip_v4_csum = NDIS_OFFLOAD_PARAMETERS_TX_RX_DISABLED;

+ /* Reset previously set hw_features flags */
+ net->hw_features &= ~NETVSC_SUPPORTED_HW_FEATURES;
+ net_device_ctx->tx_checksum_mask = 0;
+
/* Compute tx offload settings based on hw capabilities */
- net->hw_features = NETIF_F_RXCSUM;
+ net->hw_features |= NETIF_F_RXCSUM;

if ((hwcaps.csum.ip4_txcsum & NDIS_TXCSUM_ALL_TCP4) == NDIS_TXCSUM_ALL_TCP4) {
/* Can checksum TCP */
@@ -1246,10 +1201,75 @@ struct netvsc_device *rndis_filter_devic
}
}

+ /* In case some hw_features disappeared we need to remove them from
+ * net->features list as they're no longer supported.
+ */
+ net->features &= ~NETVSC_SUPPORTED_HW_FEATURES | net->hw_features;
+
netif_set_gso_max_size(net, gso_max_size);

- ret = rndis_filter_set_offload_params(net, net_device, &offloads);
- if (ret)
+ ret = rndis_filter_set_offload_params(net, nvdev, &offloads);
+
+ return ret;
+}
+
+struct netvsc_device *rndis_filter_device_add(struct hv_device *dev,
+ struct netvsc_device_info *device_info)
+{
+ struct net_device *net = hv_get_drvdata(dev);
+ struct netvsc_device *net_device;
+ struct rndis_device *rndis_device;
+ struct ndis_recv_scale_cap rsscap;
+ u32 rsscap_size = sizeof(struct ndis_recv_scale_cap);
+ u32 mtu, size;
+ const struct cpumask *node_cpu_mask;
+ u32 num_possible_rss_qs;
+ int i, ret;
+
+ rndis_device = get_rndis_device();
+ if (!rndis_device)
+ return ERR_PTR(-ENODEV);
+
+ /* Let the inner driver handle this first to create the netvsc channel
+ * NOTE! Once the channel is created, we may get a receive callback
+ * (RndisFilterOnReceive()) before this call is completed
+ */
+ net_device = netvsc_device_add(dev, device_info);
+ if (IS_ERR(net_device)) {
+ kfree(rndis_device);
+ return net_device;
+ }
+
+ /* Initialize the rndis device */
+ net_device->max_chn = 1;
+ net_device->num_chn = 1;
+
+ net_device->extension = rndis_device;
+ rndis_device->ndev = net;
+
+ /* Send the rndis initialization message */
+ ret = rndis_filter_init_device(rndis_device, net_device);
+ if (ret != 0)
+ goto err_dev_remv;
+
+ /* Get the MTU from the host */
+ size = sizeof(u32);
+ ret = rndis_filter_query_device(rndis_device, net_device,
+ RNDIS_OID_GEN_MAXIMUM_FRAME_SIZE,
+ &mtu, &size);
+ if (ret == 0 && size == sizeof(u32) && mtu < net->mtu)
+ net->mtu = mtu;
+
+ /* Get the mac address */
+ ret = rndis_filter_query_device_mac(rndis_device, net_device);
+ if (ret != 0)
+ goto err_dev_remv;
+
+ memcpy(device_info->mac_adr, rndis_device->hw_mac_adr, ETH_ALEN);
+
+ /* Query and set hardware capabilities */
+ ret = rndis_netdev_set_hwcaps(rndis_device, net_device);
+ if (ret != 0)
goto err_dev_remv;

rndis_filter_query_device_link_status(rndis_device, net_device);