[PATCH] hv_netvsc: Allocate rx indirection table size dynamically

[PATCH] hv_netvsc: Allocate rx indirection table size dynamically

[Shradha Gupta]

Allocate the size of rx indirection table dynamically in netvsc
from the value of size provided by OID_GEN_RECEIVE_SCALE_CAPABILITIES
query instead of using a constant value of ITAB_NUM.

Signed-off-by: Shradha Gupta <shradhagupta@linux.microsoft.com>
---
 drivers/net/hyperv/hyperv_net.h   |  5 ++++-
 drivers/net/hyperv/netvsc_drv.c   | 11 +++++++----
 drivers/net/hyperv/rndis_filter.c | 23 +++++++++++++++++++----
 3 files changed, 30 insertions(+), 9 deletions(-)

diff --git a/drivers/net/hyperv/hyperv_net.h b/drivers/net/hyperv/hyperv_net.h
index dd5919ec408b..1dbdb65ca8f0 100644
--- a/drivers/net/hyperv/hyperv_net.h
+++ b/drivers/net/hyperv/hyperv_net.h
@@ -74,6 +74,7 @@ struct ndis_recv_scale_cap { /* NDIS_RECEIVE_SCALE_CAPABILITIES */
 #define NDIS_RSS_HASH_SECRET_KEY_MAX_SIZE_REVISION_2   40
 
 #define ITAB_NUM 128
+#define ITAB_NUM_MAX 256
 
 struct ndis_recv_scale_param { /* NDIS_RECEIVE_SCALE_PARAMETERS */
 	struct ndis_obj_header hdr;
@@ -1034,7 +1035,9 @@ struct net_device_context {
 
 	u32 tx_table[VRSS_SEND_TAB_SIZE];
 
-	u16 rx_table[ITAB_NUM];
+	u16 *rx_table;
+
+	int rx_table_sz;
 
 	/* Ethtool settings */
 	u8 duplex;
diff --git a/drivers/net/hyperv/netvsc_drv.c b/drivers/net/hyperv/netvsc_drv.c
index 0103ff914024..5b8a7d5f9a15 100644
--- a/drivers/net/hyperv/netvsc_drv.c
+++ b/drivers/net/hyperv/netvsc_drv.c
@@ -1747,7 +1747,9 @@ static u32 netvsc_get_rxfh_key_size(struct net_device *dev)
 
 static u32 netvsc_rss_indir_size(struct net_device *dev)
 {
-	return ITAB_NUM;
+	struct net_device_context *ndc = netdev_priv(dev);
+
+	return ndc->rx_table_sz;
 }
 
 static int netvsc_get_rxfh(struct net_device *dev, u32 *indir, u8 *key,
@@ -1766,7 +1768,7 @@ static int netvsc_get_rxfh(struct net_device *dev, u32 *indir, u8 *key,
 
 	rndis_dev = ndev->extension;
 	if (indir) {
-		for (i = 0; i < ITAB_NUM; i++)
+		for (i = 0; i < ndc->rx_table_sz; i++)
 			indir[i] = ndc->rx_table[i];
 	}
 
@@ -1792,11 +1794,11 @@ static int netvsc_set_rxfh(struct net_device *dev, const u32 *indir,
 
 	rndis_dev = ndev->extension;
 	if (indir) {
-		for (i = 0; i < ITAB_NUM; i++)
+		for (i = 0; i < ndc->rx_table_sz; i++)
 			if (indir[i] >= ndev->num_chn)
 				return -EINVAL;
 
-		for (i = 0; i < ITAB_NUM; i++)
+		for (i = 0; i < ndc->rx_table_sz; i++)
 			ndc->rx_table[i] = indir[i];
 	}
 
@@ -2638,6 +2640,7 @@ static void netvsc_remove(struct hv_device *dev)
 
 	hv_set_drvdata(dev, NULL);
 
+	kfree(ndev_ctx->rx_table);
 	free_percpu(ndev_ctx->vf_stats);
 	free_netdev(net);
 }
diff --git a/drivers/net/hyperv/rndis_filter.c b/drivers/net/hyperv/rndis_filter.c
index eea777ec2541..af031e711cb2 100644
--- a/drivers/net/hyperv/rndis_filter.c
+++ b/drivers/net/hyperv/rndis_filter.c
@@ -927,7 +927,7 @@ static int rndis_set_rss_param_msg(struct rndis_device *rdev,
 	struct rndis_set_request *set;
 	struct rndis_set_complete *set_complete;
 	u32 extlen = sizeof(struct ndis_recv_scale_param) +
-		     4 * ITAB_NUM + NETVSC_HASH_KEYLEN;
+		     4 * ndc->rx_table_sz + NETVSC_HASH_KEYLEN;
 	struct ndis_recv_scale_param *rssp;
 	u32 *itab;
 	u8 *keyp;
@@ -953,7 +953,7 @@ static int rndis_set_rss_param_msg(struct rndis_device *rdev,
 	rssp->hashinfo = NDIS_HASH_FUNC_TOEPLITZ | NDIS_HASH_IPV4 |
 			 NDIS_HASH_TCP_IPV4 | NDIS_HASH_IPV6 |
 			 NDIS_HASH_TCP_IPV6;
-	rssp->indirect_tabsize = 4*ITAB_NUM;
+	rssp->indirect_tabsize = 4 * ndc->rx_table_sz;
 	rssp->indirect_taboffset = sizeof(struct ndis_recv_scale_param);
 	rssp->hashkey_size = NETVSC_HASH_KEYLEN;
 	rssp->hashkey_offset = rssp->indirect_taboffset +
@@ -961,7 +961,7 @@ static int rndis_set_rss_param_msg(struct rndis_device *rdev,
 
 	/* Set indirection table entries */
 	itab = (u32 *)(rssp + 1);
-	for (i = 0; i < ITAB_NUM; i++)
+	for (i = 0; i < ndc->rx_table_sz; i++)
 		itab[i] = ndc->rx_table[i];
 
 	/* Set hask key values */
@@ -1548,6 +1548,21 @@ struct netvsc_device *rndis_filter_device_add(struct hv_device *dev,
 	if (ret || rsscap.num_recv_que < 2)
 		goto out;
 
+	if (rsscap.num_indirect_tabent &&
+		rsscap.num_indirect_tabent <= ITAB_NUM_MAX) {
+		ndc->rx_table_sz = rsscap.num_indirect_tabent;
+	} else {
+		ndc->rx_table_sz = ITAB_NUM;
+	}
+
+	ndc->rx_table = kzalloc(sizeof(u16) * ndc->rx_table_sz,
+				GFP_KERNEL);
+	if (ndc->rx_table) {
+		netdev_err(net, "Error in allocating rx indirection table of size %d\n",
+				ndc->rx_table_sz);
+		goto out;
+	}
+
 	/* This guarantees that num_possible_rss_qs <= num_online_cpus */
 	num_possible_rss_qs = min_t(u32, num_online_cpus(),
 				    rsscap.num_recv_que);
@@ -1558,7 +1573,7 @@ struct netvsc_device *rndis_filter_device_add(struct hv_device *dev,
 	net_device->num_chn = min(net_device->max_chn, device_info->num_chn);
 
 	if (!netif_is_rxfh_configured(net)) {
-		for (i = 0; i < ITAB_NUM; i++)
+		for (i = 0; i < ndc->rx_table_sz; i++)
 			ndc->rx_table[i] = ethtool_rxfh_indir_default(
 						i, net_device->num_chn);
 	}
-- 
2.34.1

Re: [PATCH] hv_netvsc: Allocate rx indirection table size dynamically

[Simon Horman]

On Tue, May 23, 2023 at 10:57:24PM -0700, Shradha Gupta wrote:
> Allocate the size of rx indirection table dynamically in netvsc
> from the value of size provided by OID_GEN_RECEIVE_SCALE_CAPABILITIES
> query instead of using a constant value of ITAB_NUM.
> 
> Signed-off-by: Shradha Gupta <shradhagupta@linux.microsoft.com>

Hi Shradha,

thanks for your patch.

> @@ -1548,6 +1548,21 @@ struct netvsc_device *rndis_filter_device_add(struct hv_device *dev,
>  	if (ret || rsscap.num_recv_que < 2)
>  		goto out;
>  
> +	if (rsscap.num_indirect_tabent &&
> +		rsscap.num_indirect_tabent <= ITAB_NUM_MAX) {

nit: the line above is not indented correctly,
     it should line up with the inside of the opening parentheses
     on the preceding line.

     Also, I don't think the curly-brackets are needed.

	if (rsscap.num_indirect_tabent &&
	    rsscap.num_indirect_tabent <= ITAB_NUM_MAX) {

> +		ndc->rx_table_sz = rsscap.num_indirect_tabent;
> +	} else {
> +		ndc->rx_table_sz = ITAB_NUM;
> +	}
> +
> +	ndc->rx_table = kzalloc(sizeof(u16) * ndc->rx_table_sz,
> +				GFP_KERNEL);
> +	if (ndc->rx_table) {

More importantly, it looks like the condition is inverted here.
Which seems unlikely to lead to anything good happening.

	if (!ndc->rx_table) {

> +		netdev_err(net, "Error in allocating rx indirection table of size %d\n",
> +				ndc->rx_table_sz);
> +		goto out;
> +	}
> +
>  	/* This guarantees that num_possible_rss_qs <= num_online_cpus */
>  	num_possible_rss_qs = min_t(u32, num_online_cpus(),
>  				    rsscap.num_recv_que);
> @@ -1558,7 +1573,7 @@ struct netvsc_device *rndis_filter_device_add(struct hv_device *dev,
>  	net_device->num_chn = min(net_device->max_chn, device_info->num_chn);
>  
>  	if (!netif_is_rxfh_configured(net)) {
> -		for (i = 0; i < ITAB_NUM; i++)
> +		for (i = 0; i < ndc->rx_table_sz; i++)
>  			ndc->rx_table[i] = ethtool_rxfh_indir_default(
>  						i, net_device->num_chn);
>  	}

-- 
pw-bot: cr

Re: [PATCH] hv_netvsc: Allocate rx indirection table size dynamically

[Steen Hegelund]

Hi Shradha,

On Tue, 2023-05-23 at 22:57 -0700, Shradha Gupta wrote:
> [You don't often get email from shradhagupta@linux.microsoft.com. Learn why
> this is important at https://aka.ms/LearnAboutSenderIdentification ]
> 
> EXTERNAL EMAIL: Do not click links or open attachments unless you know the
> content is safe
> 
> Allocate the size of rx indirection table dynamically in netvsc
> from the value of size provided by OID_GEN_RECEIVE_SCALE_CAPABILITIES
> query instead of using a constant value of ITAB_NUM.
> 
> Signed-off-by: Shradha Gupta <shradhagupta@linux.microsoft.com>
> ---
>  drivers/net/hyperv/hyperv_net.h   |  5 ++++-
>  drivers/net/hyperv/netvsc_drv.c   | 11 +++++++----
>  drivers/net/hyperv/rndis_filter.c | 23 +++++++++++++++++++----
>  3 files changed, 30 insertions(+), 9 deletions(-)
> 
> diff --git a/drivers/net/hyperv/hyperv_net.h b/drivers/net/hyperv/hyperv_net.h
> index dd5919ec408b..1dbdb65ca8f0 100644
> --- a/drivers/net/hyperv/hyperv_net.h
> +++ b/drivers/net/hyperv/hyperv_net.h
> @@ -74,6 +74,7 @@ struct ndis_recv_scale_cap { /*
> NDIS_RECEIVE_SCALE_CAPABILITIES */
>  #define NDIS_RSS_HASH_SECRET_KEY_MAX_SIZE_REVISION_2   40
> 
>  #define ITAB_NUM 128
> +#define ITAB_NUM_MAX 256
> 
>  struct ndis_recv_scale_param { /* NDIS_RECEIVE_SCALE_PARAMETERS */
>         struct ndis_obj_header hdr;
> @@ -1034,7 +1035,9 @@ struct net_device_context {
> 
>         u32 tx_table[VRSS_SEND_TAB_SIZE];
> 
> -       u16 rx_table[ITAB_NUM];
> +       u16 *rx_table;
> +
> +       int rx_table_sz;
> 
>         /* Ethtool settings */
>         u8 duplex;
> diff --git a/drivers/net/hyperv/netvsc_drv.c b/drivers/net/hyperv/netvsc_drv.c
> index 0103ff914024..5b8a7d5f9a15 100644
> --- a/drivers/net/hyperv/netvsc_drv.c
> +++ b/drivers/net/hyperv/netvsc_drv.c
> @@ -1747,7 +1747,9 @@ static u32 netvsc_get_rxfh_key_size(struct net_device
> *dev)
> 
>  static u32 netvsc_rss_indir_size(struct net_device *dev)
>  {
> -       return ITAB_NUM;
> +       struct net_device_context *ndc = netdev_priv(dev);
> +
> +       return ndc->rx_table_sz;
>  }
> 
>  static int netvsc_get_rxfh(struct net_device *dev, u32 *indir, u8 *key,
> @@ -1766,7 +1768,7 @@ static int netvsc_get_rxfh(struct net_device *dev, u32
> *indir, u8 *key,
> 
>         rndis_dev = ndev->extension;
>         if (indir) {
> -               for (i = 0; i < ITAB_NUM; i++)
> +               for (i = 0; i < ndc->rx_table_sz; i++)
>                         indir[i] = ndc->rx_table[i];
>         }
> 
> @@ -1792,11 +1794,11 @@ static int netvsc_set_rxfh(struct net_device *dev,
> const u32 *indir,
> 
>         rndis_dev = ndev->extension;
>         if (indir) {
> -               for (i = 0; i < ITAB_NUM; i++)
> +               for (i = 0; i < ndc->rx_table_sz; i++)
>                         if (indir[i] >= ndev->num_chn)
>                                 return -EINVAL;
> 
> -               for (i = 0; i < ITAB_NUM; i++)
> +               for (i = 0; i < ndc->rx_table_sz; i++)
>                         ndc->rx_table[i] = indir[i];
>         }
> 
> @@ -2638,6 +2640,7 @@ static void netvsc_remove(struct hv_device *dev)
> 
>         hv_set_drvdata(dev, NULL);
> 
> +       kfree(ndev_ctx->rx_table);
>         free_percpu(ndev_ctx->vf_stats);
>         free_netdev(net);
>  }
> diff --git a/drivers/net/hyperv/rndis_filter.c
> b/drivers/net/hyperv/rndis_filter.c
> index eea777ec2541..af031e711cb2 100644
> --- a/drivers/net/hyperv/rndis_filter.c
> +++ b/drivers/net/hyperv/rndis_filter.c
> @@ -927,7 +927,7 @@ static int rndis_set_rss_param_msg(struct rndis_device
> *rdev,
>         struct rndis_set_request *set;
>         struct rndis_set_complete *set_complete;
>         u32 extlen = sizeof(struct ndis_recv_scale_param) +
> -                    4 * ITAB_NUM + NETVSC_HASH_KEYLEN;
> +                    4 * ndc->rx_table_sz + NETVSC_HASH_KEYLEN;
>         struct ndis_recv_scale_param *rssp;
>         u32 *itab;
>         u8 *keyp;
> @@ -953,7 +953,7 @@ static int rndis_set_rss_param_msg(struct rndis_device
> *rdev,
>         rssp->hashinfo = NDIS_HASH_FUNC_TOEPLITZ | NDIS_HASH_IPV4 |
>                          NDIS_HASH_TCP_IPV4 | NDIS_HASH_IPV6 |
>                          NDIS_HASH_TCP_IPV6;
> -       rssp->indirect_tabsize = 4*ITAB_NUM;
> +       rssp->indirect_tabsize = 4 * ndc->rx_table_sz;
>         rssp->indirect_taboffset = sizeof(struct ndis_recv_scale_param);
>         rssp->hashkey_size = NETVSC_HASH_KEYLEN;
>         rssp->hashkey_offset = rssp->indirect_taboffset +
> @@ -961,7 +961,7 @@ static int rndis_set_rss_param_msg(struct rndis_device
> *rdev,
> 
>         /* Set indirection table entries */
>         itab = (u32 *)(rssp + 1);
> -       for (i = 0; i < ITAB_NUM; i++)
> +       for (i = 0; i < ndc->rx_table_sz; i++)
>                 itab[i] = ndc->rx_table[i];
> 
>         /* Set hask key values */
> @@ -1548,6 +1548,21 @@ struct netvsc_device *rndis_filter_device_add(struct
> hv_device *dev,
>         if (ret || rsscap.num_recv_que < 2)
>                 goto out;
> 
> +       if (rsscap.num_indirect_tabent &&
> +               rsscap.num_indirect_tabent <= ITAB_NUM_MAX) {
> +               ndc->rx_table_sz = rsscap.num_indirect_tabent;
> +       } else {
> +               ndc->rx_table_sz = ITAB_NUM;
> +       }
> +
> +       ndc->rx_table = kzalloc(sizeof(u16) * ndc->rx_table_sz,
> +                               GFP_KERNEL);
> +       if (ndc->rx_table) {
> +               netdev_err(net, "Error in allocating rx indirection table of
> size %d\n",
> +                               ndc->rx_table_sz);
> +               goto out;
> +       }
> +

You are now always allocating the rx_table in the rndis_filter_device_add()
function, but this function is called both from the netvsc_probe function
and the netvsc_attach function, but as far as I can see the rx_table only
gets freed in the remove function not in the netvsc_detach.

So if there is a chance that the attach/detach will be called more times
on a existing device you will have a leak.

>         /* This guarantees that num_possible_rss_qs <= num_online_cpus */
>         num_possible_rss_qs = min_t(u32, num_online_cpus(),
>                                     rsscap.num_recv_que);
> @@ -1558,7 +1573,7 @@ struct netvsc_device *rndis_filter_device_add(struct
> hv_device *dev,
>         net_device->num_chn = min(net_device->max_chn, device_info->num_chn);
> 
>         if (!netif_is_rxfh_configured(net)) {
> -               for (i = 0; i < ITAB_NUM; i++)
> +               for (i = 0; i < ndc->rx_table_sz; i++)
>                         ndc->rx_table[i] = ethtool_rxfh_indir_default(
>                                                 i, net_device->num_chn);
>         }
> --
> 2.34.1
> 
> 

Best Regards
Steen