Host can provide send indirection table messages anytime after RSS is
enabled by calling rndis_filter_set_rss_param(). So the host provided
table values may be overwritten by the initialization in
rndis_set_subchannel().
To prevent this problem, move the tx_table initialization before calling
rndis_filter_set_rss_param().
Fixes: a6fb6aa3cfa9 ("hv_netvsc: Set tx_table to equal weight after subchannels open")
Signed-off-by: Haiyang Zhang <[email protected]>
---
drivers/net/hyperv/rndis_filter.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/drivers/net/hyperv/rndis_filter.c b/drivers/net/hyperv/rndis_filter.c
index 206b4e7..05bc5ec8 100644
--- a/drivers/net/hyperv/rndis_filter.c
+++ b/drivers/net/hyperv/rndis_filter.c
@@ -1171,6 +1171,9 @@ int rndis_set_subchannel(struct net_device *ndev,
wait_event(nvdev->subchan_open,
atomic_read(&nvdev->open_chn) == nvdev->num_chn);
+ for (i = 0; i < VRSS_SEND_TAB_SIZE; i++)
+ ndev_ctx->tx_table[i] = i % nvdev->num_chn;
+
/* ignore failures from setting rss parameters, still have channels */
if (dev_info)
rndis_filter_set_rss_param(rdev, dev_info->rss_key);
@@ -1180,9 +1183,6 @@ int rndis_set_subchannel(struct net_device *ndev,
netif_set_real_num_tx_queues(ndev, nvdev->num_chn);
netif_set_real_num_rx_queues(ndev, nvdev->num_chn);
- for (i = 0; i < VRSS_SEND_TAB_SIZE; i++)
- ndev_ctx->tx_table[i] = i % nvdev->num_chn;
-
return 0;
}
--
1.8.3.1
On Wed, 11 Dec 2019 14:26:27 -0800, Haiyang Zhang wrote:
> Host can provide send indirection table messages anytime after RSS is
> enabled by calling rndis_filter_set_rss_param(). So the host provided
> table values may be overwritten by the initialization in
> rndis_set_subchannel().
>
> To prevent this problem, move the tx_table initialization before calling
> rndis_filter_set_rss_param().
>
> Fixes: a6fb6aa3cfa9 ("hv_netvsc: Set tx_table to equal weight after subchannels open")
> Signed-off-by: Haiyang Zhang <[email protected]>
Applied, but there are two more problems with this code:
- you should not reset the indirection table if it was configured by
the user to something other than the default (use the
netif_is_rxfh_configured() helper to check for that)
- you should use the ethtool_rxfh_indir_default() wrapper
Please fix the former problem in the net tree, and after net is merged
into linux/master and net-next in a week or two please follow up with
the fix for the latter for net-next.
> diff --git a/drivers/net/hyperv/rndis_filter.c b/drivers/net/hyperv/rndis_filter.c
> index 206b4e7..05bc5ec8 100644
> --- a/drivers/net/hyperv/rndis_filter.c
> +++ b/drivers/net/hyperv/rndis_filter.c
> @@ -1171,6 +1171,9 @@ int rndis_set_subchannel(struct net_device *ndev,
> wait_event(nvdev->subchan_open,
> atomic_read(&nvdev->open_chn) == nvdev->num_chn);
>
> + for (i = 0; i < VRSS_SEND_TAB_SIZE; i++)
> + ndev_ctx->tx_table[i] = i % nvdev->num_chn;
> +
> /* ignore failures from setting rss parameters, still have channels */
> if (dev_info)
> rndis_filter_set_rss_param(rdev, dev_info->rss_key);
> @@ -1180,9 +1183,6 @@ int rndis_set_subchannel(struct net_device *ndev,
> netif_set_real_num_tx_queues(ndev, nvdev->num_chn);
> netif_set_real_num_rx_queues(ndev, nvdev->num_chn);
>
> - for (i = 0; i < VRSS_SEND_TAB_SIZE; i++)
> - ndev_ctx->tx_table[i] = i % nvdev->num_chn;
> -
> return 0;
> }
>
> -----Original Message-----
> From: Jakub Kicinski <[email protected]>
> Sent: Saturday, December 14, 2019 2:30 PM
> To: Haiyang Zhang <[email protected]>
> Cc: [email protected]; [email protected]; [email protected];
> KY Srinivasan <[email protected]>; Stephen Hemminger
> <[email protected]>; [email protected]; vkuznets
> <[email protected]>; [email protected]; [email protected]
> Subject: Re: [PATCH v2,net] hv_netvsc: Fix tx_table init in rndis_set_subchannel()
>
> On Wed, 11 Dec 2019 14:26:27 -0800, Haiyang Zhang wrote:
> > Host can provide send indirection table messages anytime after RSS is
> > enabled by calling rndis_filter_set_rss_param(). So the host provided
> > table values may be overwritten by the initialization in
> > rndis_set_subchannel().
> >
> > To prevent this problem, move the tx_table initialization before calling
> > rndis_filter_set_rss_param().
> >
> > Fixes: a6fb6aa3cfa9 ("hv_netvsc: Set tx_table to equal weight after
> subchannels open")
> > Signed-off-by: Haiyang Zhang <[email protected]>
>
> Applied, but there are two more problems with this code:
> - you should not reset the indirection table if it was configured by
> the user to something other than the default (use the
> netif_is_rxfh_configured() helper to check for that)
For Send indirection table (tx_table) ethtool doesn't have the option
to set it, and it's usually provided by the host. So we always initialize
it...
But, yes, for Receive indirection table (rx_table), I will make a fix, so
it will be set to default only for new devices, or changing the number
of channels; otherwise it will remain the same during operations like
changing MTU, ringparam.
> - you should use the ethtool_rxfh_indir_default() wrapper
For rx_table, we already use it:
rndis_device->rx_table[i] = ethtool_rxfh_indir_default(
For tx_table, I know it's the same operation (%, mod), but this wrapper
function's name is for rx_table. Should we use it for tx_table too?
>
> Please fix the former problem in the net tree, and after net is merged
> into linux/master and net-next in a week or two please follow up with
> the fix for the latter for net-next.
Sure.
Thanks,
- Haiyang
On Sun, 15 Dec 2019 16:38:00 +0000
Haiyang Zhang <[email protected]> wrote:
> > -----Original Message-----
> > From: Jakub Kicinski <[email protected]>
> > Sent: Saturday, December 14, 2019 2:30 PM
> > To: Haiyang Zhang <[email protected]>
> > Cc: [email protected]; [email protected]; [email protected];
> > KY Srinivasan <[email protected]>; Stephen Hemminger
> > <[email protected]>; [email protected]; vkuznets
> > <[email protected]>; [email protected]; [email protected]
> > Subject: Re: [PATCH v2,net] hv_netvsc: Fix tx_table init in rndis_set_subchannel()
> >
> > On Wed, 11 Dec 2019 14:26:27 -0800, Haiyang Zhang wrote:
> > > Host can provide send indirection table messages anytime after RSS is
> > > enabled by calling rndis_filter_set_rss_param(). So the host provided
> > > table values may be overwritten by the initialization in
> > > rndis_set_subchannel().
> > >
> > > To prevent this problem, move the tx_table initialization before calling
> > > rndis_filter_set_rss_param().
> > >
> > > Fixes: a6fb6aa3cfa9 ("hv_netvsc: Set tx_table to equal weight after
> > subchannels open")
> > > Signed-off-by: Haiyang Zhang <[email protected]>
> >
> > Applied, but there are two more problems with this code:
> > - you should not reset the indirection table if it was configured by
> > the user to something other than the default (use the
> > netif_is_rxfh_configured() helper to check for that)
>
> For Send indirection table (tx_table) ethtool doesn't have the option
> to set it, and it's usually provided by the host. So we always initialize
> it...
> But, yes, for Receive indirection table (rx_table), I will make a fix, so
> it will be set to default only for new devices, or changing the number
> of channels; otherwise it will remain the same during operations like
> changing MTU, ringparam.
>
>
> > - you should use the ethtool_rxfh_indir_default() wrapper
> For rx_table, we already use it:
> rndis_device->rx_table[i] = ethtool_rxfh_indir_default(
> For tx_table, I know it's the same operation (%, mod), but this wrapper
> function's name is for rx_table. Should we use it for tx_table too?
>
> >
> > Please fix the former problem in the net tree, and after net is merged
> > into linux/master and net-next in a week or two please follow up with
> > the fix for the latter for net-next.
>
> Sure.
>
> Thanks,
> - Haiyang
>
As Haiyang said, this send indirection table is unique to Hyper-V it is not part of
any of the other device models. It is not supported by ethtool. It would not be
appropriate to repurpose the existing indirection tool; the device already uses
the receive indirection table for RSS.
On Sun, 15 Dec 2019 09:11:20 -0800, Stephen Hemminger wrote:
> > > On Wed, 11 Dec 2019 14:26:27 -0800, Haiyang Zhang wrote:
> > > > Host can provide send indirection table messages anytime after RSS is
> > > > enabled by calling rndis_filter_set_rss_param(). So the host provided
> > > > table values may be overwritten by the initialization in
> > > > rndis_set_subchannel().
> > > >
> > > > To prevent this problem, move the tx_table initialization before calling
> > > > rndis_filter_set_rss_param().
> > > >
> > > > Fixes: a6fb6aa3cfa9 ("hv_netvsc: Set tx_table to equal weight after
> > > subchannels open")
> > > > Signed-off-by: Haiyang Zhang <[email protected]>
> > >
> > > Applied, but there are two more problems with this code:
> > > - you should not reset the indirection table if it was configured by
> > > the user to something other than the default (use the
> > > netif_is_rxfh_configured() helper to check for that)
> >
> > For Send indirection table (tx_table) ethtool doesn't have the option
> > to set it, and it's usually provided by the host. So we always initialize
> > it...
> > But, yes, for Receive indirection table (rx_table), I will make a fix, so
> > it will be set to default only for new devices, or changing the number
> > of channels; otherwise it will remain the same during operations like
> > changing MTU, ringparam.
Thank you!
> > > - you should use the ethtool_rxfh_indir_default() wrapper
> > For rx_table, we already use it:
> > rndis_device->rx_table[i] = ethtool_rxfh_indir_default(
> > For tx_table, I know it's the same operation (%, mod), but this wrapper
> > function's name is for rx_table. Should we use it for tx_table too?
> >
> > >
> > > Please fix the former problem in the net tree, and after net is merged
> > > into linux/master and net-next in a week or two please follow up with
> > > the fix for the latter for net-next.
> >
> > Sure.
> >
> > Thanks,
> > - Haiyang
> >
> As Haiyang said, this send indirection table is unique to Hyper-V it is not part of
> any of the other device models. It is not supported by ethtool. It would not be
> appropriate to repurpose the existing indirection tool; the device already uses
> the receive indirection table for RSS.
I see, I got confused by the use of the term RSS.