Re: [ovs-dev] [PATCH v2 2/3] netdev-dpdk: avoid reconfiguration on VIRTIO_NET_F_MQ changes
On 16/04/2019 10:45, David Marchand wrote:
> At the moment, a malicious guest might negotiate VIRTIO_NET_F_MQ and
> !VIRTIO_NET_F_MQ in a loop which would be seen as qp_num going from 1 to
> n and n to 1 continuously, triggering datapath reconfigurations at each
> transition.
>
> Limit this by only reconfiguring on increased qp_num.
> The previous patch reduced the observed cost of polling disabled queues,
> so the only cost is memory.
>
> Signed-off-by: David Marchand
> ---
> lib/netdev-dpdk.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/lib/netdev-dpdk.c b/lib/netdev-dpdk.c
> index 9ba8e67..fc554db 100644
> --- a/lib/netdev-dpdk.c
> +++ b/lib/netdev-dpdk.c
> @@ -3510,8 +3510,8 @@ new_device(int vid)
> newnode = dev->socket_id;
> }
>
> -if (dev->requested_n_txq != qp_num
> -|| dev->requested_n_rxq != qp_num
> +if (dev->requested_n_txq < qp_num
> +|| dev->requested_n_rxq < qp_num
> || dev->requested_socket_id != newnode) {
> dev->requested_socket_id = newnode;
> dev->requested_n_rxq = qp_num;
>
LGTM
Acked-by: Kevin Traynor
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Re: [ovs-dev] [PATCH v2 2/3] netdev-dpdk: avoid reconfiguration on VIRTIO_NET_F_MQ changes
On Tue, Apr 16, 2019 at 3:51 PM Ilya Maximets wrote: > On 16.04.2019 12:45, David Marchand wrote: > > At the moment, a malicious guest might negotiate VIRTIO_NET_F_MQ and > > !VIRTIO_NET_F_MQ in a loop which would be seen as qp_num going from 1 to > > n and n to 1 continuously, triggering datapath reconfigurations at each > > transition. > > > > Limit this by only reconfiguring on increased qp_num. > > The previous patch reduced the observed cost of polling disabled queues, > > so the only cost is memory. > > > > Signed-off-by: David Marchand > > --- > > It seems weird to ACK my own code. You may credit me in some other way > like From/Suggested/Co-authored tags. Any of them is OK for me. > Please, refer the > Documentation/internals/contributing/submitting-patches.rst > for details and additional constraints (like additional sign-offs). > Same for the next patch. > I did not want to take all the glory for me :-) The code is mainly yours, so Co-authored-by + SoB. > BTW, It's completely unnecessary to send new versions of the patch-set in > reply to the previous. This is specific to DPDK mail-list and not a > common practice. Complicates reading the list and searching for the right > patch versions. > Ok, so I won't chain the new version. -- David Marchand ___ dev mailing list d...@openvswitch.org https://mail.openvswitch.org/mailman/listinfo/ovs-dev
Re: [ovs-dev] [PATCH v2 2/3] netdev-dpdk: avoid reconfiguration on VIRTIO_NET_F_MQ changes
On 16.04.2019 12:45, David Marchand wrote:
> At the moment, a malicious guest might negotiate VIRTIO_NET_F_MQ and
> !VIRTIO_NET_F_MQ in a loop which would be seen as qp_num going from 1 to
> n and n to 1 continuously, triggering datapath reconfigurations at each
> transition.
>
> Limit this by only reconfiguring on increased qp_num.
> The previous patch reduced the observed cost of polling disabled queues,
> so the only cost is memory.
>
> Signed-off-by: David Marchand
> ---
It seems weird to ACK my own code. You may credit me in some other way
like From/Suggested/Co-authored tags. Any of them is OK for me.
Please, refer the Documentation/internals/contributing/submitting-patches.rst
for details and additional constraints (like additional sign-offs).
Same for the next patch.
BTW, It's completely unnecessary to send new versions of the patch-set in
reply to the previous. This is specific to DPDK mail-list and not a
common practice. Complicates reading the list and searching for the right
patch versions.
> lib/netdev-dpdk.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/lib/netdev-dpdk.c b/lib/netdev-dpdk.c
> index 9ba8e67..fc554db 100644
> --- a/lib/netdev-dpdk.c
> +++ b/lib/netdev-dpdk.c
> @@ -3510,8 +3510,8 @@ new_device(int vid)
> newnode = dev->socket_id;
> }
>
> -if (dev->requested_n_txq != qp_num
> -|| dev->requested_n_rxq != qp_num
> +if (dev->requested_n_txq < qp_num
> +|| dev->requested_n_rxq < qp_num
> || dev->requested_socket_id != newnode) {
> dev->requested_socket_id = newnode;
> dev->requested_n_rxq = qp_num;
>
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[ovs-dev] [PATCH v2 2/3] netdev-dpdk: avoid reconfiguration on VIRTIO_NET_F_MQ changes
At the moment, a malicious guest might negotiate VIRTIO_NET_F_MQ and
!VIRTIO_NET_F_MQ in a loop which would be seen as qp_num going from 1 to
n and n to 1 continuously, triggering datapath reconfigurations at each
transition.
Limit this by only reconfiguring on increased qp_num.
The previous patch reduced the observed cost of polling disabled queues,
so the only cost is memory.
Signed-off-by: David Marchand
---
lib/netdev-dpdk.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/lib/netdev-dpdk.c b/lib/netdev-dpdk.c
index 9ba8e67..fc554db 100644
--- a/lib/netdev-dpdk.c
+++ b/lib/netdev-dpdk.c
@@ -3510,8 +3510,8 @@ new_device(int vid)
newnode = dev->socket_id;
}
-if (dev->requested_n_txq != qp_num
-|| dev->requested_n_rxq != qp_num
+if (dev->requested_n_txq < qp_num
+|| dev->requested_n_rxq < qp_num
|| dev->requested_socket_id != newnode) {
dev->requested_socket_id = newnode;
dev->requested_n_rxq = qp_num;
--
1.8.3.1
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