* Re: [RFC PATCH] powerpc/pseries/mobility: notify network peers after migration
2019-11-06 0:06 [RFC PATCH] powerpc/pseries/mobility: notify network peers after migration Thomas Falcon
@ 2019-11-06 4:13 ` Russell Currey
2019-11-06 4:47 ` Thomas Falcon
2019-11-06 22:14 ` Nathan Lynch
2019-11-07 1:33 ` Michael Ellerman
2 siblings, 1 reply; 7+ messages in thread
From: Russell Currey @ 2019-11-06 4:13 UTC (permalink / raw)
To: Thomas Falcon, linuxppc-dev; +Cc: nathanl, netdev, msuchanek, tyreld
On Tue, 2019-11-05 at 18:06 -0600, Thomas Falcon wrote:
> After a migration, it is necessary to send a gratuitous ARP
> from all running interfaces so that the rest of the network
> is aware of its new location. However, some supported network
> devices are unaware that they have been migrated. To avoid network
> interruptions and other unwanted behavior, force a GARP on all
> valid, running interfaces as part of the post_mobility_fixup
> routine.
>
> Signed-off-by: Thomas Falcon <tlfalcon@linux.ibm.com>
Hi Thomas,
> ---
> arch/powerpc/platforms/pseries/mobility.c | 20 ++++++++++++++++++++
> 1 file changed, 20 insertions(+)
>
> diff --git a/arch/powerpc/platforms/pseries/mobility.c
> b/arch/powerpc/platforms/pseries/mobility.c
> index b571285f6c14..c1abc14cf2bb 100644
> --- a/arch/powerpc/platforms/pseries/mobility.c
> +++ b/arch/powerpc/platforms/pseries/mobility.c
> @@ -17,6 +17,9 @@
> #include <linux/delay.h>
> #include <linux/slab.h>
> #include <linux/stringify.h>
> +#include <linux/netdevice.h>
> +#include <linux/rtnetlink.h>
> +#include <net/net_namespace.h>
>
> #include <asm/machdep.h>
> #include <asm/rtas.h>
> @@ -331,6 +334,8 @@ void post_mobility_fixup(void)
> {
> int rc;
> int activate_fw_token;
> + struct net_device *netdev;
> + struct net *net;
>
> activate_fw_token = rtas_token("ibm,activate-firmware");
> if (activate_fw_token == RTAS_UNKNOWN_SERVICE) {
> @@ -371,6 +376,21 @@ void post_mobility_fixup(void)
> /* Possibly switch to a new RFI flush type */
> pseries_setup_rfi_flush();
>
> + /* need to force a gratuitous ARP on running interfaces */
> + rtnl_lock();
> + for_each_net(net) {
> + for_each_netdev(net, netdev) {
> + if (netif_device_present(netdev) &&
> + netif_running(netdev) &&
> + !(netdev->flags & (IFF_NOARP |
> IFF_LOOPBACK)))
> + call_netdevice_notifiers(NETDEV_NOTIFY_
> PEERS,
> + netdev);
Without curly braces following the "if" statment, the second line
(below) will be executed unconditionally, which I assume with this
indentation isn't what you want.
(reported by snowpatch)
- Russell
> + call_netdevice_notifiers(NETDEV_RESEND_
> IGMP,
> + netdev);
> + }
> + }
> + rtnl_unlock();
> +
> return;
> }
>
^ permalink raw reply [flat|nested] 7+ messages in thread* Re: [RFC PATCH] powerpc/pseries/mobility: notify network peers after migration
2019-11-06 4:13 ` Russell Currey
@ 2019-11-06 4:47 ` Thomas Falcon
0 siblings, 0 replies; 7+ messages in thread
From: Thomas Falcon @ 2019-11-06 4:47 UTC (permalink / raw)
To: Russell Currey, linuxppc-dev; +Cc: nathanl, netdev, msuchanek, tyreld
On 11/5/19 10:13 PM, Russell Currey wrote:
> On Tue, 2019-11-05 at 18:06 -0600, Thomas Falcon wrote:
>> After a migration, it is necessary to send a gratuitous ARP
>> from all running interfaces so that the rest of the network
>> is aware of its new location. However, some supported network
>> devices are unaware that they have been migrated. To avoid network
>> interruptions and other unwanted behavior, force a GARP on all
>> valid, running interfaces as part of the post_mobility_fixup
>> routine.
>>
>> Signed-off-by: Thomas Falcon <tlfalcon@linux.ibm.com>
> Hi Thomas,
>
>> ---
>> arch/powerpc/platforms/pseries/mobility.c | 20 ++++++++++++++++++++
>> 1 file changed, 20 insertions(+)
>>
>> diff --git a/arch/powerpc/platforms/pseries/mobility.c
>> b/arch/powerpc/platforms/pseries/mobility.c
>> index b571285f6c14..c1abc14cf2bb 100644
>> --- a/arch/powerpc/platforms/pseries/mobility.c
>> +++ b/arch/powerpc/platforms/pseries/mobility.c
>> @@ -17,6 +17,9 @@
>> #include <linux/delay.h>
>> #include <linux/slab.h>
>> #include <linux/stringify.h>
>> +#include <linux/netdevice.h>
>> +#include <linux/rtnetlink.h>
>> +#include <net/net_namespace.h>
>>
>> #include <asm/machdep.h>
>> #include <asm/rtas.h>
>> @@ -331,6 +334,8 @@ void post_mobility_fixup(void)
>> {
>> int rc;
>> int activate_fw_token;
>> + struct net_device *netdev;
>> + struct net *net;
>>
>> activate_fw_token = rtas_token("ibm,activate-firmware");
>> if (activate_fw_token == RTAS_UNKNOWN_SERVICE) {
>> @@ -371,6 +376,21 @@ void post_mobility_fixup(void)
>> /* Possibly switch to a new RFI flush type */
>> pseries_setup_rfi_flush();
>>
>> + /* need to force a gratuitous ARP on running interfaces */
>> + rtnl_lock();
>> + for_each_net(net) {
>> + for_each_netdev(net, netdev) {
>> + if (netif_device_present(netdev) &&
>> + netif_running(netdev) &&
>> + !(netdev->flags & (IFF_NOARP |
>> IFF_LOOPBACK)))
>> + call_netdevice_notifiers(NETDEV_NOTIFY_
>> PEERS,
>> + netdev);
> Without curly braces following the "if" statment, the second line
> (below) will be executed unconditionally, which I assume with this
> indentation isn't what you want.
>
> (reported by snowpatch)
>
> - Russell
Thanks for catching that! I'll fix that and send a v2 soon.
Tom
>> + call_netdevice_notifiers(NETDEV_RESEND_
>> IGMP,
>> + netdev);
>> + }
>> + }
>> + rtnl_unlock();
>> +
>> return;
>> }
>>
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [RFC PATCH] powerpc/pseries/mobility: notify network peers after migration
2019-11-06 0:06 [RFC PATCH] powerpc/pseries/mobility: notify network peers after migration Thomas Falcon
2019-11-06 4:13 ` Russell Currey
@ 2019-11-06 22:14 ` Nathan Lynch
2019-11-07 21:30 ` Thomas Falcon
2019-11-07 1:33 ` Michael Ellerman
2 siblings, 1 reply; 7+ messages in thread
From: Nathan Lynch @ 2019-11-06 22:14 UTC (permalink / raw)
To: Thomas Falcon; +Cc: linuxppc-dev, netdev, msuchanek, tyreld
Hi Tom,
Thomas Falcon <tlfalcon@linux.ibm.com> writes:
> After a migration, it is necessary to send a gratuitous ARP
> from all running interfaces so that the rest of the network
> is aware of its new location. However, some supported network
> devices are unaware that they have been migrated. To avoid network
> interruptions and other unwanted behavior, force a GARP on all
> valid, running interfaces as part of the post_mobility_fixup
> routine.
[...]
> @@ -331,6 +334,8 @@ void post_mobility_fixup(void)
> {
> int rc;
> int activate_fw_token;
> + struct net_device *netdev;
> + struct net *net;
>
> activate_fw_token = rtas_token("ibm,activate-firmware");
> if (activate_fw_token == RTAS_UNKNOWN_SERVICE) {
> @@ -371,6 +376,21 @@ void post_mobility_fixup(void)
> /* Possibly switch to a new RFI flush type */
> pseries_setup_rfi_flush();
>
> + /* need to force a gratuitous ARP on running interfaces */
> + rtnl_lock();
> + for_each_net(net) {
> + for_each_netdev(net, netdev) {
> + if (netif_device_present(netdev) &&
> + netif_running(netdev) &&
> + !(netdev->flags & (IFF_NOARP | IFF_LOOPBACK)))
> + call_netdevice_notifiers(NETDEV_NOTIFY_PEERS,
> + netdev);
> + call_netdevice_notifiers(NETDEV_RESEND_IGMP,
> + netdev);
> + }
> + }
> + rtnl_unlock();
> +
This isn't an outright nak, but this is not nice. It illustrates the
need to rethink the pseries partition migration code. There is no
mechanism for drivers and other interested code to prepare for a
migration or to adjust to the destination. So post_mobility_fixup() will
continue to grow into a fragile collection of calls into unrelated
subsystems until there is a better design -- either a pseries-specific
notification/callback mechanism, or something based on the pm framework.
My understanding is that this is needed specifically for ibmveth and,
unlike ibmvnic, the platform does not provide any notification to that
driver that a migration has occurred, right?
^ permalink raw reply [flat|nested] 7+ messages in thread* Re: [RFC PATCH] powerpc/pseries/mobility: notify network peers after migration
2019-11-06 22:14 ` Nathan Lynch
@ 2019-11-07 21:30 ` Thomas Falcon
0 siblings, 0 replies; 7+ messages in thread
From: Thomas Falcon @ 2019-11-07 21:30 UTC (permalink / raw)
To: Nathan Lynch; +Cc: linuxppc-dev, netdev, msuchanek, tyreld
On 11/6/19 4:14 PM, Nathan Lynch wrote:
> Hi Tom,
>
> Thomas Falcon <tlfalcon@linux.ibm.com> writes:
>> After a migration, it is necessary to send a gratuitous ARP
>> from all running interfaces so that the rest of the network
>> is aware of its new location. However, some supported network
>> devices are unaware that they have been migrated. To avoid network
>> interruptions and other unwanted behavior, force a GARP on all
>> valid, running interfaces as part of the post_mobility_fixup
>> routine.
> [...]
>
>> @@ -331,6 +334,8 @@ void post_mobility_fixup(void)
>> {
>> int rc;
>> int activate_fw_token;
>> + struct net_device *netdev;
>> + struct net *net;
>>
>> activate_fw_token = rtas_token("ibm,activate-firmware");
>> if (activate_fw_token == RTAS_UNKNOWN_SERVICE) {
>> @@ -371,6 +376,21 @@ void post_mobility_fixup(void)
>> /* Possibly switch to a new RFI flush type */
>> pseries_setup_rfi_flush();
>>
>> + /* need to force a gratuitous ARP on running interfaces */
>> + rtnl_lock();
>> + for_each_net(net) {
>> + for_each_netdev(net, netdev) {
>> + if (netif_device_present(netdev) &&
>> + netif_running(netdev) &&
>> + !(netdev->flags & (IFF_NOARP | IFF_LOOPBACK)))
>> + call_netdevice_notifiers(NETDEV_NOTIFY_PEERS,
>> + netdev);
>> + call_netdevice_notifiers(NETDEV_RESEND_IGMP,
>> + netdev);
>> + }
>> + }
>> + rtnl_unlock();
>> +
> This isn't an outright nak, but this is not nice. It illustrates the
> need to rethink the pseries partition migration code. There is no
> mechanism for drivers and other interested code to prepare for a
> migration or to adjust to the destination. So post_mobility_fixup() will
> continue to grow into a fragile collection of calls into unrelated
> subsystems until there is a better design -- either a pseries-specific
> notification/callback mechanism, or something based on the pm framework.
>
> My understanding is that this is needed specifically for ibmveth and,
> unlike ibmvnic, the platform does not provide any notification to that
> driver that a migration has occurred, right?
Correct, the ibmveth device, unlike ibmvnic, receives no signal or
notification at all in the event of a partition migration, so it can not
handle it or send a gratuitous ARP because from the driver's perspective
nothing has changed. As you've described, there is no existing notifier
in the kernel to inform interested parties that the system has migrated
or is about to migrate. Without adding the needed infrastructure to do
that, I'm not sure how else to fix this.
Tom
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [RFC PATCH] powerpc/pseries/mobility: notify network peers after migration
2019-11-06 0:06 [RFC PATCH] powerpc/pseries/mobility: notify network peers after migration Thomas Falcon
2019-11-06 4:13 ` Russell Currey
2019-11-06 22:14 ` Nathan Lynch
@ 2019-11-07 1:33 ` Michael Ellerman
2019-11-07 21:16 ` Thomas Falcon
2 siblings, 1 reply; 7+ messages in thread
From: Michael Ellerman @ 2019-11-07 1:33 UTC (permalink / raw)
To: Thomas Falcon, linuxppc-dev
Cc: nathanl, netdev, Thomas Falcon, msuchanek, tyreld
Hi Thomas,
Thomas Falcon <tlfalcon@linux.ibm.com> writes:
> After a migration, it is necessary to send a gratuitous ARP
> from all running interfaces so that the rest of the network
> is aware of its new location. However, some supported network
> devices are unaware that they have been migrated. To avoid network
> interruptions and other unwanted behavior, force a GARP on all
> valid, running interfaces as part of the post_mobility_fixup
> routine.
>
> Signed-off-by: Thomas Falcon <tlfalcon@linux.ibm.com>
> ---
> arch/powerpc/platforms/pseries/mobility.c | 20 ++++++++++++++++++++
> 1 file changed, 20 insertions(+)
This patch is in powerpc code, but it's doing networking stuff that I
don't really understand.
So I'd like an Ack from Dave or someone else in netdev land before I
merge it.
cheers
> diff --git a/arch/powerpc/platforms/pseries/mobility.c b/arch/powerpc/platforms/pseries/mobility.c
> index b571285f6c14..c1abc14cf2bb 100644
> --- a/arch/powerpc/platforms/pseries/mobility.c
> +++ b/arch/powerpc/platforms/pseries/mobility.c
> @@ -17,6 +17,9 @@
> #include <linux/delay.h>
> #include <linux/slab.h>
> #include <linux/stringify.h>
> +#include <linux/netdevice.h>
> +#include <linux/rtnetlink.h>
> +#include <net/net_namespace.h>
>
> #include <asm/machdep.h>
> #include <asm/rtas.h>
> @@ -331,6 +334,8 @@ void post_mobility_fixup(void)
> {
> int rc;
> int activate_fw_token;
> + struct net_device *netdev;
> + struct net *net;
>
> activate_fw_token = rtas_token("ibm,activate-firmware");
> if (activate_fw_token == RTAS_UNKNOWN_SERVICE) {
> @@ -371,6 +376,21 @@ void post_mobility_fixup(void)
> /* Possibly switch to a new RFI flush type */
> pseries_setup_rfi_flush();
>
> + /* need to force a gratuitous ARP on running interfaces */
> + rtnl_lock();
> + for_each_net(net) {
> + for_each_netdev(net, netdev) {
> + if (netif_device_present(netdev) &&
> + netif_running(netdev) &&
> + !(netdev->flags & (IFF_NOARP | IFF_LOOPBACK)))
> + call_netdevice_notifiers(NETDEV_NOTIFY_PEERS,
> + netdev);
> + call_netdevice_notifiers(NETDEV_RESEND_IGMP,
> + netdev);
> + }
> + }
> + rtnl_unlock();
> +
> return;
> }
>
> --
> 2.12.3
^ permalink raw reply [flat|nested] 7+ messages in thread* Re: [RFC PATCH] powerpc/pseries/mobility: notify network peers after migration
2019-11-07 1:33 ` Michael Ellerman
@ 2019-11-07 21:16 ` Thomas Falcon
0 siblings, 0 replies; 7+ messages in thread
From: Thomas Falcon @ 2019-11-07 21:16 UTC (permalink / raw)
To: Michael Ellerman, linuxppc-dev; +Cc: nathanl, netdev, msuchanek, tyreld
On 11/6/19 7:33 PM, Michael Ellerman wrote:
> Hi Thomas,
>
> Thomas Falcon <tlfalcon@linux.ibm.com> writes:
>> After a migration, it is necessary to send a gratuitous ARP
>> from all running interfaces so that the rest of the network
>> is aware of its new location. However, some supported network
>> devices are unaware that they have been migrated. To avoid network
>> interruptions and other unwanted behavior, force a GARP on all
>> valid, running interfaces as part of the post_mobility_fixup
>> routine.
>>
>> Signed-off-by: Thomas Falcon <tlfalcon@linux.ibm.com>
>> ---
>> arch/powerpc/platforms/pseries/mobility.c | 20 ++++++++++++++++++++
>> 1 file changed, 20 insertions(+)
> This patch is in powerpc code, but it's doing networking stuff that I
> don't really understand.
>
> So I'd like an Ack from Dave or someone else in netdev land before I
> merge it.
Thanks, I've already included netdev in the CC list. I'll wait and keep
an eye out for any comments from that side.
Tom
>
> cheers
>
>
>> diff --git a/arch/powerpc/platforms/pseries/mobility.c b/arch/powerpc/platforms/pseries/mobility.c
>> index b571285f6c14..c1abc14cf2bb 100644
>> --- a/arch/powerpc/platforms/pseries/mobility.c
>> +++ b/arch/powerpc/platforms/pseries/mobility.c
>> @@ -17,6 +17,9 @@
>> #include <linux/delay.h>
>> #include <linux/slab.h>
>> #include <linux/stringify.h>
>> +#include <linux/netdevice.h>
>> +#include <linux/rtnetlink.h>
>> +#include <net/net_namespace.h>
>>
>> #include <asm/machdep.h>
>> #include <asm/rtas.h>
>> @@ -331,6 +334,8 @@ void post_mobility_fixup(void)
>> {
>> int rc;
>> int activate_fw_token;
>> + struct net_device *netdev;
>> + struct net *net;
>>
>> activate_fw_token = rtas_token("ibm,activate-firmware");
>> if (activate_fw_token == RTAS_UNKNOWN_SERVICE) {
>> @@ -371,6 +376,21 @@ void post_mobility_fixup(void)
>> /* Possibly switch to a new RFI flush type */
>> pseries_setup_rfi_flush();
>>
>> + /* need to force a gratuitous ARP on running interfaces */
>> + rtnl_lock();
>> + for_each_net(net) {
>> + for_each_netdev(net, netdev) {
>> + if (netif_device_present(netdev) &&
>> + netif_running(netdev) &&
>> + !(netdev->flags & (IFF_NOARP | IFF_LOOPBACK)))
>> + call_netdevice_notifiers(NETDEV_NOTIFY_PEERS,
>> + netdev);
>> + call_netdevice_notifiers(NETDEV_RESEND_IGMP,
>> + netdev);
>> + }
>> + }
>> + rtnl_unlock();
>> +
>> return;
>> }
>>
>> --
>> 2.12.3
^ permalink raw reply [flat|nested] 7+ messages in thread