Re: [PATCH 00/11] VMBus channel interrupt reassignment

[Wei Liu]

On Mon, Apr 06, 2020 at 02:15:03AM +0200, Andrea Parri (Microsoft) wrote:
> Hi all,
> 
> This is a follow-up on the RFC submission [1].  The series introduces
> changes in the VMBus drivers to reassign the CPU that a VMbus channel
> will interrupt.  This feature can be used for load balancing or other
> purposes (e.g. CPU offlining).  The submission integrates feedback in
> the RFC to amend the handling of the 'array of channels' (patch #3).
> 
> Thanks,
>   Andrea
> 
> [1] https://lkml.kernel.org/r/20200325225505.23998-1-parri.andrea@xxxxxxxxx
> 
> Cc: "David S. Miller" <davem@xxxxxxxxxxxxx>
> Cc: Lorenzo Pieralisi <lorenzo.pieralisi@xxxxxxx>
> Cc: Andrew Murray <amurray@xxxxxxxxxxxxxxxxxxxx>
> Cc: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
> Cc: "James E.J. Bottomley" <jejb@xxxxxxxxxxxxx>
> Cc: "Martin K. Petersen" <martin.petersen@xxxxxxxxxx>
> 
> Andrea Parri (Microsoft) (11):
>   Drivers: hv: vmbus: Always handle the VMBus messages on CPU0
>   Drivers: hv: vmbus: Don't bind the offer&rescind works to a specific
>     CPU
>   Drivers: hv: vmbus: Replace the per-CPU channel lists with a global
>     array of channels
>   hv_netvsc: Disable NAPI before closing the VMBus channel
>   hv_utils: Always execute the fcopy and vss callbacks in a tasklet
>   Drivers: hv: vmbus: Use a spin lock for synchronizing channel
>     scheduling vs. channel removal
>   PCI: hv: Prepare hv_compose_msi_msg() for the
>     VMBus-channel-interrupt-to-vCPU reassignment functionality
>   Drivers: hv: vmbus: Remove the unused HV_LOCALIZED channel affinity
>     logic
>   Drivers: hv: vmbus: Synchronize init_vp_index() vs. CPU hotplug
>   Drivers: hv: vmbus: Introduce the CHANNELMSG_MODIFYCHANNEL message
>     type
>   scsi: storvsc: Re-init stor_chns when a channel interrupt is
>     re-assigned
> 

Applied to hyperv-next. Thanks.

This hunk in patch 10 doesn't apply cleanly because it conflicts with
Vitaly's patch.

diff --git a/drivers/hv/channel_mgmt.c b/drivers/hv/channel_mgmt.c
index 3785beead503d..1058c814ab06e 100644
--- a/drivers/hv/channel_mgmt.c
+++ b/drivers/hv/channel_mgmt.c
@@ -1377,7 +1377,7 @@ channel_message_table[CHANNELMSG_COUNT] = {
        { CHANNELMSG_19,                        0, NULL },
        { CHANNELMSG_20,                        0, NULL },
        { CHANNELMSG_TL_CONNECT_REQUEST,        0, NULL },
-       { CHANNELMSG_22,                        0, NULL },
+       { CHANNELMSG_MODIFYCHANNEL,             0, NULL },
        { CHANNELMSG_TL_CONNECT_RESULT,         0, NULL },
 };

I have fixed it up. New hunk looks like:

diff --git a/drivers/hv/channel_mgmt.c b/drivers/hv/channel_mgmt.c
index a6b21838e2de..9c62eb5e4135 100644
--- a/drivers/hv/channel_mgmt.c
+++ b/drivers/hv/channel_mgmt.c
@@ -1380,7 +1380,7 @@ channel_message_table[CHANNELMSG_COUNT] = {
        { CHANNELMSG_19,                        0, NULL, 0},
        { CHANNELMSG_20,                        0, NULL, 0},
        { CHANNELMSG_TL_CONNECT_REQUEST,        0, NULL, 0},
-       { CHANNELMSG_22,                        0, NULL, 0},
+       { CHANNELMSG_MODIFYCHANNEL,             0, NULL, 0},
        { CHANNELMSG_TL_CONNECT_RESULT,         0, NULL, 0},
 };

Let me know if I messed it up.

Wei.