On Wed, 2018-01-31 at 15:01 -0800, Stephen Hemminger wrote:
> On Wed, 31 Jan 2018 12:16:49 +0100
> Mohammed Gamal <mga...@redhat.com> wrote:
>
> > On Tue, 2018-01-30 at 11:29 -0800, Stephen Hemminger wrote:
> > > On Tue, 23 Jan 2018 10:34:04 +0100
> > > Mohammed Gamal <mga...@redhat.com> wrote:
> > >
> > > > Split each of the functions into two for each of send/recv
> > > > buffers
> > > >
> > > > Signed-off-by: Mohammed Gamal <mga...@redhat.com>
> > >
> > > Splitting these functions is not necessary
> >
> > How so? We need to send each message independently, and hence the
> > split
> > (see cover letter). Is there another way?
>
> This is all that is needed.
>
>
> Subject: [PATCH] hv_netvsc: work around for gpadl teardown on older
> windows
> server
>
> On WS2012 the host ignores messages after vmbus channel is closed.
> Workaround this by doing what Windows does and send the teardown
> before close on older versions of NVSP protocol.
>
> Reported-by: Mohammed Gamal <mga...@redhat.com>
> Fixes: 0cf737808ae7 ("hv_netvsc: netvsc_teardown_gpadl() split")
> Signed-off-by: Stephen Hemminger <sthem...@microsoft.com>
> ---
> drivers/net/hyperv/netvsc.c | 9 ++++++++-
> 1 file changed, 8 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/net/hyperv/netvsc.c
> b/drivers/net/hyperv/netvsc.c
> index 17e529af79dc..1a3df0eff42f 100644
> --- a/drivers/net/hyperv/netvsc.c
> +++ b/drivers/net/hyperv/netvsc.c
> @@ -574,10 +574,17 @@ void netvsc_device_remove(struct hv_device
> *device)
> */
> netdev_dbg(ndev, "net device safe to remove\n");
>
> + /* Workaround for older versions of Windows require that
> + * buffer be revoked before channel is disabled
> + */
> + if (net_device->nvsp_version < NVSP_PROTOCOL_VERSION_4)
> + netvsc_teardown_gpadl(device, net_device);
> +
> /* Now, we can close the channel safely */
> vmbus_close(device->channel);
>
> - netvsc_teardown_gpadl(device, net_device);
> + if (net_device->nvsp_version >= NVSP_PROTOCOL_VERSION_4)
> + netvsc_teardown_gpadl(device, net_device);
>
> /* And dissassociate NAPI context from device */
> for (i = 0; i < net_device->num_chn; i++)
I've tried a similar workaround before by calling
netvsc_teardown_gpadl() after netvsc_revoke_buf(), but before setting
net_device_ctx->nvdev to NULL and it caused the guest to hang when
trying to change MTU.
Let me try that change and see if it behaves differently.
