-----Original Message-----
From: Dexuan Cui <decui@microsoft.com>
Sent: Wednesday, September 11, 2019 7:38 PM
To: KY Srinivasan <kys@microsoft.com>; Haiyang Zhang
[off-list ref]; Stephen Hemminger
[off-list ref]; sashal@kernel.org; davem@davemloft.net;
linux-hyperv@vger.kernel.org; netdev@vger.kernel.org; linux-
kernel@vger.kernel.org; Michael Kelley [off-list ref]
Cc: Dexuan Cui <decui@microsoft.com>
Subject: [PATCH][PATCH net-next] hv_netvsc: Add the support of hibernation

The existing netvsc_detach() and netvsc_attach() APIs make it easy to
implement the suspend/resume callbacks.

Signed-off-by: Dexuan Cui <decui@microsoft.com>
---

This patch is basically a pure Hyper-V specific change and it has a
build dependency on the commit 271b2224d42f ("Drivers: hv: vmbus:
Implement
suspend/resume for VSC drivers for hibernation"), which is on Sasha Levin's
Hyper-V tree's hyperv-next branch:
https://nam06.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgit.k
ernel.org%2Fpub%2Fscm%2Flinux%2Fkernel%2Fgit%2Fhyperv%2Flinux.git%2
Flog%2F%3Fh%3Dhyperv-
next&amp;data=02%7C01%7Chaiyangz%40microsoft.com%7C0b84e40c446
648cc35fb08d737110e28%7C72f988bf86f141af91ab2d7cd011db47%7C1%7
C0%7C637038418703112019&amp;sdata=qd7DGFCJZ%2BDTix0VGcCe1JucV
O97E0gILpVpcxlA6EE%3D&amp;reserved=0

I request this patch should go through Sasha's tree rather than the
net-next tree.

 drivers/net/hyperv/hyperv_net.h |  3 +++
 drivers/net/hyperv/netvsc_drv.c | 59
+++++++++++++++++++++++++++++++++++++++++
 2 files changed, 62 insertions(+)

diff --git a/drivers/net/hyperv/hyperv_net.h

b/drivers/net/hyperv/hyperv_net.h
index ecc9af0..b8763ee 100644

--- a/drivers/net/hyperv/hyperv_net.h
+++ b/drivers/net/hyperv/hyperv_net.h

@@ -952,6 +952,9 @@ struct net_device_context {
 	u32 vf_alloc;
 	/* Serial number of the VF to team with */
 	u32 vf_serial;
+
+	/* Used to temporarily save the config info across hibernation */
+	struct netvsc_device_info *saved_netvsc_dev_info;
 };

 /* Per channel data */

diff --git a/drivers/net/hyperv/netvsc_drv.c

b/drivers/net/hyperv/netvsc_drv.c
index afdcc56..f920959 100644

--- a/drivers/net/hyperv/netvsc_drv.c
+++ b/drivers/net/hyperv/netvsc_drv.c

@@ -2392,6 +2392,63 @@ static int netvsc_remove(struct hv_device *dev)
 	return 0;
 }

+static int netvsc_suspend(struct hv_device *dev)
+{
+	struct net_device_context *ndev_ctx;
+	struct net_device *vf_netdev, *net;
+	struct netvsc_device *nvdev;
+	int ret;
+
+	net = hv_get_drvdata(dev);
+
+	ndev_ctx = netdev_priv(net);
+	cancel_delayed_work_sync(&ndev_ctx->dwork);
+
+	rtnl_lock();
+
+	nvdev = rtnl_dereference(ndev_ctx->nvdev);
+	if (nvdev == NULL) {
+		ret = -ENODEV;
+		goto out;
+	}
+
+	cancel_work_sync(&nvdev->subchan_work);