cxgb4vf: Quiesce Virtual Interfaces on shutdown ...

When a Virtual Machine is rebooted, KVM currently fails to issue a Function
Level Reset against any "Attached PCI Devices" (AKA "PCI Passthrough").  In
addition to leaving the attached device in a random state in the next booted
kernel (which sort of violates the entire idea of a reboot reseting hardware
state), this leaves our peer thinking that the link is still up.  (Note that
a bug has been filed with the KVM folks, #25332, but there's been no
response on that as of yet.)  So, we add a "->shutdown()" method for the
Virtual Function PCI Device to handle administrative shutdowns like a
reboot.

Signed-off-by: Casey Leedom <leedom@chelsio.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 41 insertions, 0 deletions

diff --git a/drivers/net/cxgb4vf/cxgb4vf_main.c b/drivers/net/cxgb4vf/cxgb4vf_main.c
index 2be1088ff601..6aad64df4dcb 100644
--- a/drivers/net/cxgb4vf/cxgb4vf_main.c
+++ b/drivers/net/cxgb4vf/cxgb4vf_main.c
@@ -2862,6 +2862,46 @@ static void __devexit cxgb4vf_pci_remove(struct pci_dev *pdev)
 }
 
 /*
+ * "Shutdown" quiesce the device, stopping Ingress Packet and Interrupt
+ * delivery.
+ */
+static void __devexit cxgb4vf_pci_shutdown(struct pci_dev *pdev)
+{
+        struct adapter *adapter;
+        int pidx;
+
+        adapter = pci_get_drvdata(pdev);
+        if (!adapter)
+                return;
+
+        /*
+         * Disable all Virtual Interfaces.  This will shut down the
+         * delivery of all ingress packets into the chip for these
+         * Virtual Interfaces.
+         */
+        for_each_port(adapter, pidx) {
+                struct net_device *netdev;
+                struct port_info *pi;
+
+                if (!test_bit(pidx, &adapter->registered_device_map))
+                        continue;
+
+                netdev = adapter->port[pidx];
+                if (!netdev)
+                        continue;
+
+                pi = netdev_priv(netdev);
+                t4vf_enable_vi(adapter, pi->viid, false, false);
+        }
+
+        /*
+         * Free up all Queues which will prevent further DMA and
+         * Interrupts allowing various internal pathways to drain.
+         */
+        t4vf_free_sge_resources(adapter);
+}
+
+/*
  * PCI Device registration data structures.
  */
 #define CH_DEVICE(devid, idx) \
@@ -2894,6 +2934,7 @@ static struct pci_driver cxgb4vf_driver = {
         .id_table       = cxgb4vf_pci_tbl,
         .probe          = cxgb4vf_pci_probe,
         .remove         = __devexit_p(cxgb4vf_pci_remove),
+        .shutdown       = __devexit_p(cxgb4vf_pci_shutdown),
 };
 
 /*