From 9711cd0dfc3fa414f7f64935713c07134ae67971 Mon Sep 17 00:00:00 2001 From: Jens Freimann Date: Tue, 29 Oct 2019 12:49:04 +0100 Subject: net/virtio: add failover support This patch adds support to handle failover device pairs of a virtio-net device and a (vfio-)pci device, where the virtio-net acts as the standby device and the (vfio-)pci device as the primary. The general idea is that we have a pair of devices, a (vfio-)pci and a emulated (virtio-net) device. Before migration the vfio device is unplugged and data flows to the emulated device, on the target side another (vfio-)pci device is plugged in to take over the data-path. In the guest the net_failover module will pair net devices with the same MAC address. To achieve this we need: 1. Provide a callback function for the should_be_hidden DeviceListener. It is called when the primary device is plugged in. Evaluate the QOpt passed in to check if it is the matching primary device. It returns if the device should be hidden or not. When it should be hidden it stores the device options in the VirtioNet struct and the device is added once the VIRTIO_NET_F_STANDBY feature is negotiated during virtio feature negotiation. If the virtio-net devices are not realized at the time the (vfio-)pci devices are realized, we need to connect the devices later. This way we make sure primary and standby devices can be specified in any order. 2. Register a callback for migration status notifier. When called it will unplug its primary device before the migration happens. 3. Register a callback for the migration code that checks if a device needs to be unplugged from the guest. Signed-off-by: Jens Freimann Message-Id: <20191029114905.6856-11-jfreimann@redhat.com> Reviewed-by: Michael S. Tsirkin Signed-off-by: Michael S. Tsirkin --- MAINTAINERS | 1 + 1 file changed, 1 insertion(+) (limited to 'MAINTAINERS') diff --git a/MAINTAINERS b/MAINTAINERS index 325e67a04e..c958fc71ea 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -1435,6 +1435,7 @@ S: Odd Fixes F: hw/net/ F: include/hw/net/ F: tests/virtio-net-test.c +F: docs/virtio-net-failover.rst T: git https://github.com/jasowang/qemu.git net Parallel NOR Flash devices -- cgit v1.2.3