On 30.05.2014 10:56, Daniel P. Berrange wrote:
On Thu, May 29, 2014 at 10:32:40AM +0200, Michal Privoznik wrote:Currently it is not possible to determine the speed of an interface and whether a link is actually detected from the API. Orchestrating platforms want to be able to determine when the link has failed and where multiple speeds may be available which one the interface is actually connected at. This commit introduces an extension to our interface XML (without implementation to interface driver backends): <interface type='ethernet' name='eth0'> <start mode='none'/> <mac address='aa:bb:cc:dd:ee:ff'/> <link speed='1000' state='up'/> <mtu size='1492'/> ... </interface> Where @speed is negotiated link speed in Mbits per second, and state is the current NIC state (can be one of the following: "unknown", "notpresent", "down", "lowerlayerdown","testing", "dormant", "up").This is fine for the the <interface> objects, but it is limited in usefulness for SRIOV use cases. The <interface> objects only exist for interfaces which are configured for the host. With SRIOV passthrough some of the interfaces we're interested in are not going to be configured - they're just bare devices waiting to be given to a guest.
I hear what you're saying, but unless a PCI device is given interface name I am afraid we can't do anything. For instance, if you have a NIC but detach it from the driver (echo ${PCI_ADDR} > /sys/bus/pci/drivers/<driver>/unbind), kernel still sees the PCI device (it's shown in lspci output for instance), but it's not configured anymore - kernel doesn't know device link state, hence it's not aware if NIC's link speed, etc. So tools like ethtool, ip, ifconfing won't show the device.
To deal with that, we need report all this info on the node device APIs which let us list all NICs, regardless of whether they are configured on the host or not.
Due the reasons written above I don't see much benefit in moving this to nodedev.
Michal -- libvir-list mailing list libvir-list@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/libvir-list