On 2019-07-29 10:15 a.m., Sagi Grimberg wrote: > >>> This is different from multipath on say a multi-controller PCI device >>> and trying to expose both those controllers through passthru. this is >>> where the problems we are discussing come up. >> >> I *think* there is some confusion. I *think* Sagi is talking about network multi-path (i.e. the ability for the host to connect to a controller on the target via two different network paths that fail-over as needed). I *think* Logan is talking about multi-port PCIe NVMe devices that allow namespaces to be accessed via more than one controller over PCIe (dual-port NVMe SSDs being the most obvious example of this today). > > Yes, I was referring to fabrics multipathing which is somewhat > orthogonal to the backend pci multipathing (unless I'm missing > something). Yes, so if we focus on the fabrics multipathing, the only issue I see is that only one controller can be connected to a passthru target (I believe this was at your request) so two paths simply cannot exist to begin with. I can easily remove that restriction. Logan