On Thu, Oct 15, 2026 at 02:41:55PM +0100, David Vrabel wrote: > > ping? > On 28/09/2026 16:24, David Vrabel wrote: > > When a VM has been assigned a number of PCIe devices behind a common > > PCIe switch and the VM intends to use peer-to-peer (P2P) transfers > > between the devices, it is useful to be able to more report the > > apparent PCIe bandwidth so it reflects the real handwidth of the > > underlying hardware. This allows software in the VM (such as NCCL[1]) > > to make better decisions about whether to use P2P or not. > > > > The existing emulated PCIe switch is a vintage TI XIO3130 and only > > support 2.5 GT/s and x1, so we introduces new generic upstream and > > downstream port devices (pcie-upstream-port and pcie-downstream-port), > > inspired by the existing generic pcie-root-port device. > > > > The existing experimental "x-speed" and "x-width" options are made > > non-experimental, allowing the pcie-root-port and pcie-downstream-port > > capabilities to be configured to match the hardware. > > > > The pcie-root-port device is updated to default to a Gen6 capable > > device. > > > > Finally, where a root or upstream port's bandwidth has been limited, > > we also ensure the other end of the link reports the same link status.
will merge, thanks!
