Hi all: I have a question about PCI which troubled me for a few weeks. I have a virtual machine with ubuntu 16.4.03 on KVM platform. There is a PCIe device(Xilinx PCIe IP) plugged in the host machine, and passthrough to guest via VFIO feature. On the ubuntu operation system, I am developing the pcie driver. When I use pci_alloc_irq_vectors() function to allocate 32 msi vectors, but return 1. The command `lspci -vvv` output shows MSI: Enable+ Count=1/32 Maskable+ 64bit+ there is a similar case https://stackoverflow.com/questions/49821599/multiple-msi-vectors-linux-pci-alloc-irq-vectors-return-one-while-the-devi. But not working for KVM virtual machine. I do not known why the function pci_alloc_irq_vectors() returns one ? Best regards.
