Re: [PATCH V3 08/11] PCI: hv: VMBus and PCI device IDs for PCI passthru

From: Bjorn Helgaas

Date: Tue May 12 2026 - 13:42:05 EST


On Mon, May 11, 2026 at 07:02:56PM -0700, Mukesh R wrote:
> On Hyper-V, most hypercalls related to PCI passthru to map/unmap regions,
> interrupts, etc need a device ID as a parameter. This device ID refers
> to that specific device during the lifetime of passthru.
>
> An L1VH VM only contains VMBus based devices. A device ID for a VMBus
> device is slightly different in that it uses the hv_pcibus_device info
> for building it to make sure it matches exactly what the hypervisor
> expects. This VMBus based device ID is needed when attaching devices in
> an L1VH based guest VM. Add a function to build and export it. Before
> building it, a check is done to make sure the device is a valid VMBus
> device.
>
> In remaining cases, PCI device ID is used. So, also make PCI device ID
> build function hv_build_devid_type_pci() public.

The subject line should start with a verb to help say what this patch
does. I guess it's something about adding a function to build the
device IDs expected by the hypervisor? Would be good to include the
function name too, e.g., something like this:

PCI: hv: Add foo() to build hypervisor device IDs