On Wed, Dec 10, 2025 at 03:39:45PM -0600, Bjorn Helgaas wrote: > On Tue, Dec 09, 2025 at 01:11:24PM +0800, Yu Zhang wrote: > > From: Easwar Hariharan <[email protected]> > > > > Hyper-V uses a logical device ID to identify a PCI endpoint device for > > child partitions. This ID will also be required for future hypercalls > > used by the Hyper-V IOMMU driver. > > > > Refactor the logic for building this logical device ID into a standalone > > helper function and export the interface for wider use. > > > > Signed-off-by: Easwar Hariharan <[email protected]> > > Signed-off-by: Yu Zhang <[email protected]> > > Acked-by: Bjorn Helgaas <[email protected]> > > > --- > > drivers/pci/controller/pci-hyperv.c | 28 ++++++++++++++++++++-------- > > include/asm-generic/mshyperv.h | 2 ++ > > 2 files changed, 22 insertions(+), 8 deletions(-) > > > > diff --git a/drivers/pci/controller/pci-hyperv.c > > b/drivers/pci/controller/pci-hyperv.c > > index 146b43981b27..4b82e06b5d93 100644 > > --- a/drivers/pci/controller/pci-hyperv.c > > +++ b/drivers/pci/controller/pci-hyperv.c > > @@ -598,15 +598,31 @@ static unsigned int hv_msi_get_int_vector(struct > > irq_data *data) > > > > #define hv_msi_prepare pci_msi_prepare > > > > +/** > > + * Build a "Device Logical ID" out of this PCI bus's instance GUID and the > > + * function number of the device. > > + */ > > +u64 hv_build_logical_dev_id(struct pci_dev *pdev) > > +{ > > + struct pci_bus *pbus = pdev->bus; > > + struct hv_pcibus_device *hbus = container_of(pbus->sysdata, > > + struct hv_pcibus_device, > > sysdata); > > + > > + return (u64)((hbus->hdev->dev_instance.b[5] << 24) | > > + (hbus->hdev->dev_instance.b[4] << 16) | > > + (hbus->hdev->dev_instance.b[7] << 8) | > > + (hbus->hdev->dev_instance.b[6] & 0xf8) | > > + PCI_FUNC(pdev->devfn)); > > +} > > +EXPORT_SYMBOL_GPL(hv_build_logical_dev_id); > > + > > /** > > * hv_irq_retarget_interrupt() - "Unmask" the IRQ by setting its current > > * affinity. > > * @data: Describes the IRQ > > * > > * Build new a destination for the MSI and make a hypercall to > > - * update the Interrupt Redirection Table. "Device Logical ID" > > - * is built out of this PCI bus's instance GUID and the function > > - * number of the device. > > + * update the Interrupt Redirection Table. > > */ > > static void hv_irq_retarget_interrupt(struct irq_data *data) > > { > > @@ -642,11 +658,7 @@ static void hv_irq_retarget_interrupt(struct irq_data > > *data) > > params->int_entry.source = HV_INTERRUPT_SOURCE_MSI; > > params->int_entry.msi_entry.address.as_uint32 = int_desc->address & > > 0xffffffff; > > params->int_entry.msi_entry.data.as_uint32 = int_desc->data; > > - params->device_id = (hbus->hdev->dev_instance.b[5] << 24) | > > - (hbus->hdev->dev_instance.b[4] << 16) | > > - (hbus->hdev->dev_instance.b[7] << 8) | > > - (hbus->hdev->dev_instance.b[6] & 0xf8) | > > - PCI_FUNC(pdev->devfn); > > + params->device_id = hv_build_logical_dev_id(pdev); > > params->int_target.vector = hv_msi_get_int_vector(data); > > > > if (hbus->protocol_version >= PCI_PROTOCOL_VERSION_1_2) { > > diff --git a/include/asm-generic/mshyperv.h b/include/asm-generic/mshyperv.h > > index 64ba6bc807d9..1a205ed69435 100644 > > --- a/include/asm-generic/mshyperv.h > > +++ b/include/asm-generic/mshyperv.h > > @@ -71,6 +71,8 @@ extern enum hv_partition_type hv_curr_partition_type; > > extern void * __percpu *hyperv_pcpu_input_arg; > > extern void * __percpu *hyperv_pcpu_output_arg; > > > > +extern u64 hv_build_logical_dev_id(struct pci_dev *pdev); > > Curious why you would include the "extern" in this declaration? It's > not *wrong*, but it's not necessary, and other declarations in this > file omit it, e.g., the ones below: >
Thank you, Bjorn. Actually I don't think it is necessary. Will remove it in v2. :) B.R. Yu
