Match historical subject line style for prefix and capitalization: PCI: vmd: Set devices to D0 before enabling PM L1 Substates PCI: vmd: Add DID 8086:B06F and 8086:B60B for Intel client SKUs PCI: vmd: Fix indentation issue in vmd_shutdown() On Fri, Jan 10, 2025 at 03:01:49PM +0100, Roger Pau Monne wrote: > MSI remapping bypass (directly configuring MSI entries for devices on the VMD > bus) won't work under Xen, as Xen is not aware of devices in such bus, and > hence cannot configure the entries using the pIRQ interface in the PV case, and > in the PVH case traps won't be setup for MSI entries for such devices. > > Until Xen is aware of devices in the VMD bus prevent the > VMD_FEAT_CAN_BYPASS_MSI_REMAP capability from being used when running as any > kind of Xen guest. Wrap to fit in 75 columns. Can you include a hint about *why* Xen is not aware of devices below VMD? That will help to know whether it's a permanent unfixable situation or something that could be done eventually. > Signed-off-by: Roger Pau Monné <roger.pau@xxxxxxxxxx> > --- > drivers/pci/controller/vmd.c | 9 +++++++++ > 1 file changed, 9 insertions(+) > > diff --git a/drivers/pci/controller/vmd.c b/drivers/pci/controller/vmd.c > index 264a180403a0..d9b7510ace29 100644 > --- a/drivers/pci/controller/vmd.c > +++ b/drivers/pci/controller/vmd.c > @@ -965,6 +965,15 @@ static int vmd_probe(struct pci_dev *dev, const struct pci_device_id *id) > struct vmd_dev *vmd; > int err; > > + if (xen_domain()) > + /* > + * Xen doesn't have knowledge about devices in the VMD bus. Also here. > + * Bypass of MSI remapping won't work in that case as direct > + * write to the MSI entries won't result in functional > + * interrupts. > + */ > + features &= ~VMD_FEAT_CAN_BYPASS_MSI_REMAP; > + > if (resource_size(&dev->resource[VMD_CFGBAR]) < (1 << 20)) > return -ENOMEM; > > -- > 2.46.0 >
