On 07/06/2024 8:46 pm, Marek Marczykowski-Górecki wrote: > Hi, > > I've got a new system, and it has two PCI segments: > > 0000:00:00.0 Host bridge: Intel Corporation Device 7d14 (rev 04) > 0000:00:02.0 VGA compatible controller: Intel Corporation Meteor Lake-P > [Intel Graphics] (rev 08) > ... > 10000:e0:06.0 System peripheral: Intel Corporation RST VMD Managed > Controller > 10000:e0:06.2 PCI bridge: Intel Corporation Device 7ecb (rev 10) > 10000:e1:00.0 Non-Volatile memory controller: Phison Electronics > Corporation PS5021-E21 PCIe4 NVMe Controller (DRAM-less) (rev 01) > > But looks like Xen doesn't handle it correctly: > > (XEN) 0000:e0:06.0: unknown type 0 > (XEN) 0000:e0:06.2: unknown type 0 > (XEN) 0000:e1:00.0: unknown type 0 > ... > (XEN) ==== PCI devices ==== > (XEN) ==== segment 0000 ==== > (XEN) 0000:e1:00.0 - NULL - node -1 > (XEN) 0000:e0:06.2 - NULL - node -1 > (XEN) 0000:e0:06.0 - NULL - node -1 > (XEN) 0000:2b:00.0 - d0 - node -1 - MSIs < 161 > > (XEN) 0000:00:1f.6 - d0 - node -1 - MSIs < 148 > > ... > > This isn't exactly surprising, since pci_sbdf_t.seg is uint16_t, so > 0x10000 doesn't fit. OSDev wiki says PCI Express can have 65536 PCI > Segment Groups, each with 256 bus segments. > > Fortunately, I don't need this to work, if I disable VMD in the > firmware, I get a single segment and everything works fine. >
This is a known issue. Works is being done, albeit slowly. 0x10000 is indeed not a spec-compliant PCI segment. It's something model specific the Linux VMD driver is doing. ~Andrew
