Kernel panic when passing through 2 identical PCI devices

["J. Roeleveld" <joost@xxxxxxxxxxxx>]

Hi all,

I have a domain to which I pass through 4 PCI devices:
2 NVMe drives
83:00.0   Samsung 980 NVMe
84:00.0   Samsung 980 NVMe

2 HBA Controllers
86:00.0   LSI SAS3008
87:00.0   LSI SAS3008

This works fine with Xen version 4.18.4_pre1.
However, when trying to update to 4.19, this fails.

Checking the output during boot, I think I found something. But my knowledge 
is insufficient to figure out what is causing what I am seeing and how to fix 
this.
 
>From the below (where I only focus on the 2 NVMe drives), it is similar to the 
succesfull boot up until it tries to "claiming resource 0000:84:00.0/0".
At which point sysfs fails because the entry for "84" is already present.

The SAS drives appear be dones correctly, but am unable to confirm this as the 
NVMEs are required for a succesful boot.

For completeness, I have attached the output for the failed boot, a normal 
succesfull boot (using 4.18.4_pre1) and my xl.conf (which might need 
adjusting)

=== (output for just the NVME devices) ===
pci_bus 0000:83: root bus resource [io  0x0000-0xffff]
pci_bus 0000:83: root bus resource [mem 0x00000000-0x3fffffffffff]
pci_bus 0000:83: root bus resource [bus 00-ff]
pci 0000:83:00.0: [144d:a809] type 00 class 0x010802 PCIe Endpoint
pci 0000:83:00.0: BAR 0 [mem 0xfbc00000-0xfbc03fff 64bit]
pcifront pci-0: claiming resource 0000:83:00.0/0
pcifront pci-0: Creating PCI Frontend Bus 0000:84
pcifront pci-0: PCI host bridge to bus 0000:84
pci_bus 0000:84: root bus resource [io  0x0000-0xffff]
pci_bus 0000:84: root bus resource [mem 0x00000000-0x3fffffffffff]
pci_bus 0000:84: busn_res: can not insert [bus 84-ff] under domain [bus 00-ff] 
(conflicts with (null) [bus 83-ff])
pci_bus 0000:84: root bus resource [bus 00-ff]
pci 0000:84:00.0: [144d:a809] type 00 class 0x010802 PCIe Endpoint
pci 0000:84:00.0: BAR 0 [mem 0xfbb00000-0xfbb03fff 64bit]
pcifront pci-0: claiming resource 0000:84:00.0/0
sysfs: cannot create duplicate filename '/devices/pci-0/
pci0000:84/0000:84:00.0/resource0'
CPU: 2 UID: 0 PID: 39 Comm: xenwatch Not tainted 6.12.21-gentoo-generic #1
Call Trace:
 <TASK>
 dump_stack_lvl+0x56/0x80
 sysfs_warn_dup+0x51/0x60
 sysfs_add_bin_file_mode_ns+0x8a/0xa0
 sysfs_create_bin_file+0x5e/0x80
 pci_create_attr+0xfc/0x140
 pci_create_resource_files+0x30/0x90
 pci_bus_add_device+0x26/0x80
 pci_bus_add_devices+0x27/0x60
 pcifront_rescan_root+0x18a/0x220
 pcifront_connect+0x117/0x170
 ? xenbus_read_driver_state+0x32/0x60
 ? xenbus_otherend_changed+0x49/0xa0
 ? __pfx_xenwatch_thread+0x10/0x10
 xenwatch_thread+0xf6/0x130
 ? __pfx_autoremove_wake_function+0x10/0x10
 kthread+0xea/0x100
 ? __pfx_kthread+0x10/0x10
 ret_from_fork+0x1f/0x40
 ? __pfx_kthread+0x10/0x10
 ret_from_fork_asm+0x1a/0x30
 </TASK>
===

Attachment: xl_config.txt
Description: Text document

Attachment: Boot_Succesfull.txt
Description: Text document

Attachment: Boot_Failed.txt
Description: Text document