ACS override on X399 Threadripper platform

[Maor]

I wish to separate USB controller and intel network card into separate IOMMU groups. Unfortunatelly both are connected to chipset and in one IOMMU group.

My motherboard is aorus x399 pro with TR 1950x.

 

Here is the relevant part of IOMMU groupings:

IOMMU group 0:	[1022:1452] 00:01.0 Host bridge: Advanced Micro Devices, Inc. [AMD] Family 17h (Models 00h-1fh) PCIe Dummy Host Bridge
		[1022:1453] 00:01.1 PCI bridge: Advanced Micro Devices, Inc. [AMD] Family 17h (Models 00h-0fh) PCIe GPP Bridge
		[1022:1453] 00:01.2 PCI bridge: Advanced Micro Devices, Inc. [AMD] Family 17h (Models 00h-0fh) PCIe GPP Bridge
		[1022:1453] 00:01.3 PCI bridge: Advanced Micro Devices, Inc. [AMD] Family 17h (Models 00h-0fh) PCIe GPP Bridge
		[1022:43ba] 01:00.0 USB controller: Advanced Micro Devices, Inc. [AMD] X399 Series Chipset USB 3.1 xHCI Controller (rev 02)
		[1022:43b6] 01:00.1 SATA controller: Advanced Micro Devices, Inc. [AMD] X399 Series Chipset SATA Controller (rev 02)
		[1022:43b1] 01:00.2 PCI bridge: Advanced Micro Devices, Inc. [AMD] X399 Series Chipset PCIe Bridge (rev 02)
		[1022:43b4] 02:00.0 PCI bridge: Advanced Micro Devices, Inc. [AMD] 300 Series Chipset PCIe Port (rev 02)
		[1022:43b4] 02:01.0 PCI bridge: Advanced Micro Devices, Inc. [AMD] 300 Series Chipset PCIe Port (rev 02)
		[1022:43b4] 02:02.0 PCI bridge: Advanced Micro Devices, Inc. [AMD] 300 Series Chipset PCIe Port (rev 02)
		[1022:43b4] 02:03.0 PCI bridge: Advanced Micro Devices, Inc. [AMD] 300 Series Chipset PCIe Port (rev 02)
		[1022:43b4] 02:04.0 PCI bridge: Advanced Micro Devices, Inc. [AMD] 300 Series Chipset PCIe Port (rev 02)
		[8086:1539] 04:00.0 Ethernet controller: Intel Corporation I211 Gigabit Network Connection (rev 03)
		[144d:a808] 08:00.0 Non-Volatile memory controller: Samsung Electronics Co Ltd NVMe SSD Controller SM981/PM981/PM983
		[1912:0014] 09:00.0 USB controller: Renesas Technology Corp. uPD720201 USB 3.0 Host Controller (rev 03)
IOMMU group 1:	[1022:1452] 00:02.0 Host bridge: Advanced Micro Devices, Inc. [AMD] Family 17h (Models 00h-1fh) PCIe Dummy Host Bridge
IOMMU group 2:	[1022:1452] 00:03.0 Host bridge: Advanced Micro Devices, Inc. [AMD] Family 17h (Models 00h-1fh) PCIe Dummy Host Bridge

when I try to boot with

pcie_acs_override=id:1022:43b1

or change the id to id:8086:1539 or id:1022:1452

the grouping is every time the same.

 

I can get the intel network card separeted with the option (it separates everything)

pcie_acs_override=downstream,multifunction

but I wish not to use that.

 

Can you help me to break the chipset group or tell me what is the problem with threadripper or my motherboard, that it does not work?

 

[Vr2Io]

BIOS have ACS function under AMD CBS, you may try enable that.

Edited March 30, 2020 by Benson

[Maor]

that does the same thing as downstream, which does not separate the chipset group entirely. It separates the NVMe SSDs but not the intel network card and USB controller. Combining the bios ACS patch with id:1022:43b1 does nothing.

[testdasi]

9 hours ago, Maor said:

I can get the intel network card separeted with the option (it separates everything)

pcie_acs_override=downstream,multifunction

but I wish not to use that.

Why not?

There is no other way to split them out without multifunction.

 

If you worry about all those security concerns about ACS Override, don't.

Those concerns have zero implication on typical consumer uses.

[Maor]

I am concerned about other groups which have storage drives and memory violations can cause data corruption, which I wish to prevent. I guess I will try to do heavy testing to find out how reliable is to patch whole pcie tree.