Dear Jörg, On 07/20/18 14:31, Jörg Rödel wrote: > On Tue, Jul 17, 2018 at 06:02:07PM +0200, Paul Menzel wrote: >> $ dmesg >> […] >> [ 0.145696] calling pci_iommu_init+0x0/0x3f @ 1 >> [ 0.145719] AMD-Vi: Unable to write to IOMMU perf counter. > > This is likely a firmware issue. Either the IVRS ACPI table is incorrect Please find the output from sudo iasl -d -p /dev/shm/ivrs.dsl /sys/firmware/acpi/tables/IVRS attached. [ 0.000000] ACPI: IVRS 0x000000009D3D8588 0000D0 (v02 AMD AMD IVRS 00000001 AMD 00000000) > or the BIOS did not enable the performance counter feature in the IOMMU > hardware. Is it possible to check that from the OS side? > Are you running on the latest BIOS? Yes, I am even using a “beta“ one from [1]. DMI: MSI MS-7A37/B350M MORTAR (MS-7A37), BIOS 1.G1 05/17/2018 Kind regards, Paul [1]: http://msi-ftp.de:8080/main.html?download&weblink=99df4e98c25ca3dcf0f6e7f8366cc1c7&realfilename=7A37_1g1.zip