Comment 528 for bug 1776563

I had "ivrs_ioapic[4]=00:14.0 ivrs_ioapic[5]=00:00.2" on 18.04.03LTS with BIOS v1.13 on A315-41-R909
Just flashed v1.15 and now it boots ok without any extra parameters
I share some info from /var/kernel.log

It is better to keep "ivrs_ioapic[4]=00:14.0 ivrs_ioapic[5]=00:00.2" for better performance (see below related Firmware Bug lines)?

If someone needs some more logs in order to improve the solution, just ask

Thanks in advance

In boot without extra parameters, and:

-New lines with "Firmware Bug"

Aug 16 17:13:20 enrique-Aspire-A315-41 kernel: [ 0.123596] AMD-Vi: [Firmware Bug]: : IOAPIC[4] not in IVRS table
Aug 16 17:13:20 enrique-Aspire-A315-41 kernel: [ 0.123598] AMD-Vi: [Firmware Bug]: : IOAPIC[5] not in IVRS table
Aug 16 17:13:20 enrique-Aspire-A315-41 kernel: [ 0.123599] AMD-Vi: [Firmware Bug]: : No southbridge IOAPIC found

-This line with "Firmware Bug" does not disappear, but it seems not critical (it was booting before and it boots now)

Aug 16 17:13:20 enrique-Aspire-A315-41 kernel: [ 0.179342] ACPI: [Firmware Bug]: BIOS _OSI(Linux) query ignored

-New line appears (it wasn't before) which shows something new about iommu

Aug 16 17:13:20 enrique-Aspire-A315-41 kernel: [ 1.314978] perf/amd_iommu: Detected AMD IOMMU #0 (2 banks, 4 counters/bank).