[vfio-users] Unable to enable IOMMU

[Alex Williamson]

On Sat, 12 Nov 2016 07:17:02 +0300
Имя Фамилия <vgck at list.ru> wrote:

> Thank you for your quick response! However, I'm afraid I don't understand.
> I already updated the BIOS to 1201, the most recent version.
> I found this spreadsheet:  https://docs.google.com/spreadsheets/d/1LnGpTrXalwGVNy0PWJDURhyxa3sgqkGXmvNCIvIMenk/edit#gid=0  
> Someone already got it working with the exact same hardware I have.
> Are you saying my motherboard is defective?

I'm saying that without the motherboard firmware providing a DMAR
table, it is not possible for the OS to enable VT-d support.  I can't
guess whether your motherboard is defective, but it's a
motherboard/firmware issue preventing VT-d from being enabled.  Thanks,

Alex
 
> >Saturday, November 12, 2016 3:35 AM UTC from Alex Williamson <alex.williamson at redhat.com>:
> >
> >On Sat, 12 Nov 2016 06:18:08 +0300
> >Имя Фамилия < vgck at list.ru > wrote:
> >  
> >> I'm trying to get GPU passthrough to work, but haven't gotten very far. I'm losing my mind trying to figure out what could be the problem. I'm working with a 5820k and an ASUS X99-A II, both of which support IOMMU. I enabled VT-d in the UEFI settings and added intel_iommu=on to GRUB.
> >> 
> >> I restart, and when I cat /proc/cmdline I can see the option is there there but it had no effect. There's nothing under /sys/kernel/iommu_groups, there is no iommu_group folder under /sys/bus/pci/devices/MYBUS/, and when I grep dmesg I get a generic "DMAR: IOMMU enabled" messages and a warning that I don't have AMD IOMMUv2 functionality but that's it.
> >> 
> >> dmesg contents:  http://ptpb.pw/ZpcL
> >> 
> >> Any ideas what I'm missing?  
> >
> >Time to look for a BIOS update.  These are the ACPI tables provided by
> >your motherboard firmware:
> >
> >[    0.000000] ACPI: RSDP 0x00000000BB258000 000024 (v02 ALASKA)
> >[    0.000000] ACPI: XSDT 0x00000000BB258090 00009C (v01 ALASKA A M I    01072009 AMI  00010013)
> >[    0.000000] ACPI: FACP 0x00000000BB28E828 00010C (v05 ALASKA A M I    01072009 AMI  00010013)
> >[    0.000000] ACPI: DSDT 0x00000000BB2581C8 03665C (v02 ALASKA A M I    01072009 INTL 20091013)
> >[    0.000000] ACPI: FACS 0x00000000BD4A5F80 000040
> >[    0.000000] ACPI: APIC 0x00000000BB28E938 000100 (v03 ALASKA A M I    01072009 AMI  00010013)
> >[    0.000000] ACPI: FPDT 0x00000000BB28EA38 000044 (v01 ALASKA A M I    01072009 AMI  00010013)
> >[    0.000000] ACPI: FIDT 0x00000000BB28EA80 00009C (v01 ALASKA A M I    01072009 AMI  00010013)
> >[    0.000000] ACPI: MCFG 0x00000000BB28EB20 00003C (v01 ALASKA A M I    01072009 MSFT 00000097)
> >[    0.000000] ACPI: ASF! 0x00000000BB2A5400 0000A0 (v32 INTEL   HCG     00000001 TFSM 000F4240)
> >[    0.000000] ACPI: SSDT 0x00000000BB28EBB8 00036D (v01 SataRe SataTabl 00001000 INTL 20120913)
> >[    0.000000] ACPI: UEFI 0x00000000BB28EF28 000042 (v01 ALASKA A M I    01072009      00000000)
> >[    0.000000] ACPI: HPET 0x00000000BB28EF70 000038 (v01 ALASKA A M I    00000001 INTL 20091013)
> >[    0.000000] ACPI: MSCT 0x00000000BB28EFA8 000090 (v01 ALASKA A M I    00000001 INTL 20091013)
> >[    0.000000] ACPI: SLIT 0x00000000BB28F038 00002D (v01 ALASKA A M I    00000001 INTL 20091013)
> >[    0.000000] ACPI: SRAT 0x00000000BB28F068 001158 (v03 ALASKA A M I    00000001 INTL 20091013)
> >[    0.000000] ACPI: WDDT 0x00000000BB2901C0 000040 (v01 ALASKA A M I    00000000 INTL 20091013)
> >[    0.000000] ACPI: SSDT 0x00000000BB290200 0151C1 (v02 ALASKA PmMgt    00000001 INTL 20120913)
> >[    0.000000] ACPI: BGRT 0x00000000BB2A53C8 000038 (v01 ALASKA A M I    01072009 AMI  00010013)
> >
> >The problem is that there's no DMAR table.  DMAR describes the VT-d
> >configuration and is required to enable intel_iommu.  If you have a
> >VT-d setting in the BIOS enabled, you might try saving and exiting the
> >BIOS, then doing a cold power cycle to make it take effect.  Otherwise
> >look for a BIOS update, contact Asus, or return it.  Regarding the
> >"IOMMU enabled" line in dmesg:
> >
> >http://vfio.blogspot.com/2016/09/intel-iommu-enabled-it-doesnt-mean-what.html
> >
> >Good luck,
> >Alex  
>