Date: Thu, 9 Apr 2015 11:21:28 +0300 From: Konstantin Belousov <kostikbel@gmail.com> To: Gustau P??rez <gperez@entel.upc.edu> Cc: freebsd-current@freebsd.org Subject: Re: No IOMMU/DMAR with DELL 3020 Message-ID: <20150409082128.GF2390@kib.kiev.ua> In-Reply-To: <552635A5.5070707@entel.upc.edu> References: <552635A5.5070707@entel.upc.edu>
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On Thu, Apr 09, 2015 at 10:17:41AM +0200, Gustau P??rez wrote: > > Hi, > > I'm trying xen dom0 on a DELL optiplex 3020 machine. The machine runs: > > root@xen_test:~ # uname -arn > FreeBSD xen_test 11.0-CURRENT FreeBSD 11.0-CURRENT #0 r281184: > > The box has a core i5-4590 equipped with VT-d: > > root@xen_test:~ # dmesg|grep EPT > VT-x: PAT,HLT,MTF,PAUSE,EPT,UG,VPID > Secondary Processor > Controls=0x7cff<APIC,EPT,DT,RDTSCP,x2APIC,VPID,WBINVD,UG,PAUSE-loop,RDRAND,INVPCID,VMFUNC,VMCS> > EPT Features=0x6334141<XO,PW4,UC,WB,2M,1G,INVEPT,AD,single,all> > This is VT-x, not VT-d. > Also the box has the last BIOS firmware from its vendor (DELL). > > However, even if VT-d is there, iommu is not enabled. Booting in > verbose mode shows me this: > > root@xen_test:~ # dmesg|grep DMAR > ACPI: No DMAR table found > > which is the reason iommu support isn't enabled. This means that VT-d is 'not there'. > > Shouldn't be DMAR be detected if VT-d is there? Any info I can > provide, let me know. Check BIOS settings, there could be a knob which enables VT-d. If there is no knob, you are out of lack. OS or Xen requires DMAR table filled by BIOS to detect and use VT-d hardware.
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