[Bug 224003] xen kernel panics

[Rodney W. Grimes]

> On 03/31/18 18:11, Chris wrote:
> > On 03/30/18 18:05, Rodney W. Grimes wrote:
> >
> >> I can affirm that a E56xx cpu should be very capable of supporting Xen.
> >> CPU: Intel(R) Xeon(R) CPU X5675 @ 3.07GHz (3059.07-MHz K8-class CPU)
> >> Origin="GenuineIntel" Id=0x206c2 Family=0x6 Model=0x2c Stepping=2
> >> Features=0xbfebfbff<FPU,VME,DE,PSE,TSC,MSR,PAE,MCE,CX8,APIC,SEP,MTRR,PGE,MCA,CMOV,PAT,PSE36,CLFLUSH,DTS,ACPI,MMX,FXSR,SSE,SSE2,SS,HTT,TM,PBE>
> >>
> >> Features2=0x29ee3ff<SSE3,PCLMULQDQ,DTES64,MON,DS_CPL,VMX,SMX,EST,TM2,SSSE3,CX16,xTPR,PDCM,PCID,DCA,SSE4.1,SSE4.2,POPCNT,AESNI>
> >>
> >> AMD Features=0x2c100800<SYSCALL,NX,Page1GB,RDTSCP,LM>
> >> AMD Features2=0x1<LAHF>
> >> VT-x: PAT,HLT,MTF,PAUSE,EPT,UG,VPID
> >> TSC: P-state invariant, performance statistics
> >>
> 
> Looks like this might be the problem:-
> 
> > (XEN) [VT-D]Disabling IOMMU due to Intel 5500/5520/X58 Chipset errata
> > #47, #53
> 
> Been in a rush today, but should have looked at that a bit more closely
> before posting, as istr, saw that  mentioned as a bug eleswhere back
> from 2015 or so....

https://support.citrix.com/article/CTX136517

That has some info on how to work around this issue.  You can turn
of the interrupt remapping and still have an iommu, though it is
not going be very effective for passthrough of devices.

Its linux centric, and I am not quiet sure how to apply those
knobs to loader.conf to make xen do the right thing, but it
should be possible.


-- 
Rod Grimes                                                 rgrimes at freebsd.org