Roger Pau Monné wrote on 05/12/15 18:50:

El 12/05/15 a les 17.20, Ruslan Makhmatkhanov ha escrit:

we have machine with VT-d and EPT-capable CPU:
Intel(R) Xeon(R) CPU E5504 [1]

The system is FreeBSD 11.0-CURRENT r282694 installed from iso.

But dom0 fails to boot at this hardware with "iommu must be enabled for
PVH hardware domain" [2]. VT-d support is indeed not detected at kernel
level. Here is dmesg with VT-d enabled in BIOS [3] and dmesg with VT-d
disabled in BIOS [4]. It's look like there is no difference on both
outputs. Here is the proofpic of that the system is VT-d capable and the
support is enabled in BIOS [5]. Here is acpidump -t output [6]

My bet right now is be that Xen detects that your IOMMU contains erratas
and disables it. Can you add "iommu=debug,force" to your xen_cmdline and
try again?

Also, can you paste the contents of your /boot/loader.conf?


You are right:

[VT-D] Disabling IOMMU due to Intel 5500/5520/X58 Chipset errata #47, #53

and after that:

Panic on CPU 0:
Couldn't enable IOMMU and iommu=required/force

Reboot in five seconds.

But what this means practically? Some chipset bugs preventing us to use this feature. Can this circumvented somehow? Thanks.


T.O.S. Of Reality
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