Re: PCI passthrough = NMIs

[Sheng Yang <sheng@linux.intel.com>]

On Monday 13 October 2008 23:04:34 Zwane Mwaikambo wrote:
> On Mon, 13 Oct 2008, Muli Ben-Yehuda wrote:
> > On Sun, Oct 12, 2008 at 11:09:14PM -0700, Zwane Mwaikambo wrote:
> > > Hi,
> > > 	I've been trying to get a Linux guest working with PCI passthrough
> > > of an ethernet card using the vtd branches. The device detection works
> > > and the guest reports a link, however as soon as i try and ping the
> > > guest it receives an NMI (i'm guessing this is PCI DMA related).
> > > Interrupt delivery to the guest looks fine (count increases at a low
> > > rate) and isn't shared with anything else on the host.
> > >
> > > Thanks for any hints.
> >
> > Anything in the host dmesg? Are you using VT-d?
>
> Yep using VT-d on an intel Q35, i get the following in order;
>
> pci 0000:11:0a.0: PCI INT A -> GSI 20 (level, low) -> IRQ 20
> DMAR:[DMA Read] Request device [00:1e.0] fault addr 7841000
> DMAR:[fault reason 06] PTE Read access is not set
> Uhhuh. NMI received for unknown reason a1.
> You have some hardware problem, likely on the PCI bus.
> Dazed and confused, but trying to continue
> DMAR:[DMA Write] Request device [00:1e.0] fault addr 0
> DMAR:[fault reason 05] PTE Write access is not set
> DMAR:[DMA Write] Request device [00:1e.0] fault addr 0
> DMAR:[fault reason 05] PTE Write access is not set

Do you have VT-d enabled? Also reinstalled host kernel with KVM upstream(we 
modified host kernel to support VT-d in KVM)? Look like VT-d table is not set 
up... You can check what you got with "dmesg|grep DMAR".

--
regards
Yang, Sheng
>
> The DMAR write fault printouts continue as long as you ping the IP address
> of the network card so it appears to be receiving packets.
>
> 00:1e.0 is the PCI bridge;
>
> 00:00.0 Host bridge: Intel Corporation 82Q35 Express DRAM Controller (rev
> 02) 00:02.0 VGA compatible controller: Intel Corporation 82Q35 Express
> Integrated Graphics Controller (rev 02) 00:19.0 Ethernet controller: Intel
> Corporation 82566DM-2 Gigabit Network Connection (rev 02) 00:1a.0 USB
> Controller: Intel Corporation 82801I (ICH9 Family) USB UHCI Controller #4
> (rev 02) 00:1a.1 USB Controller: Intel Corporation 82801I (ICH9 Family) USB
> UHCI Controller #5 (rev 02) 00:1a.2 USB Controller: Intel Corporation
> 82801I (ICH9 Family) USB UHCI Controller #6 (rev 02) 00:1a.7 USB
> Controller: Intel Corporation 82801I (ICH9 Family) USB2 EHCI Controller #2
> (rev 02) 00:1b.0 Audio device: Intel Corporation 82801I (ICH9 Family) HD
> Audio Controller (rev 02) 00:1c.0 PCI bridge: Intel Corporation 82801I
> (ICH9 Family) PCI Express Port 1 (rev 02) 00:1c.4 PCI bridge: Intel
> Corporation 82801I (ICH9 Family) PCI Express Port 5 (rev 02) 00:1d.0 USB
> Controller: Intel Corporation 82801I (ICH9 Family) USB UHCI Controller #1
> (rev 02) 00:1d.1 USB Controller: Intel Corporation 82801I (ICH9 Family) USB
> UHCI Controller #2 (rev 02) 00:1d.2 USB Controller: Intel Corporation
> 82801I (ICH9 Family) USB UHCI Controller #3 (rev 02) 00:1d.7 USB
> Controller: Intel Corporation 82801I (ICH9 Family) USB2 EHCI Controller #1
> (rev 02) 00:1e.0 PCI bridge: Intel Corporation 82801 PCI Bridge (rev 92)
> 00:1f.0 ISA bridge: Intel Corporation 82801IO (ICH9DO) LPC Interface
> Controller (rev 02) 00:1f.2 SATA controller: Intel Corporation
> 82801IR/IO/IH (ICH9R/DO/DH) 6 port SATA AHCI Controller (rev 02) 00:1f.3
> SMBus: Intel Corporation 82801I (ICH9 Family) SMBus Controller (rev 02)
> 00:1f.6 Signal processing controller: Intel Corporation 82801I (ICH9
> Family) Thermal Subsystem (rev 02) 0d:00.0 Ethernet controller: Intel
> Corporation 82573L Gigabit Ethernet Controller 11:04.0 IDE interface:
> Integrated Technology Express, Inc. Unknown device 8213 11:09.0 Ethernet
> controller: Intel Corporation 82557/8/9/0/1 Ethernet Pro 100 (rev 10)
> 11:0a.0 Ethernet controller: Intel Corporation 82541PI Gigabit Ethernet
> Controller (rev 05) --
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