Re: [PATCH] VT-d: improve RMRR validity checking

[Weidong Han <weidong.han@intel.com>]

Alex Williamson wrote:
> On Wed, 2010-03-10 at 06:56 -0700, Alex Williamson wrote:
>   
>> On Wed, 2010-03-10 at 15:03 +0800, Weidong Han wrote:
>>     
>>> Can you post your Xen boot logs?
>>>       
>
> I'm not sure what you're looking for in a boot log, I think I've pretty
> well described the problem.  Here's the relevant output:
>
> (XEN) IOAPIC[0]: apic_id 8, version 32, address 0xfec00000, GSI 0-23
> (XEN) IOAPIC[1]: apic_id 0, version 32, address 0xfec08000, GSI 24-47
> (XEN) IOAPIC[2]: apic_id 10, version 32, address 0xfec10000, GSI 48-71
> (XEN) Enabling APIC mode:  Phys.  Using 3 I/O APICs
> (XEN) [VT-D]dmar.c:421:   Non-existent device (84:13.0) is reported in this DRHD's scope!
> (XEN) [VT-D]dmar.c:443:   The DRHD is invalid due to there are devices under its scope are not PCI discoverable! Pls try option iommu=force or iommu=workaround_bios_bug if you really want VT-d
> (XEN) Failed to parse ACPI DMAR.  Disabling VT-d.
>
> apic_id 10 is the one described under the non-INCLUDE_PCI_ALL DRHD,
> which is not materialized on the PCI bus.  The DMAR effectively breaks
> down to:
>
> DMAR
>  - INTR_REMAP set
>
> DRHD0
>  - INCLUDE_PCI_ALL set
>  - scope includes IOAPIC 8 & 0
>
> DRHD1
>  - INCLUDE_PCI_ALL *NOT* set
>  - scope includes various PCI sub-hierarchies *AND* IOAPIC 10
>
> DRHD0 and DRHD1 are on the same PCI segment (0x0) and are peers of one
> another, so it's not possible to set INCLUDE_PCI_ALL on both DRHDs, and
> it's incorrect to list IOAPIC 10 under DRHD0.
>
> Thanks,
>
> Alex
>
>   
Alex, you are right. IOAPICs can be included in any DRHDs. Pls try 
following patch, if no problem, I will submit it.

diff -r cadf1bae9ee2 xen/drivers/passthrough/vtd/dmar.c
--- a/xen/drivers/passthrough/vtd/dmar.c    Thu Feb 25 18:26:45 2010 +0800
+++ b/xen/drivers/passthrough/vtd/dmar.c    Thu Mar 11 17:49:40 2010 +0800
@@ -437,11 +437,9 @@ acpi_parse_one_drhd(struct acpi_dmar_ent
             else
             {
                 dprintk(XENLOG_WARNING VTDPREFIX,
-                    "  The DRHD is invalid due to there are devices under "
-                    "its scope are not PCI discoverable! Pls try option "
-                    "iommu=force or iommu=workaround_bios_bug if you "
-                    "really want VT-d\n");
-                ret = -EINVAL;
+                    "  There are devices under device scope are not PCI "
+                    "discoverable! if xen fails at VT-d enabling, pls try "
+                    "option iommu=workaround_bios_bug.\n");
             }
         }
         else