Re: [Xen-devel] Panic when starting DomU with passthrough

[Espen Skoglund <espen.skoglund@xxxxxxxxxxxxx>]

I presume that 00:02.0 is the graphics card you mentioned in your
earlier mail?  Could you do an lspci on the device in question ('lspci
-vv -s 0:2.0').  Is the dumU a PV or a HVM guest?  If it is a PV
guest, is iommu=pv enabled or not?

Looks like the device is trying to write to 'fffff000' which seems
like a bit of an odd address to be accessing.

Anyhow, even if the accesses of the device seem a bit mad it still
should not be able to access random xen internal memory.  I can't see
any good reason why the assertion should be triggered.  Could you
perhaps apply the patch below to give us some more clue as to what is
happening?

Keir, could this assertion possibly be related to the recent IRQ
acktype changes?

     eSk



--
diff -r 02a8093f6bfd xen/arch/x86/irq.c
--- a/xen/arch/x86/irq.c        Thu Feb 19 11:34:10 2009 +0000
+++ b/xen/arch/x86/irq.c        Thu Feb 19 12:17:55 2009 +0000
@@ -319,6 +319,9 @@ static void __do_IRQ_guest(int vector)
     if ( action->ack_type == ACKTYPE_EOI )
     {
         sp = pending_eoi_sp(peoi);
+        if ( !((sp == 0) || (peoi[sp-1].vector < vector)) )
+            printk("sp = %d, peoi[sp-1].vector = %d, vector = %d\n",
+                   sp, peoi[sp-1].vector, vector);
         ASSERT((sp == 0) || (peoi[sp-1].vector < vector));
         ASSERT(sp < (NR_VECTORS-1));
         peoi[sp].vector = vector;


[Alexia Benington]
> Hi all,
> I'm getting panic errors when doing passthrough. The attached log
> occurs when I start DomU with passthrough on 00:02.0. Anybody else
> getting this?


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