Re: ACPI-Tables corrupted?

[Juergen Gross <juergen.gross@ts.fujitsu.com>]

On 07/29/2010 09:37 AM, Jiang, Yunhong wrote:
> Sorry that I didn't notice it is for crash kernel. In fact, I tried kexec before and never succed to bring it up.
>
> What do you mean of "stab at disabling x2apic"? You mean we need disable x2apic before transfer control to crash kernel, right?
>
> Per my understanding, with kexec, when system crash, it will jump directly to new kernel's entry point, no guest destroy (i.e. clean-up), not reset signal to cpu/chipset, right?
> If yes, another issue need be considered is VT-d. I didn't find the vt-d disable code in xen's kexec_crash code, if the new kernel has no idea of vt-d (thus does not reset the vt-d engine), it may have trouble. Or, will the kexec kernel not use device assigned to guest?
>
> Of course it is ok if crash kernel support vt-d too.

Seems to be the case here.
A patched crash kernel which just took the zapped DMAR entry as a valid one
succeeded in writing a vmcore.

Juergen

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Juergen Gross                 Principal Developer Operating Systems
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