linux-kernel - Re: [PATCH RFC v8 00/56] Add AMD Secure Nested Paging (SEV-SNP) Hypervisor Support

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Message-ID: <f4905c32f4054d4ce254b3acb9339aa1c59728b8.camel@amazon.de>
Date:   Thu, 3 Aug 2023 18:27:56 +0000
From:   "Schander, Johanna 'Mimoja' Amelie" <mimoja@...zon.de>
To:     "Graf (AWS), Alexander" <graf@...zon.de>,
        "michael.roth@....com" <michael.roth@....com>,
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Subject: Re: [PATCH RFC v8 00/56] Add AMD Secure Nested Paging (SEV-SNP)
 Hypervisor Support

We discovered that the kdump crashkernel would not work with our SEV-
SNP configuration.

After reading the device table from the previour kernel we would
see a lot of
  AMD-Vi: Completion-Wait loop timed out
errors and finally crash:
  Kernel panic - not syncing: timer doesn't work through Interrupt-
remapped IO-APIC

We found that disabeling SNP in the outgoing (crashing) kernel
would enable the crashkernel to take over the iommu config and
boot from there.

We opened a PR over on github against the rfc-v9 branch to discuss
the issue:
https://github.com/AMDESE/linux/pull/5

Cheers Johanna







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