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SubjectRe: [PATCH 0/3] Infinite loops in microcode while running guests
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On 2015-11-10 13:22, Paolo Bonzini wrote:
> Yes, these can happen. The issue is that benign exceptions are
> delivered serially, but two of them (#DB and #AC) can also happen
> during exception delivery itself. The subsequent infinite stream
> of exceptions causes the processor to never exit guest mode.
>
> Paolo
>
> Eric Northup (1):
> KVM: x86: work around infinite loop in microcode when #AC is delivered
>
> Paolo Bonzini (2):
> KVM: svm: unconditionally intercept #DB
> KVM: x86: rename update_db_bp_intercept to update_bp_intercept
>
> arch/x86/include/asm/kvm_host.h | 2 +-
> arch/x86/include/uapi/asm/svm.h | 1 +
> arch/x86/kvm/svm.c | 22 +++++++++++-----------
> arch/x86/kvm/vmx.c | 7 +++++--
> arch/x86/kvm/x86.c | 2 +-
> 5 files changed, 19 insertions(+), 15 deletions(-)
>

So this affects both Intel and AMD CPUs equally? Nice cross-vendor
"compatibility".

And it can only be triggered via #AC and #DB, or also other exceptions
(that KVM already happens to intercept)? You may guess why I'm asking...

Is any of the issues already documented in a vendor errata?

Thanks,
Jan

--
Siemens AG, Corporate Technology, CT RTC ITP SES-DE
Corporate Competence Center Embedded Linux


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