Re: [PATCH 1/2] KVM: Exception during emulation decode shouldpropagate

[Takuya Yoshikawa]

On Wed, 11 Jan 2012 18:53:30 +0200
Nadav Amit <namit@xxxxxxxxxxxxxxxxx> wrote:

> An exception might occur during decode (e.g., #PF during fetch).
> Currently, the exception is ignored and emulation is performed.

When I cleaned up insn_fetch(), I thought that fetching the instruction
which is being executed by the guest cannot cause #PF.

The possibility that a meaningless userspace might similtaneously unmap
the page, noted by Avi IIRC, was ignored intentionally, so we just fail
in such a case.

Did you see any real problem?

	Takuya


> Instead, emulation should be skipped and the fault should be injected.
> Skipping instruction should report a failure in this case.
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