Re: [PATCH 0/2] KVM: x86: Convey the exit reason to user-space on emulation failure

[David Matlack]

On Wed, Jun 30, 2021 at 9:33 AM David Matlack <dmatlack@xxxxxxxxxx> wrote:
>
> On Mon, Jun 28, 2021 at 06:31:50PM +0100, David Edmondson wrote:
> > To aid in debugging failures in the field, when instruction emulation
>
> What do you mean by a "debugging failure"?

Oh! Sorry I misread this as "*debugging failures*" rather than
"debugging *failures*". I know what you mean here :-).

>
> > fails, report the VM exit reason to userspace in order that it can be
> > recorded.
>
> What is the benefit of seeing the VM-exit reason that led to an
> emulation failure?
>
> >
> > The changes are on top of Aaron's patches from
> > https://lore.kernel.org/r/20210510144834.658457-1-aaronlewis@xxxxxxxxxx
> > which are in the KVM queue, but not yet upstream.
> >
> > David Edmondson (2):
> >   KVM: x86: Add kvm_x86_ops.get_exit_reason
> >   KVM: x86: On emulation failure, convey the exit reason to userspace
> >
> >  arch/x86/include/asm/kvm-x86-ops.h |  1 +
> >  arch/x86/include/asm/kvm_host.h    |  1 +
> >  arch/x86/kvm/svm/svm.c             |  6 ++++++
> >  arch/x86/kvm/vmx/vmx.c             |  6 ++++++
> >  arch/x86/kvm/x86.c                 | 23 +++++++++++++++++------
> >  include/uapi/linux/kvm.h           |  2 ++
> >  6 files changed, 33 insertions(+), 6 deletions(-)
> >
> > --
> > 2.30.2
> >