From mboxrd@z Thu Jan  1 00:00:00 1970
From: Paolo Bonzini <pbonzini@redhat.com>
Subject: Re: nVMX: Shadowing of CPU_BASED_VM_EXEC_CONTROL broken
Date: Wed, 08 Oct 2014 12:34:30 +0200
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Cc: kvm <kvm@vger.kernel.org>, Bandan Das <bsd@redhat.com>
To: Jan Kiszka <jan.kiszka@siemens.com>,
	Wanpeng Li <wanpeng.li@linux.intel.com>
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Il 08/10/2014 12:29, Jan Kiszka ha scritto:
>> > But it would write to the vmcs02, not to the shadow VMCS; the shadow
>> > VMCS is active during copy_shadow_to_vmcs12/copy_vmcs12_to_shadow, and
>> > at no other time.  It is not clear to me how the VIRTUAL_INTR_PENDING
>> > bit ended up from the vmcs02 (where it is perfectly fine) to the vmcs12.
> Well, but somehow that bit ends up in vmcs12, that's a fact. Also that
> the proble disappears when shadowing is disabled. Need to think about
> the path again. Maybe there is just a bug, not a conceptual issue.

Yeah, and at this point we cannot actually exclude a processor bug.  Can
you check that the bit is not in the shadow VMCS just before vmrun, or
just after enable_irq_window?

Having a kvm-unit-tests testcase could also be of some help.

Paolo