Subject: Re: [PATCH 1/4] KVM: nVMX: move vmentry tasks from prepare_vmcs12 to
 enter_vmx_non_root_mode
To: Jim Mattson <jmattson@google.com>
Cc: LKML <linux-kernel@vger.kernel.org>, kvm list <kvm@vger.kernel.org>,
        Wanpeng Li <wanpeng.li@hotmail.com>,
        David Hildenbrand <david@redhat.com>,
        =?UTF-8?B?UmFkaW0gS3LEjW3DocWZ?= <rkrcmar@redhat.com>
References: <1503521038-21073-1-git-send-email-pbonzini@redhat.com>
 <1503521038-21073-2-git-send-email-pbonzini@redhat.com>
 <CALMp9eRWY16cnqx_w72qXRARsPV3Hw=YAVHc7czpOXsbZs=_EA@mail.gmail.com>
From: Paolo Bonzini <pbonzini@redhat.com>
Message-ID: <60b2524d-485c-990f-0665-2b15e6ffabf6@redhat.com>
Date: Wed, 23 Aug 2017 23:47:22 +0200
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On 23/08/2017 23:25, Jim Mattson wrote:
>> +       if (from_vmentry) {
>> +               vmcs12->launch_state = 1;
> Because we defer most guest state validity checks to the hardware
> vmlaunch of the vmcs02, it is too early to set the vmcs12 launched
> state here. If the exit reason has the high bit set,
> vmcs12->launch_state should not be modified.

Thanks---I'll do my homework and add a testcase then. :)  The launched
state cannot be discovered with VMREAD, but I can test that a
VMLAUNCH;VMLAUNCH works and a VMLAUNCH;VMRESUME fails.

The same applies for the next instruction, which is part of step 6 of
the vmentry ("An event may be injected in the guest context").  This one
can be tested with VMREAD.

Paolo

>> +
>> +               /* vm_entry_intr_info_field is cleared on exit. Emulate this
>> +                * instead of reading the real value. */
>> +               vmcs12->vm_entry_intr_info_field &= ~INTR_INFO_VALID_MASK;