From mboxrd@z Thu Jan  1 00:00:00 1970
From: Marcelo Tosatti <mtosatti@redhat.com>
Subject: Re: [PATCH UNTESTED] KVM: VMX: Save/restore rflags.vm correctly in
 real mode
Date: Thu, 8 Apr 2010 17:01:06 -0300
Message-ID: <20100408200106.GA25347@amt.cnet>
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Cc: kvm@vger.kernel.org
To: Avi Kivity <avi@redhat.com>
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On Thu, Apr 08, 2010 at 06:19:35PM +0300, Avi Kivity wrote:
> Currently we set eflags.vm unconditionally when entering real mode emulation
> through virtual-8086 mode, and clear it unconditionally when we enter protected
> mode.  The means that the following sequence
> 
>   KVM_SET_REGS  (rflags.vm=1)
>   KVM_SET_SREGS (cr0.pe=1)
> 
> Ends up with rflags.vm clear due to KVM_SET_SREGS triggering enter_pmode().
> 
> Fix by shadowing rflags.vm (and rflags.iopl) correctly while in real mode:
> reads and writes to those bits access a shadow register instead of the actual
> register.
> 
> Signed-off-by: Avi Kivity <avi@redhat.com>

Tested and applied, thanks.