RE: [PATCH] KVM: x86: reset RVI upon system reset

["Zhang Haoyu" <zhanghy@sangfor.com>]

On 2014-12-11 19:06:33, Zhang, Yang Z wrote:
>Zhang Haoyu wrote on 2014-12-11:
>> Then?
>
>It's already in upstream KVM
>
Strange, I didn't find this commit in https://git.kernel.org/cgit/virt/kvm/kvm.git/log/
but found it from the repository downloaded by git clone  git://git.kernel.org/pub/scm/virt/kvm/kvm.git

Thanks,
Zhang Haoyu

>commit 4114c27d450bef228be9c7b0c40a888e18a3a636
>Author: Wei Wang <wei.w.wang@intel.com>
>Date:   Wed Nov 5 10:53:43 2014 +0800
>
>    KVM: x86: reset RVI upon system reset
>    
>    A bug was reported as follows: when running Windows 7 32-bit guests on qemu-kvm,
>    sometimes the guests run into blue screen during reboot. The problem was that a
>    guest's RVI was not cleared when it rebooted. This patch has fixed the problem.
>    
>    Signed-off-by: Wei Wang <wei.w.wang@intel.com>
>    Signed-off-by: Yang Zhang <yang.z.zhang@intel.com>
>    Tested-by: Rongrong Liu <rongrongx.liu@intel.com>, Da Chun <ngugc@qq.com>
>    Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
>
>
>> 
>>>> On 05/11/2014 10:02, Chen, Tiejun wrote:
>>>>>> I think both are ok.
>>>>>> If we zero max_irr in vmx_set_rvi(), we still need this check:
>>>>>> if ((is_guest_mode(vcpu) && nested_exit_on_intr(vcpu)) || max_irr
>>>>>> ==
>>>>>> -1)
>>>>> 
>>>>> No, I don't think we need to add this.
>>>> 
>>>> You don't, because the code will look like:
>>>> 
>>>>         if (is_guest_mode(vcpu) && nested_exit_on_intr(vcpu))
>>>>                 return; if (!is_guest_mode(vcpu)) {
>>>>                 vmx_set_rvi(max_irr); return;
>>>>         }
>>>>         
>>>>         if (max_irr == -1)
>>>>                 return;
>>>> and thus vmx_set_rvi() is never reached if is_guest_mode(vcpu) &&
>>>> !nested_exit_on_intr(vcpu).
>>> 
>>> I don't think the above code is perfect. Since hwapic_irr_update() is
>>> a hot point,
>> it's better to move the first check after the second check. In this
>> case, Wei's patch looks more reasonable.
>>> 
>>>> 
>>>> I applied the lapic.c part of Wei's patch, and the vmx.c part of Tiejun's patch.
>>>> 
>>>> Paolo
>>> 
>>> 
>>> Best regards,
>
>
>Best regards,
>Yang