Re: [Qemu-devel] [QEMU PATCH v2 0/2]: KVM: i386: Add support for save and restore nested state

[Liran Alon]

Another gentle ping on v2 of this series?
Patch was submitted a month ago.

Thanks,
-Liran

> On 8 Oct 2018, at 20:21, Liran Alon <address@hidden> wrote:
> 
> Gentle ping on v2 of this series.
> (I noticed 1st patch of series was already applied)
> 
> Thanks,
> -Liran
> 
>> On 16 Sep 2018, at 15:46, Liran Alon <address@hidden> wrote:
>> 
>> Hi,
>> 
>> This series aims to add support for QEMU to be able to migrate VMs that
>> are running nested hypervisors. In order to do so, it utilizes the new
>> IOCTLs introduced in KVM commit 8fcc4b5923af ("kvm: nVMX: Introduce
>> KVM_CAP_NESTED_STATE") which were created for this purpose.
>> 
>> 1st patch is not really related to the goal of the patch series. It just
>> makes CPUX86State->xsave_buf to be compiled only when needed (When
>> compiling with KVM or HVF CPU accelerator).
>> 
>> 2nd patch adds the support to migrate VMs that are running nested
>> hypervisors.
>> 
>> Regards,
>> -Liran
>> 
>> v1->v2 Changes:
>> * Renamed kvm_nested_state_length() to kvm_max_nested_state_length()
>> to better indicate it represents the max nested state size that can
>> be returned from kernel.
>> * Added error_report() calls to nested_state_post_load() to make
>> failures in migration easier to diagnose.
>> * Fixed support of migrating with various nested_state buffer sizes.
>> The following scenarios were tested:
>> (a) src and dest have same nested state size.
>>      ==> Migration succeeds.
>> (b) src don't have nested state while dest do.
>>      ==> Migration succeed and src don't send it's nested state.
>> (c) src have nested state while dest don't.
>>      ==> Migration fails as it cannot restore nested state.
>> (d) dest have bigger max nested state size than src
>>      ==> Migration succeeds.
>> (e) dest have smaller max nested state size than src but enough to store 
>> it's saved nested state
>>      ==> Migration succeeds
>> (f) dest have smaller max nested state size than src but not enough to store 
>> it's saved nested state
>>      ==> Migration fails
>> 
>