Re: [PATCH v2 0/4] kvm: arm/arm64: vgic: APRn uaccess support.

[wanghaibin <wanghaibin.wang@huawei.com>]

On 2017/7/21 21:27, Christoffer Dall wrote:

> Hi Wanghaibin,
> 
> On Mon, Jul 17, 2017 at 06:23:28PM +0800, wanghaibin wrote:
>> v2: Split the patch again to make it easier for review
>>     some fixes were proposed by Marc
>>
>> v1: the problem describe:
>> https://lists.cs.columbia.edu/pipermail/kvmarm/2017-July/026295.html
> 
> please also include the same description in the cover letter for future
> revisions of this patch series.  People may not remember the context
> (like me) or others may jump in as reviewers at a later time, and having
> to go back and look at an old posting via a link is not very friendly to
> the review process.
> 


OK, I'll do it next time.

This problem describe as follows:

In the case (GICv2 on GICv3 migration), I did the test on my board as follow:
vm boot => migrate to destination => shutdown at destination => start at destination
=> migrate back to source ... go round and begin again;

I tested many times, but unlucky, there maybe failed by accident when shutdown the vm
at destination. (GICv3 on GICv3 migration, 1000+ times, That's OK).
while failed,  we can watch the interrupts in the vm, some vcpus of the vm can not
receive the virt timer interrupt. And, these vcpus will 100% with top tool at host.

vgic_state debug file at destination shows(a active virt timer interrupt) that:
VCPU 0 TYP   ID TGT_ID PLAEHC     HWID   TARGET SRC PRI VCPU_ID
---------------------------------------------------------------
            ....................
       PPI   25      0 000001        0        1   0 160      -1
       PPI   26      0 000001        0        1   0 160      -1
       PPI   27      0 011111       27        1   0 160       0


I added log to print ICH* registers for VCPU0 at destination:
**HCR:0x1, VMCR:0xf0ec0001,SRE:0x0, ELRSR:0xe**
-----AP0R:0: 0x0------
-----AP0R:1: 0x0------
-----AP0R:2: 0x0------
-----AP0R:3: 0x0------
-----AP1R:0: 0x0------
-----AP1R:1: 0x0------
-----AP1R:2: 0x0------
-----AP1R:3: 0x0------
-----LR:0: 0xa0a0001b0000001b------
-----LR:1: 0x0------
-----LR:2: 0x0------
-----LR:3: 0x0------

and the ICH_AP1R0 value is 0x10000 at source.

At present, QEMU have supproted GICC_APRn put/set interface for emulated GICv2,
and kvm does not support the uaccess interface. This patchset try to support this.

Thanks.

> Thanks,
> -Christoffer
> 
>>
>> wanghaibin (4):
>>   kvm: arm/arm64: vgic: Implement the vGICv2 GICC_APRn uaccess
>>     interface.
>>   kvm: arm/arm64: vgic-v2: Add GICH_APRn accessors for GICv2
>>   kvm: arm/arm64: vgic-v3: add ICH_AP[01]Rn accessors for GICv3
>>   kvm: arm/arm64: vgic: clean up vGICv3 ICC_APRn sysreg uaccess
>>
>>  arch/arm64/kvm/vgic-sys-reg-v3.c | 25 +++++--------------------
>>  virt/kvm/arm/vgic/vgic-mmio-v2.c | 22 ++++++++++++++++++++--
>>  virt/kvm/arm/vgic/vgic-mmio.c    | 28 ++++++++++++++++++++++++++++
>>  virt/kvm/arm/vgic/vgic-v2.c      | 18 ++++++++++++++++++
>>  virt/kvm/arm/vgic/vgic-v3.c      | 20 ++++++++++++++++++++
>>  virt/kvm/arm/vgic/vgic.h         |  7 +++++++
>>  6 files changed, 98 insertions(+), 22 deletions(-)
>>
>> -- 
>> 1.8.3.1
>>
>>
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> 
> .
>