RE: [PATCH 1/3] virtio_iommu: Clear IOMMUPciBus pointer cache when system reset

[Duan, Zhenzhong]

>-----Original Message-----
>From: Cédric Le Goater <clg@redhat.com>
>Subject: Re: [PATCH 1/3] virtio_iommu: Clear IOMMUPciBus pointer cache
>when system reset
>
>On 1/22/24 07:40, Zhenzhong Duan wrote:
>> IOMMUPciBus pointer cache is indexed by bus number, bus number
>> may not always be a fixed value, i.e., guest reboot to different
>> kernel which set bus number with different algorithm.
>>
>> This could lead to endpoint binding to wrong iommu MR in
>> virtio_iommu_get_endpoint(), then vfio device setup wrong
>> mapping from other device.
>>
>> Signed-off-by: Zhenzhong Duan <zhenzhong.duan@intel.com>
>> ---
>>   hw/virtio/virtio-iommu.c | 2 ++
>>   1 file changed, 2 insertions(+)
>>
>> diff --git a/hw/virtio/virtio-iommu.c b/hw/virtio/virtio-iommu.c
>> index 8a4bd933c6..bfce3237f3 100644
>> --- a/hw/virtio/virtio-iommu.c
>> +++ b/hw/virtio/virtio-iommu.c
>> @@ -1264,6 +1264,8 @@ static void virtio_iommu_system_reset(void
>*opaque)
>>
>>       trace_virtio_iommu_system_reset();
>>
>> +    memset(s->iommu_pcibus_by_bus_num, 0, sizeof(s-
>>iommu_pcibus_by_bus_num));
>> +
>>       /*
>>        * config.bypass is sticky across device reset, but should be restored 
>> on
>>        * system reset
>
>you could remove the memset in virtio_iommu_device_realize() then ?

Good suggestion, will do.

Thanks
Zhenzhong