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

[Cédric Le Goater]

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 ?


Thanks,

C.