Re: [PATCH 7/7] virtio-iommu: Revert transient enablement of IOMMU MR in bypass mode

["Cédric Le Goater" <clg@redhat.com>]

On 6/26/24 10:26 AM, Eric Auger wrote:
> In 94df5b2180d6 ("virtio-iommu: Fix 64kB host page size VFIO device
> assignment"), in case of bypass mode, we transiently enabled the
> IOMMU MR to allow the set_page_size_mask() to be called and pass
> information about the page size mask constraint of cold plugged
> VFIO devices. Now we do not use the IOMMU MR callback anymore, we
> can just get rid of this hack.
> 
> Signed-off-by: Eric Auger <eric.auger@redhat.com>


Reviewed-by: Cédric Le Goater <clg@redhat.com>

Thanks,

C.


> ---
>   hw/virtio/virtio-iommu.c | 12 ------------
>   1 file changed, 12 deletions(-)
> 
> diff --git a/hw/virtio/virtio-iommu.c b/hw/virtio/virtio-iommu.c
> index b24e10de81..f87359b3e7 100644
> --- a/hw/virtio/virtio-iommu.c
> +++ b/hw/virtio/virtio-iommu.c
> @@ -1385,18 +1385,6 @@ static void virtio_iommu_freeze_granule(Notifier *notifier, void *data)
>       VirtIOIOMMU *s = container_of(notifier, VirtIOIOMMU, machine_done);
>       int granule;
>   
> -    if (likely(s->config.bypass)) {
> -        /*
> -         * Transient IOMMU MR enable to collect page_size_mask requirements
> -         * through memory_region_iommu_set_page_size_mask() called by
> -         * VFIO region_add() callback
> -         */
> -         s->config.bypass = false;
> -         virtio_iommu_switch_address_space_all(s);
> -         /* restore default */
> -         s->config.bypass = true;
> -         virtio_iommu_switch_address_space_all(s);
> -    }
>       s->granule_frozen = true;
>       granule = ctz64(s->config.page_size_mask);
>       trace_virtio_iommu_freeze_granule(BIT_ULL(granule));