Re: [RFC v2 PATCH] vdpa_sim: implement .reset_map support

[Si-Wei Liu <si-wei.liu@xxxxxxxxxx>]

On 10/18/2023 1:05 AM, Stefano Garzarella wrote:
> On Tue, Oct 17, 2023 at 10:11:33PM -0700, Si-Wei Liu wrote:
> > RFC only. Not tested on vdpa-sim-blk with user virtual address.
> > Works fine with vdpa-sim-net which uses physical address to map.
> >
> > This patch is based on top of [1].
> >
> > [1] 
> > https://lore.kernel.org/virtualization/1696928580-7520-1-git-send-email-si-wei.liu@xxxxxxxxxx/
> >
> > Signed-off-by: Si-Wei Liu <si-wei.liu@xxxxxxxxxx>
> >
> > ---
> > RFC v2:
> >  - initialize iotlb to passthrough mode in device add
>
> I tested this version and I didn't see any issue ;-)
Great, thank you so much for your help on testing my patch, Stefano!
Just for my own interest/curiosity, currently there's no vhost-vdpa 
backend client implemented for vdpa-sim-blk or any vdpa block device in 
userspace as yet, correct? So there was no test specific to vhost-vdpa 
that needs to be exercised, right?

Thanks,
-Siwei



> Tested-by: Stefano Garzarella <sgarzare@xxxxxxxxxx>
>
> > ---
> > drivers/vdpa/vdpa_sim/vdpa_sim.c | 34 ++++++++++++++++++++++++--------
> > 1 file changed, 26 insertions(+), 8 deletions(-)
> >
> > diff --git a/drivers/vdpa/vdpa_sim/vdpa_sim.c 
> > b/drivers/vdpa/vdpa_sim/vdpa_sim.c
> > index 76d41058add9..2a0a6042d61d 100644
> > --- a/drivers/vdpa/vdpa_sim/vdpa_sim.c
> > +++ b/drivers/vdpa/vdpa_sim/vdpa_sim.c
> > @@ -151,13 +151,6 @@ static void vdpasim_do_reset(struct vdpasim 
> > *vdpasim)
> >                  &vdpasim->iommu_lock);
> >     }
> >
> > -    for (i = 0; i < vdpasim->dev_attr.nas; i++) {
> > -        vhost_iotlb_reset(&vdpasim->iommu[i]);
> > -        vhost_iotlb_add_range(&vdpasim->iommu[i], 0, ULONG_MAX,
> > -                      0, VHOST_MAP_RW);
> > -        vdpasim->iommu_pt[i] = true;
> > -    }
> > -
> >     vdpasim->running = true;
> >     spin_unlock(&vdpasim->iommu_lock);
> >
> > @@ -259,8 +252,12 @@ struct vdpasim *vdpasim_create(struct 
> > vdpasim_dev_attr *dev_attr,
> >     if (!vdpasim->iommu_pt)
> >         goto err_iommu;
> >
> > -    for (i = 0; i < vdpasim->dev_attr.nas; i++)
> > +    for (i = 0; i < vdpasim->dev_attr.nas; i++) {
> >         vhost_iotlb_init(&vdpasim->iommu[i], max_iotlb_entries, 0);
> > +        vhost_iotlb_add_range(&vdpasim->iommu[i], 0, ULONG_MAX, 0,
> > +                      VHOST_MAP_RW);
> > +        vdpasim->iommu_pt[i] = true;
> > +    }
> >
> >     for (i = 0; i < dev_attr->nvqs; i++)
> >         vringh_set_iotlb(&vdpasim->vqs[i].vring, &vdpasim->iommu[0],
> > @@ -637,6 +634,25 @@ static int vdpasim_set_map(struct vdpa_device 
> > *vdpa, unsigned int asid,
> >     return ret;
> > }
> >
> > +static int vdpasim_reset_map(struct vdpa_device *vdpa, unsigned int 
> > asid)
> > +{
> > +    struct vdpasim *vdpasim = vdpa_to_sim(vdpa);
> > +
> > +    if (asid >= vdpasim->dev_attr.nas)
> > +        return -EINVAL;
> > +
> > +    spin_lock(&vdpasim->iommu_lock);
> > +    if (vdpasim->iommu_pt[asid])
> > +        goto out;
> > +    vhost_iotlb_reset(&vdpasim->iommu[asid]);
> > +    vhost_iotlb_add_range(&vdpasim->iommu[asid], 0, ULONG_MAX,
> > +                  0, VHOST_MAP_RW);
> > +    vdpasim->iommu_pt[asid] = true;
> > +out:
> > +    spin_unlock(&vdpasim->iommu_lock);
> > +    return 0;
> > +}
> > +
> > static int vdpasim_bind_mm(struct vdpa_device *vdpa, struct mm_struct 
> > *mm)
> > {
> >     struct vdpasim *vdpasim = vdpa_to_sim(vdpa);
> > @@ -759,6 +775,7 @@ static const struct vdpa_config_ops 
> > vdpasim_config_ops = {
> >     .set_group_asid         = vdpasim_set_group_asid,
> >     .dma_map                = vdpasim_dma_map,
> >     .dma_unmap              = vdpasim_dma_unmap,
> > +    .reset_map              = vdpasim_reset_map,
> >     .bind_mm        = vdpasim_bind_mm,
> >     .unbind_mm        = vdpasim_unbind_mm,
> >     .free                   = vdpasim_free,
> > @@ -796,6 +813,7 @@ static const struct vdpa_config_ops 
> > vdpasim_batch_config_ops = {
> >     .get_iova_range         = vdpasim_get_iova_range,
> >     .set_group_asid         = vdpasim_set_group_asid,
> >     .set_map                = vdpasim_set_map,
> > +    .reset_map              = vdpasim_reset_map,
> >     .bind_mm        = vdpasim_bind_mm,
> >     .unbind_mm        = vdpasim_unbind_mm,
> >     .free                   = vdpasim_free,
> > --
> > 2.39.3

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