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Date:   Wed, 18 Oct 2023 10:05:02 +0200
From:   Stefano Garzarella <sgarzare@redhat.com>
To:     Si-Wei Liu <si-wei.liu@oracle.com>
Cc:     jasowang@redhat.com, mst@redhat.com, eperezma@redhat.com,
        virtualization@lists.linux-foundation.org,
        linux-kernel@vger.kernel.org
Subject: Re: [RFC v2 PATCH] vdpa_sim: implement .reset_map support
Message-ID: <becui44lhdptriz4ds7r2b22kazofwo7i44rydacjssnwb7mrq@f6sa74zjhlfp>
References: <1697605893-30313-1-git-send-email-si-wei.liu@oracle.com>
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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@oracle.com/
>
>Signed-off-by: Si-Wei Liu <si-wei.liu@oracle.com>
>
>---
>RFC v2:
>  - initialize iotlb to passthrough mode in device add

I tested this version and I didn't see any issue ;-)

Tested-by: Stefano Garzarella <sgarzare@redhat.com>

>---
> 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
>