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authorJason Wang <jasowang@redhat.com>2020-08-04 19:20:40 +0300
committerMichael S. Tsirkin <mst@redhat.com>2020-08-06 01:39:18 +0300
commit25abc060d282132ea5c945392f900dca0a7e9bbb (patch)
tree20a86393e136ddaa5c70869e3057efb776f90ed5 /drivers/vhost
parent653055b9acd45d602435f2f70b7a85cb3130f018 (diff)
downloadlinux-25abc060d282132ea5c945392f900dca0a7e9bbb.tar.xz
vhost-vdpa: support IOTLB batching hints
This patches extend the vhost IOTLB API to accept batch updating hints form userspace. When userspace wants update the device IOTLB in a batch, it may do: 1) Write vhost_iotlb_msg with VHOST_IOTLB_BATCH_BEGIN flag 2) Perform a batch of IOTLB updating via VHOST_IOTLB_UPDATE/INVALIDATE 3) Write vhost_iotlb_msg with VHOST_IOTLB_BATCH_END flag Vhost-vdpa may decide to batch the IOMMU/IOTLB updating in step 3 when vDPA device support set_map() ops. This is useful for the vDPA device that want to know all the mappings to tweak their own DMA translation logic. For vDPA device that doesn't require set_map(), no behavior changes. This capability is advertised via VHOST_BACKEND_F_IOTLB_BATCH capability. Signed-off-by: Jason Wang <jasowang@redhat.com> Link: https://lore.kernel.org/r/20200804162048.22587-5-eli@mellanox.com Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Diffstat (limited to 'drivers/vhost')
-rw-r--r--drivers/vhost/vdpa.c36
1 files changed, 27 insertions, 9 deletions
diff --git a/drivers/vhost/vdpa.c b/drivers/vhost/vdpa.c
index 61c17d34cb39..e80db051845d 100644
--- a/drivers/vhost/vdpa.c
+++ b/drivers/vhost/vdpa.c
@@ -27,7 +27,9 @@
#include "vhost.h"
enum {
- VHOST_VDPA_BACKEND_FEATURES = (1ULL << VHOST_BACKEND_F_IOTLB_MSG_V2)
+ VHOST_VDPA_BACKEND_FEATURES =
+ (1ULL << VHOST_BACKEND_F_IOTLB_MSG_V2) |
+ (1ULL << VHOST_BACKEND_F_IOTLB_BATCH),
};
/* Currently, only network backend w/o multiqueue is supported. */
@@ -48,6 +50,7 @@ struct vhost_vdpa {
int virtio_id;
int minor;
struct eventfd_ctx *config_ctx;
+ int in_batch;
};
static DEFINE_IDA(vhost_vdpa_ida);
@@ -124,6 +127,7 @@ static void vhost_vdpa_reset(struct vhost_vdpa *v)
struct vdpa_device *vdpa = v->vdpa;
vdpa_reset(vdpa);
+ v->in_batch = 0;
}
static long vhost_vdpa_get_device_id(struct vhost_vdpa *v, u8 __user *argp)
@@ -546,13 +550,15 @@ static int vhost_vdpa_map(struct vhost_vdpa *v,
if (r)
return r;
- if (ops->dma_map)
+ if (ops->dma_map) {
r = ops->dma_map(vdpa, iova, size, pa, perm);
- else if (ops->set_map)
- r = ops->set_map(vdpa, dev->iotlb);
- else
+ } else if (ops->set_map) {
+ if (!v->in_batch)
+ r = ops->set_map(vdpa, dev->iotlb);
+ } else {
r = iommu_map(v->domain, iova, pa, size,
perm_to_iommu_flags(perm));
+ }
return r;
}
@@ -565,12 +571,14 @@ static void vhost_vdpa_unmap(struct vhost_vdpa *v, u64 iova, u64 size)
vhost_vdpa_iotlb_unmap(v, iova, iova + size - 1);
- if (ops->dma_map)
+ if (ops->dma_map) {
ops->dma_unmap(vdpa, iova, size);
- else if (ops->set_map)
- ops->set_map(vdpa, dev->iotlb);
- else
+ } else if (ops->set_map) {
+ if (!v->in_batch)
+ ops->set_map(vdpa, dev->iotlb);
+ } else {
iommu_unmap(v->domain, iova, size);
+ }
}
static int vhost_vdpa_process_iotlb_update(struct vhost_vdpa *v,
@@ -663,6 +671,8 @@ static int vhost_vdpa_process_iotlb_msg(struct vhost_dev *dev,
struct vhost_iotlb_msg *msg)
{
struct vhost_vdpa *v = container_of(dev, struct vhost_vdpa, vdev);
+ struct vdpa_device *vdpa = v->vdpa;
+ const struct vdpa_config_ops *ops = vdpa->config;
int r = 0;
r = vhost_dev_check_owner(dev);
@@ -676,6 +686,14 @@ static int vhost_vdpa_process_iotlb_msg(struct vhost_dev *dev,
case VHOST_IOTLB_INVALIDATE:
vhost_vdpa_unmap(v, msg->iova, msg->size);
break;
+ case VHOST_IOTLB_BATCH_BEGIN:
+ v->in_batch = true;
+ break;
+ case VHOST_IOTLB_BATCH_END:
+ if (v->in_batch && ops->set_map)
+ ops->set_map(vdpa, dev->iotlb);
+ v->in_batch = false;
+ break;
default:
r = -EINVAL;
break;