hollalinux
/
linux-sg2042
mirror of https://github.com/sophgo/linux-riscv.git
1
0
Fork 0
Code Issues Packages Projects Releases Wiki Activity

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>
This commit is contained in:
Jason Wang 2020-08-04 19:20:40 +03:00 committed by Michael S. Tsirkin
parent 653055b9ac
commit 25abc060d2
3 changed files with 40 additions and 9 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

36
drivers/vhost/vdpa.c
View File

@ -27,7 +27,9 @@
#include "vhost.h" #include "vhost.h"
enum { 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. */ /* Currently, only network backend w/o multiqueue is supported. */
@ -48,6 +50,7 @@ struct vhost_vdpa {
int virtio_id; int virtio_id;
int minor; int minor;
struct eventfd_ctx *config_ctx; struct eventfd_ctx *config_ctx;
int in_batch;
}; };
static DEFINE_IDA(vhost_vdpa_ida); 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; struct vdpa_device *vdpa = v->vdpa;
vdpa_reset(vdpa); vdpa_reset(vdpa);
v->in_batch = 0;
} }
static long vhost_vdpa_get_device_id(struct vhost_vdpa *v, u8 __user *argp) 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) if (r)
return r; return r;
if (ops->dma_map) if (ops->dma_map) {
r = ops->dma_map(vdpa, iova, size, pa, perm); r = ops->dma_map(vdpa, iova, size, pa, perm);
else if (ops->set_map) } else if (ops->set_map) {
r = ops->set_map(vdpa, dev->iotlb); if (!v->in_batch)
else r = ops->set_map(vdpa, dev->iotlb);
} else {
r = iommu_map(v->domain, iova, pa, size, r = iommu_map(v->domain, iova, pa, size,
perm_to_iommu_flags(perm)); perm_to_iommu_flags(perm));
}
return r; 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); vhost_vdpa_iotlb_unmap(v, iova, iova + size - 1);
if (ops->dma_map) if (ops->dma_map) {
ops->dma_unmap(vdpa, iova, size); ops->dma_unmap(vdpa, iova, size);
else if (ops->set_map) } else if (ops->set_map) {
ops->set_map(vdpa, dev->iotlb); if (!v->in_batch)
else ops->set_map(vdpa, dev->iotlb);
} else {
iommu_unmap(v->domain, iova, size); iommu_unmap(v->domain, iova, size);
}
} }
static int vhost_vdpa_process_iotlb_update(struct vhost_vdpa *v, 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_iotlb_msg *msg)
{ {
struct vhost_vdpa *v = container_of(dev, struct vhost_vdpa, vdev); 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; int r = 0;
r = vhost_dev_check_owner(dev); 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: case VHOST_IOTLB_INVALIDATE:
vhost_vdpa_unmap(v, msg->iova, msg->size); vhost_vdpa_unmap(v, msg->iova, msg->size);
break; 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: default:
r = -EINVAL; r = -EINVAL;
break; break;

2
include/uapi/linux/vhost.h
View File

@ -91,6 +91,8 @@
/* Use message type V2 */ /* Use message type V2 */
#define VHOST_BACKEND_F_IOTLB_MSG_V2 0x1 #define VHOST_BACKEND_F_IOTLB_MSG_V2 0x1
/* IOTLB can accept batching hints */
#define VHOST_BACKEND_F_IOTLB_BATCH 0x2
#define VHOST_SET_BACKEND_FEATURES _IOW(VHOST_VIRTIO, 0x25, __u64) #define VHOST_SET_BACKEND_FEATURES _IOW(VHOST_VIRTIO, 0x25, __u64)
#define VHOST_GET_BACKEND_FEATURES _IOR(VHOST_VIRTIO, 0x26, __u64) #define VHOST_GET_BACKEND_FEATURES _IOR(VHOST_VIRTIO, 0x26, __u64)

11
include/uapi/linux/vhost_types.h
View File

@ -60,6 +60,17 @@ struct vhost_iotlb_msg {
#define VHOST_IOTLB_UPDATE 2 #define VHOST_IOTLB_UPDATE 2
#define VHOST_IOTLB_INVALIDATE 3 #define VHOST_IOTLB_INVALIDATE 3
#define VHOST_IOTLB_ACCESS_FAIL 4 #define VHOST_IOTLB_ACCESS_FAIL 4
/*
* VHOST_IOTLB_BATCH_BEGIN and VHOST_IOTLB_BATCH_END allow modifying
* multiple mappings in one go: beginning with
* VHOST_IOTLB_BATCH_BEGIN, followed by any number of
* VHOST_IOTLB_UPDATE messages, and ending with VHOST_IOTLB_BATCH_END.
* When one of these two values is used as the message type, the rest
* of the fields in the message are ignored. There's no guarantee that
* these changes take place automatically in the device.
*/
#define VHOST_IOTLB_BATCH_BEGIN 5
#define VHOST_IOTLB_BATCH_END 6
__u8 type; __u8 type;
}; };