This patches allows userspace to send ASID based IOTLB message to
vhost. This idea is to use the reserved u32 field in the existing V2
IOTLB message. Vhost device should advertise this capability via
VHOST_BACKEND_F_IOTLB_ASID backend feature.
Signed-off-by: Jason Wang <[email protected]>
Signed-off-by: Gautam Dawar <[email protected]>
---
drivers/vhost/vdpa.c | 5 ++++-
drivers/vhost/vhost.c | 23 ++++++++++++++++++-----
drivers/vhost/vhost.h | 4 ++--
include/uapi/linux/vhost_types.h | 6 +++++-
4 files changed, 29 insertions(+), 9 deletions(-)
diff --git a/drivers/vhost/vdpa.c b/drivers/vhost/vdpa.c
index 6bf755f84d26..d0aacc0cc79a 100644
--- a/drivers/vhost/vdpa.c
+++ b/drivers/vhost/vdpa.c
@@ -836,7 +836,7 @@ static int vhost_vdpa_process_iotlb_update(struct vhost_vdpa *v,
msg->perm);
}
-static int vhost_vdpa_process_iotlb_msg(struct vhost_dev *dev,
+static int vhost_vdpa_process_iotlb_msg(struct vhost_dev *dev, u32 asid,
struct vhost_iotlb_msg *msg)
{
struct vhost_vdpa *v = container_of(dev, struct vhost_vdpa, vdev);
@@ -847,6 +847,9 @@ static int vhost_vdpa_process_iotlb_msg(struct vhost_dev *dev,
mutex_lock(&dev->mutex);
+ if (asid != 0)
+ return -EINVAL;
+
r = vhost_dev_check_owner(dev);
if (r)
goto unlock;
diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c
index 59edb5a1ffe2..1f514d98f0de 100644
--- a/drivers/vhost/vhost.c
+++ b/drivers/vhost/vhost.c
@@ -468,7 +468,7 @@ void vhost_dev_init(struct vhost_dev *dev,
struct vhost_virtqueue **vqs, int nvqs,
int iov_limit, int weight, int byte_weight,
bool use_worker,
- int (*msg_handler)(struct vhost_dev *dev,
+ int (*msg_handler)(struct vhost_dev *dev, u32 asid,
struct vhost_iotlb_msg *msg))
{
struct vhost_virtqueue *vq;
@@ -1090,11 +1090,14 @@ static bool umem_access_ok(u64 uaddr, u64 size, int access)
return true;
}
-static int vhost_process_iotlb_msg(struct vhost_dev *dev,
+static int vhost_process_iotlb_msg(struct vhost_dev *dev, u32 asid,
struct vhost_iotlb_msg *msg)
{
int ret = 0;
+ if (asid != 0)
+ return -EINVAL;
+
mutex_lock(&dev->mutex);
vhost_dev_lock_vqs(dev);
switch (msg->type) {
@@ -1141,6 +1144,7 @@ ssize_t vhost_chr_write_iter(struct vhost_dev *dev,
struct vhost_iotlb_msg msg;
size_t offset;
int type, ret;
+ u32 asid = 0;
ret = copy_from_iter(&type, sizeof(type), from);
if (ret != sizeof(type)) {
@@ -1156,7 +1160,16 @@ ssize_t vhost_chr_write_iter(struct vhost_dev *dev,
offset = offsetof(struct vhost_msg, iotlb) - sizeof(int);
break;
case VHOST_IOTLB_MSG_V2:
- offset = sizeof(__u32);
+ if (vhost_backend_has_feature(dev->vqs[0],
+ VHOST_BACKEND_F_IOTLB_ASID)) {
+ ret = copy_from_iter(&asid, sizeof(asid), from);
+ if (ret != sizeof(asid)) {
+ ret = -EINVAL;
+ goto done;
+ }
+ offset = sizeof(__u16);
+ } else
+ offset = sizeof(__u32);
break;
default:
ret = -EINVAL;
@@ -1171,9 +1184,9 @@ ssize_t vhost_chr_write_iter(struct vhost_dev *dev,
}
if (dev->msg_handler)
- ret = dev->msg_handler(dev, &msg);
+ ret = dev->msg_handler(dev, asid, &msg);
else
- ret = vhost_process_iotlb_msg(dev, &msg);
+ ret = vhost_process_iotlb_msg(dev, asid, &msg);
if (ret) {
ret = -EFAULT;
goto done;
diff --git a/drivers/vhost/vhost.h b/drivers/vhost/vhost.h
index 638bb640d6b4..9f238d6c7b58 100644
--- a/drivers/vhost/vhost.h
+++ b/drivers/vhost/vhost.h
@@ -161,7 +161,7 @@ struct vhost_dev {
int byte_weight;
u64 kcov_handle;
bool use_worker;
- int (*msg_handler)(struct vhost_dev *dev,
+ int (*msg_handler)(struct vhost_dev *dev, u32 asid,
struct vhost_iotlb_msg *msg);
};
@@ -169,7 +169,7 @@ bool vhost_exceeds_weight(struct vhost_virtqueue *vq, int pkts, int total_len);
void vhost_dev_init(struct vhost_dev *, struct vhost_virtqueue **vqs,
int nvqs, int iov_limit, int weight, int byte_weight,
bool use_worker,
- int (*msg_handler)(struct vhost_dev *dev,
+ int (*msg_handler)(struct vhost_dev *dev, u32 asid,
struct vhost_iotlb_msg *msg));
long vhost_dev_set_owner(struct vhost_dev *dev);
bool vhost_dev_has_owner(struct vhost_dev *dev);
diff --git a/include/uapi/linux/vhost_types.h b/include/uapi/linux/vhost_types.h
index 76ee7016c501..634cee485abb 100644
--- a/include/uapi/linux/vhost_types.h
+++ b/include/uapi/linux/vhost_types.h
@@ -87,7 +87,7 @@ struct vhost_msg {
struct vhost_msg_v2 {
__u32 type;
- __u32 reserved;
+ __u32 asid;
union {
struct vhost_iotlb_msg iotlb;
__u8 padding[64];
@@ -157,5 +157,9 @@ struct vhost_vdpa_iova_range {
#define VHOST_BACKEND_F_IOTLB_MSG_V2 0x1
/* IOTLB can accept batching hints */
#define VHOST_BACKEND_F_IOTLB_BATCH 0x2
+/* IOTLB can accept address space identifier through V2 type of IOTLB
+ * message
+ */
+#define VHOST_BACKEND_F_IOTLB_ASID 0x3
#endif
--
2.25.0
On Thu, Feb 24, 2022 at 10:26 PM Gautam Dawar <[email protected]> wrote:
>
> This patches allows userspace to send ASID based IOTLB message to
> vhost. This idea is to use the reserved u32 field in the existing V2
> IOTLB message. Vhost device should advertise this capability via
> VHOST_BACKEND_F_IOTLB_ASID backend feature.
>
> Signed-off-by: Jason Wang <[email protected]>
> Signed-off-by: Gautam Dawar <[email protected]>
> ---
> drivers/vhost/vdpa.c | 5 ++++-
> drivers/vhost/vhost.c | 23 ++++++++++++++++++-----
> drivers/vhost/vhost.h | 4 ++--
> include/uapi/linux/vhost_types.h | 6 +++++-
> 4 files changed, 29 insertions(+), 9 deletions(-)
>
> diff --git a/drivers/vhost/vdpa.c b/drivers/vhost/vdpa.c
> index 6bf755f84d26..d0aacc0cc79a 100644
> --- a/drivers/vhost/vdpa.c
> +++ b/drivers/vhost/vdpa.c
> @@ -836,7 +836,7 @@ static int vhost_vdpa_process_iotlb_update(struct vhost_vdpa *v,
> msg->perm);
> }
>
> -static int vhost_vdpa_process_iotlb_msg(struct vhost_dev *dev,
> +static int vhost_vdpa_process_iotlb_msg(struct vhost_dev *dev, u32 asid,
> struct vhost_iotlb_msg *msg)
> {
> struct vhost_vdpa *v = container_of(dev, struct vhost_vdpa, vdev);
> @@ -847,6 +847,9 @@ static int vhost_vdpa_process_iotlb_msg(struct vhost_dev *dev,
>
> mutex_lock(&dev->mutex);
>
> + if (asid != 0)
> + return -EINVAL;
> +
Should we check for asid != 0 before acquiring the mutex? Otherwise
the code never releases it.
> r = vhost_dev_check_owner(dev);
> if (r)
> goto unlock;
> diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c
> index 59edb5a1ffe2..1f514d98f0de 100644
> --- a/drivers/vhost/vhost.c
> +++ b/drivers/vhost/vhost.c
> @@ -468,7 +468,7 @@ void vhost_dev_init(struct vhost_dev *dev,
> struct vhost_virtqueue **vqs, int nvqs,
> int iov_limit, int weight, int byte_weight,
> bool use_worker,
> - int (*msg_handler)(struct vhost_dev *dev,
> + int (*msg_handler)(struct vhost_dev *dev, u32 asid,
> struct vhost_iotlb_msg *msg))
> {
> struct vhost_virtqueue *vq;
> @@ -1090,11 +1090,14 @@ static bool umem_access_ok(u64 uaddr, u64 size, int access)
> return true;
> }
>
> -static int vhost_process_iotlb_msg(struct vhost_dev *dev,
> +static int vhost_process_iotlb_msg(struct vhost_dev *dev, u32 asid,
> struct vhost_iotlb_msg *msg)
> {
> int ret = 0;
>
> + if (asid != 0)
> + return -EINVAL;
> +
> mutex_lock(&dev->mutex);
> vhost_dev_lock_vqs(dev);
> switch (msg->type) {
> @@ -1141,6 +1144,7 @@ ssize_t vhost_chr_write_iter(struct vhost_dev *dev,
> struct vhost_iotlb_msg msg;
> size_t offset;
> int type, ret;
> + u32 asid = 0;
>
> ret = copy_from_iter(&type, sizeof(type), from);
> if (ret != sizeof(type)) {
> @@ -1156,7 +1160,16 @@ ssize_t vhost_chr_write_iter(struct vhost_dev *dev,
> offset = offsetof(struct vhost_msg, iotlb) - sizeof(int);
> break;
> case VHOST_IOTLB_MSG_V2:
> - offset = sizeof(__u32);
> + if (vhost_backend_has_feature(dev->vqs[0],
> + VHOST_BACKEND_F_IOTLB_ASID)) {
> + ret = copy_from_iter(&asid, sizeof(asid), from);
> + if (ret != sizeof(asid)) {
> + ret = -EINVAL;
> + goto done;
> + }
> + offset = sizeof(__u16);
> + } else
> + offset = sizeof(__u32);
> break;
> default:
> ret = -EINVAL;
> @@ -1171,9 +1184,9 @@ ssize_t vhost_chr_write_iter(struct vhost_dev *dev,
> }
>
> if (dev->msg_handler)
> - ret = dev->msg_handler(dev, &msg);
> + ret = dev->msg_handler(dev, asid, &msg);
> else
> - ret = vhost_process_iotlb_msg(dev, &msg);
> + ret = vhost_process_iotlb_msg(dev, asid, &msg);
> if (ret) {
> ret = -EFAULT;
> goto done;
> diff --git a/drivers/vhost/vhost.h b/drivers/vhost/vhost.h
> index 638bb640d6b4..9f238d6c7b58 100644
> --- a/drivers/vhost/vhost.h
> +++ b/drivers/vhost/vhost.h
> @@ -161,7 +161,7 @@ struct vhost_dev {
> int byte_weight;
> u64 kcov_handle;
> bool use_worker;
> - int (*msg_handler)(struct vhost_dev *dev,
> + int (*msg_handler)(struct vhost_dev *dev, u32 asid,
> struct vhost_iotlb_msg *msg);
> };
>
> @@ -169,7 +169,7 @@ bool vhost_exceeds_weight(struct vhost_virtqueue *vq, int pkts, int total_len);
> void vhost_dev_init(struct vhost_dev *, struct vhost_virtqueue **vqs,
> int nvqs, int iov_limit, int weight, int byte_weight,
> bool use_worker,
> - int (*msg_handler)(struct vhost_dev *dev,
> + int (*msg_handler)(struct vhost_dev *dev, u32 asid,
> struct vhost_iotlb_msg *msg));
> long vhost_dev_set_owner(struct vhost_dev *dev);
> bool vhost_dev_has_owner(struct vhost_dev *dev);
> diff --git a/include/uapi/linux/vhost_types.h b/include/uapi/linux/vhost_types.h
> index 76ee7016c501..634cee485abb 100644
> --- a/include/uapi/linux/vhost_types.h
> +++ b/include/uapi/linux/vhost_types.h
> @@ -87,7 +87,7 @@ struct vhost_msg {
>
> struct vhost_msg_v2 {
> __u32 type;
> - __u32 reserved;
> + __u32 asid;
> union {
> struct vhost_iotlb_msg iotlb;
> __u8 padding[64];
> @@ -157,5 +157,9 @@ struct vhost_vdpa_iova_range {
> #define VHOST_BACKEND_F_IOTLB_MSG_V2 0x1
> /* IOTLB can accept batching hints */
> #define VHOST_BACKEND_F_IOTLB_BATCH 0x2
> +/* IOTLB can accept address space identifier through V2 type of IOTLB
> + * message
> + */
> +#define VHOST_BACKEND_F_IOTLB_ASID 0x3
>
> #endif
> --
> 2.25.0
>
-----Original Message-----
From: Eugenio Perez Martin <[email protected]>
Sent: Friday, March 4, 2022 3:55 PM
To: Gautam Dawar <[email protected]>
Cc: Gautam Dawar <[email protected]>; Martin Petrus Hubertus Habets <[email protected]>; Harpreet Singh Anand <[email protected]>; Tanuj Murlidhar Kamde <[email protected]>; Jason Wang <[email protected]>; Michael S. Tsirkin <[email protected]>; Zhu Lingshan <[email protected]>; Stefano Garzarella <[email protected]>; Xie Yongji <[email protected]>; Eli Cohen <[email protected]>; Si-Wei Liu <[email protected]>; Parav Pandit <[email protected]>; Longpeng <[email protected]>; virtualization <[email protected]>; [email protected]; kvm list <[email protected]>; [email protected]
Subject: Re: [RFC PATCH v2 09/19] vhost: support ASID in IOTLB API
On Thu, Feb 24, 2022 at 10:26 PM Gautam Dawar <[email protected]> wrote:
>
> This patches allows userspace to send ASID based IOTLB message to
> vhost. This idea is to use the reserved u32 field in the existing V2
> IOTLB message. Vhost device should advertise this capability via
> VHOST_BACKEND_F_IOTLB_ASID backend feature.
>
> Signed-off-by: Jason Wang <[email protected]>
> Signed-off-by: Gautam Dawar <[email protected]>
> ---
> drivers/vhost/vdpa.c | 5 ++++-
> drivers/vhost/vhost.c | 23 ++++++++++++++++++-----
> drivers/vhost/vhost.h | 4 ++--
> include/uapi/linux/vhost_types.h | 6 +++++-
> 4 files changed, 29 insertions(+), 9 deletions(-)
>
> diff --git a/drivers/vhost/vdpa.c b/drivers/vhost/vdpa.c index
> 6bf755f84d26..d0aacc0cc79a 100644
> --- a/drivers/vhost/vdpa.c
> +++ b/drivers/vhost/vdpa.c
> @@ -836,7 +836,7 @@ static int vhost_vdpa_process_iotlb_update(struct vhost_vdpa *v,
> msg->perm); }
>
> -static int vhost_vdpa_process_iotlb_msg(struct vhost_dev *dev,
> +static int vhost_vdpa_process_iotlb_msg(struct vhost_dev *dev, u32
> +asid,
> struct vhost_iotlb_msg *msg)
> {
> struct vhost_vdpa *v = container_of(dev, struct vhost_vdpa,
> vdev); @@ -847,6 +847,9 @@ static int
> vhost_vdpa_process_iotlb_msg(struct vhost_dev *dev,
>
> mutex_lock(&dev->mutex);
>
> + if (asid != 0)
> + return -EINVAL;
> +
Should we check for asid != 0 before acquiring the mutex? Otherwise the code never releases it.
[GD>>] Yes, you are right. Will fix this in next revision.
> r = vhost_dev_check_owner(dev);
> if (r)
> goto unlock;
> diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c index
> 59edb5a1ffe2..1f514d98f0de 100644
> --- a/drivers/vhost/vhost.c
> +++ b/drivers/vhost/vhost.c
> @@ -468,7 +468,7 @@ void vhost_dev_init(struct vhost_dev *dev,
> struct vhost_virtqueue **vqs, int nvqs,
> int iov_limit, int weight, int byte_weight,
> bool use_worker,
> - int (*msg_handler)(struct vhost_dev *dev,
> + int (*msg_handler)(struct vhost_dev *dev, u32
> + asid,
> struct vhost_iotlb_msg *msg))
> {
> struct vhost_virtqueue *vq;
> @@ -1090,11 +1090,14 @@ static bool umem_access_ok(u64 uaddr, u64 size, int access)
> return true;
> }
>
> -static int vhost_process_iotlb_msg(struct vhost_dev *dev,
> +static int vhost_process_iotlb_msg(struct vhost_dev *dev, u32 asid,
> struct vhost_iotlb_msg *msg) {
> int ret = 0;
>
> + if (asid != 0)
> + return -EINVAL;
> +
> mutex_lock(&dev->mutex);
> vhost_dev_lock_vqs(dev);
> switch (msg->type) {
> @@ -1141,6 +1144,7 @@ ssize_t vhost_chr_write_iter(struct vhost_dev *dev,
> struct vhost_iotlb_msg msg;
> size_t offset;
> int type, ret;
> + u32 asid = 0;
>
> ret = copy_from_iter(&type, sizeof(type), from);
> if (ret != sizeof(type)) {
> @@ -1156,7 +1160,16 @@ ssize_t vhost_chr_write_iter(struct vhost_dev *dev,
> offset = offsetof(struct vhost_msg, iotlb) - sizeof(int);
> break;
> case VHOST_IOTLB_MSG_V2:
> - offset = sizeof(__u32);
> + if (vhost_backend_has_feature(dev->vqs[0],
> + VHOST_BACKEND_F_IOTLB_ASID)) {
> + ret = copy_from_iter(&asid, sizeof(asid), from);
> + if (ret != sizeof(asid)) {
> + ret = -EINVAL;
> + goto done;
> + }
> + offset = sizeof(__u16);
> + } else
> + offset = sizeof(__u32);
> break;
> default:
> ret = -EINVAL;
> @@ -1171,9 +1184,9 @@ ssize_t vhost_chr_write_iter(struct vhost_dev *dev,
> }
>
> if (dev->msg_handler)
> - ret = dev->msg_handler(dev, &msg);
> + ret = dev->msg_handler(dev, asid, &msg);
> else
> - ret = vhost_process_iotlb_msg(dev, &msg);
> + ret = vhost_process_iotlb_msg(dev, asid, &msg);
> if (ret) {
> ret = -EFAULT;
> goto done;
> diff --git a/drivers/vhost/vhost.h b/drivers/vhost/vhost.h index
> 638bb640d6b4..9f238d6c7b58 100644
> --- a/drivers/vhost/vhost.h
> +++ b/drivers/vhost/vhost.h
> @@ -161,7 +161,7 @@ struct vhost_dev {
> int byte_weight;
> u64 kcov_handle;
> bool use_worker;
> - int (*msg_handler)(struct vhost_dev *dev,
> + int (*msg_handler)(struct vhost_dev *dev, u32 asid,
> struct vhost_iotlb_msg *msg); };
>
> @@ -169,7 +169,7 @@ bool vhost_exceeds_weight(struct vhost_virtqueue
> *vq, int pkts, int total_len); void vhost_dev_init(struct vhost_dev *, struct vhost_virtqueue **vqs,
> int nvqs, int iov_limit, int weight, int byte_weight,
> bool use_worker,
> - int (*msg_handler)(struct vhost_dev *dev,
> + int (*msg_handler)(struct vhost_dev *dev, u32
> + asid,
> struct vhost_iotlb_msg *msg));
> long vhost_dev_set_owner(struct vhost_dev *dev); bool
> vhost_dev_has_owner(struct vhost_dev *dev); diff --git
> a/include/uapi/linux/vhost_types.h b/include/uapi/linux/vhost_types.h
> index 76ee7016c501..634cee485abb 100644
> --- a/include/uapi/linux/vhost_types.h
> +++ b/include/uapi/linux/vhost_types.h
> @@ -87,7 +87,7 @@ struct vhost_msg {
>
> struct vhost_msg_v2 {
> __u32 type;
> - __u32 reserved;
> + __u32 asid;
> union {
> struct vhost_iotlb_msg iotlb;
> __u8 padding[64];
> @@ -157,5 +157,9 @@ struct vhost_vdpa_iova_range { #define
> VHOST_BACKEND_F_IOTLB_MSG_V2 0x1
> /* IOTLB can accept batching hints */ #define
> VHOST_BACKEND_F_IOTLB_BATCH 0x2
> +/* IOTLB can accept address space identifier through V2 type of IOTLB
> + * message
> + */
> +#define VHOST_BACKEND_F_IOTLB_ASID 0x3
>
> #endif
> --
> 2.25.0
>