[10/21] vhost: support ASID in IOTLB API

Message ID	20201216064818.48239-11-jasowang@redhat.com (mailing list archive)
State	New, archived
Headers	show Return-Path: <kvm-owner@kernel.org> From: Jason Wang <jasowang@redhat.com> To: mst@redhat.com, jasowang@redhat.com Cc: eperezma@redhat.com, kvm@vger.kernel.org, virtualization@lists.linux-foundation.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, lulu@redhat.com, eli@mellanox.com, lingshan.zhu@intel.com, rob.miller@broadcom.com, stefanha@redhat.com, sgarzare@redhat.com Subject: [PATCH 10/21] vhost: support ASID in IOTLB API Date: Wed, 16 Dec 2020 14:48:07 +0800 Message-Id: <20201216064818.48239-11-jasowang@redhat.com> In-Reply-To: <20201216064818.48239-1-jasowang@redhat.com> References: <20201216064818.48239-1-jasowang@redhat.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk
Series	Control VQ support in vDPA \| expand [00/21] Control VQ support in vDPA [01/21] vhost: move the backend feature bits to vhost_types.h [02/21] virtio-vdpa: don't set callback if virtio doesn't need it [03/21] vhost-vdpa: passing iotlb to IOMMU mapping helpers [04/21] vhost-vdpa: switch to use vhost-vdpa specific IOTLB [05/21] vdpa: add the missing comment for nvqs in struct vdpa_device [06/21] vdpa: introduce virtqueue groups [07/21] vdpa: multiple address spaces support [08/21] vdpa: introduce config operations for associating ASID to a virtqueue group [09/21] vhost_iotlb: split out IOTLB initialization [10/21] vhost: support ASID in IOTLB API [11/21] vhost-vdpa: introduce asid based IOTLB [12/21] vhost-vdpa: introduce uAPI to get the number of virtqueue groups [13/21] vhost-vdpa: introduce uAPI to get the number of address spaces [14/21] vhost-vdpa: uAPI to get virtqueue group id [15/21] vhost-vdpa: introduce uAPI to set group ASID [16/21] vhost-vdpa: support ASID based IOTLB API [17/21] vdpa_sim: split vdpasim_virtqueue's iov field in out_iov and in_iov [18/21] vdpa_sim: advertise VIRTIO_NET_F_MTU [19/21] vdpa_sim: factor out buffer completion logic [20/21] vdpa_sim: filter destination mac address [21/21] vdpasim: control virtqueue support

Message ID

20201216064818.48239-11-jasowang@redhat.com (mailing list archive)

State

New, archived

Headers

From: Jason Wang <jasowang@redhat.com>
To: mst@redhat.com, jasowang@redhat.com
Cc: eperezma@redhat.com, kvm@vger.kernel.org,
        virtualization@lists.linux-foundation.org, netdev@vger.kernel.org,
        linux-kernel@vger.kernel.org, lulu@redhat.com, eli@mellanox.com,
        lingshan.zhu@intel.com, rob.miller@broadcom.com,
        stefanha@redhat.com, sgarzare@redhat.com
Subject: [PATCH 10/21] vhost: support ASID in IOTLB API
Date: Wed, 16 Dec 2020 14:48:07 +0800
Message-Id: <20201216064818.48239-11-jasowang@redhat.com>
In-Reply-To: <20201216064818.48239-1-jasowang@redhat.com>
References: <20201216064818.48239-1-jasowang@redhat.com>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

Series

Control VQ support in vDPA | expand

Commit Message

Jason Wang Dec. 16, 2020, 6:48 a.m. UTC

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 <jasowang@redhat.com>
---
 drivers/vhost/vdpa.c             |  5 ++++-
 drivers/vhost/vhost.c            | 23 ++++++++++++++++++-----
 drivers/vhost/vhost.h            |  4 ++--
 include/uapi/linux/vhost_types.h |  5 ++++-
 4 files changed, 28 insertions(+), 9 deletions(-)

Comments

Eli Cohen Dec. 29, 2020, 10:20 a.m. UTC | #1

On Wed, Dec 16, 2020 at 02:48:07PM +0800, Jason Wang 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 <jasowang@redhat.com>
> ---
>  drivers/vhost/vdpa.c             |  5 ++++-
>  drivers/vhost/vhost.c            | 23 ++++++++++++++++++-----
>  drivers/vhost/vhost.h            |  4 ++--
>  include/uapi/linux/vhost_types.h |  5 ++++-
>  4 files changed, 28 insertions(+), 9 deletions(-)
> 
> diff --git a/drivers/vhost/vdpa.c b/drivers/vhost/vdpa.c
> index 03a9b3311c6c..feb6a58df22d 100644
> --- a/drivers/vhost/vdpa.c
> +++ b/drivers/vhost/vdpa.c
> @@ -739,7 +739,7 @@ static int vhost_vdpa_process_iotlb_update(struct vhost_vdpa *v,
>  	return ret;
>  }
>  
> -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);
> @@ -748,6 +748,9 @@ static int vhost_vdpa_process_iotlb_msg(struct vhost_dev *dev,
>  	struct vhost_iotlb *iotlb = v->iotlb;
>  	int r = 0;
>  
> +	if (asid != 0)
> +		return -EINVAL;
> +
>  	r = vhost_dev_check_owner(dev);
>  	if (r)
>  		return r;
> diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c
> index a262e12c6dc2..7477b724c29b 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;
> @@ -1084,11 +1084,14 @@ 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, u16 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) {
> @@ -1135,6 +1138,7 @@ ssize_t vhost_chr_write_iter(struct vhost_dev *dev,
>  	struct vhost_iotlb_msg msg;
>  	size_t offset;
>  	int type, ret;
> +	u16 asid = 0;

You assume asid occupies just 16 bits. So maybe you should reserve the
other 16 bits for future extension:

struct vhost_msg_v2 {
        __u32 type;
-       __u32 reserved;
+       __u16 asid;
+       __u16 reserved;
        union {

Moreover, maybe this should be reflected in previous patches that use
the asid:

-static int mlx5_vdpa_set_map(struct vdpa_device *vdev, struct vhost_iotlb *iotlb)
+static int mlx5_vdpa_set_map(struct vdpa_device *vdev, u16 asid,
+                            struct vhost_iotlb *iotlb)

-static int vhost_vdpa_process_iotlb_msg(struct vhost_dev *dev,
+static int vhost_vdpa_process_iotlb_msg(struct vhost_dev *dev, u16 asid,
                                        struct vhost_iotlb_msg *msg)

etc.

>  
>  	ret = copy_from_iter(&type, sizeof(type), from);
>  	if (ret != sizeof(type)) {
> @@ -1150,7 +1154,16 @@ 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;
> @@ -1165,9 +1178,9 @@ 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 b063324c7669..19753a90875c 100644
> --- a/drivers/vhost/vhost.h
> +++ b/drivers/vhost/vhost.h
> @@ -162,7 +162,7 @@ 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);
>  };
>  
> @@ -170,7 +170,7 @@ 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..222fc66ce2ac 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 +157,8 @@ 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
> -- 
> 2.25.1
>

Jason Wang Dec. 30, 2020, 4:27 a.m. UTC | #2

On 2020/12/29 下午6:20, Eli Cohen wrote:
>> -static int vhost_process_iotlb_msg(struct vhost_dev *dev,
>> +static int vhost_process_iotlb_msg(struct vhost_dev *dev, u16 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) {
>> @@ -1135,6 +1138,7 @@ ssize_t vhost_chr_write_iter(struct vhost_dev *dev,
>>   	struct vhost_iotlb_msg msg;
>>   	size_t offset;
>>   	int type, ret;
>> +	u16 asid = 0;
> You assume asid occupies just 16 bits. So maybe you should reserve the
> other 16 bits for future extension:
>
> struct vhost_msg_v2 {
>          __u32 type;
> -       __u32 reserved;
> +       __u16 asid;
> +       __u16 reserved;
>          union {
>
> Moreover, maybe this should be reflected in previous patches that use
> the asid:
>
> -static int mlx5_vdpa_set_map(struct vdpa_device *vdev, struct vhost_iotlb *iotlb)
> +static int mlx5_vdpa_set_map(struct vdpa_device *vdev, u16 asid,
> +                            struct vhost_iotlb *iotlb)
>
> -static int vhost_vdpa_process_iotlb_msg(struct vhost_dev *dev,
> +static int vhost_vdpa_process_iotlb_msg(struct vhost_dev *dev, u16 asid,
>                                          struct vhost_iotlb_msg *msg)
>
> etc.


Good catch.

This is a bug of the code actually. Since I want to stick to 32bit to be 
large enough for e.g PASID.

Will fix.

Thanks


>

diff --git a/drivers/vhost/vdpa.c b/drivers/vhost/vdpa.c
index 03a9b3311c6c..feb6a58df22d 100644
--- a/drivers/vhost/vdpa.c
+++ b/drivers/vhost/vdpa.c
@@ -739,7 +739,7 @@  static int vhost_vdpa_process_iotlb_update(struct vhost_vdpa *v,
 	return ret;
 }
 
-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);
@@ -748,6 +748,9 @@  static int vhost_vdpa_process_iotlb_msg(struct vhost_dev *dev,
 	struct vhost_iotlb *iotlb = v->iotlb;
 	int r = 0;
 
+	if (asid != 0)
+		return -EINVAL;
+
 	r = vhost_dev_check_owner(dev);
 	if (r)
 		return r;
diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c
index a262e12c6dc2..7477b724c29b 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;
@@ -1084,11 +1084,14 @@  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, u16 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) {
@@ -1135,6 +1138,7 @@  ssize_t vhost_chr_write_iter(struct vhost_dev *dev,
 	struct vhost_iotlb_msg msg;
 	size_t offset;
 	int type, ret;
+	u16 asid = 0;
 
 	ret = copy_from_iter(&type, sizeof(type), from);
 	if (ret != sizeof(type)) {
@@ -1150,7 +1154,16 @@  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;
@@ -1165,9 +1178,9 @@  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 b063324c7669..19753a90875c 100644
--- a/drivers/vhost/vhost.h
+++ b/drivers/vhost/vhost.h
@@ -162,7 +162,7 @@  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);
 };
 
@@ -170,7 +170,7 @@  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..222fc66ce2ac 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 +157,8 @@  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

[10/21] vhost: support ASID in IOTLB API

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