On 12/23/20 6:37 AM, Xia, Chenbo wrote:

Hi Maxime,

quoted

-----Original Message-----
From: Maxime Coquelin <redacted>
Sent: Tuesday, December 22, 2020 6:56 PM
To: Xia, Chenbo <redacted>; dev@dpdk.org; amorenoz@redhat.com;
jasowang@redhat.com; david.marchand@redhat.com
Cc: stable@dpdk.org
Subject: Re: [PATCH 21.02 v2 1/2] net/virtio: fix missing backend features
negotiation



On 12/21/20 7:23 AM, Xia, Chenbo wrote:

quoted

Hi Maxime,

quoted

-----Original Message-----
From: Maxime Coquelin <redacted>
Sent: Wednesday, November 25, 2020 11:21 PM
To: dev@dpdk.org; Xia, Chenbo <redacted>; amorenoz@redhat.com;
jasowang@redhat.com; david.marchand@redhat.com
Cc: Maxime Coquelin <redacted>; stable@dpdk.org
Subject: [PATCH 21.02 v2 1/2] net/virtio: fix missing backend features
negotiation

This patch adds missing backend features negotiation for
in Vhost-vDPA. Without it, IOTLB messages v2 could be sent
by Virtio-user PMD while not supported by the backend.

Fixes: 6b901437056e ("net/virtio: introduce vhost-vDPA backend")
Cc: stable@dpdk.org

Signed-off-by: Maxime Coquelin <redacted>
---
 drivers/net/virtio/virtio_user/vhost.h           |  4 ++++
 drivers/net/virtio/virtio_user/vhost_vdpa.c      | 14 ++++++++++++++
 drivers/net/virtio/virtio_user/virtio_user_dev.c | 14 ++++++++++----
 3 files changed, 28 insertions(+), 4 deletions(-)

diff --git a/drivers/net/virtio/virtio_user/vhost.h

b/drivers/net/virtio/virtio_user/vhost.h
index 210a3704e7..c1dcc50b58 100644

--- a/drivers/net/virtio/virtio_user/vhost.h
+++ b/drivers/net/virtio/virtio_user/vhost.h

@@ -86,6 +86,10 @@ enum vhost_user_request {
 	VHOST_USER_MAX
 };

+#ifndef VHOST_BACKEND_F_IOTLB_MSG_V2
+#define VHOST_BACKEND_F_IOTLB_MSG_V2 1
+#endif
+
 extern const char * const vhost_msg_strings[VHOST_USER_MAX];

 struct vhost_memory_region {

diff --git a/drivers/net/virtio/virtio_user/vhost_vdpa.c

b/drivers/net/virtio/virtio_user/vhost_vdpa.c
index c7b9349fc8..b6c81d6f17 100644

--- a/drivers/net/virtio/virtio_user/vhost_vdpa.c
+++ b/drivers/net/virtio/virtio_user/vhost_vdpa.c

@@ -35,6 +35,8 @@
 #define VHOST_VDPA_SET_STATUS _IOW(VHOST_VIRTIO, 0x72, __u8)
 #define VHOST_VDPA_SET_VRING_ENABLE	_IOW(VHOST_VIRTIO, 0x75, \
 					     struct vhost_vring_state)
+#define VHOST_SET_BACKEND_FEATURES _IOW(VHOST_VIRTIO, 0x25, __u64)
+#define VHOST_GET_BACKEND_FEATURES _IOR(VHOST_VIRTIO, 0x26, __u64)

 static uint64_t vhost_req_user_to_vdpa[] = {
 	[VHOST_USER_SET_OWNER] = VHOST_SET_OWNER,

@@ -51,6 +53,8 @@ static uint64_t vhost_req_user_to_vdpa[] = {
 	[VHOST_USER_SET_STATUS] = VHOST_VDPA_SET_STATUS,
 	[VHOST_USER_GET_STATUS] = VHOST_VDPA_GET_STATUS,
 	[VHOST_USER_SET_VRING_ENABLE] = VHOST_VDPA_SET_VRING_ENABLE,
+	[VHOST_USER_GET_PROTOCOL_FEATURES] = VHOST_GET_BACKEND_FEATURES,
+	[VHOST_USER_SET_PROTOCOL_FEATURES] = VHOST_SET_BACKEND_FEATURES,
 };

 /* no alignment requirement */

@@ -86,6 +90,11 @@ vhost_vdpa_dma_map(struct virtio_user_dev *dev, void

*addr,

quoted

quoted

 {
 	struct vhost_msg msg = {};

+	if (!(dev->protocol_features & (1ULL << VHOST_BACKEND_F_IOTLB_MSG_V2)))
{
+		PMD_DRV_LOG(ERR, "IOTLB_MSG_V2 not supported by the backend.");
+		return -1;
+	}
+
 	msg.type = VHOST_IOTLB_MSG_V2;
 	msg.iotlb.type = VHOST_IOTLB_UPDATE;
 	msg.iotlb.iova = iova;

@@ -108,6 +117,11 @@ vhost_vdpa_dma_unmap(struct virtio_user_dev *dev,

__rte_unused void *addr,
 {
 	struct vhost_msg msg = {};

+	if (!(dev->protocol_features & (1ULL << VHOST_BACKEND_F_IOTLB_MSG_V2)))
{
+		PMD_DRV_LOG(ERR, "IOTLB_MSG_V2 not supported by the backend.");
+		return -1;
+	}
+
 	msg.type = VHOST_IOTLB_MSG_V2;
 	msg.iotlb.type = VHOST_IOTLB_INVALIDATE;
 	msg.iotlb.iova = iova;

diff --git a/drivers/net/virtio/virtio_user/virtio_user_dev.c

b/drivers/net/virtio/virtio_user/virtio_user_dev.c
index 053f0267ca..96bc6b232d 100644

--- a/drivers/net/virtio/virtio_user/virtio_user_dev.c
+++ b/drivers/net/virtio/virtio_user/virtio_user_dev.c

@@ -439,11 +439,13 @@ virtio_user_dev_setup(struct virtio_user_dev *dev)
 	 1ULL << VIRTIO_F_RING_PACKED		|	\
 	 1ULL << VHOST_USER_F_PROTOCOL_FEATURES)

-#define VIRTIO_USER_SUPPORTED_PROTOCOL_FEATURES		\
+#define VHOST_USER_SUPPORTED_PROTOCOL_FEATURES		\
 	(1ULL << VHOST_USER_PROTOCOL_F_MQ |		\
 	 1ULL << VHOST_USER_PROTOCOL_F_REPLY_ACK |	\
 	 1ULL << VHOST_USER_PROTOCOL_F_STATUS)

+#define VHOST_VDPA_SUPPORTED_PROTOCOL_FEATURES		\
+	(1ULL << VHOST_BACKEND_F_IOTLB_MSG_V2)
 int
 virtio_user_dev_init(struct virtio_user_dev *dev, char *path, int queues,
 		     int cq, int queue_size, const char *mac, char **ifname,

@@ -462,9 +464,13 @@ virtio_user_dev_init(struct virtio_user_dev *dev, char

*path, int queues,
 	dev->mac_specified = 0;
 	dev->frontend_features = 0;
 	dev->unsupported_features = ~VIRTIO_USER_SUPPORTED_FEATURES;
-	dev->protocol_features = VIRTIO_USER_SUPPORTED_PROTOCOL_FEATURES;
 	dev->backend_type = backend_type;

+	if (dev->backend_type == VIRTIO_USER_BACKEND_VHOST_USER)
+		dev->protocol_features = VHOST_USER_SUPPORTED_PROTOCOL_FEATURES;
+	else if (dev->backend_type == VIRTIO_USER_BACKEND_VHOST_VDPA)
+		dev->protocol_features = VHOST_VDPA_SUPPORTED_PROTOCOL_FEATURES;
+
 	parse_mac(dev, mac);

 	if (*ifname) {

@@ -497,8 +503,8 @@ virtio_user_dev_init(struct virtio_user_dev *dev, char

*path, int queues,
 		}


-		if (dev->device_features &
-				(1ULL << VHOST_USER_F_PROTOCOL_FEATURES)) {
+		if ((dev->device_features & (1ULL <<
VHOST_USER_F_PROTOCOL_FEATURES) ||
+				dev->backend_type == VIRTIO_USER_BACKEND_VHOST_VDPA))

Do you mean:

if ((dev->device_features & (1ULL << VHOST_USER_F_PROTOCOL_FEATURES)) ||
				(dev->backend_type == VIRTIO_USER_BACKEND_VHOST_VDPA))

{

quoted

here?

Indeed!

quoted

Besides, I think it's better to update here as vhost-vdpa also uses

protocol_features.

quoted

(http://code.dpdk.org/dpdk/v20.08/source/drivers/net/virtio/virtio_user/virtio
_user_dev.h#L44)

Not sure what you mean here? Can you please elaborate?

Sorry, I'm not clear on this. It's just a small point about code comment.

In http://code.dpdk.org/dpdk/v20.11/source/drivers/net/virtio/virtio_user/virtio_user_dev.h#L52,
It says 'negotiated protocol features(vhost-user only)'. Since it's also used by vhost-vdpa now,
maybe it's better to improve it. What do you think?

I think it makes sense!
Note that in my Virtio PMD rework series, this field disappears, meaning
that once this series applied, I will need to rebase my rework on top of
it so that vhost-vdpa backend features is moved into vhost_vdpa.c.

In the mean time, I will remove the "(vhost-user only)" comment.

Thanks,
Maxime

Thanks!
Chenbo

quoted

Thanks!
Maxime

quoted

Thanks!
Chenbo

quoted

{
 			if (dev->ops->send_request(dev,
 					VHOST_USER_GET_PROTOCOL_FEATURES,
 					&protocol_features))
--
2.26.2