[dpdk-dev] [PATCH v7 00/19] vhost: add postcopy live-migration support

[dpdk-dev] [PATCH v7 00/19] vhost: add postcopy live-migration support

[Maxime Coquelin]

In this v7:
- Move vh_result enum declaration to vhost.h (Ilya)
- Remove check in read_fd_message() for more fds received
  than requested as already checked with MSG_CTRUNC (Ilya)
- Don't return an error in vhost-crypto post message handler
  if not a crypto message as all messages go through it.

With classic live-migration, the VM runs on source while its
content is being migrated to destination. When pages already
migrated to destination are dirtied by the source, they get
copied until both source and destination memory converge.
At that time, the source is stopped and destination is
started.

With postcopy live-migration, the VM is started on destination
before all the memory has been migrated. When the VM tries to
access a page that haven't been migrated yet, a pagefault is
triggered, handled by userfaultfd which pauses the thread.
A Qemu thread in charge of postcopy request the source for
the missing page. Once received and mapped, the paused thread
gets resumed.

Userfaultfd supports handling faults from a different process,
and Qemu supports postcopy with vhost-user backends since
v2.12.

One problem encountered with classic live-migration for VMs
relying on vhost-user backends is that when the traffic is
high (e.g. PVP), it happens that it never converges as
pages gets dirtied at a faster rate than they are copied
to the destination.
It is expected this problem sould be solved with using
postcopy, as rings memory and buffers will be copied once,
when destination will pagefault on them.

Note that it will certainly require a rebase to apply on top
of Nikolay's vhost-user message handling rework.

Steps to test postcopy:
1. Run DPDK's Testpmd application on source:
./install/bin/testpmd -m 512 --file-prefix=src -l 0,2 -n 4 \
  --vdev 'net_vhost0,iface=/tmp/vu-src' -- --portmask=1 -i \
  --rxq=1 --txq=1 --nb-cores=1 --eth-peer=0,52:54:00:11:22:12 \
  --no-mlockall

2. Run DPDK's Testpmd application on destination:
./install/bin/testpmd -m 512 --file-prefix=dst -l 0,2 -n 4 \
  --vdev 'net_vhost0,iface=/tmp/vu-dst,postcopy-support=1' -- --portmask=1 -i \
  --rxq=1 --txq=1 --nb-cores=1 --eth-peer=0,52:54:00:11:22:12 \
  --no-mlockall

3. Launch VM on source:
./x86_64-softmmu/qemu-system-x86_64 -enable-kvm -m 3G -smp 2 -cpu host \
  -object memory-backend-file,id=mem,size=3G,mem-path=/dev/shm,share=on \
  -numa node,memdev=mem -mem-prealloc \
  -chardev socket,id=char0,path=/tmp/vu-src \
  -netdev type=vhost-user,id=mynet1,chardev=char0,vhostforce \
  -device virtio-net-pci,netdev=mynet1 /home/virt/rhel7.6-1-clone.qcow2 \
  -net none -vnc :0 -monitor stdio

4. Launch VM on destination:
./x86_64-softmmu/qemu-system-x86_64 -enable-kvm -m 3G -smp 2 -cpu host \
  -object memory-backend-file,id=mem,size=3G,mem-path=/dev/shm,share=on \
  -numa node,memdev=mem -mem-prealloc \
  -chardev socket,id=char0,path=/tmp/vu-dst \
  -netdev type=vhost-user,id=mynet1,chardev=char0,vhostforce \
  -device virtio-net-pci,netdev=mynet1 /home/virt/rhel7.6-1-clone.qcow2 \
  -net none -vnc :1 -monitor stdio -incoming tcp::8888

5. In both testpmd prompts, start flooding the virtio-net device:
testpmd> set fwd txonly
testpmd> start

6. In destination's Qemu monitor, enable postcopy:
(qemu) migrate_set_capability postcopy-ram on

7. In source's Qemu monitor, enable postcopy and launch migration:
(qemu) migrate_set_capability postcopy-ram on
(qemu) migrate -d tcp:0:8888
(qemu) migrate_start_postcopy

Maxime Coquelin (19):
  vhost: fix messages results handling
  vhost: fix return code of messages requiring replies
  vhost: clarify reply-ack in case a reply was already sent
  vhost: fix payload size of reply
  vhost: fix error handling when mem table gets updated
  vhost: define postcopy protocol flag
  vhost: add number of fds to vhost-user messages and use it
  vhost: pass socket fd to message handling callbacks
  vhost: enable fds passing when sending vhost-user messages
  vhost: add config flag for postcopy feature
  vhost: introduce postcopy's advise message
  vhost: add support for postcopy's listen message
  vhost: register new regions with userfaultfd
  vhost: avoid useless VhostUserMemory copy
  vhost: send userfault range addresses back to qemu
  vhost: add support to postcopy's end request
  vhost: restrict postcopy live-migration enablement
  net/vhost: add parameter to enable postcopy support
  vhost: enable postcopy protocol feature

 config/common_linuxapp              |   1 +
 doc/guides/nics/vhost.rst           |   5 +
 doc/guides/prog_guide/vhost_lib.rst |   8 +
 drivers/net/vhost/rte_eth_vhost.c   |  13 ++
 lib/librte_vhost/meson.build        |   2 +
 lib/librte_vhost/rte_vhost.h        |   5 +
 lib/librte_vhost/socket.c           |  46 +++-
 lib/librte_vhost/vhost.h            |  32 ++-
 lib/librte_vhost/vhost_crypto.c     |  25 +-
 lib/librte_vhost/vhost_user.c       | 344 +++++++++++++++++++++-------
 lib/librte_vhost/vhost_user.h       |  12 +-
 11 files changed, 377 insertions(+), 116 deletions(-)

-- 
2.17.1

[dpdk-dev] [PATCH v7 01/19] vhost: fix messages results handling

[Maxime Coquelin]

Return of message handling has now changed to an enum that can
take non-negative value that is not zero in case a reply is
needed. But the code checking the variable afterwards has not
been updated, leading to success messages handling being
treated as errors.

External post and pre callbacks return type needs also to be
changed to the new enum, so that its handling is consistent.
This is done in this patch alongside with the convertion of
its only user, vhost-crypto backend.

Fixes: 0bff510b5ea6 ("vhost: unify message handling function signature")

Signed-off-by: Maxime Coquelin <maxime.coquelin@redhat.com>
---
 lib/librte_vhost/vhost.h        | 29 ++++++++++++++++------------
 lib/librte_vhost/vhost_crypto.c | 24 +++++++++++------------
 lib/librte_vhost/vhost_user.c   | 34 +++++++++------------------------
 3 files changed, 37 insertions(+), 50 deletions(-)

diff --git a/lib/librte_vhost/vhost.h b/lib/librte_vhost/vhost.h
index 25ffd7614..c12f9d876 100644
--- a/lib/librte_vhost/vhost.h
+++ b/lib/librte_vhost/vhost.h
@@ -284,6 +284,16 @@ struct guest_page {
 	uint64_t size;
 };
 
+/* The possible results of a message handling function */
+enum vh_result {
+	/* Message handling failed */
+	VH_RESULT_ERR   = -1,
+	/* Message handling successful */
+	VH_RESULT_OK    =  0,
+	/* Message handling successful and reply prepared */
+	VH_RESULT_REPLY =  1,
+};
+
 /**
  * function prototype for the vhost backend to handler specific vhost user
  * messages prior to the master message handling
@@ -292,17 +302,15 @@ struct guest_page {
  *  vhost device id
  * @param msg
  *  Message pointer.
- * @param require_reply
- *  If the handler requires sending a reply, this varaible shall be written 1,
- *  otherwise 0.
  * @param skip_master
  *  If the handler requires skipping the master message handling, this variable
  *  shall be written 1, otherwise 0.
  * @return
- *  0 on success, -1 on failure
+ *  VH_RESULT_OK on success, VH_RESULT_REPLY on success with reply,
+ *  VH_RESULT_ERR on failure
  */
-typedef int (*vhost_msg_pre_handle)(int vid, void *msg,
-		uint32_t *require_reply, uint32_t *skip_master);
+typedef enum vh_result (*vhost_msg_pre_handle)(int vid, void *msg,
+		uint32_t *skip_master);
 
 /**
  * function prototype for the vhost backend to handler specific vhost user
@@ -312,14 +320,11 @@ typedef int (*vhost_msg_pre_handle)(int vid, void *msg,
  *  vhost device id
  * @param msg
  *  Message pointer.
- * @param require_reply
- *  If the handler requires sending a reply, this varaible shall be written 1,
- *  otherwise 0.
  * @return
- *  0 on success, -1 on failure
+ *  VH_RESULT_OK on success, VH_RESULT_REPLY on success with reply,
+ *  VH_RESULT_ERR on failure
  */
-typedef int (*vhost_msg_post_handle)(int vid, void *msg,
-		uint32_t *require_reply);
+typedef enum vh_result (*vhost_msg_post_handle)(int vid, void *msg);
 
 /**
  * pre and post vhost user message handlers
diff --git a/lib/librte_vhost/vhost_crypto.c b/lib/librte_vhost/vhost_crypto.c
index 57341ef8f..c592b7a30 100644
--- a/lib/librte_vhost/vhost_crypto.c
+++ b/lib/librte_vhost/vhost_crypto.c
@@ -425,35 +425,33 @@ vhost_crypto_close_sess(struct vhost_crypto *vcrypto, uint64_t session_id)
 	return 0;
 }
 
-static int
-vhost_crypto_msg_post_handler(int vid, void *msg, uint32_t *require_reply)
+static enum vh_result
+vhost_crypto_msg_post_handler(int vid, void *msg)
 {
 	struct virtio_net *dev = get_device(vid);
 	struct vhost_crypto *vcrypto;
 	VhostUserMsg *vmsg = msg;
-	int ret = 0;
+	enum vh_result ret = VH_RESULT_OK;
 
-	if (dev == NULL || require_reply == NULL) {
+	if (dev == NULL) {
 		VC_LOG_ERR("Invalid vid %i", vid);
-		return -EINVAL;
+		return VH_RESULT_ERR;
 	}
 
 	vcrypto = dev->extern_data;
 	if (vcrypto == NULL) {
 		VC_LOG_ERR("Cannot find required data, is it initialized?");
-		return -ENOENT;
+		return VH_RESULT_ERR;
 	}
 
-	*require_reply = 0;
-
 	if (vmsg->request.master == VHOST_USER_CRYPTO_CREATE_SESS) {
 		vhost_crypto_create_sess(vcrypto,
 				&vmsg->payload.crypto_session);
-		*require_reply = 1;
-	} else if (vmsg->request.master == VHOST_USER_CRYPTO_CLOSE_SESS)
-		ret = vhost_crypto_close_sess(vcrypto, vmsg->payload.u64);
-	else
-		ret = -EINVAL;
+		ret = VH_RESULT_REPLY;
+	} else if (vmsg->request.master == VHOST_USER_CRYPTO_CLOSE_SESS) {
+		if (vhost_crypto_close_sess(vcrypto, vmsg->payload.u64))
+			ret = VH_RESULT_ERR;
+	}
 
 	return ret;
 }
diff --git a/lib/librte_vhost/vhost_user.c b/lib/librte_vhost/vhost_user.c
index 7ef3fb4a4..e8375ca34 100644
--- a/lib/librte_vhost/vhost_user.c
+++ b/lib/librte_vhost/vhost_user.c
@@ -71,16 +71,6 @@ static const char *vhost_message_str[VHOST_USER_MAX] = {
 	[VHOST_USER_CRYPTO_CLOSE_SESS] = "VHOST_USER_CRYPTO_CLOSE_SESS",
 };
 
-/* The possible results of a message handling function */
-enum vh_result {
-	/* Message handling failed */
-	VH_RESULT_ERR   = -1,
-	/* Message handling successful */
-	VH_RESULT_OK    =  0,
-	/* Message handling successful and reply prepared */
-	VH_RESULT_REPLY =  1,
-};
-
 static uint64_t
 get_blk_size(int fd)
 {
@@ -1738,14 +1728,11 @@ vhost_user_msg_handler(int vid, int fd)
 	}
 
 	if (dev->extern_ops.pre_msg_handle) {
-		uint32_t need_reply;
-
 		ret = (*dev->extern_ops.pre_msg_handle)(dev->vid,
-				(void *)&msg, &need_reply, &skip_master);
-		if (ret < 0)
+				(void *)&msg, &skip_master);
+		if (ret == VH_RESULT_ERR)
 			goto skip_to_reply;
-
-		if (need_reply)
+		else if (ret == VH_RESULT_REPLY)
 			send_vhost_reply(fd, &msg);
 
 		if (skip_master)
@@ -1783,15 +1770,12 @@ vhost_user_msg_handler(int vid, int fd)
 	}
 
 skip_to_post_handle:
-	if (!ret && dev->extern_ops.post_msg_handle) {
-		uint32_t need_reply;
-
+	if (ret != VH_RESULT_ERR && dev->extern_ops.post_msg_handle) {
 		ret = (*dev->extern_ops.post_msg_handle)(
-				dev->vid, (void *)&msg, &need_reply);
-		if (ret < 0)
+				dev->vid, (void *)&msg);
+		if (ret == VH_RESULT_ERR)
 			goto skip_to_reply;
-
-		if (need_reply)
+		else if (ret == VH_RESULT_REPLY)
 			send_vhost_reply(fd, &msg);
 	}
 
@@ -1800,10 +1784,10 @@ vhost_user_msg_handler(int vid, int fd)
 		vhost_user_unlock_all_queue_pairs(dev);
 
 	if (msg.flags & VHOST_USER_NEED_REPLY) {
-		msg.payload.u64 = !!ret;
+		msg.payload.u64 = ret == VH_RESULT_ERR;
 		msg.size = sizeof(msg.payload.u64);
 		send_vhost_reply(fd, &msg);
-	} else if (ret) {
+	} else if (ret == VH_RESULT_ERR) {
 		RTE_LOG(ERR, VHOST_CONFIG,
 			"vhost message handling failed.\n");
 		return -1;
-- 
2.17.1

[dpdk-dev] [PATCH v7 02/19] vhost: fix return code of messages requiring replies

[Maxime Coquelin]

VHOST_USER_GET_PROTOCOL_FEATURES, VHOST_USER_GET_VRING_BASE
and VHOST_USER_SET_LOG_BASE require replies, so their handlers
should return VH_RESULT_REPLY, not VH_RESULT_OK.

Fixes: 0bff510b5ea6 ("vhost: unify message handling function signature")

Signed-off-by: Maxime Coquelin <maxime.coquelin@redhat.com>
Acked-by: Ilya Maximets <i.maximets@samsung.com>
Reviewed-by: Tiwei Bie <tiwei.bie@intel.com>
---
 lib/librte_vhost/vhost_user.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/lib/librte_vhost/vhost_user.c b/lib/librte_vhost/vhost_user.c
index e8375ca34..09a90a20b 100644
--- a/lib/librte_vhost/vhost_user.c
+++ b/lib/librte_vhost/vhost_user.c
@@ -1151,7 +1151,7 @@ vhost_user_get_vring_base(struct virtio_net **pdev,
 
 	msg->size = sizeof(msg->payload.state);
 
-	return VH_RESULT_OK;
+	return VH_RESULT_REPLY;
 }
 
 /*
@@ -1208,7 +1208,7 @@ vhost_user_get_protocol_features(struct virtio_net **pdev,
 	msg->payload.u64 = protocol_features;
 	msg->size = sizeof(msg->payload.u64);
 
-	return VH_RESULT_OK;
+	return VH_RESULT_REPLY;
 }
 
 static int
@@ -1288,7 +1288,7 @@ vhost_user_set_log_base(struct virtio_net **pdev, struct VhostUserMsg *msg)
 
 	msg->size = sizeof(msg->payload.u64);
 
-	return VH_RESULT_OK;
+	return VH_RESULT_REPLY;
 }
 
 static int vhost_user_set_log_fd(struct virtio_net **pdev __rte_unused,
-- 
2.17.1

[dpdk-dev] [PATCH v7 03/19] vhost: clarify reply-ack in case a reply was already sent

[Maxime Coquelin]

For messages that require a reply, a second ack should not be
sent when reply-ack protocol feature is negotiated, even if
the corresponding flag is set in the message.

The code is compliant with the spec but it isn't clear it is,
so this patch adds a comment to make it explicit.

Suggested-by: Ilya Maximets <i.maximets@samsung.com>
Signed-off-by: Maxime Coquelin <maxime.coquelin@redhat.com>
Acked-by: Ilya Maximets <i.maximets@samsung.com>
Reviewed-by: Tiwei Bie <tiwei.bie@intel.com>
---
 lib/librte_vhost/vhost_user.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/lib/librte_vhost/vhost_user.c b/lib/librte_vhost/vhost_user.c
index 09a90a20b..a7729990d 100644
--- a/lib/librte_vhost/vhost_user.c
+++ b/lib/librte_vhost/vhost_user.c
@@ -1783,6 +1783,11 @@ vhost_user_msg_handler(int vid, int fd)
 	if (unlock_required)
 		vhost_user_unlock_all_queue_pairs(dev);
 
+	/*
+	 * If the request required a reply that was already sent,
+	 * this optional reply-ack won't be sent as the
+	 * VHOST_USER_NEED_REPLY was cleared in send_vhost_reply().
+	 */
 	if (msg.flags & VHOST_USER_NEED_REPLY) {
 		msg.payload.u64 = ret == VH_RESULT_ERR;
 		msg.size = sizeof(msg.payload.u64);
-- 
2.17.1

[dpdk-dev] [PATCH v7 04/19] vhost: fix payload size of reply

[Maxime Coquelin]

QEMU doesn't expect any payload for the reply of
VHOST_USER_SET_LOG_BASE request, so don't send any.
Note that the Vhost-user specification isn't clear about
it and would need to be fixed.

Fixes: 54f9e32305d4 ("vhost: handle dirty pages logging request")
Cc: stable@dpdk.org

Reported-by: Ilya Maximets <i.maximets@samsung.com>
Signed-off-by: Maxime Coquelin <maxime.coquelin@redhat.com>
Acked-by: Ilya Maximets <i.maximets@samsung.com>
---
 lib/librte_vhost/vhost_user.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/lib/librte_vhost/vhost_user.c b/lib/librte_vhost/vhost_user.c
index a7729990d..1ef02c943 100644
--- a/lib/librte_vhost/vhost_user.c
+++ b/lib/librte_vhost/vhost_user.c
@@ -1286,7 +1286,11 @@ vhost_user_set_log_base(struct virtio_net **pdev, struct VhostUserMsg *msg)
 	dev->log_base = dev->log_addr + off;
 	dev->log_size = size;
 
-	msg->size = sizeof(msg->payload.u64);
+	/*
+	 * The spec is not clear about it (yet), but QEMU doesn't expect
+	 * any payload in the reply.
+	 */
+	msg->size = 0;
 
 	return VH_RESULT_REPLY;
 }
-- 
2.17.1

[dpdk-dev] [PATCH v7 05/19] vhost: fix error handling when mem table gets updated

[Maxime Coquelin]

When the memory table gets updated, the rings addresses need
to be translated again. If it fails, we need to exit cleanly
by unmapping memory regions.

Fixes: d5022533c20a ("vhost: retranslate vring addr when memory table changes")
Cc: stable@dpdk.org

Signed-off-by: Maxime Coquelin <maxime.coquelin@redhat.com>
Acked-by: Ilya Maximets <i.maximets@samsung.com>
---
 lib/librte_vhost/vhost_user.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/lib/librte_vhost/vhost_user.c b/lib/librte_vhost/vhost_user.c
index 1ef02c943..83d3e6321 100644
--- a/lib/librte_vhost/vhost_user.c
+++ b/lib/librte_vhost/vhost_user.c
@@ -953,8 +953,10 @@ vhost_user_set_mem_table(struct virtio_net **pdev, struct VhostUserMsg *msg)
 			vring_invalidate(dev, vq);
 
 			dev = translate_ring_addresses(dev, i);
-			if (!dev)
-				return VH_RESULT_ERR;
+			if (!dev) {
+				dev = *pdev;
+				goto err_mmap;
+			}
 
 			*pdev = dev;
 		}
-- 
2.17.1

[dpdk-dev] [PATCH v7 06/19] vhost: define postcopy protocol flag

[Maxime Coquelin]

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Maxime Coquelin <maxime.coquelin@redhat.com>
Acked-by: Ilya Maximets <i.maximets@samsung.com>
Reviewed-by: Tiwei Bie <tiwei.bie@intel.com>
---
 lib/librte_vhost/rte_vhost.h | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/lib/librte_vhost/rte_vhost.h b/lib/librte_vhost/rte_vhost.h
index b02673d4a..9292c89c5 100644
--- a/lib/librte_vhost/rte_vhost.h
+++ b/lib/librte_vhost/rte_vhost.h
@@ -58,6 +58,10 @@ extern "C" {
 #define VHOST_USER_PROTOCOL_F_CRYPTO_SESSION 7
 #endif
 
+#ifndef VHOST_USER_PROTOCOL_F_PAGEFAULT
+#define VHOST_USER_PROTOCOL_F_PAGEFAULT 8
+#endif
+
 #ifndef VHOST_USER_PROTOCOL_F_SLAVE_SEND_FD
 #define VHOST_USER_PROTOCOL_F_SLAVE_SEND_FD 10
 #endif
-- 
2.17.1

[dpdk-dev] [PATCH v7 07/19] vhost: add number of fds to vhost-user messages and use it

[Maxime Coquelin]

As soon as some ancillary data (fds) are received, it is copied
without checking its length.

This patch adds the number of fds received to the message,
which is set in read_vhost_message().

This is preliminary work to support sending fds to Qemu.

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Maxime Coquelin <maxime.coquelin@redhat.com>
---
 lib/librte_vhost/socket.c     | 16 +++++++++++-----
 lib/librte_vhost/vhost_user.c |  2 +-
 lib/librte_vhost/vhost_user.h |  4 +++-
 3 files changed, 15 insertions(+), 7 deletions(-)

diff --git a/lib/librte_vhost/socket.c b/lib/librte_vhost/socket.c
index d63031747..c278e9b5b 100644
--- a/lib/librte_vhost/socket.c
+++ b/lib/librte_vhost/socket.c
@@ -94,18 +94,23 @@ static struct vhost_user vhost_user = {
 	.mutex = PTHREAD_MUTEX_INITIALIZER,
 };
 
-/* return bytes# of read on success or negative val on failure. */
+/*
+ * return bytes# of read on success or negative val on failure. Update fdnum
+ * with number of fds read.
+ */
 int
-read_fd_message(int sockfd, char *buf, int buflen, int *fds, int fd_num)
+read_fd_message(int sockfd, char *buf, int buflen, int *fds, int max_fds,
+		int *fd_num)
 {
 	struct iovec iov;
 	struct msghdr msgh;
-	size_t fdsize = fd_num * sizeof(int);
-	char control[CMSG_SPACE(fdsize)];
+	char control[CMSG_SPACE(max_fds * sizeof(int))];
 	struct cmsghdr *cmsg;
 	int got_fds = 0;
 	int ret;
 
+	*fd_num = 0;
+
 	memset(&msgh, 0, sizeof(msgh));
 	iov.iov_base = buf;
 	iov.iov_len  = buflen;
@@ -131,13 +136,14 @@ read_fd_message(int sockfd, char *buf, int buflen, int *fds, int fd_num)
 		if ((cmsg->cmsg_level == SOL_SOCKET) &&
 			(cmsg->cmsg_type == SCM_RIGHTS)) {
 			got_fds = (cmsg->cmsg_len - CMSG_LEN(0)) / sizeof(int);
+			*fd_num = got_fds;
 			memcpy(fds, CMSG_DATA(cmsg), got_fds * sizeof(int));
 			break;
 		}
 	}
 
 	/* Clear out unused file descriptors */
-	while (got_fds < fd_num)
+	while (got_fds < max_fds)
 		fds[got_fds++] = -1;
 
 	return ret;
diff --git a/lib/librte_vhost/vhost_user.c b/lib/librte_vhost/vhost_user.c
index 83d3e6321..c1c5f35ff 100644
--- a/lib/librte_vhost/vhost_user.c
+++ b/lib/librte_vhost/vhost_user.c
@@ -1509,7 +1509,7 @@ read_vhost_message(int sockfd, struct VhostUserMsg *msg)
 	int ret;
 
 	ret = read_fd_message(sockfd, (char *)msg, VHOST_USER_HDR_SIZE,
-		msg->fds, VHOST_MEMORY_MAX_NREGIONS);
+		msg->fds, VHOST_MEMORY_MAX_NREGIONS, &msg->fd_num);
 	if (ret <= 0)
 		return ret;
 
diff --git a/lib/librte_vhost/vhost_user.h b/lib/librte_vhost/vhost_user.h
index 42166adf2..dd0262f8f 100644
--- a/lib/librte_vhost/vhost_user.h
+++ b/lib/librte_vhost/vhost_user.h
@@ -132,6 +132,7 @@ typedef struct VhostUserMsg {
 		VhostUserVringArea area;
 	} payload;
 	int fds[VHOST_MEMORY_MAX_NREGIONS];
+	int fd_num;
 } __attribute((packed)) VhostUserMsg;
 
 #define VHOST_USER_HDR_SIZE offsetof(VhostUserMsg, payload.u64)
@@ -146,7 +147,8 @@ int vhost_user_iotlb_miss(struct virtio_net *dev, uint64_t iova, uint8_t perm);
 int vhost_user_host_notifier_ctrl(int vid, bool enable);
 
 /* socket.c */
-int read_fd_message(int sockfd, char *buf, int buflen, int *fds, int fd_num);
+int read_fd_message(int sockfd, char *buf, int buflen, int *fds, int max_fds,
+		int *fd_num);
 int send_fd_message(int sockfd, char *buf, int buflen, int *fds, int fd_num);
 
 #endif
-- 
2.17.1

[dpdk-dev] [PATCH v7 08/19] vhost: pass socket fd to message handling callbacks

[Maxime Coquelin]

This is not used for now, but will be needed for the
special handling of VHOST_USER_SET_MEM_TABLE message
once postcopy will be supported.

Signed-off-by: Maxime Coquelin <maxime.coquelin@redhat.com>
---
 lib/librte_vhost/vhost_user.c | 71 +++++++++++++++++++++++------------
 1 file changed, 47 insertions(+), 24 deletions(-)

diff --git a/lib/librte_vhost/vhost_user.c b/lib/librte_vhost/vhost_user.c
index c1c5f35ff..bce2395a3 100644
--- a/lib/librte_vhost/vhost_user.c
+++ b/lib/librte_vhost/vhost_user.c
@@ -128,14 +128,16 @@ vhost_backend_cleanup(struct virtio_net *dev)
  */
 static int
 vhost_user_set_owner(struct virtio_net **pdev __rte_unused,
-		struct VhostUserMsg *msg __rte_unused)
+			struct VhostUserMsg *msg __rte_unused,
+			int main_fd __rte_unused)
 {
 	return VH_RESULT_OK;
 }
 
 static int
 vhost_user_reset_owner(struct virtio_net **pdev,
-		struct VhostUserMsg *msg __rte_unused)
+			struct VhostUserMsg *msg __rte_unused,
+			int main_fd __rte_unused)
 {
 	struct virtio_net *dev = *pdev;
 	vhost_destroy_device_notify(dev);
@@ -149,7 +151,8 @@ vhost_user_reset_owner(struct virtio_net **pdev,
  * The features that we support are requested.
  */
 static int
-vhost_user_get_features(struct virtio_net **pdev, struct VhostUserMsg *msg)
+vhost_user_get_features(struct virtio_net **pdev, struct VhostUserMsg *msg,
+			int main_fd __rte_unused)
 {
 	struct virtio_net *dev = *pdev;
 	uint64_t features = 0;
@@ -166,7 +169,8 @@ vhost_user_get_features(struct virtio_net **pdev, struct VhostUserMsg *msg)
  * The queue number that we support are requested.
  */
 static int
-vhost_user_get_queue_num(struct virtio_net **pdev, struct VhostUserMsg *msg)
+vhost_user_get_queue_num(struct virtio_net **pdev, struct VhostUserMsg *msg,
+			int main_fd __rte_unused)
 {
 	struct virtio_net *dev = *pdev;
 	uint32_t queue_num = 0;
@@ -183,7 +187,8 @@ vhost_user_get_queue_num(struct virtio_net **pdev, struct VhostUserMsg *msg)
  * We receive the negotiated features supported by us and the virtio device.
  */
 static int
-vhost_user_set_features(struct virtio_net **pdev, struct VhostUserMsg *msg)
+vhost_user_set_features(struct virtio_net **pdev, struct VhostUserMsg *msg,
+			int main_fd __rte_unused)
 {
 	struct virtio_net *dev = *pdev;
 	uint64_t features = msg->payload.u64;
@@ -265,7 +270,8 @@ vhost_user_set_features(struct virtio_net **pdev, struct VhostUserMsg *msg)
  */
 static int
 vhost_user_set_vring_num(struct virtio_net **pdev,
-			 struct VhostUserMsg *msg)
+			struct VhostUserMsg *msg,
+			int main_fd __rte_unused)
 {
 	struct virtio_net *dev = *pdev;
 	struct vhost_virtqueue *vq = dev->virtqueue[msg->payload.state.index];
@@ -627,7 +633,8 @@ translate_ring_addresses(struct virtio_net *dev, int vq_index)
  * This function then converts these to our address space.
  */
 static int
-vhost_user_set_vring_addr(struct virtio_net **pdev, struct VhostUserMsg *msg)
+vhost_user_set_vring_addr(struct virtio_net **pdev, struct VhostUserMsg *msg,
+			int main_fd __rte_unused)
 {
 	struct virtio_net *dev = *pdev;
 	struct vhost_virtqueue *vq;
@@ -664,7 +671,8 @@ vhost_user_set_vring_addr(struct virtio_net **pdev, struct VhostUserMsg *msg)
  */
 static int
 vhost_user_set_vring_base(struct virtio_net **pdev,
-			  struct VhostUserMsg *msg)
+			struct VhostUserMsg *msg,
+			int main_fd __rte_unused)
 {
 	struct virtio_net *dev = *pdev;
 	dev->virtqueue[msg->payload.state.index]->last_used_idx  =
@@ -797,7 +805,8 @@ vhost_memory_changed(struct VhostUserMemory *new,
 }
 
 static int
-vhost_user_set_mem_table(struct virtio_net **pdev, struct VhostUserMsg *msg)
+vhost_user_set_mem_table(struct virtio_net **pdev, struct VhostUserMsg *msg,
+			int main_fd __rte_unused)
 {
 	struct virtio_net *dev = *pdev;
 	struct VhostUserMemory memory = msg->payload.memory;
@@ -1013,7 +1022,8 @@ virtio_is_ready(struct virtio_net *dev)
 }
 
 static int
-vhost_user_set_vring_call(struct virtio_net **pdev, struct VhostUserMsg *msg)
+vhost_user_set_vring_call(struct virtio_net **pdev, struct VhostUserMsg *msg,
+			int main_fd __rte_unused)
 {
 	struct virtio_net *dev = *pdev;
 	struct vhost_vring_file file;
@@ -1037,7 +1047,8 @@ vhost_user_set_vring_call(struct virtio_net **pdev, struct VhostUserMsg *msg)
 }
 
 static int vhost_user_set_vring_err(struct virtio_net **pdev __rte_unused,
-			struct VhostUserMsg *msg)
+			struct VhostUserMsg *msg,
+			int main_fd __rte_unused)
 {
 	if (!(msg->payload.u64 & VHOST_USER_VRING_NOFD_MASK))
 		close(msg->fds[0]);
@@ -1047,7 +1058,8 @@ static int vhost_user_set_vring_err(struct virtio_net **pdev __rte_unused,
 }
 
 static int
-vhost_user_set_vring_kick(struct virtio_net **pdev, struct VhostUserMsg *msg)
+vhost_user_set_vring_kick(struct virtio_net **pdev, struct VhostUserMsg *msg,
+			int main_fd __rte_unused)
 {
 	struct virtio_net *dev = *pdev;
 	struct vhost_vring_file file;
@@ -1106,7 +1118,8 @@ free_zmbufs(struct vhost_virtqueue *vq)
  */
 static int
 vhost_user_get_vring_base(struct virtio_net **pdev,
-			  struct VhostUserMsg *msg)
+			struct VhostUserMsg *msg,
+			int main_fd __rte_unused)
 {
 	struct virtio_net *dev = *pdev;
 	struct vhost_virtqueue *vq = dev->virtqueue[msg->payload.state.index];
@@ -1162,7 +1175,8 @@ vhost_user_get_vring_base(struct virtio_net **pdev,
  */
 static int
 vhost_user_set_vring_enable(struct virtio_net **pdev,
-			    struct VhostUserMsg *msg)
+			struct VhostUserMsg *msg,
+			int main_fd __rte_unused)
 {
 	struct virtio_net *dev = *pdev;
 	int enable = (int)msg->payload.state.num;
@@ -1190,7 +1204,8 @@ vhost_user_set_vring_enable(struct virtio_net **pdev,
 
 static int
 vhost_user_get_protocol_features(struct virtio_net **pdev,
-				 struct VhostUserMsg *msg)
+			struct VhostUserMsg *msg,
+			int main_fd __rte_unused)
 {
 	struct virtio_net *dev = *pdev;
 	uint64_t features, protocol_features;
@@ -1215,7 +1230,8 @@ vhost_user_get_protocol_features(struct virtio_net **pdev,
 
 static int
 vhost_user_set_protocol_features(struct virtio_net **pdev,
-				 struct VhostUserMsg *msg)
+			struct VhostUserMsg *msg,
+			int main_fd __rte_unused)
 {
 	struct virtio_net *dev = *pdev;
 	uint64_t protocol_features = msg->payload.u64;
@@ -1232,7 +1248,8 @@ vhost_user_set_protocol_features(struct virtio_net **pdev,
 }
 
 static int
-vhost_user_set_log_base(struct virtio_net **pdev, struct VhostUserMsg *msg)
+vhost_user_set_log_base(struct virtio_net **pdev, struct VhostUserMsg *msg,
+			int main_fd __rte_unused)
 {
 	struct virtio_net *dev = *pdev;
 	int fd = msg->fds[0];
@@ -1298,7 +1315,8 @@ vhost_user_set_log_base(struct virtio_net **pdev, struct VhostUserMsg *msg)
 }
 
 static int vhost_user_set_log_fd(struct virtio_net **pdev __rte_unused,
-			struct VhostUserMsg *msg)
+			struct VhostUserMsg *msg,
+			int main_fd __rte_unused)
 {
 	close(msg->fds[0]);
 	RTE_LOG(INFO, VHOST_CONFIG, "not implemented.\n");
@@ -1315,7 +1333,8 @@ static int vhost_user_set_log_fd(struct virtio_net **pdev __rte_unused,
  * a flag 'broadcast_rarp' to let rte_vhost_dequeue_burst() inject it.
  */
 static int
-vhost_user_send_rarp(struct virtio_net **pdev, struct VhostUserMsg *msg)
+vhost_user_send_rarp(struct virtio_net **pdev, struct VhostUserMsg *msg,
+			int main_fd __rte_unused)
 {
 	struct virtio_net *dev = *pdev;
 	uint8_t *mac = (uint8_t *)&msg->payload.u64;
@@ -1345,7 +1364,8 @@ vhost_user_send_rarp(struct virtio_net **pdev, struct VhostUserMsg *msg)
 }
 
 static int
-vhost_user_net_set_mtu(struct virtio_net **pdev, struct VhostUserMsg *msg)
+vhost_user_net_set_mtu(struct virtio_net **pdev, struct VhostUserMsg *msg,
+			int main_fd __rte_unused)
 {
 	struct virtio_net *dev = *pdev;
 	if (msg->payload.u64 < VIRTIO_MIN_MTU ||
@@ -1362,7 +1382,8 @@ vhost_user_net_set_mtu(struct virtio_net **pdev, struct VhostUserMsg *msg)
 }
 
 static int
-vhost_user_set_req_fd(struct virtio_net **pdev, struct VhostUserMsg *msg)
+vhost_user_set_req_fd(struct virtio_net **pdev, struct VhostUserMsg *msg,
+			int main_fd __rte_unused)
 {
 	struct virtio_net *dev = *pdev;
 	int fd = msg->fds[0];
@@ -1429,7 +1450,8 @@ is_vring_iotlb_invalidate(struct vhost_virtqueue *vq,
 }
 
 static int
-vhost_user_iotlb_msg(struct virtio_net **pdev, struct VhostUserMsg *msg)
+vhost_user_iotlb_msg(struct virtio_net **pdev, struct VhostUserMsg *msg,
+			int main_fd __rte_unused)
 {
 	struct virtio_net *dev = *pdev;
 	struct vhost_iotlb_msg *imsg = &msg->payload.iotlb;
@@ -1474,7 +1496,8 @@ vhost_user_iotlb_msg(struct virtio_net **pdev, struct VhostUserMsg *msg)
 }
 
 typedef int (*vhost_message_handler_t)(struct virtio_net **pdev,
-					struct VhostUserMsg *msg);
+					struct VhostUserMsg *msg,
+					int main_fd);
 static vhost_message_handler_t vhost_message_handlers[VHOST_USER_MAX] = {
 	[VHOST_USER_NONE] = NULL,
 	[VHOST_USER_GET_FEATURES] = vhost_user_get_features,
@@ -1749,7 +1772,7 @@ vhost_user_msg_handler(int vid, int fd)
 	if (request > VHOST_USER_NONE && request < VHOST_USER_MAX) {
 		if (!vhost_message_handlers[request])
 			goto skip_to_post_handle;
-		ret = vhost_message_handlers[request](&dev, &msg);
+		ret = vhost_message_handlers[request](&dev, &msg, fd);
 
 		switch (ret) {
 		case VH_RESULT_ERR:
-- 
2.17.1

[dpdk-dev] [PATCH v7 09/19] vhost: enable fds passing when sending vhost-user messages

[Maxime Coquelin]

Passing userfault fds to Qemu will be required for postcopy
live-migration feature.

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Maxime Coquelin <maxime.coquelin@redhat.com>
---
 lib/librte_vhost/vhost_crypto.c |  1 +
 lib/librte_vhost/vhost_user.c   | 27 +++++++++++++++------------
 2 files changed, 16 insertions(+), 12 deletions(-)

diff --git a/lib/librte_vhost/vhost_crypto.c b/lib/librte_vhost/vhost_crypto.c
index c592b7a30..9811a232a 100644
--- a/lib/librte_vhost/vhost_crypto.c
+++ b/lib/librte_vhost/vhost_crypto.c
@@ -447,6 +447,7 @@ vhost_crypto_msg_post_handler(int vid, void *msg)
 	if (vmsg->request.master == VHOST_USER_CRYPTO_CREATE_SESS) {
 		vhost_crypto_create_sess(vcrypto,
 				&vmsg->payload.crypto_session);
+		vmsg->fd_num = 0;
 		ret = VH_RESULT_REPLY;
 	} else if (vmsg->request.master == VHOST_USER_CRYPTO_CLOSE_SESS) {
 		if (vhost_crypto_close_sess(vcrypto, vmsg->payload.u64))
diff --git a/lib/librte_vhost/vhost_user.c b/lib/librte_vhost/vhost_user.c
index bce2395a3..99adcedfa 100644
--- a/lib/librte_vhost/vhost_user.c
+++ b/lib/librte_vhost/vhost_user.c
@@ -161,6 +161,7 @@ vhost_user_get_features(struct virtio_net **pdev, struct VhostUserMsg *msg,
 
 	msg->payload.u64 = features;
 	msg->size = sizeof(msg->payload.u64);
+	msg->fd_num = 0;
 
 	return VH_RESULT_REPLY;
 }
@@ -179,6 +180,7 @@ vhost_user_get_queue_num(struct virtio_net **pdev, struct VhostUserMsg *msg,
 
 	msg->payload.u64 = (uint64_t)queue_num;
 	msg->size = sizeof(msg->payload.u64);
+	msg->fd_num = 0;
 
 	return VH_RESULT_REPLY;
 }
@@ -1165,6 +1167,7 @@ vhost_user_get_vring_base(struct virtio_net **pdev,
 	vq->batch_copy_elems = NULL;
 
 	msg->size = sizeof(msg->payload.state);
+	msg->fd_num = 0;
 
 	return VH_RESULT_REPLY;
 }
@@ -1224,6 +1227,7 @@ vhost_user_get_protocol_features(struct virtio_net **pdev,
 
 	msg->payload.u64 = protocol_features;
 	msg->size = sizeof(msg->payload.u64);
+	msg->fd_num = 0;
 
 	return VH_RESULT_REPLY;
 }
@@ -1310,6 +1314,7 @@ vhost_user_set_log_base(struct virtio_net **pdev, struct VhostUserMsg *msg,
 	 * any payload in the reply.
 	 */
 	msg->size = 0;
+	msg->fd_num = 0;
 
 	return VH_RESULT_REPLY;
 }
@@ -1556,13 +1561,13 @@ read_vhost_message(int sockfd, struct VhostUserMsg *msg)
 }
 
 static int
-send_vhost_message(int sockfd, struct VhostUserMsg *msg, int *fds, int fd_num)
+send_vhost_message(int sockfd, struct VhostUserMsg *msg)
 {
 	if (!msg)
 		return 0;
 
 	return send_fd_message(sockfd, (char *)msg,
-		VHOST_USER_HDR_SIZE + msg->size, fds, fd_num);
+		VHOST_USER_HDR_SIZE + msg->size, msg->fds, msg->fd_num);
 }
 
 static int
@@ -1576,19 +1581,18 @@ send_vhost_reply(int sockfd, struct VhostUserMsg *msg)
 	msg->flags |= VHOST_USER_VERSION;
 	msg->flags |= VHOST_USER_REPLY_MASK;
 
-	return send_vhost_message(sockfd, msg, NULL, 0);
+	return send_vhost_message(sockfd, msg);
 }
 
 static int
-send_vhost_slave_message(struct virtio_net *dev, struct VhostUserMsg *msg,
-			 int *fds, int fd_num)
+send_vhost_slave_message(struct virtio_net *dev, struct VhostUserMsg *msg)
 {
 	int ret;
 
 	if (msg->flags & VHOST_USER_NEED_REPLY)
 		rte_spinlock_lock(&dev->slave_req_lock);
 
-	ret = send_vhost_message(dev->slave_req_fd, msg, fds, fd_num);
+	ret = send_vhost_message(dev->slave_req_fd, msg);
 	if (ret < 0 && (msg->flags & VHOST_USER_NEED_REPLY))
 		rte_spinlock_unlock(&dev->slave_req_lock);
 
@@ -1820,6 +1824,7 @@ vhost_user_msg_handler(int vid, int fd)
 	if (msg.flags & VHOST_USER_NEED_REPLY) {
 		msg.payload.u64 = ret == VH_RESULT_ERR;
 		msg.size = sizeof(msg.payload.u64);
+		msg.fd_num = 0;
 		send_vhost_reply(fd, &msg);
 	} else if (ret == VH_RESULT_ERR) {
 		RTE_LOG(ERR, VHOST_CONFIG,
@@ -1903,7 +1908,7 @@ vhost_user_iotlb_miss(struct virtio_net *dev, uint64_t iova, uint8_t perm)
 		},
 	};
 
-	ret = send_vhost_message(dev->slave_req_fd, &msg, NULL, 0);
+	ret = send_vhost_message(dev->slave_req_fd, &msg);
 	if (ret < 0) {
 		RTE_LOG(ERR, VHOST_CONFIG,
 				"Failed to send IOTLB miss message (%d)\n",
@@ -1919,8 +1924,6 @@ static int vhost_user_slave_set_vring_host_notifier(struct virtio_net *dev,
 						    uint64_t offset,
 						    uint64_t size)
 {
-	int *fdp = NULL;
-	size_t fd_num = 0;
 	int ret;
 	struct VhostUserMsg msg = {
 		.request.slave = VHOST_USER_SLAVE_VRING_HOST_NOTIFIER_MSG,
@@ -1936,11 +1939,11 @@ static int vhost_user_slave_set_vring_host_notifier(struct virtio_net *dev,
 	if (fd < 0)
 		msg.payload.area.u64 |= VHOST_USER_VRING_NOFD_MASK;
 	else {
-		fdp = &fd;
-		fd_num = 1;
+		msg.fds[0] = fd;
+		msg.fd_num = 1;
 	}
 
-	ret = send_vhost_slave_message(dev, &msg, fdp, fd_num);
+	ret = send_vhost_slave_message(dev, &msg);
 	if (ret < 0) {
 		RTE_LOG(ERR, VHOST_CONFIG,
 			"Failed to set host notifier (%d)\n", ret);
-- 
2.17.1

[dpdk-dev] [PATCH v7 10/19] vhost: add config flag for postcopy feature

[Maxime Coquelin]

Postcopy live-migration features relies on userfaultfd,
which was only introduced in kernel v4.3.

This patch introduces a new define to allow building vhost
library on kernels not supporting userfaultfd.

With legacy build system, user has to explicitly set
CONFIG_RTE_LIBRTE_VHOST_POSTCOPY to 'y'.

With Meson build system, RTE_LIBRTE_VHOST_POSTCOPY gets
automatically defined if userfaultfd kernel header is
present.

Suggested-by: Ilya Maximets <i.maximets@samsung.com>
Signed-off-by: Maxime Coquelin <maxime.coquelin@redhat.com>
Acked-by: Ilya Maximets <i.maximets@samsung.com>
---
 config/common_linuxapp       | 1 +
 lib/librte_vhost/meson.build | 2 ++
 2 files changed, 3 insertions(+)

diff --git a/config/common_linuxapp b/config/common_linuxapp
index 485e1467d..424100a75 100644
--- a/config/common_linuxapp
+++ b/config/common_linuxapp
@@ -14,6 +14,7 @@ CONFIG_RTE_LIBRTE_KNI=y
 CONFIG_RTE_LIBRTE_PMD_KNI=y
 CONFIG_RTE_LIBRTE_VHOST=y
 CONFIG_RTE_LIBRTE_VHOST_NUMA=y
+CONFIG_RTE_LIBRTE_VHOST_POSTCOPY=n
 CONFIG_RTE_LIBRTE_PMD_VHOST=y
 CONFIG_RTE_LIBRTE_IFC_PMD=y
 CONFIG_RTE_LIBRTE_PMD_AF_PACKET=y
diff --git a/lib/librte_vhost/meson.build b/lib/librte_vhost/meson.build
index 9d25b4d88..e33e6fc16 100644
--- a/lib/librte_vhost/meson.build
+++ b/lib/librte_vhost/meson.build
@@ -7,6 +7,8 @@ endif
 if has_libnuma == 1
 	dpdk_conf.set10('RTE_LIBRTE_VHOST_NUMA', true)
 endif
+dpdk_conf.set('RTE_LIBRTE_VHOST_POSTCOPY',
+	      cc.has_header('linux/userfaultfd.h'))
 version = 4
 allow_experimental_apis = true
 cflags += '-fno-strict-aliasing'
-- 
2.17.1

[dpdk-dev] [PATCH v7 11/19] vhost: introduce postcopy's advise message

[Maxime Coquelin]

This patch opens a userfaultfd and sends it back to Qemu's
VHOST_USER_POSTCOPY_ADVISE request.

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Maxime Coquelin <maxime.coquelin@redhat.com>
---
 lib/librte_vhost/vhost.h      |  2 ++
 lib/librte_vhost/vhost_user.c | 50 +++++++++++++++++++++++++++++++++++
 lib/librte_vhost/vhost_user.h |  3 ++-
 3 files changed, 54 insertions(+), 1 deletion(-)

diff --git a/lib/librte_vhost/vhost.h b/lib/librte_vhost/vhost.h
index c12f9d876..d81da0674 100644
--- a/lib/librte_vhost/vhost.h
+++ b/lib/librte_vhost/vhost.h
@@ -368,6 +368,8 @@ struct virtio_net {
 	int			slave_req_fd;
 	rte_spinlock_t		slave_req_lock;
 
+	int			postcopy_ufd;
+
 	/*
 	 * Device id to identify a specific backend device.
 	 * It's set to -1 for the default software implementation.
diff --git a/lib/librte_vhost/vhost_user.c b/lib/librte_vhost/vhost_user.c
index 99adcedfa..970ad5896 100644
--- a/lib/librte_vhost/vhost_user.c
+++ b/lib/librte_vhost/vhost_user.c
@@ -24,13 +24,19 @@
 #include <stdlib.h>
 #include <string.h>
 #include <unistd.h>
+#include <fcntl.h>
+#include <sys/ioctl.h>
 #include <sys/mman.h>
 #include <sys/types.h>
 #include <sys/stat.h>
+#include <sys/syscall.h>
 #include <assert.h>
 #ifdef RTE_LIBRTE_VHOST_NUMA
 #include <numaif.h>
 #endif
+#ifdef RTE_LIBRTE_VHOST_POSTCOPY
+#include <linux/userfaultfd.h>
+#endif
 
 #include <rte_common.h>
 #include <rte_malloc.h>
@@ -69,6 +75,7 @@ static const char *vhost_message_str[VHOST_USER_MAX] = {
 	[VHOST_USER_IOTLB_MSG]  = "VHOST_USER_IOTLB_MSG",
 	[VHOST_USER_CRYPTO_CREATE_SESS] = "VHOST_USER_CRYPTO_CREATE_SESS",
 	[VHOST_USER_CRYPTO_CLOSE_SESS] = "VHOST_USER_CRYPTO_CLOSE_SESS",
+	[VHOST_USER_POSTCOPY_ADVISE]  = "VHOST_USER_POSTCOPY_ADVISE",
 };
 
 static uint64_t
@@ -120,6 +127,11 @@ vhost_backend_cleanup(struct virtio_net *dev)
 		close(dev->slave_req_fd);
 		dev->slave_req_fd = -1;
 	}
+
+	if (dev->postcopy_ufd >= 0) {
+		close(dev->postcopy_ufd);
+		dev->postcopy_ufd = -1;
+	}
 }
 
 /*
@@ -1500,6 +1512,43 @@ vhost_user_iotlb_msg(struct virtio_net **pdev, struct VhostUserMsg *msg,
 	return VH_RESULT_OK;
 }
 
+static int
+vhost_user_set_postcopy_advise(struct virtio_net **pdev,
+			struct VhostUserMsg *msg,
+			int main_fd __rte_unused)
+{
+	struct virtio_net *dev = *pdev;
+#ifdef RTE_LIBRTE_VHOST_POSTCOPY
+	struct uffdio_api api_struct;
+
+	dev->postcopy_ufd = syscall(__NR_userfaultfd, O_CLOEXEC | O_NONBLOCK);
+
+	if (dev->postcopy_ufd == -1) {
+		RTE_LOG(ERR, VHOST_CONFIG, "Userfaultfd not available: %s\n",
+			strerror(errno));
+		return VH_RESULT_ERR;
+	}
+	api_struct.api = UFFD_API;
+	api_struct.features = 0;
+	if (ioctl(dev->postcopy_ufd, UFFDIO_API, &api_struct)) {
+		RTE_LOG(ERR, VHOST_CONFIG, "UFFDIO_API ioctl failure: %s\n",
+			strerror(errno));
+		close(dev->postcopy_ufd);
+		dev->postcopy_ufd = -1;
+		return VH_RESULT_ERR;
+	}
+	msg->fds[0] = dev->postcopy_ufd;
+	msg->fd_num = 1;
+
+	return VH_RESULT_REPLY;
+#else
+	dev->postcopy_ufd = -1;
+	msg->fd_num = 0;
+
+	return VH_RESULT_ERR;
+#endif
+}
+
 typedef int (*vhost_message_handler_t)(struct virtio_net **pdev,
 					struct VhostUserMsg *msg,
 					int main_fd);
@@ -1527,6 +1576,7 @@ static vhost_message_handler_t vhost_message_handlers[VHOST_USER_MAX] = {
 	[VHOST_USER_NET_SET_MTU] = vhost_user_net_set_mtu,
 	[VHOST_USER_SET_SLAVE_REQ_FD] = vhost_user_set_req_fd,
 	[VHOST_USER_IOTLB_MSG] = vhost_user_iotlb_msg,
+	[VHOST_USER_POSTCOPY_ADVISE] = vhost_user_set_postcopy_advise,
 };
 
 
diff --git a/lib/librte_vhost/vhost_user.h b/lib/librte_vhost/vhost_user.h
index dd0262f8f..2030b40a5 100644
--- a/lib/librte_vhost/vhost_user.h
+++ b/lib/librte_vhost/vhost_user.h
@@ -50,7 +50,8 @@ typedef enum VhostUserRequest {
 	VHOST_USER_IOTLB_MSG = 22,
 	VHOST_USER_CRYPTO_CREATE_SESS = 26,
 	VHOST_USER_CRYPTO_CLOSE_SESS = 27,
-	VHOST_USER_MAX = 28
+	VHOST_USER_POSTCOPY_ADVISE = 28,
+	VHOST_USER_MAX = 29
 } VhostUserRequest;
 
 typedef enum VhostUserSlaveRequest {
-- 
2.17.1

[dpdk-dev] [PATCH v7 12/19] vhost: add support for postcopy's listen message

[Maxime Coquelin]

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Maxime Coquelin <maxime.coquelin@redhat.com>
---
 lib/librte_vhost/vhost.h      |  1 +
 lib/librte_vhost/vhost_user.c | 21 +++++++++++++++++++++
 lib/librte_vhost/vhost_user.h |  3 ++-
 3 files changed, 24 insertions(+), 1 deletion(-)

diff --git a/lib/librte_vhost/vhost.h b/lib/librte_vhost/vhost.h
index d81da0674..b4abad30c 100644
--- a/lib/librte_vhost/vhost.h
+++ b/lib/librte_vhost/vhost.h
@@ -369,6 +369,7 @@ struct virtio_net {
 	rte_spinlock_t		slave_req_lock;
 
 	int			postcopy_ufd;
+	int			postcopy_listening;
 
 	/*
 	 * Device id to identify a specific backend device.
diff --git a/lib/librte_vhost/vhost_user.c b/lib/librte_vhost/vhost_user.c
index 970ad5896..051589297 100644
--- a/lib/librte_vhost/vhost_user.c
+++ b/lib/librte_vhost/vhost_user.c
@@ -76,6 +76,7 @@ static const char *vhost_message_str[VHOST_USER_MAX] = {
 	[VHOST_USER_CRYPTO_CREATE_SESS] = "VHOST_USER_CRYPTO_CREATE_SESS",
 	[VHOST_USER_CRYPTO_CLOSE_SESS] = "VHOST_USER_CRYPTO_CLOSE_SESS",
 	[VHOST_USER_POSTCOPY_ADVISE]  = "VHOST_USER_POSTCOPY_ADVISE",
+	[VHOST_USER_POSTCOPY_LISTEN]  = "VHOST_USER_POSTCOPY_LISTEN",
 };
 
 static uint64_t
@@ -132,6 +133,8 @@ vhost_backend_cleanup(struct virtio_net *dev)
 		close(dev->postcopy_ufd);
 		dev->postcopy_ufd = -1;
 	}
+
+	dev->postcopy_listening = 0;
 }
 
 /*
@@ -1549,6 +1552,23 @@ vhost_user_set_postcopy_advise(struct virtio_net **pdev,
 #endif
 }
 
+static int
+vhost_user_set_postcopy_listen(struct virtio_net **pdev,
+			struct VhostUserMsg *msg __rte_unused,
+			int main_fd __rte_unused)
+{
+	struct virtio_net *dev = *pdev;
+
+	if (dev->mem && dev->mem->nregions) {
+		RTE_LOG(ERR, VHOST_CONFIG,
+			"Regions already registered at postcopy-listen\n");
+		return VH_RESULT_ERR;
+	}
+	dev->postcopy_listening = 1;
+
+	return VH_RESULT_OK;
+}
+
 typedef int (*vhost_message_handler_t)(struct virtio_net **pdev,
 					struct VhostUserMsg *msg,
 					int main_fd);
@@ -1577,6 +1597,7 @@ static vhost_message_handler_t vhost_message_handlers[VHOST_USER_MAX] = {
 	[VHOST_USER_SET_SLAVE_REQ_FD] = vhost_user_set_req_fd,
 	[VHOST_USER_IOTLB_MSG] = vhost_user_iotlb_msg,
 	[VHOST_USER_POSTCOPY_ADVISE] = vhost_user_set_postcopy_advise,
+	[VHOST_USER_POSTCOPY_LISTEN] = vhost_user_set_postcopy_listen,
 };
 
 
diff --git a/lib/librte_vhost/vhost_user.h b/lib/librte_vhost/vhost_user.h
index 2030b40a5..55d8659ba 100644
--- a/lib/librte_vhost/vhost_user.h
+++ b/lib/librte_vhost/vhost_user.h
@@ -51,7 +51,8 @@ typedef enum VhostUserRequest {
 	VHOST_USER_CRYPTO_CREATE_SESS = 26,
 	VHOST_USER_CRYPTO_CLOSE_SESS = 27,
 	VHOST_USER_POSTCOPY_ADVISE = 28,
-	VHOST_USER_MAX = 29
+	VHOST_USER_POSTCOPY_LISTEN = 29,
+	VHOST_USER_MAX = 30
 } VhostUserRequest;
 
 typedef enum VhostUserSlaveRequest {
-- 
2.17.1

[dpdk-dev] [PATCH v7 13/19] vhost: register new regions with userfaultfd

[Maxime Coquelin]

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Maxime Coquelin <maxime.coquelin@redhat.com>
---
 lib/librte_vhost/vhost_user.c | 26 ++++++++++++++++++++++++++
 1 file changed, 26 insertions(+)

diff --git a/lib/librte_vhost/vhost_user.c b/lib/librte_vhost/vhost_user.c
index 051589297..91c301ae2 100644
--- a/lib/librte_vhost/vhost_user.c
+++ b/lib/librte_vhost/vhost_user.c
@@ -965,6 +965,32 @@ vhost_user_set_mem_table(struct virtio_net **pdev, struct VhostUserMsg *msg,
 			mmap_size,
 			alignment,
 			mmap_offset);
+
+		if (dev->postcopy_listening) {
+#ifdef RTE_LIBRTE_VHOST_POSTCOPY
+			struct uffdio_register reg_struct;
+
+			reg_struct.range.start = (uint64_t)(uintptr_t)mmap_addr;
+			reg_struct.range.len = mmap_size;
+			reg_struct.mode = UFFDIO_REGISTER_MODE_MISSING;
+
+			if (ioctl(dev->postcopy_ufd, UFFDIO_REGISTER,
+						&reg_struct)) {
+				RTE_LOG(ERR, VHOST_CONFIG,
+					"Failed to register ufd for region %d: (ufd = %d) %s\n",
+					i, dev->postcopy_ufd,
+					strerror(errno));
+				goto err_mmap;
+			}
+			RTE_LOG(INFO, VHOST_CONFIG,
+				"\t userfaultfd registered for range : %llx - %llx\n",
+				reg_struct.range.start,
+				reg_struct.range.start +
+				reg_struct.range.len - 1);
+#else
+			goto err_mmap;
+#endif
+		}
 	}
 
 	for (i = 0; i < dev->nr_vring; i++) {
-- 
2.17.1

[dpdk-dev] [PATCH v7 14/19] vhost: avoid useless VhostUserMemory copy

[Maxime Coquelin]

The VHOST_USER_SET_MEM_TABLE payload is copied when handled,
whereas it could directly be referenced.

This is not very important, but next, we'll need to update the
payload and send it back to Qemu.

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Maxime Coquelin <maxime.coquelin@redhat.com>
Acked-by: Ilya Maximets <i.maximets@samsung.com>
---
 lib/librte_vhost/vhost_user.c | 24 ++++++++++++------------
 1 file changed, 12 insertions(+), 12 deletions(-)

diff --git a/lib/librte_vhost/vhost_user.c b/lib/librte_vhost/vhost_user.c
index 91c301ae2..d17c3b0ec 100644
--- a/lib/librte_vhost/vhost_user.c
+++ b/lib/librte_vhost/vhost_user.c
@@ -826,7 +826,7 @@ vhost_user_set_mem_table(struct virtio_net **pdev, struct VhostUserMsg *msg,
 			int main_fd __rte_unused)
 {
 	struct virtio_net *dev = *pdev;
-	struct VhostUserMemory memory = msg->payload.memory;
+	struct VhostUserMemory *memory = &msg->payload.memory;
 	struct rte_vhost_mem_region *reg;
 	void *mmap_addr;
 	uint64_t mmap_size;
@@ -836,17 +836,17 @@ vhost_user_set_mem_table(struct virtio_net **pdev, struct VhostUserMsg *msg,
 	int populate;
 	int fd;
 
-	if (memory.nregions > VHOST_MEMORY_MAX_NREGIONS) {
+	if (memory->nregions > VHOST_MEMORY_MAX_NREGIONS) {
 		RTE_LOG(ERR, VHOST_CONFIG,
-			"too many memory regions (%u)\n", memory.nregions);
+			"too many memory regions (%u)\n", memory->nregions);
 		return VH_RESULT_ERR;
 	}
 
-	if (dev->mem && !vhost_memory_changed(&memory, dev->mem)) {
+	if (dev->mem && !vhost_memory_changed(memory, dev->mem)) {
 		RTE_LOG(INFO, VHOST_CONFIG,
 			"(%d) memory regions not changed\n", dev->vid);
 
-		for (i = 0; i < memory.nregions; i++)
+		for (i = 0; i < memory->nregions; i++)
 			close(msg->fds[i]);
 
 		return VH_RESULT_OK;
@@ -878,25 +878,25 @@ vhost_user_set_mem_table(struct virtio_net **pdev, struct VhostUserMsg *msg,
 	}
 
 	dev->mem = rte_zmalloc("vhost-mem-table", sizeof(struct rte_vhost_memory) +
-		sizeof(struct rte_vhost_mem_region) * memory.nregions, 0);
+		sizeof(struct rte_vhost_mem_region) * memory->nregions, 0);
 	if (dev->mem == NULL) {
 		RTE_LOG(ERR, VHOST_CONFIG,
 			"(%d) failed to allocate memory for dev->mem\n",
 			dev->vid);
 		return VH_RESULT_ERR;
 	}
-	dev->mem->nregions = memory.nregions;
+	dev->mem->nregions = memory->nregions;
 
-	for (i = 0; i < memory.nregions; i++) {
+	for (i = 0; i < memory->nregions; i++) {
 		fd  = msg->fds[i];
 		reg = &dev->mem->regions[i];
 
-		reg->guest_phys_addr = memory.regions[i].guest_phys_addr;
-		reg->guest_user_addr = memory.regions[i].userspace_addr;
-		reg->size            = memory.regions[i].memory_size;
+		reg->guest_phys_addr = memory->regions[i].guest_phys_addr;
+		reg->guest_user_addr = memory->regions[i].userspace_addr;
+		reg->size            = memory->regions[i].memory_size;
 		reg->fd              = fd;
 
-		mmap_offset = memory.regions[i].mmap_offset;
+		mmap_offset = memory->regions[i].mmap_offset;
 
 		/* Check for memory_size + mmap_offset overflow */
 		if (mmap_offset >= -reg->size) {
-- 
2.17.1

[dpdk-dev] [PATCH v7 15/19] vhost: send userfault range addresses back to qemu

[Maxime Coquelin]

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Maxime Coquelin <maxime.coquelin@redhat.com>
---
 lib/librte_vhost/vhost_user.c | 47 ++++++++++++++++++++++++++++++++---
 1 file changed, 44 insertions(+), 3 deletions(-)

diff --git a/lib/librte_vhost/vhost_user.c b/lib/librte_vhost/vhost_user.c
index d17c3b0ec..8890abbe8 100644
--- a/lib/librte_vhost/vhost_user.c
+++ b/lib/librte_vhost/vhost_user.c
@@ -79,6 +79,9 @@ static const char *vhost_message_str[VHOST_USER_MAX] = {
 	[VHOST_USER_POSTCOPY_LISTEN]  = "VHOST_USER_POSTCOPY_LISTEN",
 };
 
+static int send_vhost_reply(int sockfd, struct VhostUserMsg *msg);
+static int read_vhost_message(int sockfd, struct VhostUserMsg *msg);
+
 static uint64_t
 get_blk_size(int fd)
 {
@@ -823,7 +826,7 @@ vhost_memory_changed(struct VhostUserMemory *new,
 
 static int
 vhost_user_set_mem_table(struct virtio_net **pdev, struct VhostUserMsg *msg,
-			int main_fd __rte_unused)
+			int main_fd)
 {
 	struct virtio_net *dev = *pdev;
 	struct VhostUserMemory *memory = &msg->payload.memory;
@@ -967,11 +970,49 @@ vhost_user_set_mem_table(struct virtio_net **pdev, struct VhostUserMsg *msg,
 			mmap_offset);
 
 		if (dev->postcopy_listening) {
+			/*
+			 * We haven't a better way right now than sharing
+			 * DPDK's virtual address with Qemu, so that Qemu can
+			 * retrieve the region offset when handling userfaults.
+			 */
+			memory->regions[i].userspace_addr =
+				reg->host_user_addr;
+		}
+	}
+	if (dev->postcopy_listening) {
+		/* Send the addresses back to qemu */
+		msg->fd_num = 0;
+		send_vhost_reply(main_fd, msg);
+
+		/* Wait for qemu to acknolwedge it's got the addresses
+		 * we've got to wait before we're allowed to generate faults.
+		 */
+		VhostUserMsg ack_msg;
+		if (read_vhost_message(main_fd, &ack_msg) <= 0) {
+			RTE_LOG(ERR, VHOST_CONFIG,
+				"Failed to read qemu ack on postcopy set-mem-table\n");
+			goto err_mmap;
+		}
+		if (ack_msg.request.master != VHOST_USER_SET_MEM_TABLE) {
+			RTE_LOG(ERR, VHOST_CONFIG,
+				"Bad qemu ack on postcopy set-mem-table (%d)\n",
+				ack_msg.request.master);
+			goto err_mmap;
+		}
+
+		/* Now userfault register and we can use the memory */
+		for (i = 0; i < memory->nregions; i++) {
 #ifdef RTE_LIBRTE_VHOST_POSTCOPY
+			reg = &dev->mem->regions[i];
 			struct uffdio_register reg_struct;
 
-			reg_struct.range.start = (uint64_t)(uintptr_t)mmap_addr;
-			reg_struct.range.len = mmap_size;
+			/*
+			 * Let's register all the mmap'ed area to ensure
+			 * alignment on page boundary.
+			 */
+			reg_struct.range.start =
+				(uint64_t)(uintptr_t)reg->mmap_addr;
+			reg_struct.range.len = reg->mmap_size;
 			reg_struct.mode = UFFDIO_REGISTER_MODE_MISSING;
 
 			if (ioctl(dev->postcopy_ufd, UFFDIO_REGISTER,
-- 
2.17.1

[dpdk-dev] [PATCH v7 16/19] vhost: add support to postcopy's end request

[Maxime Coquelin]

The master sends this message before stopping handling
userfaults, so that the backend closes the userfaultfd.

The master waits for the slave to acknowledge the request
with an empty 64bits payload for synchronization purpose.

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Maxime Coquelin <maxime.coquelin@redhat.com>
---
 lib/librte_vhost/vhost_user.c | 21 +++++++++++++++++++++
 lib/librte_vhost/vhost_user.h |  3 ++-
 2 files changed, 23 insertions(+), 1 deletion(-)

diff --git a/lib/librte_vhost/vhost_user.c b/lib/librte_vhost/vhost_user.c
index 8890abbe8..0560f2f96 100644
--- a/lib/librte_vhost/vhost_user.c
+++ b/lib/librte_vhost/vhost_user.c
@@ -77,6 +77,7 @@ static const char *vhost_message_str[VHOST_USER_MAX] = {
 	[VHOST_USER_CRYPTO_CLOSE_SESS] = "VHOST_USER_CRYPTO_CLOSE_SESS",
 	[VHOST_USER_POSTCOPY_ADVISE]  = "VHOST_USER_POSTCOPY_ADVISE",
 	[VHOST_USER_POSTCOPY_LISTEN]  = "VHOST_USER_POSTCOPY_LISTEN",
+	[VHOST_USER_POSTCOPY_END]  = "VHOST_USER_POSTCOPY_END",
 };
 
 static int send_vhost_reply(int sockfd, struct VhostUserMsg *msg);
@@ -1636,6 +1637,25 @@ vhost_user_set_postcopy_listen(struct virtio_net **pdev,
 	return VH_RESULT_OK;
 }
 
+static int
+vhost_user_postcopy_end(struct virtio_net **pdev, struct VhostUserMsg *msg,
+			int main_fd __rte_unused)
+{
+	struct virtio_net *dev = *pdev;
+
+	dev->postcopy_listening = 0;
+	if (dev->postcopy_ufd >= 0) {
+		close(dev->postcopy_ufd);
+		dev->postcopy_ufd = -1;
+	}
+
+	msg->payload.u64 = 0;
+	msg->size = sizeof(msg->payload.u64);
+	msg->fd_num = 0;
+
+	return VH_RESULT_REPLY;
+}
+
 typedef int (*vhost_message_handler_t)(struct virtio_net **pdev,
 					struct VhostUserMsg *msg,
 					int main_fd);
@@ -1665,6 +1685,7 @@ static vhost_message_handler_t vhost_message_handlers[VHOST_USER_MAX] = {
 	[VHOST_USER_IOTLB_MSG] = vhost_user_iotlb_msg,
 	[VHOST_USER_POSTCOPY_ADVISE] = vhost_user_set_postcopy_advise,
 	[VHOST_USER_POSTCOPY_LISTEN] = vhost_user_set_postcopy_listen,
+	[VHOST_USER_POSTCOPY_END] = vhost_user_postcopy_end,
 };
 
 
diff --git a/lib/librte_vhost/vhost_user.h b/lib/librte_vhost/vhost_user.h
index 55d8659ba..73b1fe2b9 100644
--- a/lib/librte_vhost/vhost_user.h
+++ b/lib/librte_vhost/vhost_user.h
@@ -52,7 +52,8 @@ typedef enum VhostUserRequest {
 	VHOST_USER_CRYPTO_CLOSE_SESS = 27,
 	VHOST_USER_POSTCOPY_ADVISE = 28,
 	VHOST_USER_POSTCOPY_LISTEN = 29,
-	VHOST_USER_MAX = 30
+	VHOST_USER_POSTCOPY_END = 30,
+	VHOST_USER_MAX = 31
 } VhostUserRequest;
 
 typedef enum VhostUserSlaveRequest {
-- 
2.17.1

[dpdk-dev] [PATCH v7 17/19] vhost: restrict postcopy live-migration enablement

[Maxime Coquelin]

Postcopy live-migration feature requires the application to
not populate the guest memory. As the vhost library cannot
prevent the application to that (e.g. preventing the
application to call mlockall()), the feature is disabled by
default.

The application should only enable the feature if it does not
force the guest memory to be populated.

In case the user passes the RTE_VHOST_USER_POSTCOPY_SUPPORT
flag at registration but the feature was not compiled,
registration fails.

For the same reason, postcopy and dequeue zero copy features
are not compatible, so don't advertize postcopy support if
dequeue zero copy is requested.

Signed-off-by: Maxime Coquelin <maxime.coquelin@redhat.com>
---
 doc/guides/prog_guide/vhost_lib.rst |  8 ++++++++
 lib/librte_vhost/rte_vhost.h        |  1 +
 lib/librte_vhost/socket.c           | 30 ++++++++++++++++++++++++++---
 lib/librte_vhost/vhost_user.c       |  6 +++++-
 4 files changed, 41 insertions(+), 4 deletions(-)

diff --git a/doc/guides/prog_guide/vhost_lib.rst b/doc/guides/prog_guide/vhost_lib.rst
index 77af4d775..c77df338f 100644
--- a/doc/guides/prog_guide/vhost_lib.rst
+++ b/doc/guides/prog_guide/vhost_lib.rst
@@ -106,6 +106,14 @@ The following is an overview of some key Vhost API functions:
     Enabling this flag with these Qemu version results in Qemu being blocked
     when multiple queue pairs are declared.
 
+  - ``RTE_VHOST_USER_POSTCOPY_SUPPORT``
+
+    Postcopy live-migration support will be enabled when this flag is set.
+    It is disabled by default.
+
+    Enabling this flag should only be done when the calling application does
+    not pre-fault the guest shared memory, otherwise migration would fail.
+
 * ``rte_vhost_driver_set_features(path, features)``
 
   This function sets the feature bits the vhost-user driver supports. The
diff --git a/lib/librte_vhost/rte_vhost.h b/lib/librte_vhost/rte_vhost.h
index 9292c89c5..d280ac420 100644
--- a/lib/librte_vhost/rte_vhost.h
+++ b/lib/librte_vhost/rte_vhost.h
@@ -28,6 +28,7 @@ extern "C" {
 #define RTE_VHOST_USER_NO_RECONNECT	(1ULL << 1)
 #define RTE_VHOST_USER_DEQUEUE_ZERO_COPY	(1ULL << 2)
 #define RTE_VHOST_USER_IOMMU_SUPPORT	(1ULL << 3)
+#define RTE_VHOST_USER_POSTCOPY_SUPPORT		(1ULL << 4)
 
 /** Protocol features. */
 #ifndef VHOST_USER_PROTOCOL_F_MQ
diff --git a/lib/librte_vhost/socket.c b/lib/librte_vhost/socket.c
index c278e9b5b..01b60ff9e 100644
--- a/lib/librte_vhost/socket.c
+++ b/lib/librte_vhost/socket.c
@@ -51,6 +51,8 @@ struct vhost_user_socket {
 	uint64_t supported_features;
 	uint64_t features;
 
+	uint64_t protocol_features;
+
 	/*
 	 * Device id to identify a specific backend device.
 	 * It's set to -1 for the default software implementation.
@@ -726,7 +728,7 @@ rte_vhost_driver_get_protocol_features(const char *path,
 	did = vsocket->vdpa_dev_id;
 	vdpa_dev = rte_vdpa_get_device(did);
 	if (!vdpa_dev || !vdpa_dev->ops->get_protocol_features) {
-		*protocol_features = VHOST_USER_PROTOCOL_FEATURES;
+		*protocol_features = vsocket->protocol_features;
 		goto unlock_exit;
 	}
 
@@ -739,7 +741,7 @@ rte_vhost_driver_get_protocol_features(const char *path,
 		goto unlock_exit;
 	}
 
-	*protocol_features = VHOST_USER_PROTOCOL_FEATURES
+	*protocol_features = vsocket->protocol_features
 		& vdpa_protocol_features;
 
 unlock_exit:
@@ -858,11 +860,21 @@ rte_vhost_driver_register(const char *path, uint64_t flags)
 	vsocket->use_builtin_virtio_net = true;
 	vsocket->supported_features = VIRTIO_NET_SUPPORTED_FEATURES;
 	vsocket->features           = VIRTIO_NET_SUPPORTED_FEATURES;
+	vsocket->protocol_features  = VHOST_USER_PROTOCOL_FEATURES;
 
-	/* Dequeue zero copy can't assure descriptors returned in order */
+	/*
+	 * Dequeue zero copy can't assure descriptors returned in order.
+	 * Also, it requires that the guest memory is populated, which is
+	 * not compatible with postcopy.
+	 */
 	if (vsocket->dequeue_zero_copy) {
 		vsocket->supported_features &= ~(1ULL << VIRTIO_F_IN_ORDER);
 		vsocket->features &= ~(1ULL << VIRTIO_F_IN_ORDER);
+
+		RTE_LOG(INFO, VHOST_CONFIG,
+			"Dequeue zero copy requested, disabling postcopy support\n");
+		vsocket->protocol_features &=
+			~(1ULL << VHOST_USER_PROTOCOL_F_PAGEFAULT);
 	}
 
 	if (!(flags & RTE_VHOST_USER_IOMMU_SUPPORT)) {
@@ -870,6 +882,18 @@ rte_vhost_driver_register(const char *path, uint64_t flags)
 		vsocket->features &= ~(1ULL << VIRTIO_F_IOMMU_PLATFORM);
 	}
 
+	if (!(flags & RTE_VHOST_USER_POSTCOPY_SUPPORT)) {
+		vsocket->protocol_features &=
+			~(1ULL << VHOST_USER_PROTOCOL_F_PAGEFAULT);
+	} else {
+#ifndef RTE_LIBRTE_VHOST_POSTCOPY
+		RTE_LOG(ERR, VHOST_CONFIG,
+			"Postcopy requested but not compiled\n");
+		ret = -1;
+		goto out_mutex;
+#endif
+	}
+
 	if ((flags & RTE_VHOST_USER_CLIENT) != 0) {
 		vsocket->reconnect = !(flags & RTE_VHOST_USER_NO_RECONNECT);
 		if (vsocket->reconnect && reconn_tid == 0) {
diff --git a/lib/librte_vhost/vhost_user.c b/lib/librte_vhost/vhost_user.c
index 0560f2f96..508228a3c 100644
--- a/lib/librte_vhost/vhost_user.c
+++ b/lib/librte_vhost/vhost_user.c
@@ -1322,7 +1322,11 @@ vhost_user_set_protocol_features(struct virtio_net **pdev,
 {
 	struct virtio_net *dev = *pdev;
 	uint64_t protocol_features = msg->payload.u64;
-	if (protocol_features & ~VHOST_USER_PROTOCOL_FEATURES) {
+	uint64_t slave_protocol_features = 0;
+
+	rte_vhost_driver_get_protocol_features(dev->ifname,
+			&slave_protocol_features);
+	if (protocol_features & ~slave_protocol_features) {
 		RTE_LOG(ERR, VHOST_CONFIG,
 			"(%d) received invalid protocol features.\n",
 			dev->vid);
-- 
2.17.1

[dpdk-dev] [PATCH v7 18/19] net/vhost: add parameter to enable postcopy support

[Maxime Coquelin]

Introduce a new postcopy-support parameter to Vhost PMD that
passes the RTE_VHOST_USER_POSTCOPY_SUPPORT flag at vhost
device register time.

Flag should only be set if application does not prefault guest
memory using, for example, mlockall() syscall.

Default value is 0, meaning that postcopy support is disabled
unless specified explicitly.

Example to enable postcopy support for a given device:

--vdev 'net_vhost0,iface=/tmp/vhost-user1,postcopy-support=1'

Signed-off-by: Maxime Coquelin <maxime.coquelin@redhat.com>
---
 doc/guides/nics/vhost.rst         |  5 +++++
 drivers/net/vhost/rte_eth_vhost.c | 13 +++++++++++++
 2 files changed, 18 insertions(+)

diff --git a/doc/guides/nics/vhost.rst b/doc/guides/nics/vhost.rst
index 4f7ae8990..23f2e87aa 100644
--- a/doc/guides/nics/vhost.rst
+++ b/doc/guides/nics/vhost.rst
@@ -71,6 +71,11 @@ The user can specify below arguments in `--vdev` option.
     It is used to enable iommu support in vhost library.
     (Default: 0 (disabled))
 
+#.  ``postcopy-support``:
+
+    It is used to enable postcopy live-migration support in vhost library.
+    (Default: 0 (disabled))
+
 Vhost PMD event handling
 ------------------------
 
diff --git a/drivers/net/vhost/rte_eth_vhost.c b/drivers/net/vhost/rte_eth_vhost.c
index aa6052221..1330f06ba 100644
--- a/drivers/net/vhost/rte_eth_vhost.c
+++ b/drivers/net/vhost/rte_eth_vhost.c
@@ -30,6 +30,7 @@ enum {VIRTIO_RXQ, VIRTIO_TXQ, VIRTIO_QNUM};
 #define ETH_VHOST_CLIENT_ARG		"client"
 #define ETH_VHOST_DEQUEUE_ZERO_COPY	"dequeue-zero-copy"
 #define ETH_VHOST_IOMMU_SUPPORT		"iommu-support"
+#define ETH_VHOST_POSTCOPY_SUPPORT	"postcopy-support"
 #define VHOST_MAX_PKT_BURST 32
 
 static const char *valid_arguments[] = {
@@ -38,6 +39,7 @@ static const char *valid_arguments[] = {
 	ETH_VHOST_CLIENT_ARG,
 	ETH_VHOST_DEQUEUE_ZERO_COPY,
 	ETH_VHOST_IOMMU_SUPPORT,
+	ETH_VHOST_POSTCOPY_SUPPORT,
 	NULL
 };
 
@@ -1339,6 +1341,7 @@ rte_pmd_vhost_probe(struct rte_vdev_device *dev)
 	int client_mode = 0;
 	int dequeue_zero_copy = 0;
 	int iommu_support = 0;
+	int postcopy_support = 0;
 	struct rte_eth_dev *eth_dev;
 	const char *name = rte_vdev_device_name(dev);
 
@@ -1411,6 +1414,16 @@ rte_pmd_vhost_probe(struct rte_vdev_device *dev)
 			flags |= RTE_VHOST_USER_IOMMU_SUPPORT;
 	}
 
+	if (rte_kvargs_count(kvlist, ETH_VHOST_POSTCOPY_SUPPORT) == 1) {
+		ret = rte_kvargs_process(kvlist, ETH_VHOST_POSTCOPY_SUPPORT,
+					 &open_int, &postcopy_support);
+		if (ret < 0)
+			goto out_free;
+
+		if (postcopy_support)
+			flags |= RTE_VHOST_USER_POSTCOPY_SUPPORT;
+	}
+
 	if (dev->device.numa_node == SOCKET_ID_ANY)
 		dev->device.numa_node = rte_socket_id();
 
-- 
2.17.1

[dpdk-dev] [PATCH v7 19/19] vhost: enable postcopy protocol feature

[Maxime Coquelin]

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Maxime Coquelin <maxime.coquelin@redhat.com>
---
 lib/librte_vhost/vhost_user.h | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/lib/librte_vhost/vhost_user.h b/lib/librte_vhost/vhost_user.h
index 73b1fe2b9..dc97be843 100644
--- a/lib/librte_vhost/vhost_user.h
+++ b/lib/librte_vhost/vhost_user.h
@@ -22,7 +22,8 @@
 					 (1ULL << VHOST_USER_PROTOCOL_F_SLAVE_REQ) | \
 					 (1ULL << VHOST_USER_PROTOCOL_F_CRYPTO_SESSION) | \
 					 (1ULL << VHOST_USER_PROTOCOL_F_SLAVE_SEND_FD) | \
-					 (1ULL << VHOST_USER_PROTOCOL_F_HOST_NOTIFIER))
+					 (1ULL << VHOST_USER_PROTOCOL_F_HOST_NOTIFIER) | \
+					 (1ULL << VHOST_USER_PROTOCOL_F_PAGEFAULT))
 
 typedef enum VhostUserRequest {
 	VHOST_USER_NONE = 0,
-- 
2.17.1

Re: [dpdk-dev] [PATCH v7 00/19] vhost: add postcopy live-migration support

[Maxime Coquelin]

On 10/12/2018 02:40 PM, Maxime Coquelin wrote:
> In this v7:
> - Move vh_result enum declaration to vhost.h (Ilya)
> - Remove check in read_fd_message() for more fds received
>    than requested as already checked with MSG_CTRUNC (Ilya)
> - Don't return an error in vhost-crypto post message handler
>    if not a crypto message as all messages go through it.
> 
> With classic live-migration, the VM runs on source while its
> content is being migrated to destination. When pages already
> migrated to destination are dirtied by the source, they get
> copied until both source and destination memory converge.
> At that time, the source is stopped and destination is
> started.
> 
> With postcopy live-migration, the VM is started on destination
> before all the memory has been migrated. When the VM tries to
> access a page that haven't been migrated yet, a pagefault is
> triggered, handled by userfaultfd which pauses the thread.
> A Qemu thread in charge of postcopy request the source for
> the missing page. Once received and mapped, the paused thread
> gets resumed.
> 
> Userfaultfd supports handling faults from a different process,
> and Qemu supports postcopy with vhost-user backends since
> v2.12.
> 
> One problem encountered with classic live-migration for VMs
> relying on vhost-user backends is that when the traffic is
> high (e.g. PVP), it happens that it never converges as
> pages gets dirtied at a faster rate than they are copied
> to the destination.
> It is expected this problem sould be solved with using
> postcopy, as rings memory and buffers will be copied once,
> when destination will pagefault on them.
> 
> Note that it will certainly require a rebase to apply on top
> of Nikolay's vhost-user message handling rework.
> 
> Steps to test postcopy:
> 1. Run DPDK's Testpmd application on source:
> ./install/bin/testpmd -m 512 --file-prefix=src -l 0,2 -n 4 \
>    --vdev 'net_vhost0,iface=/tmp/vu-src' -- --portmask=1 -i \
>    --rxq=1 --txq=1 --nb-cores=1 --eth-peer=0,52:54:00:11:22:12 \
>    --no-mlockall
> 
> 2. Run DPDK's Testpmd application on destination:
> ./install/bin/testpmd -m 512 --file-prefix=dst -l 0,2 -n 4 \
>    --vdev 'net_vhost0,iface=/tmp/vu-dst,postcopy-support=1' -- --portmask=1 -i \
>    --rxq=1 --txq=1 --nb-cores=1 --eth-peer=0,52:54:00:11:22:12 \
>    --no-mlockall
> 
> 3. Launch VM on source:
> ./x86_64-softmmu/qemu-system-x86_64 -enable-kvm -m 3G -smp 2 -cpu host \
>    -object memory-backend-file,id=mem,size=3G,mem-path=/dev/shm,share=on \
>    -numa node,memdev=mem -mem-prealloc \
>    -chardev socket,id=char0,path=/tmp/vu-src \
>    -netdev type=vhost-user,id=mynet1,chardev=char0,vhostforce \
>    -device virtio-net-pci,netdev=mynet1 /home/virt/rhel7.6-1-clone.qcow2 \
>    -net none -vnc :0 -monitor stdio
> 
> 4. Launch VM on destination:
> ./x86_64-softmmu/qemu-system-x86_64 -enable-kvm -m 3G -smp 2 -cpu host \
>    -object memory-backend-file,id=mem,size=3G,mem-path=/dev/shm,share=on \
>    -numa node,memdev=mem -mem-prealloc \
>    -chardev socket,id=char0,path=/tmp/vu-dst \
>    -netdev type=vhost-user,id=mynet1,chardev=char0,vhostforce \
>    -device virtio-net-pci,netdev=mynet1 /home/virt/rhel7.6-1-clone.qcow2 \
>    -net none -vnc :1 -monitor stdio -incoming tcp::8888
> 
> 5. In both testpmd prompts, start flooding the virtio-net device:
> testpmd> set fwd txonly
> testpmd> start
> 
> 6. In destination's Qemu monitor, enable postcopy:
> (qemu) migrate_set_capability postcopy-ram on
> 
> 7. In source's Qemu monitor, enable postcopy and launch migration:
> (qemu) migrate_set_capability postcopy-ram on
> (qemu) migrate -d tcp:0:8888
> (qemu) migrate_start_postcopy
> 
> Maxime Coquelin (19):
>    vhost: fix messages results handling
>    vhost: fix return code of messages requiring replies
>    vhost: clarify reply-ack in case a reply was already sent
>    vhost: fix payload size of reply
>    vhost: fix error handling when mem table gets updated
>    vhost: define postcopy protocol flag
>    vhost: add number of fds to vhost-user messages and use it
>    vhost: pass socket fd to message handling callbacks
>    vhost: enable fds passing when sending vhost-user messages
>    vhost: add config flag for postcopy feature
>    vhost: introduce postcopy's advise message
>    vhost: add support for postcopy's listen message
>    vhost: register new regions with userfaultfd
>    vhost: avoid useless VhostUserMemory copy
>    vhost: send userfault range addresses back to qemu
>    vhost: add support to postcopy's end request
>    vhost: restrict postcopy live-migration enablement
>    net/vhost: add parameter to enable postcopy support
>    vhost: enable postcopy protocol feature
> 
>   config/common_linuxapp              |   1 +
>   doc/guides/nics/vhost.rst           |   5 +
>   doc/guides/prog_guide/vhost_lib.rst |   8 +
>   drivers/net/vhost/rte_eth_vhost.c   |  13 ++
>   lib/librte_vhost/meson.build        |   2 +
>   lib/librte_vhost/rte_vhost.h        |   5 +
>   lib/librte_vhost/socket.c           |  46 +++-
>   lib/librte_vhost/vhost.h            |  32 ++-
>   lib/librte_vhost/vhost_crypto.c     |  25 +-
>   lib/librte_vhost/vhost_user.c       | 344 +++++++++++++++++++++-------
>   lib/librte_vhost/vhost_user.h       |  12 +-
>   11 files changed, 377 insertions(+), 116 deletions(-)
> 

Applied to dpdk-next-virtio/master.

Maxime