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From: Maxime Coquelin <maxime.coquelin@redhat.com>
To: dev@dpdk.org, tiwei.bie@intel.com, zhihong.wang@intel.com,
	jfreimann@redhat.com
Cc: dgilbert@redhat.com, Maxime Coquelin <maxime.coquelin@redhat.com>
Subject: [dpdk-dev] [PATCH 11/12] vhost: add flag to enable postcopy live-migration
Date: Wed, 26 Sep 2018 09:27:04 +0200	[thread overview]
Message-ID: <20180926072705.22641-12-maxime.coquelin@redhat.com> (raw)
In-Reply-To: <20180926072705.22641-1-maxime.coquelin@redhat.com>

Postcopy live-migration feature require 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.

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           | 11 +++++++++--
 3 files changed, 18 insertions(+), 2 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 b3cc6990d..b26afbffa 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 c04d3d305..a7beeeda4 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.
@@ -731,7 +733,7 @@ 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;
 	}
 
@@ -744,7 +746,7 @@ 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:
@@ -863,6 +865,7 @@ 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 */
 	if (vsocket->dequeue_zero_copy) {
@@ -875,6 +878,10 @@ 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);
+
 	if ((flags & RTE_VHOST_USER_CLIENT) != 0) {
 		vsocket->reconnect = !(flags & RTE_VHOST_USER_NO_RECONNECT);
 		if (vsocket->reconnect && reconn_tid == 0) {
-- 
2.17.1

  parent reply	other threads:[~2018-09-26  7:27 UTC|newest]

Thread overview: 23+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-09-26  7:26 [dpdk-dev] [PATCH 00/12] vhost: add postcopy live-migration support Maxime Coquelin
2018-09-26  7:26 ` [dpdk-dev] [PATCH 01/12] vhost: define postcopy protocol flag Maxime Coquelin
2018-09-26  7:26 ` [dpdk-dev] [PATCH 02/12] vhost: add number of fds to vhost-user messages and use it Maxime Coquelin
2018-09-26  7:26 ` [dpdk-dev] [PATCH 03/12] vhost: enable fds passing when sending vhost-user messages Maxime Coquelin
2018-09-26  7:26 ` [dpdk-dev] [PATCH 04/12] vhost: introduce postcopy's advise message Maxime Coquelin
2018-09-26 15:22   ` Alejandro Lucero
2018-09-27  9:35     ` Maxime Coquelin
     [not found]   ` <CGME20180927082608eucas1p17cd1d99e54134fb2a6de3151e52048f3@eucas1p1.samsung.com>
2018-09-27  8:28     ` [dpdk-dev] [04/12] " Ilya Maximets
2018-09-28 10:40       ` Ilya Maximets
2018-09-28 12:13         ` Bruce Richardson
2018-09-28 13:17           ` Ilya Maximets
2018-09-28 13:24             ` Bruce Richardson
2018-09-28 13:49               ` Maxime Coquelin
2018-09-26  7:26 ` [dpdk-dev] [PATCH 05/12] vhost: add support for postcopy's listen message Maxime Coquelin
2018-09-26  7:26 ` [dpdk-dev] [PATCH 06/12] vhost: register new regions with userfaultfd Maxime Coquelin
2018-09-26 15:31   ` Alejandro Lucero
2018-09-27  9:37     ` Maxime Coquelin
2018-09-26  7:27 ` [dpdk-dev] [PATCH 07/12] vhost: avoid useless VhostUserMemory copy Maxime Coquelin
2018-09-26  7:27 ` [dpdk-dev] [PATCH 08/12] vhost: send userfault range addresses back to qemu Maxime Coquelin
2018-09-26  7:27 ` [dpdk-dev] [PATCH 09/12] vhost: add support to postcopy's end request Maxime Coquelin
2018-09-26  7:27 ` [dpdk-dev] [PATCH 10/12] vhost: enable postcopy protocol feature Maxime Coquelin
2018-09-26  7:27 ` Maxime Coquelin [this message]
2018-09-26  7:27 ` [dpdk-dev] [PATCH 12/12] net/vhost: add parameter to enable postcopy migration support Maxime Coquelin

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