import 15.2.0 Octopus source

[ceph.git] / ceph / src / spdk / dpdk / doc / guides / prog_guide / vhost_lib.rst

diff --git a/ceph/src/spdk/dpdk/doc/guides/prog_guide/vhost_lib.rst b/ceph/src/spdk/dpdk/doc/guides/prog_guide/vhost_lib.rst
index 77af4d775a7431dc4a3cef447e6b805a878a59d0..fc3ee43531d0cc945b82a920d23a4f8995032107 100644 (file)
--- a/ceph/src/spdk/dpdk/doc/guides/prog_guide/vhost_lib.rst
+++ b/ceph/src/spdk/dpdk/doc/guides/prog_guide/vhost_lib.rst
@@ -63,7 +63,7 @@ The following is an overview of some key Vhost API functions:
       512).
 
     * zero copy is really good for VM2VM case. For iperf between two VMs, the
-      boost could be above 70% (when TSO is enableld).
+      boost could be above 70% (when TSO is enabled).
 
     * For zero copy in VM2NIC case, guest Tx used vring may be starved if the
       PMD driver consume the mbuf but not release them timely.
@@ -92,6 +92,9 @@ The following is an overview of some key Vhost API functions:
       to use vfio-pci driver, please insert vfio-pci kernel module in noiommu
       mode.
 
+    * The consumer of zero copy mbufs should consume these mbufs as soon as
+      possible, otherwise it may block the operations in vhost.
+
   - ``RTE_VHOST_USER_IOMMU_SUPPORT``
 
     IOMMU support will be enabled when this flag is set. It is disabled by
@@ -106,6 +109,14 @@ 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