[Qemu-devel] [PATCH V5 09/12] NUMA: add qmp command set-mem-policy to set memory policy for NUMA node

[Wanlong Gao]

This QMP command allows user set guest node's memory policy
through the QMP protocol. The qmp-shell command is like:
    set-mem-policy nodeid=0 policy=membind host-nodes=0-1

Signed-off-by: Wanlong Gao <address@hidden>
---
 numa.c           | 55 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
 qapi-schema.json | 19 +++++++++++++++++++
 qmp-commands.hx  | 35 +++++++++++++++++++++++++++++++++++
 3 files changed, 109 insertions(+)

diff --git a/numa.c b/numa.c
index 24c886b..3befc56 100644
--- a/numa.c
+++ b/numa.c
@@ -29,6 +29,7 @@
 #include "qapi/opts-visitor.h"
 #include "qapi/dealloc-visitor.h"
 #include "exec/memory.h"
+#include "qmp-commands.h"
 
 #ifdef CONFIG_NUMA
 #include <numa.h>
@@ -378,3 +379,57 @@ void set_numa_modes(void)
         }
     }
 }
+
+void qmp_set_mem_policy(int64_t nodeid, bool has_policy, const char *policy,
+                        bool has_host_nodes, const char *host_nodes, Error 
**errp)
+{
+    unsigned int flags;
+    DECLARE_BITMAP(host_mem, MAX_CPUMASK_BITS);
+
+    if (nodeid >= nb_numa_nodes) {
+        error_setg(errp, "Only has '%d' NUMA nodes", nb_numa_nodes);
+        return;
+    }
+
+    bitmap_copy(host_mem, numa_info[nodeid].host_mem, MAX_CPUMASK_BITS);
+    flags = numa_info[nodeid].flags;
+
+    numa_info[nodeid].flags = NODE_HOST_NONE;
+    bitmap_zero(numa_info[nodeid].host_mem, MAX_CPUMASK_BITS);
+
+    if (!has_policy) {
+        if (set_node_mem_policy(nodeid) == -1) {
+            error_setg(errp, "Failed to set memory policy for node%lu", 
nodeid);
+            goto error;
+        }
+        return;
+    }
+
+    if (numa_mem_parse_policy(nodeid, policy) == -1) {
+        error_setg(errp, "Failed to parse memory policy: %s", policy);
+        goto error;
+    }
+
+    if (!has_host_nodes) {
+        bitmap_fill(numa_info[nodeid].host_mem, MAX_CPUMASK_BITS);
+    }
+
+    if (host_nodes) {
+        if (numa_mem_parse_hostnodes(nodeid, host_nodes) == -1) {
+            error_setg(errp, "Failed to parse host nodes range %s", 
host_nodes);
+            goto error;
+        }
+    }
+
+    if (set_node_mem_policy(nodeid) == -1) {
+        error_setg(errp, "Failed to set memory policy for node%lu", nodeid);
+        goto error;
+    }
+
+    return;
+
+error:
+    bitmap_copy(numa_info[nodeid].host_mem, host_mem, MAX_CPUMASK_BITS);
+    numa_info[nodeid].flags = flags;
+    return;
+}
diff --git a/qapi-schema.json b/qapi-schema.json
index 49eac70..fd4c615 100644
--- a/qapi-schema.json
+++ b/qapi-schema.json
@@ -3729,3 +3729,22 @@
    '*size':            'size',
    '*policy':          'str',
    '*host-nodes':      'str' }}
+
+##
+# @set-mem-policy:
+#
+# Set the host memory binding policy for guest NUMA node.
+#
+# @nodeid: The node ID of guest NUMA node to set memory policy to.
+#
+# @policy: #optional The memory policy to be set (default 'default').
+#
+# @host-nodes: #optional The host nodes range for memory policy.
+#
+# Returns: Nothing on success
+#
+# Since: 1.6
+##
+{ 'command': 'set-mem-policy',
+  'data': {'nodeid': 'int', '*policy': 'str',
+           '*host-nodes': 'str'} }
diff --git a/qmp-commands.hx b/qmp-commands.hx
index e075df4..aac88e0 100644
--- a/qmp-commands.hx
+++ b/qmp-commands.hx
@@ -3047,3 +3047,38 @@ Example:
 <- { "return": {} }
 
 EQMP
+
+    {
+        .name      = "set-mem-policy",
+        .args_type = "nodeid:i,policy:s?,host-nodes:s?",
+        .help      = "Set the host memory binding policy for guest NUMA node",
+        .mhandler.cmd_new = qmp_marshal_input_set_mem_policy,
+    },
+
+SQMP
+set-mem-policy
+------
+
+Set the host memory binding policy for guest NUMA node
+
+Arguments:
+
+- "nodeid": The nodeid of guest NUMA node to set memory policy to.
+            (json-int)
+- "policy": The memory policy string to set.
+            (json-string, optional)
+- "host-nodes": The host nodes contained to this memory policy.
+                (json-string, optional)
+
+Example:
+
+-> { "execute": "set-mem-policy", "arguments": { "nodeid": 0, "policy": 
"membind",
+                                                 "host-nodes": "0-1" }}
+<- { "return": {} }
+
+Notes:
+    1. If "policy" is not set, the memory policy of this "nodeid" will be set
+       to "default".
+    2. If "host-nodes" is not set, the node mask of this "policy" will be set
+       to "all".
+EQMP
-- 
1.8.3.2.634.g7a3187e