[Qemu-devel] [PATCH V2 7/9] NUMA: add qmp command set-mpol to set memory policy for NUMA node

[Wanlong Gao <gaowanlong@cn.fujitsu.com>]

The QMP command let it be able to set node's memory policy
through the QMP protocol. The qmp-shell command is like:
    set-mpol nodeid=0 mem-policy=membind mem-hostnode=0-1

Signed-off-by: Wanlong Gao <gaowanlong@cn.fujitsu.com>
---
 cpus.c           | 54 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
 qapi-schema.json | 15 +++++++++++++++
 qmp-commands.hx  | 35 +++++++++++++++++++++++++++++++++++
 3 files changed, 104 insertions(+)

diff --git a/cpus.c b/cpus.c
index 677ee15..9c2706c 100644
--- a/cpus.c
+++ b/cpus.c
@@ -1432,3 +1432,57 @@ void qmp_inject_nmi(Error **errp)
     error_set(errp, QERR_UNSUPPORTED);
 #endif
 }
+
+void qmp_set_mpol(int64_t nodeid, bool has_mpol, const char *mpol,
+                  bool has_hostnode, const char *hostnode, 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_mpol) {
+        if (set_node_mpol(nodeid) == -1) {
+            error_setg(errp, "Failed to set memory policy for node%lu", nodeid);
+            goto error;
+        }
+        return;
+    }
+
+    numa_node_parse_mpol(nodeid, mpol, errp);
+    if (error_is_set(errp)) {
+        goto error;
+    }
+
+    if (!has_hostnode) {
+        bitmap_fill(numa_info[nodeid].host_mem, MAX_CPUMASK_BITS);
+    }
+
+    if (hostnode) {
+        numa_node_parse_hostnode(nodeid, hostnode, errp);
+        if (error_is_set(errp)) {
+            goto error;
+        }
+    }
+
+    if (set_node_mpol(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 a80ee40..cedcbe1 100644
--- a/qapi-schema.json
+++ b/qapi-schema.json
@@ -3608,3 +3608,18 @@
             '*cpuid-input-ecx': 'int',
             'cpuid-register': 'X86CPURegister32',
             'features': 'int' } }
+
+# @set-mpol:
+#
+# Set the host memory binding policy for guest NUMA node.
+#
+# @nodeid: The node ID of guest NUMA node to set memory policy to.
+#
+# @mem-policy: The memory policy string to set.
+#
+# @mem-hostnode: The host node or node range for memory policy.
+#
+# Since: 1.6.0
+##
+{ 'command': 'set-mpol', 'data': {'nodeid': 'int', '*mem-policy': 'str',
+                                  '*mem-hostnode': 'str'} }
diff --git a/qmp-commands.hx b/qmp-commands.hx
index 8cea5e5..7bb5038 100644
--- a/qmp-commands.hx
+++ b/qmp-commands.hx
@@ -2997,3 +2997,38 @@ Example:
 <- { "return": {} }
 
 EQMP
+
+    {
+        .name      = "set-mpol",
+        .args_type = "nodeid:i,mem-policy:s?,mem-hostnode:s?",
+        .help      = "Set the host memory binding policy for guest NUMA node",
+        .mhandler.cmd_new = qmp_marshal_input_set_mpol,
+    },
+
+SQMP
+set-mpol
+------
+
+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)
+- "mem-policy": The memory policy string to set.
+                (json-string, optional)
+- "mem-hostnode": The host nodes contained to mpol.
+                  (json-string, optional)
+
+Example:
+
+-> { "execute": "set-mpol", "arguments": { "nodeid": 0, "mem-policy": "membind",
+                                           "mem-hostnode": "0-1" }}
+<- { "return": {} }
+
+Notes:
+    1. If "mem-policy" is not set, the memory policy of this "nodeid" will be set
+       to "default".
+    2. If "mem-hostnode" is not set, the node mask of this "mpol" will be set
+       to "all".
+EQMP
-- 
1.8.3.1.448.gfb7dfaa