[Qemu-devel] [PATCH 5/7] NUMA: add qmp command set-mpol to set memory policy for NUMA node

[Wanlong Gao]

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 mpol=membind nodemask=0-1

Signed-off-by: Wanlong Gao <address@hidden>
---
 cpus.c                  | 61 +++++++++++++++++++++++++++++++++++++++++++++++++
 include/sysemu/sysemu.h |  1 +
 qapi-schema.json        | 13 +++++++++++
 qmp-commands.hx         | 35 ++++++++++++++++++++++++++++
 vl.c                    |  2 +-
 5 files changed, 111 insertions(+), 1 deletion(-)

diff --git a/cpus.c b/cpus.c
index b868932..a2836e9 100644
--- a/cpus.c
+++ b/cpus.c
@@ -1431,3 +1431,64 @@ 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_nodemask, const char *nodemask, Error **errp)
+{
+    unsigned int ret;
+    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) {
+            goto error;
+        }
+        return;
+    }
+
+    if (!strcmp(mpol, "membind")) {
+        numa_info[nodeid].flags |= NODE_HOST_BIND;
+    } else if (!strcmp(mpol, "interleave")) {
+        numa_info[nodeid].flags |= NODE_HOST_INTERLEAVE;
+    } else if (!strcmp(mpol, "preferred")) {
+        numa_info[nodeid].flags |= NODE_HOST_PREFERRED;
+    } else {
+        error_setg(errp, "Invalid NUMA policy '%s'", mpol);
+        goto error;
+    }
+
+    if (!has_nodemask) {
+        bitmap_fill(numa_info[nodeid].host_mem, MAX_CPUMASK_BITS);
+    }
+
+    if (nodemask) {
+        ret = numa_node_parse_mpol(nodemask, numa_info[nodeid].host_mem);
+    }
+    if (ret == 4) {
+        goto error;
+    } else if (ret & 1) {
+        numa_info[nodeid].flags |= NODE_HOST_RELATIVE;
+    }
+
+    if (set_node_mpol(nodeid) == -1) {
+        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/include/sysemu/sysemu.h b/include/sysemu/sysemu.h
index 993b8e0..7d804af 100644
--- a/include/sysemu/sysemu.h
+++ b/include/sysemu/sysemu.h
@@ -144,6 +144,7 @@ struct node_info {
     unsigned int flags;
 };
 extern struct node_info numa_info[MAX_NODES];
+extern unsigned int numa_node_parse_mpol(const char *str, unsigned long *bm);
 
 #define MAX_OPTION_ROMS 16
 typedef struct QEMUOptionRom {
diff --git a/qapi-schema.json b/qapi-schema.json
index a80ee40..403c703 100644
--- a/qapi-schema.json
+++ b/qapi-schema.json
@@ -3608,3 +3608,16 @@
             '*cpuid-input-ecx': 'int',
             'cpuid-register': 'X86CPURegister32',
             'features': 'int' } }
+
+# @set-mpol:
+#
+# Set the host memory binding policy for guest NUMA node.
+#
+# @node-id: The node ID of guest NUMA node to set memory policy to.
+#
+# @mpol: The memory policy string to set.
+#
+# Since: 1.6.0
+##
+{ 'command': 'set-mpol', 'data': {'nodeid': 'int', '*mpol': 'str',
+                                  '*nodemask': 'str'} }
diff --git a/qmp-commands.hx b/qmp-commands.hx
index 8cea5e5..930c844 100644
--- a/qmp-commands.hx
+++ b/qmp-commands.hx
@@ -2997,3 +2997,38 @@ Example:
 <- { "return": {} }
 
 EQMP
+
+    {
+        .name      = "set-mpol",
+        .args_type = "nodeid:i,mpol:s?,nodemask: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)
+- "mpol": The memory policy string to set.
+           (json-string, optional)
+- "nodemask": The node mask contained to mpol.
+                (json-string, optional)
+
+Example:
+
+-> { "execute": "set-mpol", "arguments": { "nodeid": 0, "mpol": "membind",
+                                           "nodemask": "0-1" }}
+<- { "return": {} }
+
+Notes:
+    1. If "mpol" is not set, the memory policy of this "nodeid" will be set
+       to "default".
+    2. If "nodemask" is not set, the node mask of this "mpol" will be set
+       to "all".
+EQMP
diff --git a/vl.c b/vl.c
index ada9fb2..73af85e 100644
--- a/vl.c
+++ b/vl.c
@@ -1348,7 +1348,7 @@ error:
     exit(1);
 }
 
-static unsigned int numa_node_parse_mpol(const char *str, unsigned long *bm)
+unsigned int numa_node_parse_mpol(const char *str, unsigned long *bm)
 {
     unsigned long long value, endvalue;
     char *endptr;
-- 
1.8.3.rc2.10.g0c2b1cf