[Qemu-devel] [RFC PATCH 3/4] qmp: Introduce memchar_write QMP command

[Lei Li]

Signed-off-by: Lei Li <address@hidden>
---
 qapi-schema.json |   20 ++++++++++++++++++++
 qemu-char.c      |   19 +++++++++++++++++++
 qmp-commands.hx  |   29 +++++++++++++++++++++++++++++
 3 files changed, 68 insertions(+), 0 deletions(-)

diff --git a/qapi-schema.json b/qapi-schema.json
index bc55ed2..3c8530f 100644
--- a/qapi-schema.json
+++ b/qapi-schema.json
@@ -206,6 +206,26 @@
 { 'command': 'query-chardev', 'returns': ['ChardevInfo'] }
 
 ##
+# @memchar_write:
+#
+# Provide writing interface for memchardev. Write data to memchar
+# char device.
+#
+# @chardev: the name of the memchar char device.
+#
+# @size: the size to write in bytes.
+#
+# @data: the source data write to memchar.
+#
+# Returns: Nothing on success
+#          If an I/O error occurs while writing, IOError
+#
+# Since: 1.2
+##
+{ 'command': 'memchar_write',
+  'data': {'chardev': 'str', 'size': 'int', 'data': 'str'} }
+
+##
 # @CommandInfo:
 #
 # Information about a QMP command
diff --git a/qemu-char.c b/qemu-char.c
index 087c92d..1012e65 100644
--- a/qemu-char.c
+++ b/qemu-char.c
@@ -2636,6 +2636,25 @@ size_t qemu_chr_mem_osize(const CharDriverState *chr)
     return d->cbuf_count;
 }
 
+void qmp_memchar_write(const char *chardev, int64_t size,
+                       uint8_t *data, Error **errp)
+{
+    CharDriverState *chr;
+    int ret;
+
+    chr = qemu_chr_find(chardev);
+
+    if(!chr) {
+        qemu_chr_init_mem(chr, size);
+    }
+
+    ret = mem_chr_write(chr, data, size);
+    if (ret <= 0) {
+        error_set(errp, QERR_IO_ERROR);
+        return;
+    }
+}
+
 QemuOpts *qemu_chr_parse_compat(const char *label, const char *filename)
 {
     char host[65], port[33], width[8], height[8];
diff --git a/qmp-commands.hx b/qmp-commands.hx
index e3cf3c5..182f1e6 100644
--- a/qmp-commands.hx
+++ b/qmp-commands.hx
@@ -441,6 +441,35 @@ Note: inject-nmi is only supported for x86 guest 
currently, it will
 EQMP
 
     {
+        .name       = "memchar_write",
+        .args_type  = "chardev:s,size:i,data:s",
+        .mhandler.cmd_new = qmp_marshal_input_memchar_write,
+    },
+
+SQMP
+memchar_write
+-------------
+
+Provide writing interface for memchardev. Write data to memchar
+char device.
+
+Arguments:
+
+- "chardev": the name of the char device, must be unique (json-string)
+- "size": the memory size, in bytes (json-int)
+- "data": the source data writed to memchar (json-string)
+
+Example:
+
+-> { "execute": "memchar_write",
+                "arguments": { "chardev": foo,
+                               "size": 1000,
+                               "data": "data string" } }
+<- { "return": {} }
+
+EQMP
+
+    {
         .name       = "xen-save-devices-state",
         .args_type  = "filename:F",
     .mhandler.cmd_new = qmp_marshal_input_xen_save_devices_state,
-- 
1.7.7.6