Signed-off-by: Lei Li <li...@linux.vnet.ibm.com>
---
hmp-commands.hx | 19 ++++++++++++++++++
hmp.c | 17 ++++++++++++++++
hmp.h | 1 +
qapi-schema.json | 27 ++++++++++++++++++++++++-
qemu-char.c | 57 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
qmp-commands.hx | 34 ++++++++++++++++++++++++++++++++
6 files changed, 154 insertions(+), 1 deletions(-)
diff --git a/hmp-commands.hx b/hmp-commands.hx
index 305b0d7..c79c9d3 100644
--- a/hmp-commands.hx
+++ b/hmp-commands.hx
@@ -855,6 +855,25 @@ to char device 'memory'.
ETEXI
{
+ .name = "memchar_read",
+ .args_type = "chardev:s,size:i",
+ .params = "chardev size",
+ .mhandler.cmd = hmp_memchar_read,
+ },
+
+STEXI
+@item memchar_read @var{chardev}
+@findex memchar_read
+Provide read interface for CirMemCharDriver. Read from char device
+'memory' and return @var{size} of the data.
+
+@var{size} is the size of data want to read from. Refer to unencoded
+size of the raw data, would adjust to the init size of the memchar
+if the requested size is larger than it.
+
+ETEXI
+
+ {
.name = "migrate",
.args_type = "detach:-d,blk:-b,inc:-i,uri:s",
.params = "[-d] [-b] [-i] uri",
diff --git a/hmp.c b/hmp.c
index 1ffb3d6..0465c42 100644
--- a/hmp.c
+++ b/hmp.c
@@ -695,6 +695,23 @@ void hmp_memchar_write(Monitor *mon, const QDict *qdict)
hmp_handle_error(mon, &errp);
}
+void hmp_memchar_read(Monitor *mon, const QDict *qdict)
+{
+ uint32_t size = qdict_get_int(qdict, "size");
+ const char *chardev = qdict_get_str(qdict, "chardev");
+ char *data;
+ Error *errp = NULL;
+
+ data = qmp_memchar_read(chardev, size, false, 0, &errp);
+ if (errp) {
+ monitor_printf(mon, "%s\n", error_get_pretty(errp));
+ error_free(errp);
+ return;
+ }
+
+ monitor_printf(mon, "%s\n", data);
+}
+
static void hmp_cont_cb(void *opaque, int err)
{
if (!err) {
diff --git a/hmp.h b/hmp.h
index 6c3ec45..6289037 100644
--- a/hmp.h
+++ b/hmp.h
@@ -44,6 +44,7 @@ void hmp_cpu(Monitor *mon, const QDict *qdict);
void hmp_memsave(Monitor *mon, const QDict *qdict);
void hmp_pmemsave(Monitor *mon, const QDict *qdict);
void hmp_memchar_write(Monitor *mon, const QDict *qdict);
+void hmp_memchar_read(Monitor *mon, const QDict *qdict);
void hmp_cont(Monitor *mon, const QDict *qdict);
void hmp_system_wakeup(Monitor *mon, const QDict *qdict);
void hmp_inject_nmi(Monitor *mon, const QDict *qdict);
diff --git a/qapi-schema.json b/qapi-schema.json
index f0acaac..0696902 100644
--- a/qapi-schema.json
+++ b/qapi-schema.json
@@ -346,7 +346,7 @@
#
# @chardev: the name of the memory char device.
#
-# @size: the size to write in bytes. Should be power of 2.
+# @size: the size to write in bytes.
#
# @data: the source data write to memchar.
#
@@ -366,6 +366,31 @@
'*format': 'DataFormat'} }
##
+# @memchar-read:
+#
+# Provide read interface for memchardev. Read from the char
+# device 'memory' and return the data.
+#
+# @chardev: the name of the memory char device.
+#
+# @size: the size to read in bytes.
+#
+# @format: #optional the format of the data want to read from
+# memchardev, by default is 'utf8'.
+#
+# Returns: The data read from memchar as string
+# If @chardev is not a valid memchr device, DeviceNotFound
+#
+# Notes: For now assume 'drop' behaver, which would result in reads
+# returning empty strings.
+#
+# Since: 1.3
+##
+{ 'command': 'memchar-read',
+ 'data': {'chardev': 'str', 'size': 'int', '*format': 'DataFormat'},
+ 'returns': 'str' }
+
+##
# @CommandInfo:
#
# Information about a QMP command
diff --git a/qemu-char.c b/qemu-char.c
index 92b4cec..a16276a 100644
--- a/qemu-char.c
+++ b/qemu-char.c
@@ -2771,6 +2771,63 @@ void qmp_memchar_write(const char *chardev, int64_t size,
}
}
+char *qmp_memchar_read(const char *chardev, int64_t size,
+ bool has_format, enum DataFormat format,
+ Error **errp)
+{
+ CharDriverState *chr;
+ guchar *read_data;
+ char *data = NULL;
+ int ret;
+ size_t count;
+
+ chr = qemu_chr_find(chardev);
+ if (!chr) {
+ error_set(errp, QERR_DEVICE_NOT_FOUND, chardev);
+ return NULL;
+ }
+
+ if (qemu_is_chr(chr, "memory")) {
+ error_setg(errp,"%s is not memory char device\n", chardev);
+ return NULL;
+ }
+
+ if (size <= 0) {
+ error_setg(errp, "Failed to read from device %s", chardev);
+ return NULL;
+ }
+
+ /* XXX: Return the empty strings when the buffer is empty. */
+ if (cirmem_chr_is_empty(chr)) {
+ error_setg(errp, "Memory device %s is empty", chardev);
+ return NULL;
+ }
+
+ count = qemu_chr_cirmem_count(chr);
+ size = size > count ? count : size;
+ read_data = g_malloc0(size + 1);
+
+ ret = cirmem_chr_read(chr, read_data, size);
+ if (ret < 0) {
+ error_setg(errp, "Failed to read from device %s", chardev);
+ goto fail;
+ }
+
+ if (has_format && (format == DATA_FORMAT_BASE64)) {
+ if (read_data) {
+ data = g_base64_encode(read_data, (size_t)size);
+ }
+ } else {
+ data = (char *)read_data;
+ }
+
+ return data;
+
+fail:
+ g_free(read_data);
+ return NULL;
+}
+
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 ae3ab5a..2e9b33a 100644
--- a/qmp-commands.hx
+++ b/qmp-commands.hx
@@ -500,6 +500,40 @@ Example:
EQMP
{
+ .name = "memchar-read",
+ .args_type = "chardev:s,size:i,format:s?",
+ .help = "return the size of data from memchar chardev",
+ .mhandler.cmd_new = qmp_marshal_input_memchar_read,
+ },
+
+SQMP
+memchar-read
+-------------
+
+Provide read interface for CirMemCharDriver. Read from the char
+device memory and return the data.
+
+Arguments:
+
+- "chardev": the name of the char device, must be unique (json-string)
+- "size": the memory size wanted to read in bytes(refer to unencoded
+ size of the raw data), would adjust to the init size of the
+ memchar if the requested size is larger than it. (json-int)
+- "format": the data format write to memchardev, default is
+ utf8. (json-string, optional)
+ - Possible values: "utf8", "base64"
+
+Example:
+
+-> { "execute": "memchar-read",
+ "arguments": { "chardev": foo,
+ "size": 1000,
+ "format": "utf8" } }
+<- { "return": "data string..." }
+
+EQMP
+
+ {
.name = "xen-save-devices-state",
.args_type = "filename:F",
.mhandler.cmd_new = qmp_marshal_input_xen_save_devices_state,
--
1.7.7.6
