Subject: [PATCH 8/9] monitor: New command __com.redhat_drive_add

From: Markus Armbruster <[email-masked]>
Date: Thu, 1 Jul 2010 12:06:53 -0300

RH-Author: Markus Armbruster <[email-masked]>
Message-id: <[email-masked]>
Patchwork-id: 10416
O-Subject: [PATCH RHEL6 qemu-kvm v2] monitor: New command __com.redhat_drive_add
Bugzilla: 581963
RH-Acked-by: Jes Sorensen <[email-masked]>
RH-Acked-by: Daniel P. Berrange <[email-masked]>
RH-Acked-by: Luiz Capitulino <[email-masked]>

>From 47597d12609010b758cc37be76d4fa76205a81ec Mon Sep 17 00:00:00 2001
From: Markus Armbruster <[email-masked]>
Date: Thu, 1 Jul 2010 07:40:28 +0200
Subject: [PATCH] monitor: New command __com.redhat_drive_add

We need drive hot plug for 6.0.  Upstream's drive_add is ugly, and being
replaced.  Because of that, upstream doesn't want it in QMP.  Because
the replacement is not yet ready, provide a simple, relatively clean,
QMP-enabled command as vendor extension.

It's essentially drive_add specialized to if=none, with superfluous crap
cut, and error handling fixed.  QError conversion is shallow: any
drive_init() failure gets reported as DeviceInitFailed.  drive_init()
reports details to stderr, as before.

Code is minimally invasive, which makes it a bit ugly in places
(qemu_simple_drive_opts *cough*).

Signed-off-by: Markus Armbruster <[email-masked]>
---
v2: Handle check_parm() failure correctly

BZ 581963
Upstream: not applicable
Testing: Dan Berrange tested a slightly older version (same code, just
no docs) successfully with libvirt.
Based on da4605503f7cfd4826ce69057a36dd81cbb87344, because I need Luiz's
doc series.

 hw/device-hotplug.c |   64 +++++++++++++++++++++++++++++++++++++++++++++++++++
 qemu-config.c       |   15 ++++++++++++
 qemu-monitor.hx     |   51 ++++++++++++++++++++++++++++++++++++++++
 sysemu.h            |    1 +
 4 files changed, 131 insertions(+), 0 deletions(-)

Signed-off-by: Eduardo Habkost <[email-masked]>
---
 hw/device-hotplug.c |   64 +++++++++++++++++++++++++++++++++++++++++++++++++++
 qemu-config.c       |   15 ++++++++++++
 qemu-monitor.hx     |   51 ++++++++++++++++++++++++++++++++++++++++
 sysemu.h            |    1 +
 4 files changed, 131 insertions(+), 0 deletions(-)

diff --git a/hw/device-hotplug.c b/hw/device-hotplug.c
index 9cc8376..3b957b2 100644
--- a/hw/device-hotplug.c
+++ b/hw/device-hotplug.c
@@ -24,6 +24,7 @@
 
 #include "hw.h"
 #include "boards.h"
+#include "qerror.h"
 #include "net.h"
 #include "block_int.h"
 #include "sysemu.h"
@@ -46,3 +47,66 @@ DriveInfo *add_init_drive(const char *optstr)
 
     return dinfo;
 }
+
+static void check_parm(const char *key, QObject *obj, void *opaque)
+{
+    static const char *valid_keys[] = {
+        "id", "cyls", "heads", "secs", "trans", "media", "snapshot",
+        "file", "cache", "aio", "format", "serial", "rerror", "werror",
+        "readonly", NULL
+    };
+    int *stopped = opaque;
+    const char **p;
+
+    if (*stopped) {
+        return;
+    }
+
+    for (p = valid_keys; *p; p++) {
+        if (!strcmp(key, *p)) {
+            return;
+        }
+    }
+    
+    qerror_report(QERR_INVALID_PARAMETER, key);
+    *stopped = 1;
+}
+
+int simple_drive_add(Monitor *mon, const QDict *qdict, QObject **ret_data)
+{
+    int stopped, fatal_error;
+    QemuOpts *opts;
+    DriveInfo *dinfo;
+
+    if (!qdict_haskey(qdict, "id")) {
+        qerror_report(QERR_MISSING_PARAMETER, "id");
+        return -1;
+    }
+
+    stopped = 0;
+    qdict_iter(qdict, check_parm, &stopped);
+    if (stopped) {
+        return -1;
+    }
+
+    opts = qemu_opts_from_qdict(&qemu_drive_opts, qdict);
+    if (!opts) {
+        return -1;
+    }
+    qemu_opt_set(opts, "if", "none");
+    dinfo = drive_init(opts, current_machine, &fatal_error);
+    if (!dinfo && fatal_error) {
+        qerror_report(QERR_DEVICE_INIT_FAILED, /* close enough */
+                      qemu_opts_id(opts));
+        /* drive_init() can leave an empty drive behind, reap it */
+        dinfo = drive_get_by_id(qemu_opts_id(opts));
+        if (dinfo) {
+            drive_uninit(dinfo);
+        } else {
+            qemu_opts_del(opts);
+        }
+        return -1;
+    }
+
+    return 0;
+}
diff --git a/qemu-config.c b/qemu-config.c
index 3999dc5..04c7a4d 100644
--- a/qemu-config.c
+++ b/qemu-config.c
@@ -88,6 +88,20 @@ QemuOptsList qemu_drive_opts = {
     },
 };
 
+QemuOptsList qemu_simple_drive_opts = {
+    .name = "simple-drive",
+    .implied_opt_name = "format",
+    .head = QTAILQ_HEAD_INITIALIZER(qemu_simple_drive_opts.head),
+    .desc = {
+        /*
+         * no elements => accept any
+         * sanity checking will happen later
+         * when setting device properties
+         */
+        { /* end if list */ }
+    }
+};
+
 QemuOptsList qemu_chardev_opts = {
     .name = "chardev",
     .implied_opt_name = "backend",
@@ -374,6 +388,7 @@ QemuOptsList qemu_spice_opts = {
 
 static QemuOptsList *vm_config_groups[] = {
     &qemu_drive_opts,
+    &qemu_simple_drive_opts,
     &qemu_chardev_opts,
     &qemu_device_opts,
     &qemu_netdev_opts,
diff --git a/qemu-monitor.hx b/qemu-monitor.hx
index f6795fc..e09bc88 100644
--- a/qemu-monitor.hx
+++ b/qemu-monitor.hx
@@ -1570,6 +1570,57 @@ Note: This command must be issued before issuing any other command.
 
 EQMP
 
+    {
+        .name       = RFQDN_REDHAT "drive_add",
+        .args_type  = "simple-drive:O",
+        .params     = "id=name,[file=file][,format=f][,media=d]...",
+        .help       = "Create a drive similar to -device if=none.",
+	.user_print = monitor_user_noop,
+        .mhandler.cmd_new = simple_drive_add,
+    },
+
+STEXI
+@item __com.redhat_drive_add
+@findex __com.redhat_drive_add
+Create a drive similar to -device if=none.
+ETEXI
+SQMP
+__com.redhat_drive_add
+----------------------
+
+Create a drive similar to -device if=none.
+
+Arguments:
+
+- "id": Drive ID, must be unique (json-string)
+- "file": Disk image (json-string, optional)
+- "format": Disk format (json-string, optional)
+- "aio": How to perform asynchronous disk I/O (json-string, optional)
+- "cache": Host cache use policy (json-string, optional)
+- "cyls", "heads", "secs": Disk geometry (json-int, optional)
+- "trans": BIOS translation mode (json-string, optional)
+- "media": Media type (json-string, optional)
+- "readonly": Open image read-only (json-bool, optional)
+- "rerror": What to do on read error (json-string, optional)
+- "werror": What to do on write error (json-string, optional)
+- "serial": Drive serial number (json-string, optional)
+- "snapshot": Enable snapshot mode (json-bool, optional)
+
+Example:
+
+1. Add a drive without medium:
+
+-> { "execute": "__com.redhat_drive_add", "arguments": { "id": "foo" } }
+<- {"return": {}}
+
+2. Add a drive with 
+
+-> { "execute": "__com.redhat_drive_add",
+     "arguments": { "id": "bar", "file": "tmp.qcow2", "format": "qcow2" } }
+<- {"return": {}}
+
+EQMP
+
 #if defined(CONFIG_SPICE)
     {
         .name       = RFQDN_REDHAT "set_password",
diff --git a/sysemu.h b/sysemu.h
index d8c119b..f20abd6 100644
--- a/sysemu.h
+++ b/sysemu.h
@@ -205,6 +205,7 @@ void qemu_system_cpu_hot_add(int cpu, int state);
 /* device-hotplug */
 
 DriveInfo *add_init_drive(const char *opts);
+int simple_drive_add(Monitor *mon, const QDict *qdict, QObject **ret_data);
 
 /* pci-hotplug */
 void pci_device_hot_add(Monitor *mon, const QDict *qdict);
-- 
1.7.0.3