[Qemu-devel] [PATCH 06/40] qdev-ify: xen backends

[Alexander Graf <agraf@suse.de>]

From: Gerd Hoffmann <kraxel@redhat.com>

This patch converts the xen backend code to qdev.

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Signed-off-by: Alexander Graf <agraf@suse.de>
---
 hw/xen_backend.c    |  176 ++++++++++++++++++++++++++++++++-------------------
 hw/xen_backend.h    |    9 ++-
 hw/xen_console.c    |   10 +++-
 hw/xen_disk.c       |   10 +++-
 hw/xen_machine_pv.c |    6 +--
 hw/xen_nic.c        |   10 +++-
 hw/xenfb.c          |   14 ++++-
 7 files changed, 158 insertions(+), 77 deletions(-)

diff --git a/hw/xen_backend.c b/hw/xen_backend.c
index a2e408f..0d6a96b 100644
--- a/hw/xen_backend.c
+++ b/hw/xen_backend.c
@@ -42,13 +42,21 @@
 
 /* ------------------------------------------------------------- */
 
+typedef struct XenBus {
+    BusState qbus;
+} XenBus;
+
 /* public */
 int xen_xc;
 struct xs_handle *xenstore = NULL;
 const char *xen_protocol;
 
 /* private */
-static QTAILQ_HEAD(XenDeviceHead, XenDevice) xendevs = QTAILQ_HEAD_INITIALIZER(xendevs);
+static struct BusInfo xen_bus_info = {
+    .name       = "Xen",
+    .size       = sizeof(XenBus),
+};
+static XenBus *xenbus;
 static int debug = 0;
 
 /* ------------------------------------------------------------- */
@@ -163,14 +171,16 @@ int xen_be_set_state(struct XenDevice *xendev, enum xenbus_state state)
 
 struct XenDevice *xen_be_find_xendev(const char *type, int dom, int dev)
 {
+    struct DeviceState *qdev;
     struct XenDevice *xendev;
 
-    QTAILQ_FOREACH(xendev, &xendevs, next) {
+    QLIST_FOREACH(qdev, &xenbus->qbus.children, sibling) {
+        xendev = container_of(qdev, struct XenDevice, qdev);
 	if (xendev->dom != dom)
 	    continue;
 	if (xendev->dev != dev)
 	    continue;
-	if (strcmp(xendev->type, type) != 0)
+	if (strcmp(xendev->ops->type, type) != 0)
 	    continue;
 	return xendev;
     }
@@ -180,28 +190,34 @@ struct XenDevice *xen_be_find_xendev(const char *type, int dom, int dev)
 /*
  * get xen backend device, allocate a new one if it doesn't exist.
  */
-static struct XenDevice *xen_be_get_xendev(const char *type, int dom, int dev,
+static struct XenDevice *xen_be_get_xendev(int dom, int dev,
                                            struct XenDevOps *ops)
 {
+    struct DeviceState *qdev;
     struct XenDevice *xendev;
+    char name[64];
     char *dom0;
 
-    xendev = xen_be_find_xendev(type, dom, dev);
+    xendev = xen_be_find_xendev(ops->type, dom, dev);
     if (xendev)
 	return xendev;
 
+    /* create new xendev */
+    snprintf(name, sizeof(name), "xen-%s", ops->type);
+    qdev = qdev_create(&xenbus->qbus, name);
+    qdev_init_nofail(qdev);
+    xendev = container_of(qdev, struct XenDevice, qdev);
+
     /* init new xendev */
-    xendev = qemu_mallocz(ops->size);
-    xendev->type  = type;
     xendev->dom   = dom;
     xendev->dev   = dev;
     xendev->ops   = ops;
 
     dom0 = xs_get_domain_path(xenstore, 0);
     snprintf(xendev->be, sizeof(xendev->be), "%s/backend/%s/%d/%d",
-	     dom0, xendev->type, xendev->dom, xendev->dev);
+	     dom0, xendev->ops->type, xendev->dom, xendev->dev);
     snprintf(xendev->name, sizeof(xendev->name), "%s-%d",
-	     xendev->type, xendev->dev);
+	     xendev->ops->type, xendev->dev);
     free(dom0);
 
     xendev->debug      = debug;
@@ -210,7 +226,7 @@ static struct XenDevice *xen_be_get_xendev(const char *type, int dom, int dev,
     xendev->evtchndev = xc_evtchn_open();
     if (xendev->evtchndev < 0) {
 	xen_be_printf(NULL, 0, "can't open evtchn device\n");
-	qemu_free(xendev);
+	qdev_free(&xendev->qdev);
 	return NULL;
     }
     fcntl(xc_evtchn_fd(xendev->evtchndev), F_SETFD, FD_CLOEXEC);
@@ -220,15 +236,13 @@ static struct XenDevice *xen_be_get_xendev(const char *type, int dom, int dev,
 	if (xendev->gnttabdev < 0) {
 	    xen_be_printf(NULL, 0, "can't open gnttab device\n");
 	    xc_evtchn_close(xendev->evtchndev);
-	    qemu_free(xendev);
+	    qdev_free(&xendev->qdev);
 	    return NULL;
 	}
     } else {
 	xendev->gnttabdev = -1;
     }
 
-    QTAILQ_INSERT_TAIL(&xendevs, xendev, next);
-
     if (xendev->ops->alloc)
 	xendev->ops->alloc(xendev);
 
@@ -238,43 +252,44 @@ static struct XenDevice *xen_be_get_xendev(const char *type, int dom, int dev,
 /*
  * release xen backend device.
  */
-static struct XenDevice *xen_be_del_xendev(int dom, int dev)
+static void xen_be_del_xendev(int dom, int dev, struct XenDevOps *ops)
 {
-    struct XenDevice *xendev, *xnext;
-
-    /*
-     * This is pretty much like QTAILQ_FOREACH(xendev, &xendevs, next) but
-     * we save the next pointer in xnext because we might free xendev.
-     */
-    xnext = xendevs.tqh_first;
-    while (xnext) {
-        xendev = xnext;
-        xnext = xendev->next.tqe_next;
-
-	if (xendev->dom != dom)
-	    continue;
-	if (xendev->dev != dev && dev != -1)
-	    continue;
-
-	if (xendev->ops->free)
-	    xendev->ops->free(xendev);
-
-	if (xendev->fe) {
-	    char token[XEN_BUFSIZE];
-	    snprintf(token, sizeof(token), "fe:%p", xendev);
-	    xs_unwatch(xenstore, xendev->fe, token);
-	    qemu_free(xendev->fe);
-	}
-
-	if (xendev->evtchndev >= 0)
-	    xc_evtchn_close(xendev->evtchndev);
-	if (xendev->gnttabdev >= 0)
-	    xc_gnttab_close(xendev->gnttabdev);
-
-	QTAILQ_REMOVE(&xendevs, xendev, next);
-	qemu_free(xendev);
-    }
-    return NULL;
+    struct DeviceState *qdev;
+    struct XenDevice *xendev;
+    int done;
+
+    do {
+        done = 1;
+        QLIST_FOREACH(qdev, &xenbus->qbus.children, sibling) {
+            xendev = container_of(qdev, struct XenDevice, qdev);
+            if (xendev->dom != dom)
+                continue;
+            if (xendev->dev != dev && dev != -1)
+                continue;
+            if (xendev->ops != ops)
+                continue;
+
+            if (xendev->ops->free)
+                xendev->ops->free(xendev);
+
+            if (xendev->fe) {
+                char token[XEN_BUFSIZE];
+                snprintf(token, sizeof(token), "fe:%p", xendev);
+                xs_unwatch(xenstore, xendev->fe, token);
+                qemu_free(xendev->fe);
+            }
+
+            if (xendev->evtchndev >= 0)
+                xc_evtchn_close(xendev->evtchndev);
+            if (xendev->gnttabdev >= 0)
+                xc_gnttab_close(xendev->gnttabdev);
+
+            qdev_free(&xendev->qdev);
+
+            done = 0;
+            break;
+        }
+    } while (!done);
 }
 
 /*
@@ -498,7 +513,7 @@ void xen_be_check_state(struct XenDevice *xendev)
 
 /* ------------------------------------------------------------- */
 
-static int xenstore_scan(const char *type, int dom, struct XenDevOps *ops)
+static int xenstore_scan(int dom, struct XenDevOps *ops)
 {
     struct XenDevice *xendev;
     char path[XEN_BUFSIZE], token[XEN_BUFSIZE];
@@ -507,8 +522,8 @@ static int xenstore_scan(const char *type, int dom, struct XenDevOps *ops)
 
     /* setup watch */
     dom0 = xs_get_domain_path(xenstore, 0);
-    snprintf(token, sizeof(token), "be:%p:%d:%p", type, dom, ops);
-    snprintf(path, sizeof(path), "%s/backend/%s/%d", dom0, type, dom);
+    snprintf(token, sizeof(token), "be:%d:%p", dom, ops);
+    snprintf(path, sizeof(path), "%s/backend/%s/%d", dom0, ops->type, dom);
     free(dom0);
     if (!xs_watch(xenstore, path, token)) {
 	xen_be_printf(NULL, 0, "xen be: watching backend path (%s) failed\n", path);
@@ -520,7 +535,7 @@ static int xenstore_scan(const char *type, int dom, struct XenDevOps *ops)
     if (!dev)
 	return 0;
     for (j = 0; j < cdev; j++) {
-	xendev = xen_be_get_xendev(type, dom, atoi(dev[j]), ops);
+	xendev = xen_be_get_xendev(dom, atoi(dev[j]), ops);
 	if (xendev == NULL)
 	    continue;
 	xen_be_check_state(xendev);
@@ -529,15 +544,14 @@ static int xenstore_scan(const char *type, int dom, struct XenDevOps *ops)
     return 0;
 }
 
-static void xenstore_update_be(char *watch, char *type, int dom,
-			       struct XenDevOps *ops)
+static void xenstore_update_be(char *watch, int dom, struct XenDevOps *ops)
 {
     struct XenDevice *xendev;
     char path[XEN_BUFSIZE], *dom0;
     unsigned int len, dev;
 
     dom0 = xs_get_domain_path(xenstore, 0);
-    len = snprintf(path, sizeof(path), "%s/backend/%s/%d", dom0, type, dom);
+    len = snprintf(path, sizeof(path), "%s/backend/%s/%d", dom0, ops->type, dom);
     free(dom0);
     if (strncmp(path, watch, len) != 0)
 	return;
@@ -551,10 +565,10 @@ static void xenstore_update_be(char *watch, char *type, int dom,
 
     if (0) {
 	/* FIXME: detect devices being deleted from xenstore ... */
-	xen_be_del_xendev(dom, dev);
+	xen_be_del_xendev(dom, dev, ops);
     }
 
-    xendev = xen_be_get_xendev(type, dom, dev, ops);
+    xendev = xen_be_get_xendev(dom, dev, ops);
     if (xendev != NULL) {
 	xen_be_backend_changed(xendev, path);
 	xen_be_check_state(xendev);
@@ -580,16 +594,16 @@ static void xenstore_update_fe(char *watch, struct XenDevice *xendev)
 static void xenstore_update(void *unused)
 {
     char **vec = NULL;
-    intptr_t type, ops, ptr;
+    intptr_t ops, ptr;
     unsigned int dom, count;
 
     vec = xs_read_watch(xenstore, &count);
     if (vec == NULL)
 	goto cleanup;
 
-    if (sscanf(vec[XS_WATCH_TOKEN], "be:%" PRIxPTR ":%d:%" PRIxPTR,
-               &type, &dom, &ops) == 3)
-	xenstore_update_be(vec[XS_WATCH_PATH], (void*)type, dom, (void*)ops);
+    if (sscanf(vec[XS_WATCH_TOKEN], "be:%d:%" PRIxPTR,
+               &dom, &ops) == 2)
+	xenstore_update_be(vec[XS_WATCH_PATH], dom, (void*)ops);
     if (sscanf(vec[XS_WATCH_TOKEN], "fe:%" PRIxPTR, &ptr) == 1)
 	xenstore_update_fe(vec[XS_WATCH_PATH], (void*)ptr);
 
@@ -642,9 +656,43 @@ err:
     return -1;
 }
 
-int xen_be_register(const char *type, struct XenDevOps *ops)
+void xen_create_bus(DeviceState *parent)
 {
-    return xenstore_scan(type, xen_domid, ops);
+    DeviceInfo *info;
+    BusState *qbus;
+
+    qbus = qbus_create(&xen_bus_info, parent, NULL);
+    xenbus = DO_UPCAST(XenBus, qbus, qbus);
+    for (info = device_info_list; info != NULL; info = info->next) {
+        if (info->bus_info != &xen_bus_info)
+            continue;
+        xenstore_scan(xen_domid, DO_UPCAST(struct XenDevOps, qinfo, info));
+    }
+
+    qbus->allow_hotplug = 1;
+}
+
+static int xen_be_initfn(DeviceState *dev, DeviceInfo *info)
+{
+#if 0
+    struct XenDevOps *ops = container_of(info, struct XenDevOps, qinfo);
+    struct XenDevice *xendev = container_of(dev, struct XenDevice, qdev);
+
+    /* nothing to do as create + init isn't really splitted. */
+#endif
+    return 0;
+}
+
+void xen_qdev_register(struct XenDevOps *ops)
+{
+    char name[64];
+
+    snprintf(name, sizeof(name), "xen-%s", ops->type);
+    ops->qinfo.name = qemu_strdup(name);
+    ops->qinfo.init = xen_be_initfn;
+    ops->qinfo.bus_info = &xen_bus_info;
+    ops->qinfo.no_user = 1,
+    qdev_register(&ops->qinfo);
 }
 
 int xen_be_bind_evtchn(struct XenDevice *xendev)
diff --git a/hw/xen_backend.h b/hw/xen_backend.h
index 1b428e3..f53a742 100644
--- a/hw/xen_backend.h
+++ b/hw/xen_backend.h
@@ -4,6 +4,7 @@
 #include "xen_common.h"
 #include "sysemu.h"
 #include "net.h"
+#include "qdev.h"
 
 /* ------------------------------------------------------------- */
 
@@ -17,7 +18,8 @@ struct XenDevice;
 #define DEVOPS_FLAG_IGNORE_STATE  2
 
 struct XenDevOps {
-    size_t    size;
+    DeviceInfo qinfo;
+    char      type[64];
     uint32_t  flags;
     void      (*alloc)(struct XenDevice *xendev);
     int       (*init)(struct XenDevice *xendev);
@@ -30,7 +32,7 @@ struct XenDevOps {
 };
 
 struct XenDevice {
-    const char         *type;
+    DeviceState        qdev;
     int                dom;
     int                dev;
     char               name[64];
@@ -78,7 +80,8 @@ void xen_be_check_state(struct XenDevice *xendev);
 
 /* xen backend driver bits */
 int xen_be_init(void);
-int xen_be_register(const char *type, struct XenDevOps *ops);
+void xen_create_bus(DeviceState *parent);
+void xen_qdev_register(struct XenDevOps *ops);
 int xen_be_set_state(struct XenDevice *xendev, enum xenbus_state state);
 int xen_be_bind_evtchn(struct XenDevice *xendev);
 void xen_be_unbind_evtchn(struct XenDevice *xendev);
diff --git a/hw/xen_console.c b/hw/xen_console.c
index d2261f4..a980dc8 100644
--- a/hw/xen_console.c
+++ b/hw/xen_console.c
@@ -260,10 +260,18 @@ static void con_event(struct XenDevice *xendev)
 /* -------------------------------------------------------------------- */
 
 struct XenDevOps xen_console_ops = {
-    .size       = sizeof(struct XenConsole),
+    .qinfo.size = sizeof(struct XenConsole),
+    .type       = "console",
     .flags      = DEVOPS_FLAG_IGNORE_STATE,
     .init       = con_init,
     .connect    = con_connect,
     .event      = con_event,
     .disconnect = con_disconnect,
 };
+
+static void xen_console_register_devices(void)
+{
+    xen_qdev_register(&xen_console_ops);
+}
+
+device_init(xen_console_register_devices)
diff --git a/hw/xen_disk.c b/hw/xen_disk.c
index 06752de..5392f58 100644
--- a/hw/xen_disk.c
+++ b/hw/xen_disk.c
@@ -774,7 +774,8 @@ static void blk_event(struct XenDevice *xendev)
 }
 
 struct XenDevOps xen_blkdev_ops = {
-    .size       = sizeof(struct XenBlkDev),
+    .qinfo.size = sizeof(struct XenBlkDev),
+    .type       = "qdisk",
     .flags      = DEVOPS_FLAG_NEED_GNTDEV,
     .alloc      = blk_alloc,
     .init       = blk_init,
@@ -783,3 +784,10 @@ struct XenDevOps xen_blkdev_ops = {
     .event      = blk_event,
     .free       = blk_free,
 };
+
+static void xen_blkdev_register_devices(void)
+{
+    xen_qdev_register(&xen_blkdev_ops);
+}
+
+device_init(xen_blkdev_register_devices)
diff --git a/hw/xen_machine_pv.c b/hw/xen_machine_pv.c
index 77a34bf..b94d6e9 100644
--- a/hw/xen_machine_pv.c
+++ b/hw/xen_machine_pv.c
@@ -75,11 +75,7 @@ static void xen_init_pv(ram_addr_t ram_size,
         break;
     }
 
-    xen_be_register("console", &xen_console_ops);
-    xen_be_register("vkbd", &xen_kbdmouse_ops);
-    xen_be_register("vfb", &xen_framebuffer_ops);
-    xen_be_register("qdisk", &xen_blkdev_ops);
-    xen_be_register("qnic", &xen_netdev_ops);
+    xen_create_bus(NULL);
 
     /* configure framebuffer */
     if (xenfb_enabled) {
diff --git a/hw/xen_nic.c b/hw/xen_nic.c
index 08055b8..02d3c4e 100644
--- a/hw/xen_nic.c
+++ b/hw/xen_nic.c
@@ -411,7 +411,8 @@ static int net_free(struct XenDevice *xendev)
 /* ------------------------------------------------------------- */
 
 struct XenDevOps xen_netdev_ops = {
-    .size       = sizeof(struct XenNetDev),
+    .qinfo.size = sizeof(struct XenNetDev),
+    .type       = "qnic",
     .flags      = DEVOPS_FLAG_NEED_GNTDEV,
     .init       = net_init,
     .connect    = net_connect,
@@ -419,3 +420,10 @@ struct XenDevOps xen_netdev_ops = {
     .disconnect = net_disconnect,
     .free       = net_free,
 };
+
+static void xen_netdev_register_devices(void)
+{
+    xen_qdev_register(&xen_netdev_ops);
+}
+
+device_init(xen_netdev_register_devices)
diff --git a/hw/xenfb.c b/hw/xenfb.c
index da5297b..293210f 100644
--- a/hw/xenfb.c
+++ b/hw/xenfb.c
@@ -953,7 +953,8 @@ static void fb_event(struct XenDevice *xendev)
 /* -------------------------------------------------------------------- */
 
 struct XenDevOps xen_kbdmouse_ops = {
-    .size       = sizeof(struct XenInput),
+    .qinfo.size = sizeof(struct XenInput),
+    .type       = "vkbd",
     .init       = input_init,
     .connect    = input_connect,
     .disconnect = input_disconnect,
@@ -961,7 +962,8 @@ struct XenDevOps xen_kbdmouse_ops = {
 };
 
 struct XenDevOps xen_framebuffer_ops = {
-    .size       = sizeof(struct XenFB),
+    .qinfo.size = sizeof(struct XenFB),
+    .type       = "vfb",
     .init       = fb_init,
     .connect    = fb_connect,
     .disconnect = fb_disconnect,
@@ -1011,3 +1013,11 @@ wait_more:
     xen_be_check_state(xin);
     xen_be_check_state(xfb);
 }
+
+static void xenfb_register_devices(void)
+{
+    xen_qdev_register(&xen_kbdmouse_ops);
+    xen_qdev_register(&xen_framebuffer_ops);
+}
+
+device_init(xenfb_register_devices)
-- 
1.6.0.2