hw/xen: Add xenstore operations to allow redirection to internal emulation

Signed-off-by: Paul Durrant <pdurrant@amazon.com>
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Reviewed-by: Paul Durrant <paul@xen.org>

6 files changed, 183 insertions, 32 deletions

diff --git a/include/hw/xen/xen-bus-helper.h b/include/hw/xen/xen-bus-helper.h
index 8782f30..d8dcc2f 100644
--- a/include/hw/xen/xen-bus-helper.h
+++ b/include/hw/xen/xen-bus-helper.h
@@ -8,40 +8,40 @@
 #ifndef HW_XEN_BUS_HELPER_H
 #define HW_XEN_BUS_HELPER_H
 
-#include "hw/xen/xen_common.h"
+#include "hw/xen/xen_backend_ops.h"
 
 const char *xs_strstate(enum xenbus_state state);
 
-void xs_node_create(struct xs_handle *xsh,  xs_transaction_t tid,
-                    const char *node, struct xs_permissions perms[],
-                    unsigned int nr_perms, Error **errp);
-void xs_node_destroy(struct xs_handle *xsh,  xs_transaction_t tid,
+void xs_node_create(struct qemu_xs_handle *h,  xs_transaction_t tid,
+                    const char *node, unsigned int owner, unsigned int domid,
+                    unsigned int perms, Error **errp);
+void xs_node_destroy(struct qemu_xs_handle *h,  xs_transaction_t tid,
                      const char *node, Error **errp);
 
 /* Write to node/key unless node is empty, in which case write to key */
-void xs_node_vprintf(struct xs_handle *xsh,  xs_transaction_t tid,
+void xs_node_vprintf(struct qemu_xs_handle *h,  xs_transaction_t tid,
                      const char *node, const char *key, Error **errp,
                      const char *fmt, va_list ap)
     G_GNUC_PRINTF(6, 0);
-void xs_node_printf(struct xs_handle *xsh,  xs_transaction_t tid,
+void xs_node_printf(struct qemu_xs_handle *h,  xs_transaction_t tid,
                     const char *node, const char *key, Error **errp,
                     const char *fmt, ...)
     G_GNUC_PRINTF(6, 7);
 
 /* Read from node/key unless node is empty, in which case read from key */
-int xs_node_vscanf(struct xs_handle *xsh,  xs_transaction_t tid,
+int xs_node_vscanf(struct qemu_xs_handle *h,  xs_transaction_t tid,
                    const char *node, const char *key, Error **errp,
                    const char *fmt, va_list ap)
     G_GNUC_SCANF(6, 0);
-int xs_node_scanf(struct xs_handle *xsh,  xs_transaction_t tid,
+int xs_node_scanf(struct qemu_xs_handle *h,  xs_transaction_t tid,
                   const char *node, const char *key, Error **errp,
                   const char *fmt, ...)
     G_GNUC_SCANF(6, 7);
 
 /* Watch node/key unless node is empty, in which case watch key */
-void xs_node_watch(struct xs_handle *xsh, const char *node, const char *key,
-                   char *token, Error **errp);
-void xs_node_unwatch(struct xs_handle *xsh, const char *node, const char *key,
-                     const char *token, Error **errp);
+struct qemu_xs_watch *xs_node_watch(struct qemu_xs_handle *h, const char *node,
+                                    const char *key, xs_watch_fn fn,
+                                    void *opaque, Error **errp);
+void xs_node_unwatch(struct qemu_xs_handle *h, struct qemu_xs_watch *w);
 
 #endif /* HW_XEN_BUS_HELPER_H */
diff --git a/include/hw/xen/xen-bus.h b/include/hw/xen/xen-bus.h
index 5a90e79..f435898 100644
--- a/include/hw/xen/xen-bus.h
+++ b/include/hw/xen/xen-bus.h
@@ -9,29 +9,23 @@
 #define HW_XEN_BUS_H
 
 #include "hw/xen/xen_backend_ops.h"
-#include "hw/xen/interface/io/xenbus.h"
 #include "hw/sysbus.h"
 #include "qemu/notify.h"
 #include "qom/object.h"
 
-typedef void (*XenWatchHandler)(void *opaque);
-
-typedef struct XenWatchList XenWatchList;
-typedef struct XenWatch XenWatch;
 typedef struct XenEventChannel XenEventChannel;
 
 struct XenDevice {
     DeviceState qdev;
     domid_t frontend_id;
     char *name;
-    struct xs_handle *xsh;
-    XenWatchList *watch_list;
+    struct qemu_xs_handle *xsh;
     char *backend_path, *frontend_path;
     enum xenbus_state backend_state, frontend_state;
     Notifier exit;
-    XenWatch *backend_state_watch, *frontend_state_watch;
+    struct qemu_xs_watch *backend_state_watch, *frontend_state_watch;
     bool backend_online;
-    XenWatch *backend_online_watch;
+    struct qemu_xs_watch *backend_online_watch;
     xengnttab_handle *xgth;
     bool inactive;
     QLIST_HEAD(, XenEventChannel) event_channels;
@@ -64,10 +58,9 @@ OBJECT_DECLARE_TYPE(XenDevice, XenDeviceClass, XEN_DEVICE)
 struct XenBus {
     BusState qbus;
     domid_t backend_id;
-    struct xs_handle *xsh;
-    XenWatchList *watch_list;
+    struct qemu_xs_handle *xsh;
     unsigned int backend_types;
-    XenWatch **backend_watch;
+    struct qemu_xs_watch **backend_watch;
     QLIST_HEAD(, XenDevice) inactive_devices;
 };
 
diff --git a/include/hw/xen/xen-legacy-backend.h b/include/hw/xen/xen-legacy-backend.h
index ab28583..6c307c5 100644
--- a/include/hw/xen/xen-legacy-backend.h
+++ b/include/hw/xen/xen-legacy-backend.h
@@ -2,7 +2,6 @@
 #define HW_XEN_LEGACY_BACKEND_H
 
 #include "hw/xen/xen_backend_ops.h"
-#include "hw/xen/interface/io/xenbus.h"
 #include "hw/xen/xen_pvdev.h"
 #include "net/net.h"
 #include "qom/object.h"
@@ -16,7 +15,7 @@ DECLARE_INSTANCE_CHECKER(XenLegacyDevice, XENBACKEND,
                          TYPE_XENBACKEND)
 
 /* variables */
-extern struct xs_handle *xenstore;
+extern struct qemu_xs_handle *xenstore;
 extern const char *xen_protocol;
 extern DeviceState *xen_sysdev;
 extern BusState *xen_sysbus;
@@ -31,9 +30,6 @@ int xenstore_write_be_int64(struct XenLegacyDevice *xendev, const char *node,
 char *xenstore_read_be_str(struct XenLegacyDevice *xendev, const char *node);
 int xenstore_read_be_int(struct XenLegacyDevice *xendev, const char *node,
                          int *ival);
-void xenstore_update_fe(char *watch, struct XenLegacyDevice *xendev);
-void xenstore_update_be(char *watch, char *type, int dom,
-                        struct XenDevOps *ops);
 char *xenstore_read_fe_str(struct XenLegacyDevice *xendev, const char *node);
 int xenstore_read_fe_int(struct XenLegacyDevice *xendev, const char *node,
                          int *ival);
diff --git a/include/hw/xen/xen_backend_ops.h b/include/hw/xen/xen_backend_ops.h
index 0dff06b..90cca85 100644
--- a/include/hw/xen/xen_backend_ops.h
+++ b/include/hw/xen/xen_backend_ops.h
@@ -12,6 +12,10 @@
 #ifndef QEMU_XEN_BACKEND_OPS_H
 #define QEMU_XEN_BACKEND_OPS_H
 
+#include "hw/xen/xen.h"
+#include "hw/xen/interface/xen.h"
+#include "hw/xen/interface/io/xenbus.h"
+
 /*
  * For the time being, these operations map fairly closely to the API of
  * the actual Xen libraries, e.g. libxenevtchn. As we complete the migration
@@ -36,6 +40,16 @@ typedef uint32_t grant_ref_t;
 #define XEN_PAGE_SIZE        (1UL << XEN_PAGE_SHIFT)
 #define XEN_PAGE_MASK        (~(XEN_PAGE_SIZE - 1))
 
+#ifndef xen_rmb
+#define xen_rmb() smp_rmb()
+#endif
+#ifndef xen_wmb
+#define xen_wmb() smp_wmb()
+#endif
+#ifndef xen_mb
+#define xen_mb() smp_mb()
+#endif
+
 struct evtchn_backend_ops {
     xenevtchn_handle *(*open)(void);
     int (*bind_interdomain)(xenevtchn_handle *xc, uint32_t domid,
@@ -240,6 +254,155 @@ static inline int qemu_xen_foreignmem_unmap(void *addr, size_t pages)
     return xen_foreignmem_ops->unmap(addr, pages);
 }
 
+typedef void (*xs_watch_fn)(void *opaque, const char *path);
+
+struct qemu_xs_handle;
+struct qemu_xs_watch;
+typedef uint32_t xs_transaction_t;
+
+#define XBT_NULL 0
+
+#define XS_PERM_NONE  0x00
+#define XS_PERM_READ  0x01
+#define XS_PERM_WRITE 0x02
+
+struct xenstore_backend_ops {
+    struct qemu_xs_handle *(*open)(void);
+    void (*close)(struct qemu_xs_handle *h);
+    char *(*get_domain_path)(struct qemu_xs_handle *h, unsigned int domid);
+    char **(*directory)(struct qemu_xs_handle *h, xs_transaction_t t,
+                        const char *path, unsigned int *num);
+    void *(*read)(struct qemu_xs_handle *h, xs_transaction_t t,
+                  const char *path, unsigned int *len);
+    bool (*write)(struct qemu_xs_handle *h, xs_transaction_t t,
+                  const char *path, const void *data, unsigned int len);
+    bool (*create)(struct qemu_xs_handle *h, xs_transaction_t t,
+                   unsigned int owner, unsigned int domid,
+                   unsigned int perms, const char *path);
+    bool (*destroy)(struct qemu_xs_handle *h, xs_transaction_t t,
+               const char *path);
+    struct qemu_xs_watch *(*watch)(struct qemu_xs_handle *h, const char *path,
+                                   xs_watch_fn fn, void *opaque);
+    void (*unwatch)(struct qemu_xs_handle *h, struct qemu_xs_watch *w);
+    xs_transaction_t (*transaction_start)(struct qemu_xs_handle *h);
+    bool (*transaction_end)(struct qemu_xs_handle *h, xs_transaction_t t,
+                            bool abort);
+};
+
+extern struct xenstore_backend_ops *xen_xenstore_ops;
+
+static inline struct qemu_xs_handle *qemu_xen_xs_open(void)
+{
+    if (!xen_xenstore_ops) {
+        return NULL;
+    }
+    return xen_xenstore_ops->open();
+}
+
+static inline void qemu_xen_xs_close(struct qemu_xs_handle *h)
+{
+    if (!xen_xenstore_ops) {
+        return;
+    }
+    xen_xenstore_ops->close(h);
+}
+
+static inline char *qemu_xen_xs_get_domain_path(struct qemu_xs_handle *h,
+                                                unsigned int domid)
+{
+    if (!xen_xenstore_ops) {
+        return NULL;
+    }
+    return xen_xenstore_ops->get_domain_path(h, domid);
+}
+
+static inline char **qemu_xen_xs_directory(struct qemu_xs_handle *h,
+                                           xs_transaction_t t, const char *path,
+                                           unsigned int *num)
+{
+    if (!xen_xenstore_ops) {
+        return NULL;
+    }
+    return xen_xenstore_ops->directory(h, t, path, num);
+}
+
+static inline void *qemu_xen_xs_read(struct qemu_xs_handle *h,
+                                     xs_transaction_t t, const char *path,
+                                     unsigned int *len)
+{
+    if (!xen_xenstore_ops) {
+        return NULL;
+    }
+    return xen_xenstore_ops->read(h, t, path, len);
+}
+
+static inline bool qemu_xen_xs_write(struct qemu_xs_handle *h,
+                                     xs_transaction_t t, const char *path,
+                                     const void *data, unsigned int len)
+{
+    if (!xen_xenstore_ops) {
+        return false;
+    }
+    return xen_xenstore_ops->write(h, t, path, data, len);
+}
+
+static inline bool qemu_xen_xs_create(struct qemu_xs_handle *h,
+                                      xs_transaction_t t, unsigned int owner,
+                                      unsigned int domid, unsigned int perms,
+                                      const char *path)
+{
+    if (!xen_xenstore_ops) {
+        return false;
+    }
+    return xen_xenstore_ops->create(h, t, owner, domid, perms, path);
+}
+
+static inline bool qemu_xen_xs_destroy(struct qemu_xs_handle *h,
+                                       xs_transaction_t t, const char *path)
+{
+    if (!xen_xenstore_ops) {
+        return false;
+    }
+    return xen_xenstore_ops->destroy(h, t, path);
+}
+
+static inline struct qemu_xs_watch *qemu_xen_xs_watch(struct qemu_xs_handle *h,
+                                                      const char *path,
+                                                      xs_watch_fn fn,
+                                                      void *opaque)
+{
+    if (!xen_xenstore_ops) {
+        return NULL;
+    }
+    return xen_xenstore_ops->watch(h, path, fn, opaque);
+}
+
+static inline void qemu_xen_xs_unwatch(struct qemu_xs_handle *h,
+                                       struct qemu_xs_watch *w)
+{
+    if (!xen_xenstore_ops) {
+        return;
+    }
+    xen_xenstore_ops->unwatch(h, w);
+}
+
+static inline xs_transaction_t qemu_xen_xs_transaction_start(struct qemu_xs_handle *h)
+{
+    if (!xen_xenstore_ops) {
+        return XBT_NULL;
+    }
+    return xen_xenstore_ops->transaction_start(h);
+}
+
+static inline bool qemu_xen_xs_transaction_end(struct qemu_xs_handle *h,
+                                               xs_transaction_t t, bool abort)
+{
+    if (!xen_xenstore_ops) {
+        return false;
+    }
+    return xen_xenstore_ops->transaction_end(h, t, abort);
+}
+
 void setup_xen_backend_ops(void);
 
 #endif /* QEMU_XEN_BACKEND_OPS_H */
diff --git a/include/hw/xen/xen_common.h b/include/hw/xen/xen_common.h
index 632ce61..7edcf3e 100644
--- a/include/hw/xen/xen_common.h
+++ b/include/hw/xen/xen_common.h
@@ -12,7 +12,6 @@
 
 #include <xenctrl.h>
 #include <xenstore.h>
-#include "hw/xen/interface/io/xenbus.h"
 
 #include "hw/xen/xen.h"
 #include "hw/pci/pci_device.h"
diff --git a/include/hw/xen/xen_pvdev.h b/include/hw/xen/xen_pvdev.h
index 9c27b14..d8eea35 100644
--- a/include/hw/xen/xen_pvdev.h
+++ b/include/hw/xen/xen_pvdev.h
@@ -39,6 +39,7 @@ struct XenLegacyDevice {
     char               name[64];
     int                debug;
 
+    struct qemu_xs_watch *watch;
     enum xenbus_state  be_state;
     enum xenbus_state  fe_state;
     int                online;
@@ -64,7 +65,6 @@ int xenstore_write_int64(const char *base, const char *node, int64_t ival);
 char *xenstore_read_str(const char *base, const char *node);
 int xenstore_read_int(const char *base, const char *node, int *ival);
 int xenstore_read_uint64(const char *base, const char *node, uint64_t *uval);
-void xenstore_update(void *unused);
 
 const char *xenbus_strstate(enum xenbus_state state);