OvmfPkg/XenBusDxe: Add XenStore client implementation

XenStore is a key/value database, which is running on another virtual
machine. It can be accessed through shared memory. This is a client
implementation.

Change in V3:
- moving xs_wire.h from patch #1 to this patch
- fix return value of XenStoreListDirectory
- Use a timeout to print a debug message if the other side of the
  xenstore ring does not notify through the event channel.
  This is done with the new XenStoreWaitForEvent function.
- Have XenStoreReadReply check status of XenStoreProcessMessage and
  return an error if needed.
- Have XenStoreTalkv return the status of XenStoreReadReply.
- Have a loop to check for the quiescent of the response ring in the
  XenStoreInitComms function. (with a timeout of 5 seconds)
- use the recently introduced XenStore 'closing' feature.

Change in V2:
- Change comment style, from freebsd to ovmf
- Fix type of EventChannel
- Fix debug print, no more cast
- Implement XenStoreDeinit.
- Clean up comments
- Fix few codding style issue
- Add FAIL xenstore status value.

Origin: FreeBSD 10.0
License: This patch adds several files under the MIT licence.
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Anthony PERARD <anthony.perard@citrix.com>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Acked-by: Jordan Justen <jordan.l.justen@intel.com>

git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@16267 6f19259b-4bc3-4df7-8a09-765794883524

1 files changed, 149 insertions, 0 deletions

diff --git a/OvmfPkg/Include/IndustryStandard/Xen/io/xs_wire.h b/OvmfPkg/Include/IndustryStandard/Xen/io/xs_wire.h
new file mode 100644
index 0000000000..6f302d1447
--- /dev/null
+++ b/OvmfPkg/Include/IndustryStandard/Xen/io/xs_wire.h
@@ -0,0 +1,149 @@
+/*

+ * Details of the "wire" protocol between Xen Store Daemon and client

+ * library or guest kernel.

+ *

+ * Permission is hereby granted, free of charge, to any person obtaining a copy

+ * of this software and associated documentation files (the "Software"), to

+ * deal in the Software without restriction, including without limitation the

+ * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or

+ * sell copies of the Software, and to permit persons to whom the Software is

+ * furnished to do so, subject to the following conditions:

+ *

+ * The above copyright notice and this permission notice shall be included in

+ * all copies or substantial portions of the Software.

+ *

+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR

+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,

+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE

+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER

+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING

+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER

+ * DEALINGS IN THE SOFTWARE.

+ *

+ * Copyright (C) 2005 Rusty Russell IBM Corporation

+ */

+

+#ifndef _XS_WIRE_H

+#define _XS_WIRE_H

+

+enum xsd_sockmsg_type

+{

+    XS_DEBUG,

+    XS_DIRECTORY,

+    XS_READ,

+    XS_GET_PERMS,

+    XS_WATCH,

+    XS_UNWATCH,

+    XS_TRANSACTION_START,

+    XS_TRANSACTION_END,

+    XS_INTRODUCE,

+    XS_RELEASE,

+    XS_GET_DOMAIN_PATH,

+    XS_WRITE,

+    XS_MKDIR,

+    XS_RM,

+    XS_SET_PERMS,

+    XS_WATCH_EVENT,

+    XS_ERROR,

+    XS_IS_DOMAIN_INTRODUCED,

+    XS_RESUME,

+    XS_SET_TARGET,

+    XS_RESTRICT,

+    XS_RESET_WATCHES,

+

+    XS_INVALID = 0xffff /* Guaranteed to remain an invalid type */

+};

+

+#define XS_WRITE_NONE "NONE"

+#define XS_WRITE_CREATE "CREATE"

+#define XS_WRITE_CREATE_EXCL "CREATE|EXCL"

+

+/* We hand errors as strings, for portability. */

+struct xsd_errors

+{

+    INT32 errnum;

+    const CHAR8 *errstring;

+};

+#ifdef EINVAL

+#define XSD_ERROR(x) { x, #x }

+/* LINTED: static unused */

+static struct xsd_errors xsd_errors[]

+#if defined(__GNUC__)

+__attribute__((unused))

+#endif

+    = {

+    XSD_ERROR(EINVAL),

+    XSD_ERROR(EACCES),

+    XSD_ERROR(EEXIST),

+    XSD_ERROR(EISDIR),

+    XSD_ERROR(ENOENT),

+    XSD_ERROR(ENOMEM),

+    XSD_ERROR(ENOSPC),

+    XSD_ERROR(EIO),

+    XSD_ERROR(ENOTEMPTY),

+    XSD_ERROR(ENOSYS),

+    XSD_ERROR(EROFS),

+    XSD_ERROR(EBUSY),

+    XSD_ERROR(EAGAIN),

+    XSD_ERROR(EISCONN),

+    XSD_ERROR(E2BIG)

+};

+#endif

+

+struct xsd_sockmsg

+{

+    UINT32 type;  /* XS_??? */

+    UINT32 req_id;/* Request identifier, echoed in daemon's response.  */

+    UINT32 tx_id; /* Transaction id (0 if not related to a transaction). */

+    UINT32 len;   /* Length of data following this. */

+

+    /* Generally followed by nul-terminated string(s). */

+};

+

+enum xs_watch_type

+{

+    XS_WATCH_PATH = 0,

+    XS_WATCH_TOKEN

+};

+

+/*

+ * `incontents 150 xenstore_struct XenStore wire protocol.

+ *

+ * Inter-domain shared memory communications. */

+#define XENSTORE_RING_SIZE 1024

+typedef UINT32 XENSTORE_RING_IDX;

+#define MASK_XENSTORE_IDX(idx) ((idx) & (XENSTORE_RING_SIZE-1))

+struct xenstore_domain_interface {

+    CHAR8 req[XENSTORE_RING_SIZE]; /* Requests to xenstore daemon. */

+    CHAR8 rsp[XENSTORE_RING_SIZE]; /* Replies and async watch events. */

+    XENSTORE_RING_IDX req_cons, req_prod;

+    XENSTORE_RING_IDX rsp_cons, rsp_prod;

+    UINT32 server_features; /* Bitmap of features supported by the server */

+    UINT32 connection;

+};

+

+/* Violating this is very bad.  See docs/misc/xenstore.txt. */

+#define XENSTORE_PAYLOAD_MAX 4096

+

+/* Violating these just gets you an error back */

+#define XENSTORE_ABS_PATH_MAX 3072

+#define XENSTORE_REL_PATH_MAX 2048

+

+/* The ability to reconnect a ring */

+#define XENSTORE_SERVER_FEATURE_RECONNECTION 1

+

+/* Valid values for the connection field */

+#define XENSTORE_CONNECTED 0 /* the steady-state */

+#define XENSTORE_RECONNECT 1 /* guest has initiated a reconnect */

+

+#endif /* _XS_WIRE_H */

+

+/*

+ * Local variables:

+ * mode: C

+ * c-file-style: "BSD"

+ * c-basic-offset: 4

+ * tab-width: 4

+ * indent-tabs-mode: nil

+ * End:

+ */