[vmware] Expose GuestRPC mechanism in 64-bit builds

The GuestRPC mechanism (used for VMWARE_SETTINGS and CONSOLE_VMWARE)
does not use any real-mode code and so can be exposed in both 64-bit
and 32-bit builds.

Reported-by: Matthew Helton <mwhelton@gmail.com>
Signed-off-by: Michael Brown <mcb30@ipxe.org>

7 files changed, 953 insertions, 0 deletions

diff --git a/src/arch/x86/Makefile b/src/arch/x86/Makefile
index 98c49b98d..4ab741db7 100644
--- a/src/arch/x86/Makefile
+++ b/src/arch/x86/Makefile
@@ -6,6 +6,7 @@ INCDIRS		+= arch/x86/include
 #
 SRCDIRS		+= arch/x86/core
 SRCDIRS		+= arch/x86/interface/efi
+SRCDIRS		+= arch/x86/interface/vmware
 SRCDIRS		+= arch/x86/prefix
 SRCDIRS		+= arch/x86/hci/commands
 SRCDIRS		+= arch/x86/drivers/xen
diff --git a/src/arch/x86/include/ipxe/guestrpc.h b/src/arch/x86/include/ipxe/guestrpc.h
new file mode 100644
index 000000000..bc3d85506
--- /dev/null
+++ b/src/arch/x86/include/ipxe/guestrpc.h
@@ -0,0 +1,68 @@
+#ifndef _IPXE_GUESTRPC_H
+#define _IPXE_GUESTRPC_H
+
+/** @file
+ *
+ * VMware GuestRPC mechanism
+ *
+ */
+
+FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
+
+#include <stdint.h>
+#include <ipxe/vmware.h>
+
+/** GuestRPC magic number */
+#define GUESTRPC_MAGIC 0x49435052 /* "RPCI" */
+
+/** Open RPC channel */
+#define GUESTRPC_OPEN 0x00
+
+/** Open RPC channel success status */
+#define GUESTRPC_OPEN_SUCCESS 0x00010000
+
+/** Send RPC command length */
+#define GUESTRPC_COMMAND_LEN 0x01
+
+/** Send RPC command length success status */
+#define GUESTRPC_COMMAND_LEN_SUCCESS 0x00810000
+
+/** Send RPC command data */
+#define GUESTRPC_COMMAND_DATA 0x02
+
+/** Send RPC command data success status */
+#define GUESTRPC_COMMAND_DATA_SUCCESS 0x00010000
+
+/** Receive RPC reply length */
+#define GUESTRPC_REPLY_LEN 0x03
+
+/** Receive RPC reply length success status */
+#define GUESTRPC_REPLY_LEN_SUCCESS 0x00830000
+
+/** Receive RPC reply data */
+#define GUESTRPC_REPLY_DATA 0x04
+
+/** Receive RPC reply data success status */
+#define GUESTRPC_REPLY_DATA_SUCCESS 0x00010000
+
+/** Finish receiving RPC reply */
+#define GUESTRPC_REPLY_FINISH 0x05
+
+/** Finish receiving RPC reply success status */
+#define GUESTRPC_REPLY_FINISH_SUCCESS 0x00010000
+
+/** Close RPC channel */
+#define GUESTRPC_CLOSE 0x06
+
+/** Close RPC channel success status */
+#define GUESTRPC_CLOSE_SUCCESS 0x00010000
+
+/** RPC command success status */
+#define GUESTRPC_SUCCESS 0x2031 /* "1 " */
+
+extern int guestrpc_open ( void );
+extern void guestrpc_close ( int channel );
+extern int guestrpc_command ( int channel, const char *command, char *reply,
+			      size_t reply_len );
+
+#endif /* _IPXE_GUESTRPC_H */
diff --git a/src/arch/x86/include/ipxe/vmware.h b/src/arch/x86/include/ipxe/vmware.h
new file mode 100644
index 000000000..24f60a03a
--- /dev/null
+++ b/src/arch/x86/include/ipxe/vmware.h
@@ -0,0 +1,81 @@
+#ifndef _IPXE_VMWARE_H
+#define _IPXE_VMWARE_H
+
+/** @file
+ *
+ * VMware backdoor mechanism
+ *
+ */
+
+FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
+
+#include <stdint.h>
+
+/** VMware backdoor I/O port */
+#define VMW_PORT 0x5658
+
+/** VMware backdoor magic value */
+#define VMW_MAGIC 0x564d5868 /* "VMXh" */
+
+/** VMware backdoor magic instruction */
+#define VMW_BACKDOOR "inl %%dx, %%eax"
+
+/** Get VMware version */
+#define VMW_CMD_GET_VERSION 0x0a
+
+/** Issue GuestRPC command */
+#define VMW_CMD_GUESTRPC 0x1e
+
+/**
+ * Get VMware version
+ *
+ * @ret version		VMware version(?)
+ * @ret magic		VMware magic number, if present
+ * @ret product_type	VMware product type
+ */
+static inline __attribute__ (( always_inline )) void
+vmware_cmd_get_version ( uint32_t *version, uint32_t *magic,
+			 uint32_t *product_type ) {
+	uint32_t discard_d;
+
+	/* Perform backdoor call */
+	__asm__ __volatile__ ( VMW_BACKDOOR
+			       : "=a" ( *version ), "=b" ( *magic ),
+				 "=c" ( *product_type ), "=d" ( discard_d )
+			       : "0" ( VMW_MAGIC ), "1" ( 0 ),
+				 "2" ( VMW_CMD_GET_VERSION ),
+				 "3" ( VMW_PORT ) );
+}
+
+/**
+ * Issue GuestRPC command
+ *
+ * @v channel		Channel number
+ * @v subcommand	GuestRPC subcommand
+ * @v parameter		Subcommand-specific parameter
+ * @ret edxhi		Subcommand-specific result
+ * @ret ebx		Subcommand-specific result
+ * @ret status		Command status
+ */
+static inline __attribute__ (( always_inline )) uint32_t
+vmware_cmd_guestrpc ( int channel, uint16_t subcommand, uint32_t parameter,
+		      uint16_t *edxhi, uint32_t *ebx ) {
+	uint32_t discard_a;
+	uint32_t status;
+	uint32_t edx;
+
+	/* Perform backdoor call */
+	__asm__ __volatile__ ( VMW_BACKDOOR
+			       : "=a" ( discard_a ), "=b" ( *ebx ),
+				 "=c" ( status ), "=d" ( edx )
+			       : "0" ( VMW_MAGIC ), "1" ( parameter ),
+				 "2" ( VMW_CMD_GUESTRPC | ( subcommand << 16 )),
+				 "3" ( VMW_PORT | ( channel << 16 ) ) );
+	*edxhi = ( edx >> 16 );
+
+	return status;
+}
+
+extern int vmware_present ( void );
+
+#endif /* _IPXE_VMWARE_H */
diff --git a/src/arch/x86/interface/vmware/guestinfo.c b/src/arch/x86/interface/vmware/guestinfo.c
new file mode 100644
index 000000000..a0530c8d1
--- /dev/null
+++ b/src/arch/x86/interface/vmware/guestinfo.c
@@ -0,0 +1,271 @@
+/*
+ * Copyright (C) 2012 Michael Brown <mbrown@fensystems.co.uk>.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of the
+ * License, or any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+ * 02110-1301, USA.
+ */
+
+FILE_LICENCE ( GPL2_OR_LATER );
+
+/** @file
+ *
+ * VMware GuestInfo settings
+ *
+ */
+
+#include <stdint.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include <errno.h>
+#include <ipxe/init.h>
+#include <ipxe/settings.h>
+#include <ipxe/netdevice.h>
+#include <ipxe/guestrpc.h>
+
+/** GuestInfo GuestRPC channel */
+static int guestinfo_channel;
+
+/**
+ * Fetch value of typed GuestInfo setting
+ *
+ * @v settings		Settings block
+ * @v setting		Setting to fetch
+ * @v type		Setting type to attempt (or NULL for default)
+ * @v data		Buffer to fill with setting data
+ * @v len		Length of buffer
+ * @ret found		Setting found in GuestInfo
+ * @ret len		Length of setting data, or negative error
+ */
+static int guestinfo_fetch_type ( struct settings *settings,
+				  struct setting *setting,
+				  const struct setting_type *type,
+				  void *data, size_t len, int *found ) {
+	const char *parent_name = settings->parent->name;
+	char command[ 24 /* "info-get guestinfo.ipxe." */ +
+		      strlen ( parent_name ) + 1 /* "." */ +
+		      strlen ( setting->name ) + 1 /* "." */ +
+		      ( type ? strlen ( type->name ) : 0 ) + 1 /* NUL */ ];
+	struct setting *predefined;
+	char *info;
+	int info_len;
+	int check_len;
+	int ret;
+
+	/* Construct info-get command */
+	snprintf ( command, sizeof ( command ),
+		   "info-get guestinfo.ipxe.%s%s%s%s%s",
+		   parent_name, ( parent_name[0] ? "." : "" ), setting->name,
+		   ( type ? "." : "" ), ( type ? type->name : "" ) );
+
+	/* Check for existence and obtain length of GuestInfo value */
+	info_len = guestrpc_command ( guestinfo_channel, command, NULL, 0 );
+	if ( info_len < 0 ) {
+		ret = info_len;
+		goto err_get_info_len;
+	}
+
+	/* Mark as found */
+	*found = 1;
+
+	/* Determine default type if necessary */
+	if ( ! type ) {
+		predefined = find_setting ( setting->name );
+		type = ( predefined ? predefined->type : &setting_type_string );
+	}
+	assert ( type != NULL );
+
+	/* Allocate temporary block to hold GuestInfo value */
+	info = zalloc ( info_len + 1 /* NUL */ );
+	if ( ! info ) {
+		DBGC ( settings, "GuestInfo %p could not allocate %d bytes\n",
+		       settings, info_len );
+		ret = -ENOMEM;
+		goto err_alloc;
+	}
+	info[info_len] = '\0';
+
+	/* Fetch GuestInfo value */
+	check_len = guestrpc_command ( guestinfo_channel, command,
+				       info, info_len );
+	if ( check_len < 0 ) {
+		ret = check_len;
+		goto err_get_info;
+	}
+	if ( check_len != info_len ) {
+		DBGC ( settings, "GuestInfo %p length mismatch (expected %d, "
+		       "got %d)\n", settings, info_len, check_len );
+		ret = -EIO;
+		goto err_get_info;
+	}
+	DBGC2 ( settings, "GuestInfo %p found %s = \"%s\"\n",
+		settings, &command[9] /* Skip "info-get " */, info );
+
+	/* Parse GuestInfo value according to type */
+	ret = setting_parse ( type, info, data, len );
+	if ( ret < 0 ) {
+		DBGC ( settings, "GuestInfo %p could not parse \"%s\" as %s: "
+		       "%s\n", settings, info, type->name, strerror ( ret ) );
+		goto err_parse;
+	}
+
+ err_parse:
+ err_get_info:
+	free ( info );
+ err_alloc:
+ err_get_info_len:
+	return ret;
+}
+
+/**
+ * Fetch value of GuestInfo setting
+ *
+ * @v settings		Settings block
+ * @v setting		Setting to fetch
+ * @v data		Buffer to fill with setting data
+ * @v len		Length of buffer
+ * @ret len		Length of setting data, or negative error
+ */
+static int guestinfo_fetch ( struct settings *settings,
+			     struct setting *setting,
+			     void *data, size_t len ) {
+	struct setting_type *type;
+	int found = 0;
+	int ret;
+
+	/* Try default type first */
+	ret = guestinfo_fetch_type ( settings, setting, NULL,
+				     data, len, &found );
+	if ( found )
+		return ret;
+
+	/* Otherwise, try all possible types */
+	for_each_table_entry ( type, SETTING_TYPES ) {
+		ret = guestinfo_fetch_type ( settings, setting, type,
+					     data, len, &found );
+		if ( found )
+			return ret;
+	}
+
+	/* Not found */
+	return -ENOENT;
+}
+
+/** GuestInfo settings operations */
+static struct settings_operations guestinfo_settings_operations = {
+	.fetch = guestinfo_fetch,
+};
+
+/** GuestInfo settings */
+static struct settings guestinfo_settings = {
+	.refcnt = NULL,
+	.siblings = LIST_HEAD_INIT ( guestinfo_settings.siblings ),
+	.children = LIST_HEAD_INIT ( guestinfo_settings.children ),
+	.op = &guestinfo_settings_operations,
+};
+
+/** Initialise GuestInfo settings */
+static void guestinfo_init ( void ) {
+	int rc;
+
+	/* Open GuestRPC channel */
+	guestinfo_channel = guestrpc_open();
+	if ( guestinfo_channel < 0 ) {
+		rc = guestinfo_channel;
+		DBG ( "GuestInfo could not open channel: %s\n",
+		      strerror ( rc ) );
+		return;
+	}
+
+	/* Register root GuestInfo settings */
+	if ( ( rc = register_settings ( &guestinfo_settings, NULL,
+					"vmware" ) ) != 0 ) {
+		DBG ( "GuestInfo could not register settings: %s\n",
+		      strerror ( rc ) );
+		return;
+	}
+}
+
+/** GuestInfo settings initialiser */
+struct init_fn guestinfo_init_fn __init_fn ( INIT_NORMAL ) = {
+	.initialise = guestinfo_init,
+};
+
+/**
+ * Create per-netdevice GuestInfo settings
+ *
+ * @v netdev		Network device
+ * @ret rc		Return status code
+ */
+static int guestinfo_net_probe ( struct net_device *netdev ) {
+	struct settings *settings;
+	int rc;
+
+	/* Do nothing unless we have a GuestInfo channel available */
+	if ( guestinfo_channel < 0 )
+		return 0;
+
+	/* Allocate and initialise settings block */
+	settings = zalloc ( sizeof ( *settings ) );
+	if ( ! settings ) {
+		rc = -ENOMEM;
+		goto err_alloc;
+	}
+	settings_init ( settings, &guestinfo_settings_operations, NULL, NULL );
+
+	/* Register settings */
+	if ( ( rc = register_settings ( settings, netdev_settings ( netdev ),
+					"vmware" ) ) != 0 ) {
+		DBGC ( settings, "GuestInfo %p could not register for %s: %s\n",
+		       settings, netdev->name, strerror ( rc ) );
+		goto err_register;
+	}
+	DBGC ( settings, "GuestInfo %p registered for %s\n",
+	       settings, netdev->name );
+
+	return 0;
+
+ err_register:
+	free ( settings );
+ err_alloc:
+	return rc;
+}
+
+/**
+ * Remove per-netdevice GuestInfo settings
+ *
+ * @v netdev		Network device
+ */
+static void guestinfo_net_remove ( struct net_device *netdev ) {
+	struct settings *parent = netdev_settings ( netdev );
+	struct settings *settings;
+
+	list_for_each_entry ( settings, &parent->children, siblings ) {
+		if ( settings->op == &guestinfo_settings_operations ) {
+			DBGC ( settings, "GuestInfo %p unregistered for %s\n",
+			       settings, netdev->name );
+			unregister_settings ( settings );
+			free ( settings );
+			return;
+		}
+	}
+}
+
+/** GuestInfo per-netdevice driver */
+struct net_driver guestinfo_net_driver __net_driver = {
+	.name = "GuestInfo",
+	.probe = guestinfo_net_probe,
+	.remove = guestinfo_net_remove,
+};
diff --git a/src/arch/x86/interface/vmware/guestrpc.c b/src/arch/x86/interface/vmware/guestrpc.c
new file mode 100644
index 000000000..ef7ee8151
--- /dev/null
+++ b/src/arch/x86/interface/vmware/guestrpc.c
@@ -0,0 +1,332 @@
+/*
+ * Copyright (C) 2012 Michael Brown <mbrown@fensystems.co.uk>.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of the
+ * License, or any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+ * 02110-1301, USA.
+ *
+ * You can also choose to distribute this program under the terms of
+ * the Unmodified Binary Distribution Licence (as given in the file
+ * COPYING.UBDL), provided that you have satisfied its requirements.
+ */
+
+FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
+
+/** @file
+ *
+ * VMware GuestRPC mechanism
+ *
+ */
+
+#include <stdint.h>
+#include <string.h>
+#include <errno.h>
+#include <assert.h>
+#include <ipxe/vmware.h>
+#include <ipxe/guestrpc.h>
+
+/* Disambiguate the various error causes */
+#define EPROTO_OPEN __einfo_error ( EINFO_EPROTO_OPEN )
+#define EINFO_EPROTO_OPEN \
+	__einfo_uniqify ( EINFO_EPROTO, 0x00, "GuestRPC open failed" )
+#define EPROTO_COMMAND_LEN __einfo_error ( EINFO_EPROTO_COMMAND_LEN )
+#define EINFO_EPROTO_COMMAND_LEN \
+	__einfo_uniqify ( EINFO_EPROTO, 0x01, "GuestRPC command length failed" )
+#define EPROTO_COMMAND_DATA __einfo_error ( EINFO_EPROTO_COMMAND_DATA )
+#define EINFO_EPROTO_COMMAND_DATA \
+	__einfo_uniqify ( EINFO_EPROTO, 0x02, "GuestRPC command data failed" )
+#define EPROTO_REPLY_LEN __einfo_error ( EINFO_EPROTO_REPLY_LEN )
+#define EINFO_EPROTO_REPLY_LEN \
+	__einfo_uniqify ( EINFO_EPROTO, 0x03, "GuestRPC reply length failed" )
+#define EPROTO_REPLY_DATA __einfo_error ( EINFO_EPROTO_REPLY_DATA )
+#define EINFO_EPROTO_REPLY_DATA \
+	__einfo_uniqify ( EINFO_EPROTO, 0x04, "GuestRPC reply data failed" )
+#define EPROTO_REPLY_FINISH __einfo_error ( EINFO_EPROTO_REPLY_FINISH )
+#define EINFO_EPROTO_REPLY_FINISH \
+	__einfo_uniqify ( EINFO_EPROTO, 0x05, "GuestRPC reply finish failed" )
+#define EPROTO_CLOSE __einfo_error ( EINFO_EPROTO_CLOSE )
+#define EINFO_EPROTO_CLOSE \
+	__einfo_uniqify ( EINFO_EPROTO, 0x06, "GuestRPC close failed" )
+
+/**
+ * Open GuestRPC channel
+ *
+ * @ret channel		Channel number, or negative error
+ */
+int guestrpc_open ( void ) {
+	uint16_t channel;
+	uint32_t discard_b;
+	uint32_t status;
+
+	/* Issue GuestRPC command */
+	status = vmware_cmd_guestrpc ( 0, GUESTRPC_OPEN, GUESTRPC_MAGIC,
+				       &channel, &discard_b );
+	if ( status != GUESTRPC_OPEN_SUCCESS ) {
+		DBGC ( GUESTRPC_MAGIC, "GuestRPC open failed: status %08x\n",
+		       status );
+		return -EPROTO_OPEN;
+	}
+
+	DBGC ( GUESTRPC_MAGIC, "GuestRPC channel %d opened\n", channel );
+	return channel;
+}
+
+/**
+ * Send GuestRPC command length
+ *
+ * @v channel		Channel number
+ * @v len		Command length
+ * @ret rc		Return status code
+ */
+static int guestrpc_command_len ( int channel, size_t len ) {
+	uint16_t discard_d;
+	uint32_t discard_b;
+	uint32_t status;
+
+	/* Issue GuestRPC command */
+	status = vmware_cmd_guestrpc ( channel, GUESTRPC_COMMAND_LEN, len,
+				       &discard_d, &discard_b );
+	if ( status != GUESTRPC_COMMAND_LEN_SUCCESS ) {
+		DBGC ( GUESTRPC_MAGIC, "GuestRPC channel %d send command "
+		       "length %zd failed: status %08x\n",
+		       channel, len, status );
+		return -EPROTO_COMMAND_LEN;
+	}
+
+	return 0;
+}
+
+/**
+ * Send GuestRPC command data
+ *
+ * @v channel		Channel number
+ * @v data		Command data
+ * @ret rc		Return status code
+ */
+static int guestrpc_command_data ( int channel, uint32_t data ) {
+	uint16_t discard_d;
+	uint32_t discard_b;
+	uint32_t status;
+
+	/* Issue GuestRPC command */
+	status = vmware_cmd_guestrpc ( channel, GUESTRPC_COMMAND_DATA, data,
+				       &discard_d, &discard_b );
+	if ( status != GUESTRPC_COMMAND_DATA_SUCCESS ) {
+		DBGC ( GUESTRPC_MAGIC, "GuestRPC channel %d send command "
+		       "data %08x failed: status %08x\n",
+		       channel, data, status );
+		return -EPROTO_COMMAND_DATA;
+	}
+
+	return 0;
+}
+
+/**
+ * Receive GuestRPC reply length
+ *
+ * @v channel		Channel number
+ * @ret reply_id	Reply ID
+ * @ret len		Reply length, or negative error
+ */
+static int guestrpc_reply_len ( int channel, uint16_t *reply_id ) {
+	uint32_t len;
+	uint32_t status;
+
+	/* Issue GuestRPC command */
+	status = vmware_cmd_guestrpc ( channel, GUESTRPC_REPLY_LEN, 0,
+				       reply_id, &len );
+	if ( status != GUESTRPC_REPLY_LEN_SUCCESS ) {
+		DBGC ( GUESTRPC_MAGIC, "GuestRPC channel %d receive reply "
+		       "length failed: status %08x\n", channel, status );
+		return -EPROTO_REPLY_LEN;
+	}
+
+	return len;
+}
+
+/**
+ * Receive GuestRPC reply data
+ *
+ * @v channel		Channel number
+ * @v reply_id		Reply ID
+ * @ret data		Reply data
+ * @ret rc		Return status code
+ */
+static int guestrpc_reply_data ( int channel, uint16_t reply_id,
+				 uint32_t *data ) {
+	uint16_t discard_d;
+	uint32_t status;
+
+	/* Issue GuestRPC command */
+	status = vmware_cmd_guestrpc ( channel, GUESTRPC_REPLY_DATA, reply_id,
+				       &discard_d, data );
+	if ( status != GUESTRPC_REPLY_DATA_SUCCESS ) {
+		DBGC ( GUESTRPC_MAGIC, "GuestRPC channel %d receive reply "
+		       "%d data failed: status %08x\n",
+		       channel, reply_id, status );
+		return -EPROTO_REPLY_DATA;
+	}
+
+	return 0;
+}
+
+/**
+ * Finish receiving GuestRPC reply
+ *
+ * @v channel		Channel number
+ * @v reply_id		Reply ID
+ * @ret rc		Return status code
+ */
+static int guestrpc_reply_finish ( int channel, uint16_t reply_id ) {
+	uint16_t discard_d;
+	uint32_t discard_b;
+	uint32_t status;
+
+	/* Issue GuestRPC command */
+	status = vmware_cmd_guestrpc ( channel, GUESTRPC_REPLY_FINISH, reply_id,
+				       &discard_d, &discard_b );
+	if ( status != GUESTRPC_REPLY_FINISH_SUCCESS ) {
+		DBGC ( GUESTRPC_MAGIC, "GuestRPC channel %d finish reply %d "
+		       "failed: status %08x\n", channel, reply_id, status );
+		return -EPROTO_REPLY_FINISH;
+	}
+
+	return 0;
+}
+
+/**
+ * Close GuestRPC channel
+ *
+ * @v channel		Channel number
+ */
+void guestrpc_close ( int channel ) {
+	uint16_t discard_d;
+	uint32_t discard_b;
+	uint32_t status;
+
+	/* Issue GuestRPC command */
+	status = vmware_cmd_guestrpc ( channel, GUESTRPC_CLOSE, 0,
+				       &discard_d, &discard_b );
+	if ( status != GUESTRPC_CLOSE_SUCCESS ) {
+		DBGC ( GUESTRPC_MAGIC, "GuestRPC channel %d close failed: "
+		       "status %08x\n", channel, status );
+		return;
+	}
+
+	DBGC ( GUESTRPC_MAGIC, "GuestRPC channel %d closed\n", channel );
+}
+
+/**
+ * Issue GuestRPC command
+ *
+ * @v channel		Channel number
+ * @v command		Command
+ * @v reply		Reply buffer
+ * @v reply_len		Length of reply buffer
+ * @ret len		Length of reply, or negative error
+ *
+ * The actual length of the reply will be returned even if the buffer
+ * was too small.
+ */
+int guestrpc_command ( int channel, const char *command, char *reply,
+		       size_t reply_len ) {
+	const uint8_t *command_bytes = ( ( const void * ) command );
+	uint8_t *reply_bytes = ( ( void * ) reply );
+	size_t command_len = strlen ( command );
+	int orig_reply_len = reply_len;
+	uint16_t status;
+	uint8_t *status_bytes = ( ( void * ) &status );
+	size_t status_len = sizeof ( status );
+	uint32_t data;
+	uint16_t reply_id;
+	int len;
+	int remaining;
+	unsigned int i;
+	int rc;
+
+	DBGC2 ( GUESTRPC_MAGIC, "GuestRPC channel %d issuing command:\n",
+		channel );
+	DBGC2_HDA ( GUESTRPC_MAGIC, 0, command, command_len );
+
+	/* Sanity check */
+	assert ( ( reply != NULL ) || ( reply_len == 0 ) );
+
+	/* Send command length */
+	if ( ( rc = guestrpc_command_len ( channel, command_len ) ) < 0 )
+		return rc;
+
+	/* Send command data */
+	while ( command_len ) {
+		data = 0;
+		for ( i = sizeof ( data ) ; i ; i-- ) {
+			if ( command_len ) {
+				data = ( ( data & ~0xff ) |
+					 *(command_bytes++) );
+				command_len--;
+			}
+			data = ( ( data << 24 ) | ( data >> 8 ) );
+		}
+		if ( ( rc = guestrpc_command_data ( channel, data ) ) < 0 )
+			return rc;
+	}
+
+	/* Receive reply length */
+	if ( ( len = guestrpc_reply_len ( channel, &reply_id ) ) < 0 ) {
+		rc = len;
+		return rc;
+	}
+
+	/* Receive reply */
+	for ( remaining = len ; remaining > 0 ; remaining -= sizeof ( data ) ) {
+		if ( ( rc = guestrpc_reply_data ( channel, reply_id,
+						  &data ) ) < 0 ) {
+			return rc;
+		}
+		for ( i = sizeof ( data ) ; i ; i-- ) {
+			if ( status_len ) {
+				*(status_bytes++) = ( data & 0xff );
+				status_len--;
+				len--;
+			} else if ( reply_len ) {
+				*(reply_bytes++) = ( data & 0xff );
+				reply_len--;
+			}
+			data = ( ( data << 24 ) | ( data >> 8 ) );
+		}
+	}
+
+	/* Finish receiving RPC reply */
+	if ( ( rc = guestrpc_reply_finish ( channel, reply_id ) ) < 0 )
+		return rc;
+
+	DBGC2 ( GUESTRPC_MAGIC, "GuestRPC channel %d received reply (id %d, "
+		"length %d):\n", channel, reply_id, len );
+	DBGC2_HDA ( GUESTRPC_MAGIC, 0, &status, sizeof ( status ) );
+	DBGC2_HDA ( GUESTRPC_MAGIC, sizeof ( status ), reply,
+		    ( ( len < orig_reply_len ) ? len : orig_reply_len ) );
+
+	/* Check reply status */
+	if ( status != GUESTRPC_SUCCESS ) {
+		DBGC ( GUESTRPC_MAGIC, "GuestRPC channel %d command failed "
+		       "(status %04x, reply id %d, reply length %d):\n",
+		       channel, status, reply_id, len );
+		DBGC_HDA ( GUESTRPC_MAGIC, 0, command, command_len );
+		DBGC_HDA ( GUESTRPC_MAGIC, 0, &status, sizeof ( status ) );
+		DBGC_HDA ( GUESTRPC_MAGIC, sizeof ( status ), reply,
+			   ( ( len < orig_reply_len ) ? len : orig_reply_len ));
+		return -EIO;
+	}
+
+	return len;
+}
diff --git a/src/arch/x86/interface/vmware/vmconsole.c b/src/arch/x86/interface/vmware/vmconsole.c
new file mode 100644
index 000000000..f7df4f75b
--- /dev/null
+++ b/src/arch/x86/interface/vmware/vmconsole.c
@@ -0,0 +1,138 @@
+/*
+ * Copyright (C) 2012 Michael Brown <mbrown@fensystems.co.uk>.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of the
+ * License, or any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+ * 02110-1301, USA.
+ *
+ * You can also choose to distribute this program under the terms of
+ * the Unmodified Binary Distribution Licence (as given in the file
+ * COPYING.UBDL), provided that you have satisfied its requirements.
+ */
+
+FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
+
+/** @file
+ *
+ * VMware logfile console
+ *
+ */
+
+#include <string.h>
+#include <ipxe/console.h>
+#include <ipxe/lineconsole.h>
+#include <ipxe/init.h>
+#include <ipxe/guestrpc.h>
+#include <config/console.h>
+
+/** VMware logfile console buffer size */
+#define VMCONSOLE_BUFSIZE 128
+
+/* Set default console usage if applicable */
+#if ! ( defined ( CONSOLE_VMWARE ) && CONSOLE_EXPLICIT ( CONSOLE_VMWARE ) )
+#undef CONSOLE_VMWARE
+#define CONSOLE_VMWARE ( CONSOLE_USAGE_ALL & ~CONSOLE_USAGE_TUI )
+#endif
+
+/** VMware logfile console GuestRPC channel */
+static int vmconsole_channel;
+
+/** VMware logfile console line buffer */
+static struct {
+	char prefix[4];
+	char message[VMCONSOLE_BUFSIZE];
+} vmconsole_buffer = {
+	.prefix = "log ",
+};
+
+/** VMware logfile console ANSI escape sequence handlers */
+static struct ansiesc_handler vmconsole_handlers[] = {
+	{ 0, NULL }
+};
+
+/** VMware logfile line console */
+static struct line_console vmconsole_line = {
+	.buffer = vmconsole_buffer.message,
+	.len = sizeof ( vmconsole_buffer.message ),
+	.ctx = {
+		.handlers = vmconsole_handlers,
+	},
+};
+
+/** VMware logfile console recursion marker */
+static int vmconsole_entered;
+
+/**
+ * Print a character to VMware logfile console
+ *
+ * @v character		Character to be printed
+ */
+static void vmconsole_putchar ( int character ) {
+	int rc;
+
+	/* Ignore if we are already mid-logging */
+	if ( vmconsole_entered )
+		return;
+
+	/* Fill line buffer */
+	if ( line_putchar ( &vmconsole_line, character ) == 0 )
+		return;
+
+	/* Guard against re-entry */
+	vmconsole_entered = 1;
+
+	/* Send log message */
+	if ( ( rc = guestrpc_command ( vmconsole_channel,
+				       vmconsole_buffer.prefix, NULL, 0 ) ) <0){
+		DBG ( "VMware console could not send log message: %s\n",
+		      strerror ( rc ) );
+	}
+
+	/* Clear re-entry flag */
+	vmconsole_entered = 0;
+}
+
+/** VMware logfile console driver */
+struct console_driver vmconsole __console_driver = {
+	.putchar = vmconsole_putchar,
+	.disabled = CONSOLE_DISABLED,
+	.usage = CONSOLE_VMWARE,
+};
+
+/**
+ * Initialise VMware logfile console
+ *
+ */
+static void vmconsole_init ( void ) {
+	int rc;
+
+	/* Attempt to open console */
+	vmconsole_channel = guestrpc_open();
+	if ( vmconsole_channel < 0 ) {
+		rc = vmconsole_channel;
+		DBG ( "VMware console could not be initialised: %s\n",
+		      strerror ( rc ) );
+		return;
+	}
+
+	/* Mark console as available */
+	vmconsole.disabled = 0;
+}
+
+/**
+ * VMware logfile console initialisation function
+ */
+struct init_fn vmconsole_init_fn __init_fn ( INIT_CONSOLE ) = {
+	.initialise = vmconsole_init,
+};
diff --git a/src/arch/x86/interface/vmware/vmware.c b/src/arch/x86/interface/vmware/vmware.c
new file mode 100644
index 000000000..a415465fb
--- /dev/null
+++ b/src/arch/x86/interface/vmware/vmware.c
@@ -0,0 +1,62 @@
+/*
+ * Copyright (C) 2012 Michael Brown <mbrown@fensystems.co.uk>.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of the
+ * License, or any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+ * 02110-1301, USA.
+ *
+ * You can also choose to distribute this program under the terms of
+ * the Unmodified Binary Distribution Licence (as given in the file
+ * COPYING.UBDL), provided that you have satisfied its requirements.
+ */
+
+FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
+
+/** @file
+ *
+ * VMware backdoor mechanism
+ *
+ * Based on the unofficial documentation at
+ *
+ *   http://sites.google.com/site/chitchatvmback/backdoor
+ *
+ */
+
+#include <stdint.h>
+#include <errno.h>
+#include <ipxe/vmware.h>
+
+/**
+ * Detect VMware presence
+ *
+ * @ret rc		Return status code
+ */
+int vmware_present ( void ) {
+	uint32_t version;
+	uint32_t magic;
+	uint32_t product_type;
+
+	/* Perform backdoor call */
+	vmware_cmd_get_version ( &version, &magic, &product_type );
+
+	/* Check for VMware presence */
+	if ( magic != VMW_MAGIC ) {
+		DBGC ( VMW_MAGIC, "VMware not present\n" );
+		return -ENOENT;
+	}
+
+	DBGC ( VMW_MAGIC, "VMware product type %04x version %08x detected\n",
+	       product_type, version );
+	return 0;
+}