guestrpc module to handle VMware backdoor port GuestRPC functionality

Convert existing FreeBSD vmware_hvcall function to take a channel
and parameter arguments.

Added vmware_guestrpc_cmd() to send GuestRPC commands to the VMware
hypervisor. The sbuf argument is used for both the command to send
and to store the data to return to the caller.

The following KPIs can be used to get and set FreeBSD-specific guest
information in key/value pairs:
 * vmware_guestrpc_set_guestinfo
   - set a value into the guestinfo.fbsd.<keyword> key
 * vmware_guestrpc_get_guestinfo
   - get the value stored in the guestinfo.fbsd.<keyword> key

Add VMware devices to x86 NOTES

Reviewed by:	jhb
Obtained from:	Juniper Networks, Inc.
Differential Revision:	https://reviews.freebsd.org/D44528

2 files changed, 43 insertions, 2 deletions

diff --git a/sys/x86/include/vmware.h b/sys/x86/include/vmware.h
index 38bca8c146a7..5ab6462b862d 100644
--- a/sys/x86/include/vmware.h
+++ b/sys/x86/include/vmware.h
@@ -31,19 +31,23 @@
 #define	VMW_HVPORT		0x5658
 
 #define	VMW_HVCMD_GETVERSION	10
+#define	VMW_HVCMD_GUESTRPC	30
 #define	VMW_HVCMD_GETHZ		45
 #define	VMW_HVCMD_GETVCPU_INFO	68
 
+#define	VMW_HVCMD_DEFAULT_PARAM	UINT_MAX
+
 #define	VMW_VCPUINFO_LEGACY_X2APIC	(1 << 3)
 #define	VMW_VCPUINFO_VCPU_RESERVED	(1 << 31)
 
 static __inline void
-vmware_hvcall(u_int cmd, u_int *p)
+vmware_hvcall(int chan, u_int cmd, u_int param, u_int *p)
 {
 
 	__asm __volatile("inl %w3, %0"
 	: "=a" (p[0]), "=b" (p[1]), "=c" (p[2]), "=d" (p[3])
-	: "0" (VMW_HVMAGIC), "1" (UINT_MAX), "2" (cmd), "3" (VMW_HVPORT)
+	: "0" (VMW_HVMAGIC), "1" (param), "2" (cmd),
+	  "3" (VMW_HVPORT | (chan << 16))
 	: "memory");
 }
 
diff --git a/sys/x86/include/vmware_guestrpc.h b/sys/x86/include/vmware_guestrpc.h
new file mode 100644
index 000000000000..24055b6c249e
--- /dev/null
+++ b/sys/x86/include/vmware_guestrpc.h
@@ -0,0 +1,37 @@
+/*-
+ * SPDX-License-Identifier: BSD-2-Clause
+ *
+ * Copyright (c) 2015-2024, Juniper Networks, Inc.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#ifndef _X86_VMWARE_GUESTRPC_H_
+#define _X86_VMWARE_GUESTRPC_H_
+
+struct sbuf;
+
+int	vmware_guestrpc_cmd(struct sbuf *sbufp);
+int	vmware_guestrpc_set_guestinfo(const char *keyword, const char *val);
+int	vmware_guestrpc_get_guestinfo(const char *keyword, struct sbuf *sbufp);
+
+#endif /* _X86_VMWARE_GUESTRPC_H_ */