dm: vpit: add vPIT support

vPIT is used as a source of system timer by UEFI (e.g. OVMF).

This is ported from Bhyve, with a few changes:

- move to user space, using POSIX timer
- support timer mode 3
- improve the emulation of OUT and STATUS byte
- improve the emulation of counter behavior
- improve the emulation of CE update in periodic mode
- treat CR == 0 as 0x10000

Origin: FreeBSD
License: BSD-3-Clause
URL: https://svnweb.freebsd.org/
commit: 283291
Purpose: Adding vPIT support.
Maintained-by: External

Tracked-On: #1392
Signed-off-by: Peter Fang <peter.fang@intel.com>
Acked-by: Yin Fengwei <fengwei.yin@intel.com>

devicemodel/include/macros.h

@@ -1,8 +1,35 @@
-/*
- * Copyright (C) 2018 Intel Corporation. All rights reserved.
- *
+/*-
  * SPDX-License-Identifier: BSD-3-Clause
  *
+ * Copyright (c) 2018 Intel Corporation. All rights reserved.
+ * Copyright (c) 1982, 1986, 1993
+ *	The Regents of the University of California.  All rights reserved.
+ *
+ * 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.
+ * 3. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 REGENTS 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.
+ *
+ * $FreeBSD$
  */
 
 #ifndef _MACROS_H_
@@ -17,4 +44,30 @@
 #define	MB		(1024 * 1024UL)
 #define	GB		(1024 * 1024 * 1024UL)
 
+/* Operations on timespecs */
+#define	timespecclear(tvp)	((tvp)->tv_sec = (tvp)->tv_nsec = 0)
+#define	timespecisset(tvp)	((tvp)->tv_sec || (tvp)->tv_nsec)
+#define	timespeccmp(tvp, uvp, cmp)					\
+	(((tvp)->tv_sec == (uvp)->tv_sec) ?				\
+	    ((tvp)->tv_nsec cmp (uvp)->tv_nsec) :			\
+	    ((tvp)->tv_sec cmp (uvp)->tv_sec))
+#define	timespecadd(vvp, uvp)						\
+	do {								\
+		(vvp)->tv_sec += (uvp)->tv_sec;				\
+		(vvp)->tv_nsec += (uvp)->tv_nsec;			\
+		if ((vvp)->tv_nsec >= 1000000000) {			\
+			(vvp)->tv_sec++;				\
+			(vvp)->tv_nsec -= 1000000000;			\
+		}							\
+	} while (0)
+#define	timespecsub(vvp, uvp)						\
+	do {								\
+		(vvp)->tv_sec -= (uvp)->tv_sec;				\
+		(vvp)->tv_nsec -= (uvp)->tv_nsec;			\
+		if ((vvp)->tv_nsec < 0) {				\
+			(vvp)->tv_sec--;				\
+			(vvp)->tv_nsec += 1000000000;			\
+		}							\
+	} while (0)
+
 #endif

devicemodel/include/types.h

@@ -37,6 +37,7 @@ typedef uint64_t cap_ioctl_t;
 
 #define SET_FOREACH(pvar, set)                      \
 	for (pvar = SET_BEGIN(set); pvar < SET_LIMIT(set); pvar++)
+
 #define nitems(x) (sizeof((x)) / sizeof((x)[0]))
 #define roundup2(x, y)  (((x)+((y)-1))&(~((y)-1)))
 #define rounddown2(x, y) ((x)&(~((y)-1)))

devicemodel/include/vmmapi.h

@@ -62,6 +62,7 @@ struct vmctx {
 	/* fields to track virtual devices */
 	void *atkbdc_base;
 	void *vrtc;
+	void *vpit;
 	void *ioc_dev;
 };