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Date:      Tue, 25 Mar 2014 19:20:34 +0000 (UTC)
From:      Tycho Nightingale <tychon@FreeBSD.org>
To:        src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org
Subject:   svn commit: r263744 - in head: sys/amd64/include sys/amd64/vmm sys/amd64/vmm/io sys/modules/vmm usr.sbin/bhyve
Message-ID:  <201403251920.s2PJKYnX047892@svn.freebsd.org>

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Author: tychon
Date: Tue Mar 25 19:20:34 2014
New Revision: 263744
URL: http://svnweb.freebsd.org/changeset/base/263744

Log:
  Move the atpit device model from userspace into vmm.ko for better
  precision and lower latency.
  
  Approved by:	grehan (co-mentor)

Added:
  head/sys/amd64/vmm/io/vatpit.c   (contents, props changed)
  head/sys/amd64/vmm/io/vatpit.h   (contents, props changed)
Deleted:
  head/usr.sbin/bhyve/pit_8254.c
  head/usr.sbin/bhyve/pit_8254.h
Modified:
  head/sys/amd64/include/vmm.h
  head/sys/amd64/vmm/vmm.c
  head/sys/amd64/vmm/vmm_ioport.c
  head/sys/modules/vmm/Makefile
  head/usr.sbin/bhyve/Makefile

Modified: head/sys/amd64/include/vmm.h
==============================================================================
--- head/sys/amd64/include/vmm.h	Tue Mar 25 19:17:22 2014	(r263743)
+++ head/sys/amd64/include/vmm.h	Tue Mar 25 19:20:34 2014	(r263744)
@@ -191,6 +191,7 @@ struct vmspace *vm_get_vmspace(struct vm
 int vm_assign_pptdev(struct vm *vm, int bus, int slot, int func);
 int vm_unassign_pptdev(struct vm *vm, int bus, int slot, int func);
 struct vatpic *vm_atpic(struct vm *vm);
+struct vatpit *vm_atpit(struct vm *vm);
 
 /*
  * Inject exception 'vme' into the guest vcpu. This function returns 0 on

Added: head/sys/amd64/vmm/io/vatpit.c
==============================================================================
--- /dev/null	00:00:00 1970	(empty, because file is newly added)
+++ head/sys/amd64/vmm/io/vatpit.c	Tue Mar 25 19:20:34 2014	(r263744)
@@ -0,0 +1,370 @@
+/*-
+ * Copyright (c) 2014 Tycho Nightingale <tycho.nightingale@pluribusnetworks.com>
+ * Copyright (c) 2011 NetApp, Inc.
+ * 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.
+ *
+ * THIS SOFTWARE IS PROVIDED BY NETAPP, INC ``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 NETAPP, INC 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.
+ */
+
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#include <sys/param.h>
+#include <sys/types.h>
+#include <sys/queue.h>
+#include <sys/cpuset.h>
+#include <sys/kernel.h>
+#include <sys/lock.h>
+#include <sys/malloc.h>
+#include <sys/mutex.h>
+#include <sys/systm.h>
+
+#include <machine/vmm.h>
+
+#include "vmm_ktr.h"
+#include "vatpic.h"
+#include "vioapic.h"
+#include "vatpit.h"
+
+static MALLOC_DEFINE(M_VATPIT, "atpit", "bhyve virtual atpit (8254)");
+
+#define	VATPIT_LOCK(vatpit)		mtx_lock_spin(&((vatpit)->mtx))
+#define	VATPIT_UNLOCK(vatpit)		mtx_unlock_spin(&((vatpit)->mtx))
+#define	VATPIT_LOCKED(vatpit)		mtx_owned(&((vatpit)->mtx))
+
+#define	TIMER_SEL_MASK		0xc0
+#define	TIMER_RW_MASK		0x30
+#define	TIMER_MODE_MASK		0x0f
+#define	TIMER_SEL_READBACK	0xc0
+
+#define	PIT_8254_FREQ		1193182
+#define	TIMER_DIV(freq, hz)	(((freq) + (hz) / 2) / (hz))
+
+struct vatpit_callout_arg {
+	struct vatpit	*vatpit;
+	int		channel_num;
+};
+
+
+struct channel {
+	int		mode;
+	uint16_t	initial;	/* initial counter value */
+	sbintime_t	now_sbt;	/* uptime when counter was loaded */
+	uint8_t		cr[2];
+	uint8_t		ol[2];
+	int		crbyte;
+	int		olbyte;
+	int		frbyte;
+	struct callout	callout;
+	sbintime_t	callout_sbt;	/* target time */
+	struct vatpit_callout_arg callout_arg;
+};
+
+struct vatpit {
+	struct vm	*vm;
+	struct mtx	mtx;
+
+	sbintime_t	freq_sbt;
+
+	struct channel	channel[3];
+};
+
+#define	VATPIT_CTR0(vatpit, fmt)					\
+	VM_CTR0((vatpit)->vm, fmt)
+
+#define	VATPIT_CTR1(vatpit, fmt, a1)					\
+	VM_CTR1((vatpit)->vm, fmt, a1)
+
+#define	VATPIT_CTR2(vatpit, fmt, a1, a2)				\
+	VM_CTR2((vatpit)->vm, fmt, a1, a2)
+
+#define	VATPIT_CTR3(vatpit, fmt, a1, a2, a3)				\
+	VM_CTR3((vatpit)->vm, fmt, a1, a2, a3)
+
+#define	VATPIT_CTR4(vatpit, fmt, a1, a2, a3, a4)			\
+	VM_CTR4((vatpit)->vm, fmt, a1, a2, a3, a4)
+
+static void pit_timer_start_cntr0(struct vatpit *vatpit);
+
+static void
+vatpit_callout_handler(void *a)
+{
+	struct vatpit_callout_arg *arg = a;
+	struct vatpit *vatpit;
+	struct callout *callout;
+	struct channel *c;
+
+	vatpit = arg->vatpit;
+	c = &vatpit->channel[arg->channel_num];
+	callout = &c->callout;
+
+	VATPIT_CTR1(vatpit, "atpit t%d fired", arg->channel_num);
+
+	VATPIT_LOCK(vatpit);
+
+	if (callout_pending(callout))		/* callout was reset */
+		goto done;
+
+	if (!callout_active(callout))		/* callout was stopped */
+		goto done;
+
+	callout_deactivate(callout);
+
+	if (c->mode == TIMER_RATEGEN) {
+		pit_timer_start_cntr0(vatpit);
+	}
+
+	vatpic_pulse_irq(vatpit->vm, 0);
+	vioapic_pulse_irq(vatpit->vm, 2);
+
+done:
+	VATPIT_UNLOCK(vatpit);
+	return;
+}
+
+static void
+pit_timer_start_cntr0(struct vatpit *vatpit)
+{
+	struct channel *c;
+	sbintime_t delta, precision;
+
+	c = &vatpit->channel[0];
+	if (c->initial != 0) {
+		delta = c->initial * vatpit->freq_sbt;
+		precision = delta >> tc_precexp;
+		c->callout_sbt = c->callout_sbt + delta;
+
+		callout_reset_sbt(&c->callout, c->callout_sbt,
+		    precision, vatpit_callout_handler, &c->callout_arg,
+		    C_ABSOLUTE);
+	}
+}
+
+static uint16_t
+pit_update_counter(struct vatpit *vatpit, struct channel *c, bool latch)
+{
+	uint16_t lval;
+	sbintime_t delta_ticks;
+
+	/* cannot latch a new value until the old one has been consumed */
+	if (latch && c->olbyte != 0)
+		return (0);
+
+	if (c->initial == 0) {
+		/*
+		 * This is possibly an o/s bug - reading the value of
+		 * the timer without having set up the initial value.
+		 *
+		 * The original user-space version of this code set
+		 * the timer to 100hz in this condition; do the same
+		 * here.
+		 */
+		c->initial = TIMER_DIV(PIT_8254_FREQ, 100);
+		c->now_sbt = sbinuptime();
+	}
+
+	delta_ticks = (sbinuptime() - c->now_sbt) / vatpit->freq_sbt;
+
+	lval = c->initial - delta_ticks % c->initial;
+
+	if (latch) {
+		c->olbyte = 2;
+		c->ol[1] = lval;		/* LSB */
+		c->ol[0] = lval >> 8;		/* MSB */
+	}
+
+	return (lval);
+}
+
+static int
+vatpit_update_mode(struct vatpit *vatpit, uint8_t val)
+{
+	struct channel *c;
+	int sel, rw, mode;
+
+	sel = val & TIMER_SEL_MASK;
+	rw = val & TIMER_RW_MASK;
+	mode = val & TIMER_MODE_MASK;
+
+	if (sel == TIMER_SEL_READBACK)
+		return (-1);
+
+	if (rw != TIMER_LATCH && rw != TIMER_16BIT)
+		return (-1);
+
+	if (rw != TIMER_LATCH) {
+		/*
+		 * Counter mode is not affected when issuing a
+		 * latch command.
+		 */
+		if (mode != TIMER_INTTC &&
+		    mode != TIMER_RATEGEN &&
+		    mode != TIMER_SQWAVE &&
+		    mode != TIMER_SWSTROBE)
+			return (-1);
+	}
+
+	c = &vatpit->channel[sel >> 6];
+	if (rw == TIMER_LATCH)
+		pit_update_counter(vatpit, c, true);
+	else {
+		c->mode = mode;
+		c->olbyte = 0;	/* reset latch after reprogramming */
+	}
+
+	return (0);
+}
+
+static int
+vatpit_get_out(struct vatpit *vatpit, int channel)
+{
+	struct channel *c;
+	sbintime_t delta_ticks;
+	int out;
+
+	c = &vatpit->channel[channel];
+
+	switch (c->mode) {
+	case TIMER_INTTC:
+		delta_ticks = (sbinuptime() - c->now_sbt) / vatpit->freq_sbt;
+		out = ((c->initial - delta_ticks) <= 0);
+		break;
+	default:
+		out = 0;
+		break;
+	}
+
+	return (out);
+}
+
+int
+vatpit_handler(void *vm, int vcpuid, struct vm_exit *vmexit)
+{
+	struct vatpit *vatpit;
+	struct channel *c;
+	int port;
+	uint8_t val;
+	int error;
+
+	vatpit = vm_atpit(vm);
+
+	if (vmexit->u.inout.bytes != 1)
+		return (-1);
+
+	val = vmexit->u.inout.eax;
+	port = vmexit->u.inout.port;
+
+	if (port == TIMER_MODE) {
+		if (vmexit->u.inout.in != 0) {
+			VATPIT_CTR0(vatpit, "vatpit attempt to read mode");
+			return (-1);
+		}
+
+		VATPIT_LOCK(vatpit);
+		error = vatpit_update_mode(vatpit, val);
+		VATPIT_UNLOCK(vatpit);
+
+		return (error);
+	}
+
+	/* counter ports */
+	KASSERT(port >= TIMER_CNTR0 && vmexit->u.inout.port <= TIMER_CNTR2,
+	    ("invalid port 0x%x", port));
+	c = &vatpit->channel[port - TIMER_CNTR0];
+
+	VATPIT_LOCK(vatpit);
+	if (vmexit->u.inout.in) {
+		/*
+		 * The spec says that once the output latch is completely
+		 * read it should revert to "following" the counter. Use
+		 * the free running counter for this case (i.e. Linux
+		 * TSC calibration). Assuming the access mode is 16-bit,
+		 * toggle the MSB/LSB bit on each read.
+		 */
+		if (c->olbyte == 0) {
+			uint16_t tmp;
+
+			tmp = pit_update_counter(vatpit, c, false);
+			if (c->frbyte)
+				tmp >>= 8;
+			tmp &= 0xff;
+			vmexit->u.inout.eax = tmp;
+			c->frbyte ^= 1;
+		}  else
+			vmexit->u.inout.eax = c->ol[--c->olbyte];
+	} else {
+		c->cr[c->crbyte++] = vmexit->u.inout.eax;
+		if (c->crbyte == 2) {
+			c->frbyte = 0;
+			c->crbyte = 0;
+			c->initial = c->cr[0] | (uint16_t)c->cr[1] << 8;
+			c->now_sbt = sbinuptime();
+			/* Start an interval timer for channel 0 */
+			if (port == TIMER_CNTR0) {
+				c->callout_sbt = c->now_sbt;
+				pit_timer_start_cntr0(vatpit);
+			}
+			if (c->initial == 0)
+				c->initial = 0xffff;
+		}
+	}
+	VATPIT_UNLOCK(vatpit);
+
+	return (0);
+}
+
+struct vatpit *
+vatpit_init(struct vm *vm)
+{
+	struct vatpit *vatpit;
+	struct bintime bt;
+	struct vatpit_callout_arg *arg;
+	int i;
+
+	vatpit = malloc(sizeof(struct vatpit), M_VATPIT, M_WAITOK | M_ZERO);
+	vatpit->vm = vm;
+
+	mtx_init(&vatpit->mtx, "vatpit lock", NULL, MTX_SPIN);
+
+	FREQ2BT(PIT_8254_FREQ, &bt);
+	vatpit->freq_sbt = bttosbt(bt);
+
+	for (i = 0; i < 3; i++) {
+		callout_init(&vatpit->channel[i].callout, true);
+		arg = &vatpit->channel[i].callout_arg;
+		arg->vatpit = vatpit;
+		arg->channel_num = i;
+	}
+
+	return (vatpit);
+}
+
+void
+vatpit_cleanup(struct vatpit *vatpit)
+{
+	int i;
+
+	for (i = 0; i < 3; i++)
+		callout_drain(&vatpit->channel[i].callout);
+
+	free(vatpit, M_VATPIT);
+}

Added: head/sys/amd64/vmm/io/vatpit.h
==============================================================================
--- /dev/null	00:00:00 1970	(empty, because file is newly added)
+++ head/sys/amd64/vmm/io/vatpit.h	Tue Mar 25 19:20:34 2014	(r263744)
@@ -0,0 +1,40 @@
+/*-
+ * Copyright (c) 2014 Tycho Nightingale <tycho.nightingale@pluribusnetworks.com>
+ * Copyright (c) 2011 NetApp, Inc.
+ * 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.
+ *
+ * THIS SOFTWARE IS PROVIDED BY NETAPP, INC ``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 NETAPP, INC 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 _VATPIT_H_
+#define	_VATPIT_H_
+
+#include <machine/timerreg.h>
+
+struct vatpit *vatpit_init(struct vm *vm);
+void vatpit_cleanup(struct vatpit *vatpit);
+
+int vatpit_handler(void *vm, int vcpuid, struct vm_exit *vmexit);
+
+#endif	/* _VATPIT_H_ */

Modified: head/sys/amd64/vmm/vmm.c
==============================================================================
--- head/sys/amd64/vmm/vmm.c	Tue Mar 25 19:17:22 2014	(r263743)
+++ head/sys/amd64/vmm/vmm.c	Tue Mar 25 19:20:34 2014	(r263744)
@@ -68,6 +68,7 @@ __FBSDID("$FreeBSD$");
 #include "vmm_mem.h"
 #include "vmm_util.h"
 #include "vatpic.h"
+#include "vatpit.h"
 #include "vhpet.h"
 #include "vioapic.h"
 #include "vlapic.h"
@@ -119,6 +120,7 @@ struct vm {
 	struct vhpet	*vhpet;		/* virtual HPET */
 	struct vioapic	*vioapic;	/* virtual ioapic */
 	struct vatpic	*vatpic;	/* virtual atpic */
+	struct vatpit	*vatpit;	/* virtual atpit */
 	struct vmspace	*vmspace;	/* guest's address space */
 	struct vcpu	vcpu[VM_MAXCPU];
 	int		num_mem_segs;
@@ -349,6 +351,7 @@ vm_create(const char *name, struct vm **
 	vm->vioapic = vioapic_init(vm);
 	vm->vhpet = vhpet_init(vm);
 	vm->vatpic = vatpic_init(vm);
+	vm->vatpit = vatpit_init(vm);
 
 	for (i = 0; i < VM_MAXCPU; i++) {
 		vcpu_init(vm, i);
@@ -381,6 +384,7 @@ vm_destroy(struct vm *vm)
 	if (vm->iommu != NULL)
 		iommu_destroy_domain(vm->iommu);
 
+	vatpit_cleanup(vm->vatpit);
 	vhpet_cleanup(vm->vhpet);
 	vatpic_cleanup(vm->vatpic);
 	vioapic_cleanup(vm->vioapic);
@@ -1740,3 +1744,9 @@ vm_atpic(struct vm *vm)
 {
 	return (vm->vatpic);
 }
+
+struct vatpit *
+vm_atpit(struct vm *vm)
+{
+	return (vm->vatpit);
+}

Modified: head/sys/amd64/vmm/vmm_ioport.c
==============================================================================
--- head/sys/amd64/vmm/vmm_ioport.c	Tue Mar 25 19:17:22 2014	(r263743)
+++ head/sys/amd64/vmm/vmm_ioport.c	Tue Mar 25 19:20:34 2014	(r263744)
@@ -36,11 +36,16 @@ __FBSDID("$FreeBSD$");
 #include <machine/vmm.h>
 
 #include "vatpic.h"
+#include "vatpit.h"
 #include "vmm_ioport.h"
 
 #define	MAX_IOPORTS		1280
 
 ioport_handler_func_t ioport_handler[MAX_IOPORTS] = {
+	[TIMER_MODE] = vatpit_handler,
+	[TIMER_CNTR0] = vatpit_handler,
+	[TIMER_CNTR1] = vatpit_handler,
+	[TIMER_CNTR2] = vatpit_handler,
 	[IO_ICU1] = vatpic_master_handler,
 	[IO_ICU1 + ICU_IMR_OFFSET] = vatpic_master_handler,
 	[IO_ICU2] = vatpic_slave_handler,

Modified: head/sys/modules/vmm/Makefile
==============================================================================
--- head/sys/modules/vmm/Makefile	Tue Mar 25 19:17:22 2014	(r263743)
+++ head/sys/modules/vmm/Makefile	Tue Mar 25 19:20:34 2014	(r263744)
@@ -29,6 +29,7 @@ SRCS+=	vmm.c		\
 SRCS+=	iommu.c		\
 	ppt.c           \
 	vatpic.c	\
+	vatpit.c	\
 	vhpet.c		\
 	vioapic.c	\
 	vlapic.c

Modified: head/usr.sbin/bhyve/Makefile
==============================================================================
--- head/usr.sbin/bhyve/Makefile	Tue Mar 25 19:17:22 2014	(r263743)
+++ head/usr.sbin/bhyve/Makefile	Tue Mar 25 19:20:34 2014	(r263744)
@@ -27,7 +27,6 @@ SRCS=	\
 	pci_virtio_block.c	\
 	pci_virtio_net.c	\
 	pci_uart.c		\
-	pit_8254.c		\
 	pm.c			\
 	pmtmr.c			\
 	post.c			\



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