svn commit: r276039 - in projects/paravirt/sys: amd64/include conf dev/xen/timer i386/include x86/include x86/x86
Bryan Venteicher
bryanv at FreeBSD.org
Sun Dec 21 23:20:06 UTC 2014
Author: bryanv
Date: Sun Dec 21 23:20:02 2014
New Revision: 276039
URL: https://svnweb.freebsd.org/changeset/base/276039
Log:
Generalized parts of the XEN timer code into pvclock
This will later be used to support KVM clock. Until I can sort out
how to best include the pvclock.h header in the generic XEN headers,
use ugly casts in the XEN code to keep it compiling.
Added:
projects/paravirt/sys/amd64/include/pvclock.h (contents, props changed)
projects/paravirt/sys/i386/include/pvclock.h (contents, props changed)
projects/paravirt/sys/x86/include/pvclock.h (contents, props changed)
projects/paravirt/sys/x86/x86/pvclock.c (contents, props changed)
Modified:
projects/paravirt/sys/conf/files.amd64
projects/paravirt/sys/conf/files.i386
projects/paravirt/sys/dev/xen/timer/timer.c
Added: projects/paravirt/sys/amd64/include/pvclock.h
==============================================================================
--- /dev/null 00:00:00 1970 (empty, because file is newly added)
+++ projects/paravirt/sys/amd64/include/pvclock.h Sun Dec 21 23:20:02 2014 (r276039)
@@ -0,0 +1,6 @@
+/*-
+ * This file is in the public domain.
+ */
+/* $FreeBSD$ */
+
+#include <x86/pvclock.h>
Modified: projects/paravirt/sys/conf/files.amd64
==============================================================================
--- projects/paravirt/sys/conf/files.amd64 Sun Dec 21 23:09:59 2014 (r276038)
+++ projects/paravirt/sys/conf/files.amd64 Sun Dec 21 23:20:02 2014 (r276039)
@@ -569,6 +569,7 @@ x86/x86/mptable.c optional mptable
x86/x86/mptable_pci.c optional mptable pci
x86/x86/msi.c optional pci
x86/x86/nexus.c standard
+x86/x86/pvclock.c standard
x86/x86/tsc.c standard
x86/x86/delay.c standard
x86/xen/hvm.c optional xenhvm
Modified: projects/paravirt/sys/conf/files.i386
==============================================================================
--- projects/paravirt/sys/conf/files.i386 Sun Dec 21 23:09:59 2014 (r276038)
+++ projects/paravirt/sys/conf/files.i386 Sun Dec 21 23:20:02 2014 (r276039)
@@ -588,6 +588,7 @@ x86/x86/mptable_pci.c optional apic nat
x86/x86/msi.c optional apic pci
x86/x86/nexus.c standard
x86/x86/tsc.c standard
+x86/x86/pvclock.c standard
x86/x86/delay.c standard
x86/xen/hvm.c optional xenhvm
x86/xen/xen_intr.c optional xen | xenhvm
Modified: projects/paravirt/sys/dev/xen/timer/timer.c
==============================================================================
--- projects/paravirt/sys/dev/xen/timer/timer.c Sun Dec 21 23:09:59 2014 (r276038)
+++ projects/paravirt/sys/dev/xen/timer/timer.c Sun Dec 21 23:20:02 2014 (r276039)
@@ -59,6 +59,7 @@ __FBSDID("$FreeBSD$");
#include <machine/clock.h>
#include <machine/_inttypes.h>
#include <machine/smp.h>
+#include <machine/pvclock.h>
#include <dev/xen/timer/timer.h>
@@ -95,9 +96,6 @@ struct xentimer_softc {
struct eventtimer et;
};
-/* Last time; this guarantees a monotonically increasing clock. */
-volatile uint64_t xen_timer_last_time = 0;
-
static void
xentimer_identify(driver_t *driver, device_t parent)
{
@@ -148,128 +146,20 @@ xentimer_probe(device_t dev)
return (BUS_PROBE_NOWILDCARD);
}
-/*
- * Scale a 64-bit delta by scaling and multiplying by a 32-bit fraction,
- * yielding a 64-bit result.
- */
-static inline uint64_t
-scale_delta(uint64_t delta, uint32_t mul_frac, int shift)
-{
- uint64_t product;
-
- if (shift < 0)
- delta >>= -shift;
- else
- delta <<= shift;
-
-#if defined(__i386__)
- {
- uint32_t tmp1, tmp2;
-
- /**
- * For i386, the formula looks like:
- *
- * lower = (mul_frac * (delta & UINT_MAX)) >> 32
- * upper = mul_frac * (delta >> 32)
- * product = lower + upper
- */
- __asm__ (
- "mul %5 ; "
- "mov %4,%%eax ; "
- "mov %%edx,%4 ; "
- "mul %5 ; "
- "xor %5,%5 ; "
- "add %4,%%eax ; "
- "adc %5,%%edx ; "
- : "=A" (product), "=r" (tmp1), "=r" (tmp2)
- : "a" ((uint32_t)delta), "1" ((uint32_t)(delta >> 32)),
- "2" (mul_frac) );
- }
-#elif defined(__amd64__)
- {
- unsigned long tmp;
-
- __asm__ (
- "mulq %[mul_frac] ; shrd $32, %[hi], %[lo]"
- : [lo]"=a" (product), [hi]"=d" (tmp)
- : "0" (delta), [mul_frac]"rm"((uint64_t)mul_frac));
- }
-#else
-#error "xentimer: unsupported architecture"
-#endif
-
- return (product);
-}
-
-static uint64_t
-get_nsec_offset(struct vcpu_time_info *tinfo)
-{
-
- return (scale_delta(rdtsc() - tinfo->tsc_timestamp,
- tinfo->tsc_to_system_mul, tinfo->tsc_shift));
-}
-
-/*
- * Read the current hypervisor system uptime value from Xen.
- * See <xen/interface/xen.h> for a description of how this works.
- */
-static uint32_t
-xen_fetch_vcpu_tinfo(struct vcpu_time_info *dst, struct vcpu_time_info *src)
-{
-
- do {
- dst->version = src->version;
- rmb();
- dst->tsc_timestamp = src->tsc_timestamp;
- dst->system_time = src->system_time;
- dst->tsc_to_system_mul = src->tsc_to_system_mul;
- dst->tsc_shift = src->tsc_shift;
- rmb();
- } while ((src->version & 1) | (dst->version ^ src->version));
-
- return (dst->version);
-}
-
/**
* \brief Get the current time, in nanoseconds, since the hypervisor booted.
*
* \param vcpu vcpu_info structure to fetch the time from.
*
- * \note This function returns the current CPU's idea of this value, unless
- * it happens to be less than another CPU's previously determined value.
*/
static uint64_t
xen_fetch_vcpu_time(struct vcpu_info *vcpu)
{
- struct vcpu_time_info dst;
- struct vcpu_time_info *src;
- uint32_t pre_version;
- uint64_t now;
- volatile uint64_t last;
+ struct pvclock_vcpu_time_info *time;
- src = &vcpu->time;
-
- do {
- pre_version = xen_fetch_vcpu_tinfo(&dst, src);
- barrier();
- now = dst.system_time + get_nsec_offset(&dst);
- barrier();
- } while (pre_version != src->version);
+ time = (struct pvclock_vcpu_time_info *) &vcpu->time;
- /*
- * Enforce a monotonically increasing clock time across all
- * VCPUs. If our time is too old, use the last time and return.
- * Otherwise, try to update the last time.
- */
- do {
- last = xen_timer_last_time;
- if (last > now) {
- now = last;
- break;
- }
- } while (!atomic_cmpset_64(&xen_timer_last_time, last, now));
-
- return (now);
+ return (pvclock_get_timecount(time));
}
static uint32_t
@@ -302,15 +192,11 @@ static void
xen_fetch_wallclock(struct timespec *ts)
{
shared_info_t *src = HYPERVISOR_shared_info;
- uint32_t version = 0;
+ struct pvclock_wall_clock *wc;
- do {
- version = src->wc_version;
- rmb();
- ts->tv_sec = src->wc_sec;
- ts->tv_nsec = src->wc_nsec;
- rmb();
- } while ((src->wc_version & 1) | (version ^ src->wc_version));
+ wc = (struct pvclock_wall_clock *) &src->wc_version;
+
+ pvclock_get_wallclock(wc, ts);
}
static void
@@ -574,7 +460,7 @@ xentimer_resume(device_t dev)
}
/* Reset the last uptime value */
- xen_timer_last_time = 0;
+ pvclock_resume();
/* Reset the RTC clock */
inittodr(time_second);
Added: projects/paravirt/sys/i386/include/pvclock.h
==============================================================================
--- /dev/null 00:00:00 1970 (empty, because file is newly added)
+++ projects/paravirt/sys/i386/include/pvclock.h Sun Dec 21 23:20:02 2014 (r276039)
@@ -0,0 +1,6 @@
+/*-
+ * This file is in the public domain.
+ */
+/* $FreeBSD$ */
+
+#include <x86/pvclock.h>
Added: projects/paravirt/sys/x86/include/pvclock.h
==============================================================================
--- /dev/null 00:00:00 1970 (empty, because file is newly added)
+++ projects/paravirt/sys/x86/include/pvclock.h Sun Dec 21 23:20:02 2014 (r276039)
@@ -0,0 +1,57 @@
+/*-
+ * Copyright (c) 2014, Bryan Venteicher <bryanv at FreeBSD.org>
+ * 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 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.
+ *
+ * $FreeBSD$
+ */
+
+#ifndef X86_PVCLOCK
+#define X86_PVCLOCK
+
+struct pvclock_vcpu_time_info {
+ uint32_t version;
+ uint32_t pad0;
+ uint64_t tsc_timestamp;
+ uint64_t system_time;
+ uint32_t tsc_to_system_mul;
+ int8_t tsc_shift;
+ uint8_t flags;
+ uint8_t pad[2];
+} __packed;
+
+#define PVCLOCK_FLAG_TSC_STABLE 0x01
+#define PVCLOCK_FLAG_GUEST_PASUED 0x02
+
+struct pvclock_wall_clock {
+ uint32_t version;
+ uint32_t sec;
+ uint32_t nsec;
+} __packed;
+
+void pvclock_resume(void);
+uint64_t pvclock_get_timecount(struct pvclock_vcpu_time_info *ti);
+void pvclock_get_wallclock(struct pvclock_wall_clock *wc,
+ struct timespec *ts);
+
+#endif
Added: projects/paravirt/sys/x86/x86/pvclock.c
==============================================================================
--- /dev/null 00:00:00 1970 (empty, because file is newly added)
+++ projects/paravirt/sys/x86/x86/pvclock.c Sun Dec 21 23:20:02 2014 (r276039)
@@ -0,0 +1,181 @@
+/*-
+ * Copyright (c) 2009 Adrian Chadd
+ * Copyright (c) 2012 Spectra Logic Corporation
+ * Copyright (c) 2014 Bryan Venteicher
+ * 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 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.
+ */
+
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#include <sys/param.h>
+#include <sys/proc.h>
+
+#include <machine/cpufunc.h>
+#include <machine/cpu.h>
+#include <machine/atomic.h>
+#include <machine/pvclock.h>
+
+/*
+ * Last time; this guarantees a monotonically increasing clock for when
+ * a stable TSC is not provided.
+ */
+static volatile uint64_t pvclock_last_cycles;
+
+void
+pvclock_resume(void)
+{
+
+ atomic_store_rel_64(&pvclock_last_cycles, 0);
+}
+
+/*
+ * Scale a 64-bit delta by scaling and multiplying by a 32-bit fraction,
+ * yielding a 64-bit result.
+ */
+static inline uint64_t
+pvclock_scale_delta(uint64_t delta, uint32_t mul_frac, int shift)
+{
+ uint64_t product;
+
+ if (shift < 0)
+ delta >>= -shift;
+ else
+ delta <<= shift;
+
+#if defined(__i386__)
+ {
+ uint32_t tmp1, tmp2;
+
+ /**
+ * For i386, the formula looks like:
+ *
+ * lower = (mul_frac * (delta & UINT_MAX)) >> 32
+ * upper = mul_frac * (delta >> 32)
+ * product = lower + upper
+ */
+ __asm__ (
+ "mul %5 ; "
+ "mov %4,%%eax ; "
+ "mov %%edx,%4 ; "
+ "mul %5 ; "
+ "xor %5,%5 ; "
+ "add %4,%%eax ; "
+ "adc %5,%%edx ; "
+ : "=A" (product), "=r" (tmp1), "=r" (tmp2)
+ : "a" ((uint32_t)delta), "1" ((uint32_t)(delta >> 32)),
+ "2" (mul_frac) );
+ }
+#elif defined(__amd64__)
+ {
+ unsigned long tmp;
+
+ __asm__ (
+ "mulq %[mul_frac] ; shrd $32, %[hi], %[lo]"
+ : [lo]"=a" (product), [hi]"=d" (tmp)
+ : "0" (delta), [mul_frac]"rm"((uint64_t)mul_frac));
+ }
+#else
+#error "pvclock: unsupported x86 architecture?"
+#endif
+
+ return (product);
+}
+
+static uint64_t
+pvclock_get_nsec_offset(struct pvclock_vcpu_time_info *ti)
+{
+ uint64_t delta;
+
+ delta = rdtsc() - ti->tsc_timestamp;
+
+ return (pvclock_scale_delta(delta, ti->tsc_to_system_mul,
+ ti->tsc_shift));
+}
+
+static void
+pvclock_read_time_info(struct pvclock_vcpu_time_info *ti,
+ uint64_t *cycles, uint8_t *flags)
+{
+ uint32_t version;
+
+ do {
+ version = ti->version;
+ rmb();
+ *cycles = ti->system_time + pvclock_get_nsec_offset(ti);
+ *flags = ti->flags;
+ rmb();
+ } while ((ti->version & 1) != 0 || ti->version != version);
+}
+
+static void
+pvclock_read_wall_clock(struct pvclock_wall_clock *wc, uint32_t *sec,
+ uint32_t *nsec)
+{
+ uint32_t version;
+
+ do {
+ version = wc->version;
+ rmb();
+ *sec = wc->sec;
+ *nsec = wc->nsec;
+ rmb();
+ } while ((wc->version & 1) != 0 || wc->version != version);
+}
+
+uint64_t
+pvclock_get_timecount(struct pvclock_vcpu_time_info *ti)
+{
+ uint64_t now;
+ uint8_t flags;
+ volatile uint64_t last;
+
+ pvclock_read_time_info(ti, &now, &flags);
+
+ if (flags & PVCLOCK_FLAG_TSC_STABLE)
+ return (now);
+
+ /*
+ * Enforce a monotonically increasing clock time across all VCPUs.
+ * If our time is too old, use the last time and return. Otherwise,
+ * try to update the last time.
+ */
+ do {
+ last = atomic_load_acq_64(&pvclock_last_cycles);
+ if (last > now)
+ return (last);
+ } while (!atomic_cmpset_64(&pvclock_last_cycles, last, now));
+
+ return (now);
+}
+
+void
+pvclock_get_wallclock(struct pvclock_wall_clock *wc, struct timespec *ts)
+{
+ uint32_t sec, nsec;
+
+ pvclock_read_wall_clock(wc, &sec, &nsec);
+ ts->tv_sec = sec;
+ ts->tv_nsec = nsec;
+}
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