svn commit: r310048 - in head/sys/dev/hyperv: include vmbus vmbus/amd64
Sepherosa Ziehau
sephe at FreeBSD.org
Wed Dec 14 03:20:58 UTC 2016
Author: sephe
Date: Wed Dec 14 03:20:57 2016
New Revision: 310048
URL: https://svnweb.freebsd.org/changeset/base/310048
Log:
hyperv: Implement "enlightened" time counter, which is rdtsc based.
Reviewed by: kib
MFC after: 1 week
Sponsored by: Microsoft
Differential Revision: https://reviews.freebsd.org/D8763
Modified:
head/sys/dev/hyperv/include/hyperv.h
head/sys/dev/hyperv/vmbus/amd64/hyperv_machdep.c
head/sys/dev/hyperv/vmbus/hyperv_reg.h
Modified: head/sys/dev/hyperv/include/hyperv.h
==============================================================================
--- head/sys/dev/hyperv/include/hyperv.h Wed Dec 14 03:01:15 2016 (r310047)
+++ head/sys/dev/hyperv/include/hyperv.h Wed Dec 14 03:20:57 2016 (r310048)
@@ -45,6 +45,7 @@
#define CPUID_HV_MSR_HYPERCALL 0x0020 /* MSR_HV_GUEST_OS_ID
* MSR_HV_HYPERCALL */
#define CPUID_HV_MSR_VP_INDEX 0x0040 /* MSR_HV_VP_INDEX */
+#define CPUID_HV_MSR_REFERENCE_TSC 0x0200 /* MSR_HV_REFERENCE_TSC */
#define CPUID_HV_MSR_GUEST_IDLE 0x0400 /* MSR_HV_GUEST_IDLE */
#ifndef NANOSEC
Modified: head/sys/dev/hyperv/vmbus/amd64/hyperv_machdep.c
==============================================================================
--- head/sys/dev/hyperv/vmbus/amd64/hyperv_machdep.c Wed Dec 14 03:01:15 2016 (r310047)
+++ head/sys/dev/hyperv/vmbus/amd64/hyperv_machdep.c Wed Dec 14 03:20:57 2016 (r310048)
@@ -28,7 +28,37 @@
__FBSDID("$FreeBSD$");
#include <sys/param.h>
+#include <sys/kernel.h>
+#include <sys/systm.h>
+#include <sys/timetc.h>
+
+#include <machine/cpufunc.h>
+#include <machine/cputypes.h>
+#include <machine/md_var.h>
+
+#include <dev/hyperv/include/hyperv.h>
+#include <dev/hyperv/include/hyperv_busdma.h>
#include <dev/hyperv/vmbus/hyperv_machdep.h>
+#include <dev/hyperv/vmbus/hyperv_reg.h>
+#include <dev/hyperv/vmbus/hyperv_var.h>
+
+struct hyperv_reftsc_ctx {
+ struct hyperv_reftsc *tsc_ref;
+ struct hyperv_dma tsc_ref_dma;
+};
+
+static struct timecounter hyperv_tsc_timecounter = {
+ .tc_get_timecount = NULL, /* based on CPU vendor. */
+ .tc_poll_pps = NULL,
+ .tc_counter_mask = 0xffffffff,
+ .tc_frequency = HYPERV_TIMER_FREQ,
+ .tc_name = "Hyper-V-TSC",
+ .tc_quality = 3000,
+ .tc_flags = 0,
+ .tc_priv = NULL
+};
+
+static struct hyperv_reftsc_ctx hyperv_ref_tsc;
uint64_t
hypercall_md(volatile void *hc_addr, uint64_t in_val,
@@ -41,3 +71,85 @@ hypercall_md(volatile void *hc_addr, uin
"c" (in_val), "d" (in_paddr), "m" (hc_addr));
return (status);
}
+
+#define HYPERV_TSC_TIMECOUNT(fence) \
+static u_int \
+hyperv_tsc_timecount_##fence(struct timecounter *tc) \
+{ \
+ struct hyperv_reftsc *tsc_ref = hyperv_ref_tsc.tsc_ref; \
+ uint32_t seq; \
+ \
+ while ((seq = atomic_load_acq_int(&tsc_ref->tsc_seq)) != 0) { \
+ uint64_t disc, ret, tsc; \
+ uint64_t scale = tsc_ref->tsc_scale; \
+ int64_t ofs = tsc_ref->tsc_ofs; \
+ \
+ fence(); \
+ tsc = rdtsc(); \
+ \
+ /* ret = ((tsc * scale) >> 64) + ofs */ \
+ __asm__ __volatile__ ("mulq %3" : \
+ "=d" (ret), "=a" (disc) : \
+ "a" (tsc), "r" (scale)); \
+ ret += ofs; \
+ \
+ atomic_thread_fence_acq(); \
+ if (tsc_ref->tsc_seq == seq) \
+ return (ret); \
+ \
+ /* Sequence changed; re-sync. */ \
+ } \
+ /* Fallback to the generic timecounter, i.e. rdmsr. */ \
+ return (rdmsr(MSR_HV_TIME_REF_COUNT)); \
+} \
+struct __hack
+
+HYPERV_TSC_TIMECOUNT(lfence);
+HYPERV_TSC_TIMECOUNT(mfence);
+
+static void
+hyperv_tsc_tcinit(void *dummy __unused)
+{
+ uint64_t val, orig;
+
+ if ((hyperv_features &
+ (CPUID_HV_MSR_TIME_REFCNT | CPUID_HV_MSR_REFERENCE_TSC)) !=
+ (CPUID_HV_MSR_TIME_REFCNT | CPUID_HV_MSR_REFERENCE_TSC) ||
+ (cpu_feature & CPUID_SSE2) == 0) /* SSE2 for mfence/lfence */
+ return;
+
+ switch (cpu_vendor_id) {
+ case CPU_VENDOR_AMD:
+ hyperv_tsc_timecounter.tc_get_timecount =
+ hyperv_tsc_timecount_mfence;
+ break;
+
+ case CPU_VENDOR_INTEL:
+ hyperv_tsc_timecounter.tc_get_timecount =
+ hyperv_tsc_timecount_lfence;
+ break;
+
+ default:
+ /* Unsupport CPU vendors. */
+ return;
+ }
+
+ hyperv_ref_tsc.tsc_ref = hyperv_dmamem_alloc(NULL, PAGE_SIZE, 0,
+ sizeof(struct hyperv_reftsc), &hyperv_ref_tsc.tsc_ref_dma,
+ BUS_DMA_WAITOK | BUS_DMA_ZERO);
+ if (hyperv_ref_tsc.tsc_ref == NULL) {
+ printf("hyperv: reftsc page allocation failed\n");
+ return;
+ }
+
+ orig = rdmsr(MSR_HV_REFERENCE_TSC);
+ val = MSR_HV_REFTSC_ENABLE | (orig & MSR_HV_REFTSC_RSVD_MASK) |
+ ((hyperv_ref_tsc.tsc_ref_dma.hv_paddr >> PAGE_SHIFT) <<
+ MSR_HV_REFTSC_PGSHIFT);
+ wrmsr(MSR_HV_REFERENCE_TSC, val);
+
+ /* Register "enlightened" timecounter. */
+ tc_init(&hyperv_tsc_timecounter);
+}
+SYSINIT(hyperv_tsc_init, SI_SUB_DRIVERS, SI_ORDER_FIRST, hyperv_tsc_tcinit,
+ NULL);
Modified: head/sys/dev/hyperv/vmbus/hyperv_reg.h
==============================================================================
--- head/sys/dev/hyperv/vmbus/hyperv_reg.h Wed Dec 14 03:01:15 2016 (r310047)
+++ head/sys/dev/hyperv/vmbus/hyperv_reg.h Wed Dec 14 03:20:57 2016 (r310048)
@@ -57,6 +57,11 @@
#define MSR_HV_VP_INDEX 0x40000002
+#define MSR_HV_REFERENCE_TSC 0x40000021
+#define MSR_HV_REFTSC_ENABLE 0x0001ULL
+#define MSR_HV_REFTSC_RSVD_MASK 0x0ffeULL
+#define MSR_HV_REFTSC_PGSHIFT 12
+
#define MSR_HV_SCONTROL 0x40000080
#define MSR_HV_SCTRL_ENABLE 0x0001ULL
#define MSR_HV_SCTRL_RSVD_MASK 0xfffffffffffffffeULL
@@ -124,6 +129,17 @@
#define CPUID_LEAF_HV_HWFEATURES 0x40000006
/*
+ * Hyper-V Reference TSC
+ */
+struct hyperv_reftsc {
+ volatile uint32_t tsc_seq;
+ volatile uint32_t tsc_rsvd1;
+ volatile uint64_t tsc_scale;
+ volatile int64_t tsc_ofs;
+} __packed __aligned(PAGE_SIZE);
+CTASSERT(sizeof(struct hyperv_reftsc) == PAGE_SIZE);
+
+/*
* Hyper-V Monitor Notification Facility
*/
struct hyperv_mon_param {
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