git: 9ef7df022a46 - main - hyperv: Register hyperv_timecounter later during boot

From: Mark Johnston <markj_at_FreeBSD.org>
Date: Mon, 25 Oct 2021 17:28:52 UTC
The branch main has been updated by markj:

URL: https://cgit.FreeBSD.org/src/commit/?id=9ef7df022a467776aa616b92fe5783e4261e84c6

commit 9ef7df022a467776aa616b92fe5783e4261e84c6
Author:     Mark Johnston <markj@FreeBSD.org>
AuthorDate: 2021-10-25 17:08:38 +0000
Commit:     Mark Johnston <markj@FreeBSD.org>
CommitDate: 2021-10-25 17:25:01 +0000

    hyperv: Register hyperv_timecounter later during boot
    
    Previously the MSR-based timecounter was registered during
    SI_SUB_HYPERVISOR, i.e., very early during boot, and before SI_SUB_LOCK.
    After commit 621fd9dcb2d8 this triggers a panic since the timecounter
    list lock is not yet initialized.
    
    The hyperv timecounter does not need to be registered so early, so defer
    that to SI_SUB_DRIVERS, at the same time the hyperv TSC timecounter is
    registered.
    
    Reported by:    whu
    Approved by:    whu
    Fixes:          621fd9dcb2d8 ("timecounter: Lock the timecounter list")
    MFC after:      1 week
    Sponsored by:   The FreeBSD Foundation
---
 sys/dev/hyperv/vmbus/hyperv.c | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/sys/dev/hyperv/vmbus/hyperv.c b/sys/dev/hyperv/vmbus/hyperv.c
index 5bb38fde8241..2c413664cd07 100644
--- a/sys/dev/hyperv/vmbus/hyperv.c
+++ b/sys/dev/hyperv/vmbus/hyperv.c
@@ -247,6 +247,13 @@ hyperv_init(void *dummy __unused)
 	/* Set guest id */
 	wrmsr(MSR_HV_GUEST_OS_ID, MSR_HV_GUESTID_FREEBSD);
 
+}
+SYSINIT(hyperv_initialize, SI_SUB_HYPERVISOR, SI_ORDER_FIRST, hyperv_init,
+    NULL);
+
+static void
+hyperv_tc_init(void *arg __unused)
+{
 	if (hyperv_features & CPUID_HV_MSR_TIME_REFCNT) {
 		/* Register Hyper-V timecounter */
 		tc_init(&hyperv_timecounter);
@@ -258,8 +265,7 @@ hyperv_init(void *dummy __unused)
 		hyperv_tc64 = hyperv_tc64_rdmsr;
 	}
 }
-SYSINIT(hyperv_initialize, SI_SUB_HYPERVISOR, SI_ORDER_FIRST, hyperv_init,
-    NULL);
+SYSINIT(hyperv_tc_init, SI_SUB_DRIVERS, SI_ORDER_FIRST, hyperv_tc_init, NULL);
 
 static void
 hypercall_memfree(void)