From 1d2c60d6345a6b81c5bfd559daf413c6669f6d28 Mon Sep 17 00:00:00 2001
From: patrick <patrick@openbsd.org>
Date: Tue, 31 Aug 2021 15:52:59 +0000
Subject: [PATCH] Identify the paravirtual bus earlier, as we need to make sure
 that we have a working delay func ready before the first occurence of
 delay().  This is necessary on Hyper-V Gen 2 VMs where we don't use the TSC.

Discussed with the hackroom
ok kettenis@
---
 sys/arch/amd64/amd64/identcpu.c | 13 ++++++++++++-
 sys/arch/amd64/amd64/mainbus.c  |  8 +-------
 2 files changed, 13 insertions(+), 8 deletions(-)

diff --git a/sys/arch/amd64/amd64/identcpu.c b/sys/arch/amd64/amd64/identcpu.c
index b74955a6a61..c977e64de96 100644
--- a/sys/arch/amd64/amd64/identcpu.c
+++ b/sys/arch/amd64/amd64/identcpu.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: identcpu.c,v 1.119 2021/08/31 15:11:54 kettenis Exp $	*/
+/*	$OpenBSD: identcpu.c,v 1.120 2021/08/31 15:52:59 patrick Exp $	*/
 /*	$NetBSD: identcpu.c,v 1.1 2003/04/26 18:39:28 fvdl Exp $	*/
 
 /*
@@ -41,10 +41,15 @@
 #include <sys/sysctl.h>
 
 #include "vmm.h"
+#include "pvbus.h"
 
 #include <machine/cpu.h>
 #include <machine/cpufunc.h>
 
+#if NPVBUS > 0
+#include <dev/pv/pvvar.h>
+#endif
+
 void	replacesmap(void);
 void	replacemeltdown(void);
 uint64_t cpu_freq(struct cpu_info *);
@@ -522,6 +527,12 @@ identifycpu(struct cpu_info *ci)
 		ci->ci_model += ((ci->ci_signature >> 16) & 0x0f) << 4;
 	}
 
+#if NPVBUS > 0
+	/* Detect hypervisors early, attach the paravirtual bus later */
+	if (CPU_IS_PRIMARY(ci) && cpu_ecxfeature & CPUIDECX_HV)
+		pvbus_identify();
+#endif
+
 	if (ci->ci_feature_flags && ci->ci_feature_flags & CPUID_TSC) {
 		/* Has TSC, check if it's constant */
 		if (!strcmp(cpu_vendor, "GenuineIntel")) {
diff --git a/sys/arch/amd64/amd64/mainbus.c b/sys/arch/amd64/amd64/mainbus.c
index ed8bd9c4368..b74c98781a8 100644
--- a/sys/arch/amd64/amd64/mainbus.c
+++ b/sys/arch/amd64/amd64/mainbus.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: mainbus.c,v 1.50 2020/05/14 13:07:11 kettenis Exp $	*/
+/*	$OpenBSD: mainbus.c,v 1.51 2021/08/31 15:52:59 patrick Exp $	*/
 /*	$NetBSD: mainbus.c,v 1.1 2003/04/26 18:39:29 fvdl Exp $	*/
 
 /*
@@ -167,12 +167,6 @@ mainbus_attach(struct device *parent, struct device *self, void *aux)
 
 	printf("\n");
 
-#if NPVBUS > 0
-	/* Detect hypervisors early, attach the paravirtual bus later */
-	if (cpu_ecxfeature & CPUIDECX_HV)
-		pvbus_identify();
-#endif
-
 #if NEFIFB > 0
 	efifb_cnremap();
 #endif
-- 
2.20.1