From 5720dca01aa846aef724a48c8af1c05ae034abe6 Mon Sep 17 00:00:00 2001
From: mlarkin <mlarkin@openbsd.org>
Date: Wed, 11 Jul 2018 14:48:40 +0000
Subject: [PATCH] Detect vmm(4) in the bootloader and automatically switch to
 the serial console at 115200 baud.

tested by phessler and myself, ok deraadt
---
 sys/arch/amd64/stand/boot/conf.c     |  4 ++--
 sys/arch/amd64/stand/cdboot/conf.c   |  4 ++--
 sys/arch/amd64/stand/libsa/machdep.c | 26 ++++++++++++++++++++++++--
 sys/arch/amd64/stand/pxeboot/conf.c  |  4 ++--
 4 files changed, 30 insertions(+), 8 deletions(-)

diff --git a/sys/arch/amd64/stand/boot/conf.c b/sys/arch/amd64/stand/boot/conf.c
index 0154b0b389b..37c1ffea52c 100644
--- a/sys/arch/amd64/stand/boot/conf.c
+++ b/sys/arch/amd64/stand/boot/conf.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: conf.c,v 1.40 2018/04/18 16:34:58 deraadt Exp $	*/
+/*	$OpenBSD: conf.c,v 1.41 2018/07/11 14:48:40 mlarkin Exp $	*/
 
 /*
  * Copyright (c) 1996 Michael Shalayeff
@@ -40,7 +40,7 @@
 #include <biosdev.h>
 #include <dev/cons.h>
 
-const char version[] = "3.39";
+const char version[] = "3.40";
 int	debug = 1;
 
 
diff --git a/sys/arch/amd64/stand/cdboot/conf.c b/sys/arch/amd64/stand/cdboot/conf.c
index 7eaae57d984..41f976fc5b7 100644
--- a/sys/arch/amd64/stand/cdboot/conf.c
+++ b/sys/arch/amd64/stand/cdboot/conf.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: conf.c,v 1.35 2018/04/18 16:34:58 deraadt Exp $	*/
+/*	$OpenBSD: conf.c,v 1.36 2018/07/11 14:48:40 mlarkin Exp $	*/
 
 /*
  * Copyright (c) 2004 Tom Cosgrove
@@ -41,7 +41,7 @@
 #include <biosdev.h>
 #include <dev/cons.h>
 
-const char version[] = "3.39";
+const char version[] = "3.40";
 int	debug = 1;
 
 
diff --git a/sys/arch/amd64/stand/libsa/machdep.c b/sys/arch/amd64/stand/libsa/machdep.c
index c6664ba33a9..246cda51cd8 100644
--- a/sys/arch/amd64/stand/libsa/machdep.c
+++ b/sys/arch/amd64/stand/libsa/machdep.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: machdep.c,v 1.6 2015/09/18 13:30:56 miod Exp $	*/
+/*	$OpenBSD: machdep.c,v 1.7 2018/07/11 14:48:40 mlarkin Exp $	*/
 
 /*
  * Copyright (c) 2004 Tom Cosgrove
@@ -31,6 +31,8 @@
 #include "biosdev.h"
 #include <machine/apmvar.h>
 #include <machine/biosvar.h>
+#include <machine/specialreg.h>
+#include <machine/vmmvar.h>
 
 #ifdef EFIBOOT
 #include "efiboot.h"
@@ -44,11 +46,15 @@ volatile struct BIOS_regs	BIOS_regs;
 #define CKPT(c) /* c */
 #endif
 
+const char *vmm_hv_signature = VMM_HV_SIGNATURE;
+
 void
 machdep(void)
 {
-	int i, j;
+	int i, j, vmm = 0;
 	struct i386_boot_probes *pr;
+	uint32_t dummy, ebx, ecx, edx;
+	dev_t dev;
 
 	/*
 	 * The list of probe routines is now in conf.c.
@@ -65,6 +71,22 @@ machdep(void)
 			printf("\n");
 		}
 	}
+
+	CPUID(0x1, dummy, dummy, ecx, dummy);
+	if (ecx & CPUIDECX_HV) {
+		CPUID(0x40000000, dummy, ebx, ecx, edx);
+		if (memcmp(&ebx, &vmm_hv_signature[0], sizeof(uint32_t)) == 0 &&
+		    memcmp(&ecx, &vmm_hv_signature[4], sizeof(uint32_t)) == 0 &&
+		    memcmp(&edx, &vmm_hv_signature[8], sizeof(uint32_t)) == 0)
+			vmm = 1;
+	}
+
+	/* Set console to com0/115200 by default in vmm */
+	if (vmm) {
+		dev = ttydev("com0");
+		cnspeed(dev, 115200);
+		cnset(dev);
+	}
 }
 
 int
diff --git a/sys/arch/amd64/stand/pxeboot/conf.c b/sys/arch/amd64/stand/pxeboot/conf.c
index fd4103a3ddb..4d40f45d7fc 100644
--- a/sys/arch/amd64/stand/pxeboot/conf.c
+++ b/sys/arch/amd64/stand/pxeboot/conf.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: conf.c,v 1.39 2018/04/18 16:34:58 deraadt Exp $	*/
+/*	$OpenBSD: conf.c,v 1.40 2018/07/11 14:48:40 mlarkin Exp $	*/
 
 /*
  * Copyright (c) 2004 Tom Cosgrove
@@ -43,7 +43,7 @@
 #include "pxeboot.h"
 #include "pxe_net.h"
 
-const char version[] = "3.39";
+const char version[] = "3.40";
 int	debug = 0;
 
 void (*sa_cleanup)(void) = pxe_shutdown;
-- 
2.20.1