From c5b0b0ba47703b28f0772382ff1e65eda209db4e Mon Sep 17 00:00:00 2001
From: Matthew Dillon <dillon@dragonflybsd.org>
Date: Mon, 2 Jul 2007 02:37:05 +0000
Subject: [PATCH] Add an option (-n ncpus) to specify the number of cpus a
 virtual kernel should simulate.  The virtual kernel must be built with
 options SMP. 1-32 cpus may be simulated regardless of the number of real
 cpus.  The virtual kernel will create a thread for each cpu.

---
 share/man/man7/vkernel.7             |  8 +++++++-
 sys/platform/vkernel/i386/mp.c       |  5 ++---
 sys/platform/vkernel/include/smp.h   |  4 +++-
 sys/platform/vkernel/platform/init.c | 30 +++++++++++++++++++++++-----
 4 files changed, 37 insertions(+), 10 deletions(-)

diff --git a/share/man/man7/vkernel.7 b/share/man/man7/vkernel.7
index e694c6273c..0b20b8be10 100644
--- a/share/man/man7/vkernel.7
+++ b/share/man/man7/vkernel.7
@@ -29,7 +29,7 @@
 .\" OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 .\" SUCH DAMAGE.
 .\"
-.\" $DragonFly: src/share/man/man7/vkernel.7,v 1.21 2007/06/23 20:52:41 swildner Exp $
+.\" $DragonFly: src/share/man/man7/vkernel.7,v 1.22 2007/07/02 02:37:02 dillon Exp $
 .\"
 .Dd June 14, 2007
 .Dt VKERNEL 7
@@ -51,6 +51,7 @@
 .Op Fl i Ar file
 .Op Fl I Ar interface Ns Op Ar :address1 Ns Oo Ar :address2 Oc Ns Oo Ar /netmask Oc
 .Op Fl m Ar size
+.Op Fl n Ar numcpus
 .Op Fl p Ar file
 .Op Fl r Ar file
 .Sh DESCRIPTION
@@ -150,6 +151,11 @@ Lowercase versions of
 and
 .Cm G
 are allowed.
+.It Fl n Ar numcpus
+Specify the number of cpus you wish to emulate.
+Up to 32 cpus are supported.
+The virtual kernel must be built with options SMP to use this option
+and will default to 2 cpus unless otherwise specified.
 .It Fl p Ar file
 Specify a file in which to store the process ID.
 A warning is issued if this file cannot be opened for writing.
diff --git a/sys/platform/vkernel/i386/mp.c b/sys/platform/vkernel/i386/mp.c
index c86628f473..9f24de1ab6 100644
--- a/sys/platform/vkernel/i386/mp.c
+++ b/sys/platform/vkernel/i386/mp.c
@@ -31,7 +31,7 @@
  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  *
- * $DragonFly: src/sys/platform/vkernel/i386/mp.c,v 1.3 2007/07/01 04:02:33 dillon Exp $
+ * $DragonFly: src/sys/platform/vkernel/i386/mp.c,v 1.4 2007/07/02 02:37:03 dillon Exp $
  */
 
 
@@ -142,8 +142,7 @@ mp_start(void)
 {
 	int shift;
 
-	/* XXX testing 2 cpus */
-	ncpus = 2;
+	ncpus = optcpus;
 
 	mp_naps = ncpus - 1;
 
diff --git a/sys/platform/vkernel/include/smp.h b/sys/platform/vkernel/include/smp.h
index 277cd39394..1bfc088634 100644
--- a/sys/platform/vkernel/include/smp.h
+++ b/sys/platform/vkernel/include/smp.h
@@ -7,7 +7,7 @@
  * ----------------------------------------------------------------------------
  *
  * $FreeBSD: src/sys/i386/include/smp.h,v 1.50.2.5 2001/02/13 22:32:45 tegge Exp $
- * $DragonFly: src/sys/platform/vkernel/include/smp.h,v 1.2 2007/06/18 18:57:13 josepht Exp $
+ * $DragonFly: src/sys/platform/vkernel/include/smp.h,v 1.3 2007/07/02 02:37:04 dillon Exp $
  *
  */
 
@@ -50,6 +50,8 @@ void	bootMP			(void);
 
 /* global data in apic_vector.s */
 extern volatile u_int		stopped_cpus;
+extern int			optcpus;	/* from main() */
+
 #if 0
 extern volatile u_int		started_cpus;
 
diff --git a/sys/platform/vkernel/platform/init.c b/sys/platform/vkernel/platform/init.c
index 789c679c9c..a209f7a887 100644
--- a/sys/platform/vkernel/platform/init.c
+++ b/sys/platform/vkernel/platform/init.c
@@ -31,7 +31,7 @@
  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  * 
- * $DragonFly: src/sys/platform/vkernel/platform/init.c,v 1.40 2007/06/19 17:25:48 dillon Exp $
+ * $DragonFly: src/sys/platform/vkernel/platform/init.c,v 1.41 2007/07/02 02:37:05 dillon Exp $
  */
 
 #include <sys/types.h>
@@ -96,6 +96,7 @@ vpte_t	*KernelPTD;
 vpte_t	*KernelPTA;	/* Warning: Offset for direct VA translation */
 u_int cpu_feature;	/* XXX */
 u_int tsc_present;	/* XXX */
+int optcpus;		/* number of cpus - see mp_start() */
 
 struct privatespace *CPU_prvspace;
 
@@ -110,7 +111,7 @@ static void init_disk(char *diskExp[], int diskFileNum, enum vkdisk_type type);
 static void init_netif(char *netifExp[], int netifFileNum);
 static void writepid( void );
 static void cleanpid( void );
-static void usage(const char *ctl);
+static void usage(const char *str);
 
 static int save_ac;
 static char **save_av;
@@ -140,8 +141,11 @@ main(int ac, char **av)
 	 * Process options
 	 */
 	kernel_mem_readonly = 1;
+#ifdef SMP
+	optcpus = 2;
+#endif
 
-	while ((c = getopt(ac, av, "c:svm:r:e:i:p:I:U")) != -1) {
+	while ((c = getopt(ac, av, "c:svm:n:r:e:i:p:I:U")) != -1) {
 		switch(c) {
 		case 'e':
 			/*
@@ -203,6 +207,21 @@ main(int ac, char **av)
 				}
 			}
 			break;
+		case 'n':
+			/*
+			 * This value is set up by mp_start(), don't just
+			 * set ncpus here.
+			 */
+#ifdef SMP
+			optcpus = strtol(optarg, NULL, 0);
+			if (optcpus < 1 || optcpus > 32)
+				usage("Bad ncpus, valid range is 1-32");
+#else
+			if (strtol(optarg, NULL, 0) != 1) {
+				usage("You built a UP vkernel, only 1 cpu!");
+			}
+#endif
+			
 		case 'p':
 			pid_file = optarg;	
 			break;
@@ -1077,9 +1096,10 @@ cleanpid( void )
 
 static
 void
-usage(const char *ctl)
+usage(const char *str)
 {
-	
+	fprintf(stderr, "%s\n", str);
+	exit(1);
 }
 
 void
-- 
2.41.0