vmm/vmd/vmctl: standardize memory units to bytes

At different points in the vm lifecycle vmm(4), vmctl(8), and vmd(8)
refer to a vm's memory range sizes in either bytes or megabytes.
This is needlessly complex.

Switch to using bytes everywhere and adjust types and constants
accordingly. While this makes it possible to specify vm's with
memory in fractions of megabytes, the logic requiring whole
megabyte values remains.

Feedback from deraadt@, mlarkin@, and Matthew Martin.

ok mlarkin@

3 files changed, 29 insertions, 14 deletions

diff --git a/usr.sbin/vmctl/main.c b/usr.sbin/vmctl/main.c
index 0f7e4329a00..37fc4dc642a 100644
--- a/usr.sbin/vmctl/main.c
+++ b/usr.sbin/vmctl/main.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: main.c,v 1.68 2021/07/12 15:09:22 beck Exp $	*/
+/*	$OpenBSD: main.c,v 1.69 2022/05/03 21:39:18 dv Exp $	*/
 
 /*
  * Copyright (c) 2015 Reyk Floeter <reyk@openbsd.org>
@@ -404,23 +404,38 @@ parse_network(struct parse_result *res, char *word)
 int
 parse_size(struct parse_result *res, char *word)
 {
-	long long val = 0;
+	char		 result[FMT_SCALED_STRSIZE];
+	long long 	 val = 0;
 
 	if (word != NULL) {
 		if (scan_scaled(word, &val) != 0) {
-			warn("invalid size: %s", word);
+			warn("invalid memory size: %s", word);
 			return (-1);
 		}
 	}
 
 	if (val < (1024 * 1024)) {
-		warnx("size must be at least one megabyte");
+		warnx("memory size must be at least 1MB");
 		return (-1);
-	} else
-		res->size = val / 1024 / 1024;
+	}
 
-	if ((res->size * 1024 * 1024) != val)
-		warnx("size rounded to %lld megabytes", res->size);
+	if (val > VMM_MAX_VM_MEM_SIZE) {
+		if (fmt_scaled(VMM_MAX_VM_MEM_SIZE, result) == 0)
+			warnx("memory size too large (limit is %s)", result);
+		else
+			warnx("memory size too large");
+		return (-1);
+	}
+
+	/* Round down to the megabyte. */
+	res->size = (val / (1024 * 1024)) * (1024 * 1024);
+
+	if (res->size != (size_t)val) {
+		if (fmt_scaled(res->size, result) == 0)
+			warnx("memory size rounded to %s", result);
+		else
+			warnx("memory size rounded to %zu bytes", res->size);
+	}
 
 	return (0);
 }
diff --git a/usr.sbin/vmctl/vmctl.c b/usr.sbin/vmctl/vmctl.c
index 4c0b62fc6e1..b1977f95051 100644
--- a/usr.sbin/vmctl/vmctl.c
+++ b/usr.sbin/vmctl/vmctl.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: vmctl.c,v 1.79 2021/06/10 19:50:05 dv Exp $	*/
+/*	$OpenBSD: vmctl.c,v 1.80 2022/05/03 21:39:18 dv Exp $	*/
 
 /*
  * Copyright (c) 2014 Mike Larkin <mlarkin@openbsd.org>
@@ -73,7 +73,7 @@ struct imsgbuf *ibuf;
  *  ENOMEM if a memory allocation failure occurred.
  */
 int
-vm_start(uint32_t start_id, const char *name, int memsize, int nnics,
+vm_start(uint32_t start_id, const char *name, size_t memsize, int nnics,
     char **nics, int ndisks, char **disks, int *disktypes, char *kernel,
     char *iso, char *instance, unsigned int bootdevice)
 {
@@ -122,7 +122,7 @@ vm_start(uint32_t start_id, const char *name, int memsize, int nnics,
 
 	/*
 	 * XXX: vmd(8) fills in the actual memory ranges. vmctl(8)
-	 * just passes in the actual memory size in MB here.
+	 * just passes in the actual memory size here.
 	 */
 	vcp->vcp_nmemranges = 1;
 	vcp->vcp_memranges[0].vmr_size = memsize;
diff --git a/usr.sbin/vmctl/vmctl.h b/usr.sbin/vmctl/vmctl.h
index 4fd2b787deb..6d84c7b1c6c 100644
--- a/usr.sbin/vmctl/vmctl.h
+++ b/usr.sbin/vmctl/vmctl.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: vmctl.h,v 1.34 2021/01/27 07:21:12 deraadt Exp $	*/
+/*	$OpenBSD: vmctl.h,v 1.35 2022/05/03 21:39:18 dv Exp $	*/
 
 /*
  * Copyright (c) 2015 Reyk Floeter <reyk@openbsd.org>
@@ -48,7 +48,7 @@ struct parse_result {
 	char			*name;
 	char			*path;
 	char			*isopath;
-	long long		 size;
+	size_t			 size;
 	int			 nifs;
 	char			**nets;
 	int			 nnets;
@@ -93,7 +93,7 @@ int	 open_imagefile(int, const char *, int,
 int	 create_imagefile(int, const char *, const char *, long, const char **);
 int	 create_raw_imagefile(const char *, long);
 int	 create_qc2_imagefile(const char *, const char *, long);
-int	 vm_start(uint32_t, const char *, int, int, char **, int,
+int	 vm_start(uint32_t, const char *, size_t, int, char **, int,
 	    char **, int *, char *, char *, char *, unsigned int);
 int	 vm_start_complete(struct imsg *, int *, int);
 void	 terminate_vm(uint32_t, const char *, unsigned int);