From 192a99d1d73d351ff7305cf7aecaa2210bcb6647 Mon Sep 17 00:00:00 2001
From: Cyrill Gorcunov <gorcunov@gmail.com>
Date: Sun, 11 Jul 2010 14:06:30 +0400
Subject: [PATCH] kvm: Add --mem= option

Which allow an user to specify the amount of memory
he would like to provide for kernel.

Signed-off-by: Cyrill Gorcunov <gorcunov@gmail.com>
---
 include/kvm/kvm.h |  2 +-
 kvm.c             |  4 ++--
 main.c            | 15 +++++++++++++--
 3 files changed, 16 insertions(+), 5 deletions(-)

diff --git a/include/kvm/kvm.h b/include/kvm/kvm.h
index 7acca0e..88fa6e8 100644
--- a/include/kvm/kvm.h
+++ b/include/kvm/kvm.h
@@ -31,7 +31,7 @@ struct kvm {
 	struct interrupt_table	interrupt_table;
 };
 
-struct kvm *kvm__init(const char *kvm_dev);
+struct kvm *kvm__init(const char *kvm_dev, unsigned long ram_size);
 void kvm__delete(struct kvm *self);
 void kvm__setup_cpuid(struct kvm *self);
 void kvm__enable_singlestep(struct kvm *self);
diff --git a/kvm.c b/kvm.c
index 045fcd8..3baa67e 100644
--- a/kvm.c
+++ b/kvm.c
@@ -151,7 +151,7 @@ static bool kvm__cpu_supports_vm(void)
 	return regs.ecx & (1 << feature);
 }
 
-struct kvm *kvm__init(const char *kvm_dev)
+struct kvm *kvm__init(const char *kvm_dev, unsigned long ram_size)
 {
 	struct kvm_userspace_memory_region mem;
 	struct kvm_pit_config pit_config = { .flags = 0, };
@@ -192,7 +192,7 @@ struct kvm *kvm__init(const char *kvm_dev)
 	if (ret < 0)
 		die_perror("KVM_CREATE_PIT2 ioctl");
 
-	self->ram_size		= 64UL * 1024UL * 1024UL;
+	self->ram_size		= ram_size;
 
 	page_size	= sysconf(_SC_PAGESIZE);
 	if (posix_memalign(&self->ram_start, page_size, self->ram_size) != 0)
diff --git a/main.c b/main.c
index 57ae33b..f3e69ae 100644
--- a/main.c
+++ b/main.c
@@ -14,7 +14,10 @@ extern bool ioport_debug;
 
 static void usage(char *argv[])
 {
-	fprintf(stderr, "  usage: %s [--single-step] [--ioport-debug] [--params=<kernel-params>] [--kernel=]<kernel-image>\n",
+	fprintf(stderr, "  usage: %s "
+		"[--single-step] [--ioport-debug] "
+		"[--kvm-dev=device] [--mem=MB] [--params=<kernel-params>] "
+		"[--kernel=]<kernel-image>\n",
 		argv[0]);
 	exit(1);
 }
@@ -44,6 +47,7 @@ int main(int argc, char *argv[])
 	const char *kernel_filename = NULL;
 	const char *kernel_cmdline = NULL;
 	const char *kvm_dev = "/dev/kvm";
+	unsigned long ram_size = 64UL << 20;
 	bool single_step = false;
 	int i;
 
@@ -62,6 +66,13 @@ int main(int argc, char *argv[])
 		} else if (option_matches(argv[i], "--single-step")) {
 			single_step	= true;
 			continue;
+		} else if (option_matches(argv[i], "--mem=")) {
+			unsigned long val = atol(&argv[i][6]) << 20;
+			if (val < ram_size)
+				die("Not enough memory specified: %sMB (min %luMB)",
+					argv[i], ram_size >> 20);
+			ram_size = val;
+			continue;
 		} else if (option_matches(argv[i], "--ioport-debug")) {
 			ioport_debug	= true;
 			continue;
@@ -78,7 +89,7 @@ int main(int argc, char *argv[])
 	if (!kernel_filename)
 		usage(argv);
 
-	kvm = kvm__init(kvm_dev);
+	kvm = kvm__init(kvm_dev, ram_size);
 
 	kvm__setup_cpuid(kvm);