kvm tools: Separate BIOS specifics into own file

Instead of calling various BIOS routines from kvm.c better to have all BIOS
specifics sit in bios.c.

Signed-off-by: Cyrill Gorcunov <gorcunov@gmail.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>

bios.c

@@ -1,4 +1,6 @@
 #include "kvm/kvm.h"
+#include "kvm/boot-protocol.h"
+#include "kvm/e820.h"
 #include "kvm/interrupt.h"
 #include "kvm/util.h"
 
@@ -46,6 +48,49 @@ static void setup_irq_handler(struct kvm *kvm, struct irq_handler *handler)
 	interrupt_table__set(&kvm->interrupt_table, &intr_desc, handler->irq);
 }
 
+/**
+ * e820_setup - setup some simple E820 memory map
+ * @kvm - guest system descriptor
+ */
+static void e820_setup(struct kvm *kvm)
+{
+	struct e820_entry *mem_map;
+	unsigned char *size;
+	unsigned int i = 0;
+
+	size		= guest_flat_to_host(kvm, E820_MAP_SIZE);
+	mem_map		= guest_flat_to_host(kvm, E820_MAP_START);
+
+	*size		= E820_MEM_AREAS;
+
+	mem_map[i++]	= (struct e820_entry) {
+		.addr		= REAL_MODE_IVT_BEGIN,
+		.size		= EBDA_START - REAL_MODE_IVT_BEGIN,
+		.type		= E820_MEM_USABLE,
+	};
+	mem_map[i++]	= (struct e820_entry) {
+		.addr		= EBDA_START,
+		.size		= VGA_RAM_BEGIN - EBDA_START,
+		.type		= E820_MEM_RESERVED,
+	};
+	mem_map[i++]	= (struct e820_entry) {
+		.addr		= MB_BIOS_BEGIN,
+		.size		= MB_BIOS_END - MB_BIOS_BEGIN,
+		.type		= E820_MEM_RESERVED,
+	};
+	mem_map[i++]	= (struct e820_entry) {
+		.addr		= BZ_KERNEL_START,
+		.size		= kvm->ram_size - BZ_KERNEL_START,
+		.type		= E820_MEM_USABLE,
+	};
+
+	BUILD_BUG_ON(i > E820_MEM_AREAS);
+}
+
+/**
+ * setup_bios - inject BIOS into guest memory
+ * @kvm - guest system descriptor
+ */
 void setup_bios(struct kvm *kvm)
 {
 	unsigned long address = MB_BIOS_BEGIN;
@@ -73,6 +118,9 @@ void setup_bios(struct kvm *kvm)
 	p = guest_flat_to_host(kvm, MB_BIOS_BEGIN);
 	memcpy(p, bios_rom, bios_rom_size);
 
+	/* E820 memory map must be present */
+	e820_setup(kvm);
+
 	/*
 	 * Setup a *fake* real mode vector table, it has only
 	 * one real hadler which does just iret

include/kvm/boot-protocol.h

@@ -0,0 +1,16 @@
+/*
+ * Linux boot protocol specifics
+ */
+
+#ifndef BOOT_PROTOCOL_H_
+#define BOOT_PROTOCOL_H_
+
+/*
+ * The protected mode kernel part of a modern bzImage is loaded
+ * at 1 MB by default.
+ */
+#define BZ_DEFAULT_SETUP_SECTS		4
+#define BZ_KERNEL_START			0x100000UL
+#define INITRD_START			0x1000000UL
+
+#endif /* BOOT_PROTOCOL_H_ */

include/kvm/e820.h

@@ -8,6 +8,8 @@
 #define E820_MEM_USABLE		1
 #define E820_MEM_RESERVED	2
 
+#define E820_MEM_AREAS		4
+
 struct e820_entry {
 	uint64_t addr;	/* start of memory segment */
 	uint64_t size;	/* size of memory segment */

include/kvm/kvm.h

@@ -41,7 +41,7 @@ void kvm__enable_singlestep(struct kvm *self);
 bool kvm__load_kernel(struct kvm *kvm, const char *kernel_filename,
 			const char *initrd_filename, const char *kernel_cmdline);
 void kvm__reset_vcpu(struct kvm *self);
-void kvm__setup_mem(struct kvm *self);
+void kvm__setup_bios(struct kvm *self);
 void kvm__start_timer(struct kvm *self);
 void kvm__run(struct kvm *self);
 void kvm__irq_line(struct kvm *self, int irq, int level);

include/kvm/util.h

@@ -37,6 +37,8 @@ extern void warning(const char *err, ...) __attribute__((format (printf, 1, 2)))
 extern void info(const char *err, ...) __attribute__((format (printf, 1, 2)));
 extern void set_die_routine(void (*routine)(const char *err, va_list params) NORETURN);
 
+#define BUILD_BUG_ON(condition) ((void)sizeof(char[1 - 2*!!(condition)]))
+
 #define DIE_IF(cnd)						\
 do {								\
 	if (cnd)						\

kvm.c

@@ -2,7 +2,7 @@
 
 #include "kvm/cpufeature.h"
 #include "kvm/interrupt.h"
-#include "kvm/e820.h"
+#include "kvm/boot-protocol.h"
 #include "kvm/util.h"
 
 #include <linux/kvm.h>
@@ -273,13 +273,6 @@ static int load_flat_binary(struct kvm *self, int fd)
 	return true;
 }
 
-/*
- * The protected mode kernel part of a modern bzImage is loaded at 1 MB by
- * default.
- */
-#define BZ_KERNEL_START			0x100000UL
-#define INITRD_START			0x1000000UL
-#define BZ_DEFAULT_SETUP_SECTS		4
 static const char *BZIMAGE_MAGIC	= "HdrS";
 
 static bool load_bzimage(struct kvm *self, int fd_kernel,
@@ -571,36 +564,19 @@ void kvm__reset_vcpu(struct kvm *self)
 	kvm__setup_msrs(self);
 }
 
-void kvm__setup_mem(struct kvm *self)
+/**
+ * kvm__setup_bios - inject BIOS into guest system memory
+ * @self - guest system descriptor
+ *
+ * This function is a main routine where we poke guest memory
+ * and install BIOS there.
+ */
+void kvm__setup_bios(struct kvm *self)
 {
-	struct e820_entry *mem_map;
-	unsigned char *size;
+	/* standart minimal configuration */
+	setup_bios(self);
 
-	size		= guest_flat_to_host(self, E820_MAP_SIZE);
-	mem_map		= guest_flat_to_host(self, E820_MAP_START);
-
-	*size		= 4;
-
-	mem_map[0]	= (struct e820_entry) {
-		.addr		= REAL_MODE_IVT_BEGIN,
-		.size		= EBDA_START - REAL_MODE_IVT_BEGIN,
-		.type		= E820_MEM_USABLE,
-	};
-	mem_map[1]	= (struct e820_entry) {
-		.addr		= EBDA_START,
-		.size		= VGA_RAM_BEGIN - EBDA_START,
-		.type		= E820_MEM_RESERVED,
-	};
-	mem_map[2]	= (struct e820_entry) {
-		.addr		= MB_BIOS_BEGIN,
-		.size		= MB_BIOS_END - MB_BIOS_BEGIN,
-		.type		= E820_MEM_RESERVED,
-	};
-	mem_map[3]	= (struct e820_entry) {
-		.addr		= BZ_KERNEL_START,
-		.size		= self->ram_size - BZ_KERNEL_START,
-		.type		= E820_MEM_USABLE,
-	};
+	/* FIXME: SMP, ACPI and friends here */
 }
 
 #define TIMER_INTERVAL_NS 1000000	/* 1 msec */

main.c

@@ -162,9 +162,7 @@ int main(int argc, char *argv[])
 
 	kvm__reset_vcpu(kvm);
 
-	setup_bios(kvm);
-
-	kvm__setup_mem(kvm);
+	kvm__setup_bios(kvm);
 
 	if (single_step)
 		kvm__enable_singlestep(kvm);