vm load: fix bug in loading kernel

According to the explaination for pref_address
in Documentation/x86/boot.txt, a relocating bootloader
should attempt to load kernel at pref_address if possible.
But due to a non-relocatable kernel will unconditionally
move itself and to run at perf address, no need to copy
kernel to perf_address by bootloader.

Signed-off-by: Zheng, Gen <gen.zheng@intel.com>

Author: zhenggen

hypervisor/arch/x86/guest/guest.c

@@ -37,6 +37,7 @@
 #include <acrn_hv_defs.h>
 #include <hv_debug.h>
 #include <multiboot.h>
+#include <zeropage.h>
 
 #define ACRN_DBG_GUEST	6
 

hypervisor/boot/multiboot.c

@@ -37,6 +37,7 @@
 #include <acrn_hv_defs.h>
 #include <hv_debug.h>
 #include <multiboot.h>
+#include <zeropage.h>
 
 #define BOOT_ARGS_LOAD_ADDR				0x24EFC000
 
@@ -102,6 +103,25 @@ static void parse_other_modules(struct vm *vm,
 	}
 }
 
+static void *get_kernel_load_addr(void *kernel_src_addr)
+{
+	struct zero_page *zeropage;
+
+	/* According to the explaination for pref_address
+	 * in Documentation/x86/boot.txt, a relocating
+	 * bootloader should attempt to load kernel at pref_address
+	 * if possible. A non-relocatable kernel will unconditionally
+	 * move itself and to run at this address, so no need to copy
+	 * kernel to perf_address by bootloader, if kernel is
+	 * non-relocatable.
+	 */
+	zeropage = (struct zero_page *)kernel_src_addr;
+	if (zeropage->hdr.relocatable_kernel)
+		return (void *)zeropage->hdr.pref_addr;
+
+	return kernel_src_addr;
+}
+
 int init_vm0_boot_info(struct vm *vm)
 {
 	struct multiboot_module *mods = NULL;
@@ -141,7 +161,7 @@ int init_vm0_boot_info(struct vm *vm)
 	vm->sw.kernel_info.kernel_size =
 		mods[0].mm_mod_end - mods[0].mm_mod_start;
 	vm->sw.kernel_info.kernel_load_addr =
-		(void *)(uint64_t)mods[0].mm_mod_start;
+		get_kernel_load_addr(vm->sw.kernel_info.kernel_src_addr);
 
 	vm->sw.linux_info.bootargs_src_addr =
 		(void *)(uint64_t)mods[0].mm_string;

hypervisor/common/vm_load.c

@@ -34,32 +34,7 @@
 #include <hv_arch.h>
 #include <bsp_extern.h>
 #include <hv_debug.h>
-
-struct zero_page {
-	uint8_t pad1[0x1e8];	/* 0x000 */
-	uint8_t e820_nentries;	/* 0x1e8 */
-	uint8_t pad2[0x8];	/* 0x1e9 */
-
-	struct {
-		uint8_t setup_sects;	/* 0x1f1 */
-		uint8_t hdr_pad1[0x1e];	/* 0x1f2 */
-		uint8_t loader_type;	/* 0x210 */
-		uint8_t load_flags;	/* 0x211 */
-		uint8_t hdr_pad2[0x6];	/* 0x212 */
-		uint32_t ramdisk_addr;	/* 0x218 */
-		uint32_t ramdisk_size;	/* 0x21c */
-		uint8_t hdr_pad3[0x8];	/* 0x220 */
-		uint32_t bootargs_addr;	/* 0x228 */
-		uint8_t hdr_pad4[0x1c];	/* 0x22c */
-		uint32_t payload_offset;/* 0x248 */
-		uint32_t payload_length;/* 0x24c */
-		uint8_t hdr_pad5[0x18];	/* 0x250 */
-	} __packed hdr;
-
-	uint8_t pad3[0x68];	/* 0x268 */
-	struct e820_entry e820[0x80];	/* 0x2d0 */
-	uint8_t pad4[0x330];	/* 0xcd0 */
-} __packed;
+#include <zeropage.h>
 
 static uint32_t create_e820_table(struct e820_entry *_e820)
 {

hypervisor/include/arch/x86/zeropage.h

@@ -0,0 +1,64 @@
+/*
+ * Copyright (C) 2018 Intel Corporation. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ *   * Redistributions of source code must retain the above copyright
+ *     notice, this list of conditions and the following disclaimer.
+ *   * Redistributions in binary form must reproduce the above copyright
+ *     notice, this list of conditions and the following disclaimer in
+ *     the documentation and/or other materials provided with the
+ *     distribution.
+ *   * Neither the name of Intel Corporation nor the names of its
+ *     contributors may be used to endorse or promote products derived
+ *     from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#ifndef ZEROPAGE_H
+#define ZEROPAGE_H
+
+struct zero_page {
+	uint8_t pad1[0x1e8];	/* 0x000 */
+	uint8_t e820_nentries;	/* 0x1e8 */
+	uint8_t pad2[0x8];	/* 0x1e9 */
+
+	struct {
+		uint8_t setup_sects;	/* 0x1f1 */
+		uint8_t hdr_pad1[0x1e];	/* 0x1f2 */
+		uint8_t loader_type;	/* 0x210 */
+		uint8_t load_flags;	/* 0x211 */
+		uint8_t hdr_pad2[0x6];	/* 0x212 */
+		uint32_t ramdisk_addr;	/* 0x218 */
+		uint32_t ramdisk_size;	/* 0x21c */
+		uint8_t hdr_pad3[0x8];	/* 0x220 */
+		uint32_t bootargs_addr;	/* 0x228 */
+		uint8_t hdr_pad4[0x8];	/* 0x22c */
+		uint8_t relocatable_kernel; /* 0x234 */
+		uint8_t hdr_pad5[0x13];    /* 0x235 */
+		uint32_t payload_offset;/* 0x248 */
+		uint32_t payload_length;/* 0x24c */
+		uint8_t hdr_pad6[0x8];	/* 0x250 */
+		uint64_t pref_addr;     /* 0x258 */
+		uint8_t hdr_pad7[8];    /* 0x260 */
+	} __packed hdr;
+
+	uint8_t pad3[0x68];	/* 0x268 */
+	struct e820_entry e820[0x80];	/* 0x2d0 */
+	uint8_t pad4[0x330];	/* 0xcd0 */
+} __packed;
+
+#endif