pvh: use x86/HVM direct boot ABI
These changes (along with corresponding QEMU and Linux kernel changes)
enable a guest to be booted using the x86/HVM direct boot ABI.
QEMU parses the uncompressed kernel binary passed to it via -kernel
to read the ELF Note which contains the address to be loaded. QEMU
then depends on qboot to populate the start_info struct needed by
the direct boot ABI and configure the guest e820 tables before
jumping to the loaded kernel entry.
Signed-off-by: George Kennedy <George.Kennedy@oracle.com>
Signed-off-by: Liam Merwick <Liam.Merwick@oracle.com>
diff --git a/fw_cfg.c b/fw_cfg.c
index f5aac73..09bb0d3 100644
--- a/fw_cfg.c
+++ b/fw_cfg.c
@@ -6,8 +6,12 @@
#include "fw_cfg.h"
#include "bswap.h"
#include "linuxboot.h"
+#include "memaccess.h"
#include "multiboot.h"
#include "benchmark.h"
+#include "start_info.h"
+
+extern struct hvm_start_info start_info;
struct fw_cfg_file {
uint32_t size;
@@ -184,6 +188,66 @@
panic();
}
+static void pvh_e820_setup()
+{
+ struct hvm_memmap_table_entry *pvh_e820p;
+ int i, pvh_e820_sz;
+
+ pvh_e820_sz = sizeof(struct hvm_memmap_table_entry) * e820->nr_map;
+
+ pvh_e820p = malloc(pvh_e820_sz);
+ memset(pvh_e820p, 0, pvh_e820_sz);
+
+ for (i = 0; i < e820->nr_map; i++) {
+ pvh_e820p[i].addr = e820->map[i].addr;
+ pvh_e820p[i].size = e820->map[i].size;
+ pvh_e820p[i].type = e820->map[i].type;
+ }
+ start_info.memmap_paddr = (uintptr_t)pvh_e820p;
+ start_info.memmap_entries = e820->nr_map;
+}
+
+static void boot_pvh_from_fw_cfg(void)
+{
+ void *kernel_entry;
+ uint32_t sz;
+ struct linuxboot_args args;
+ struct hvm_modlist_entry ramdisk_mod;
+
+ start_info.magic = XEN_HVM_START_MAGIC_VALUE;
+ start_info.version = 1;
+ start_info.flags = 0;
+ start_info.nr_modules = 1;
+ start_info.reserved = 0;
+
+ fw_cfg_select(FW_CFG_CMDLINE_SIZE);
+ args.cmdline_size = fw_cfg_readl_le();
+ args.cmdline_addr = malloc(args.cmdline_size);
+ fw_cfg_read_entry(FW_CFG_CMDLINE_DATA, args.cmdline_addr,
+ args.cmdline_size);
+ start_info.cmdline_paddr = (uintptr_t)args.cmdline_addr;
+
+ /* Use this field for pvhboot. Not used by pvhboot otherwise */
+ fw_cfg_read_entry(FW_CFG_KERNEL_DATA, &ramdisk_mod,
+ sizeof(ramdisk_mod));
+ ramdisk_mod.cmdline_paddr = (uintptr_t)&ramdisk_mod;
+ start_info.modlist_paddr = (uintptr_t)&ramdisk_mod;
+
+ pvh_e820_setup();
+
+ fw_cfg_select(FW_CFG_KERNEL_SIZE);
+ sz = fw_cfg_readl_le();
+ if (!sz)
+ panic();
+
+ fw_cfg_select(FW_CFG_KERNEL_ENTRY);
+ kernel_entry = (void *) fw_cfg_readl_le();
+
+ asm volatile("jmp *%2" : : "a" (0x2badb002),
+ "b"(&start_info), "c"(kernel_entry));
+ panic();
+}
+
void boot_from_fwcfg(void)
{
struct linuxboot_args args;
@@ -208,8 +272,13 @@
fw_cfg_select(FW_CFG_SETUP_DATA);
fw_cfg_read(args.header, sizeof(args.header));
- if (!parse_bzimage(&args))
+ if (!parse_bzimage(&args)) {
+ uint8_t *header = args.header;
+
+ if (ldl_p(header) == 0x464c457f) /* ELF magic */
+ boot_pvh_from_fw_cfg();
boot_multiboot_from_fw_cfg();
+ }
/* SETUP_DATA already selected */
if (args.setup_size > sizeof(args.header))
diff --git a/linuxboot.c b/linuxboot.c
index d7eac74..cfcaf2d 100644
--- a/linuxboot.c
+++ b/linuxboot.c
@@ -2,10 +2,13 @@
#include "linuxboot.h"
#include "memaccess.h"
#include "ioport.h"
+#include "start_info.h"
#include "string.h"
#include "stdio.h"
#include "benchmark.h"
+struct hvm_start_info start_info = {0};
+
bool parse_bzimage(struct linuxboot_args *args)
{
uint8_t *header = args->header;
diff --git a/tables.c b/tables.c
index 32b2406..9493691 100644
--- a/tables.c
+++ b/tables.c
@@ -2,6 +2,9 @@
#include "stdio.h"
#include "fw_cfg.h"
#include "string.h"
+#include "start_info.h"
+
+extern struct hvm_start_info start_info;
struct loader_cmd {
uint32_t cmd;
@@ -67,6 +70,13 @@
set_file_addr(id, p);
fw_cfg_read_file(id, p, n);
+
+ /* For PVH boot, save the PA where the RSDP is stored */
+ if (zone == ALLOC_FSEG) {
+ if (!memcmp(p, "RSD PTR ", 8)) {
+ start_info.rsdp_paddr = (uintptr_t)id_to_addr(id);
+ }
+ }
}
static void do_ptr(char *dest, char *src, uint32_t offset, uint8_t size)
