These changes (along with corresponding qboot and Linux kernel changes)
enable a guest to be booted using the x86/HVM direct boot ABI.
This commit adds a load_elfboot() routine to pass the size and
location of the kernel entry point to qboot (which will fill in
the start_info struct information needed to to boot the guest).
Having loaded the ELF binary, load_linux() will run qboot
which continues the boot.
The address for the kernel entry point has already been read
from an ELF Note in the uncompressed kernel binary earlier
in pc_memory_init().
Signed-off-by: George Kennedy <address@hidden>
Signed-off-by: Liam Merwick <address@hidden>
---
hw/i386/pc.c | 72 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 72 insertions(+)
diff --git a/hw/i386/pc.c b/hw/i386/pc.c
index 056aa46d99b9..d3012cbd8597 100644
--- a/hw/i386/pc.c
+++ b/hw/i386/pc.c
@@ -54,6 +54,7 @@
#include "sysemu/qtest.h"
#include "kvm_i386.h"
#include "hw/xen/xen.h"
+#include "hw/xen/start_info.h"
#include "ui/qemu-spice.h"
#include "exec/memory.h"
#include "exec/address-spaces.h"
@@ -1098,6 +1099,50 @@ done:
return pvh_start_addr != 0;
}
+static bool load_elfboot(const char *kernel_filename,
+ int kernel_file_size,
+ uint8_t *header,
+ size_t pvh_xen_start_addr,
+ FWCfgState *fw_cfg)
+{
+ uint32_t flags = 0;
+ uint32_t mh_load_addr = 0;
+ uint32_t elf_kernel_size = 0;
+ uint64_t elf_entry;
+ uint64_t elf_low, elf_high;
+ int kernel_size;
+
+ if (ldl_p(header) != 0x464c457f) {
+ return false; /* no elfboot */
+ }
+
+ bool elf_is64 = header[EI_CLASS] == ELFCLASS64;
+ flags = elf_is64 ?
+ ((Elf64_Ehdr *)header)->e_flags : ((Elf32_Ehdr *)header)->e_flags;
+
+ if (flags & 0x00010004) { /* LOAD_ELF_HEADER_HAS_ADDR */
+ error_report("elfboot unsupported flags = %x", flags);
+ exit(1);
+ }
+
+ kernel_size = load_elf(kernel_filename, NULL, NULL, &elf_entry,
+ &elf_low, &elf_high, 0, I386_ELF_MACHINE,
+ 0, 0);
+
+ if (kernel_size < 0) {
+ error_report("Error while loading elf kernel");
+ exit(1);
+ }
+ mh_load_addr = elf_low;
+ elf_kernel_size = elf_high - elf_low;
+
+ fw_cfg_add_i32(fw_cfg, FW_CFG_KERNEL_ENTRY, pvh_xen_start_addr);
+ fw_cfg_add_i32(fw_cfg, FW_CFG_KERNEL_ADDR, mh_load_addr);
+ fw_cfg_add_i32(fw_cfg, FW_CFG_KERNEL_SIZE, elf_kernel_size);
+
+ return true;
+}
+
static void load_linux(PCMachineState *pcms,
FWCfgState *fw_cfg)
{
@@ -1138,6 +1183,33 @@ static void load_linux(PCMachineState *pcms,
if (ldl_p(header+0x202) == 0x53726448) {
protocol = lduw_p(header+0x206);
} else {
+ /* If the kernel address for using the x86/HVM direct boot ABI has
+ * been saved then proceed with booting the uncompressed kernel */
+ if (pvh_start_addr) {
+ if (load_elfboot(kernel_filename, kernel_size,
+ header, pvh_start_addr, fw_cfg)) {
+ struct hvm_modlist_entry ramdisk_mod = { 0 };
+
+ fclose(f);
+
+ fw_cfg_add_i32(fw_cfg, FW_CFG_CMDLINE_SIZE,
+ strlen(kernel_cmdline) + 1);
+ fw_cfg_add_string(fw_cfg, FW_CFG_CMDLINE_DATA, kernel_cmdline);
+
+ assert(machine->device_memory != NULL);
+ ramdisk_mod.paddr = machine->device_memory->base;
+ ramdisk_mod.size =
+ memory_region_size(&machine->device_memory->mr);
+
+ fw_cfg_add_bytes(fw_cfg, FW_CFG_KERNEL_DATA, &ramdisk_mod,
+ sizeof(ramdisk_mod));
+ fw_cfg_add_i32(fw_cfg, FW_CFG_SETUP_SIZE, sizeof(header));
+ fw_cfg_add_bytes(fw_cfg, FW_CFG_SETUP_DATA,
+ header, sizeof(header));
+
+ return;
+ }
+ }
/* This looks like a multiboot kernel. If it is, let's stop
treating it like a Linux kernel. */
if (load_multiboot(fw_cfg, f, kernel_filename, initrd_filename,
--
1.8.3.1