We should not hardcode the VM ramdisk load address right after kernel
load address because of two reasons:
1. Per Linux kernel boot protocol, the Kernel need a size of
contiguous memory(i.e. init_size field in zeropage) from
its load address to boot, then the address would overlap
with ramdisk;
2. The hardcoded address could not be ensured as a valid address
in guest e820 table, especially with a huge ramdisk;
Also we should not hardcode the VM kernel load address to its pref_address
which work for non-relocatable kernel only. For a relocatable kernel,
it could run from any valid address where bootloader load to.
The patch will set the VM kernel and ramdisk load address by scanning
guest e820 table with find_space_from_ve820() api:
1. For SOS VM, the ramdisk has been loaded by multiboot bootloader
already so set the load address as module source address,
the relocatable kernel would be relocated to a appropriate address
out space of hypervisor and boot modules to avoid guest memory
copy corruption;
2. For pre-launched VM, the kernel would be loaded to pref_address
first, then ramdisk will be put to a appropriate address out space
of kernel according to guest memory layout and maximum ramdisk
address limit under 4GB;
Tracked-On: #5879
Signed-off-by: Victor Sun <victor.sun@intel.com>
Reviewed-by: Jason Chen CJ <jason.cj.chen@intel.com>