This large commit combines a number of smaller commits in order to add
64-bit VM support to the VMM. The commits do the following:

    * Load elfs of the same architecture size
    * Support reading 64-bit vaddrs from elf files
    * Create initial address space based on guest architecture
    * Allow instruction decoding of 4-level paging scheme
    * Do not exit VMX state based on CR3 load/store in 64-bit mode
    * Use seL4_Word for vmcs and user context fields
    * Handle additional general purpose registers
    * Handle 64-bit MSRs
    * Configure 64-bit guests to boot in long mode
    * Let guest know about 64-bit hardware features in 64-bit mode
    * Add FADT and DSDT tables
    * Track guest state for additional 64-bit registers
    * Add new function to print 64-bit guest context
    * Properly emulate 64-bit trampoline code
    * Define access rights macros for vmcs initialization
    * Hardcode FADT table information
    * Set an initial stack pointer before running guest
    * Handle fetching cross-page instructions
    * Add additional x86 instruction prefixes

CCDC-GVSC DISTRIBUTION A.  Approved for public release; distribution
unlimited. OPSEC#4481.

Co-authored-by: Chris Guikema <[email protected]>
Signed-off-by: Damon Lee <[email protected]>

Signed-off-by: Damon Lee <[email protected]>

As the comment in the file explains, optimisation level -O3 on gcc 8.4
is too aggressive and causes issues for the guest VM. The problem isn't
limited to a single function or group of functions but rather the entire
file for some reason that requires extra investigation (but is not worth
the time to do so).

Signed-off-by: Damon Lee <[email protected]>

Previously, the physical address of the ACPI tables were being
tracked. This caused a Linux error while parsing the ACPI tables. Since
Linux does not have access to those memory regions, they would appear
empty, causing an Invalid Table Length bug print. By tracking the
virtual address that Linux expects and placing the vaddr into the ACPI
tables, Linux can parse the tables properly.

Signed-off-by: Chris Guikema <[email protected]>