OvmfPkg: Add platform specific reset vector code for X64

KVM has a bug that prevents using page tables in the ROM if the ROM
region utilizes the KVM READONLY memory feature. Therefore, we
avoid using page tables stored in the ROM.

Since OVMF doesn't require memory initialization, we just build
page table entries in RAM at 0x80000 very early in the OVMF boot
process. This address is just after the 'temp RAM' which is set
up by the SEC module.

Currently we only set up 4GB of page tables for OVMF's PEI,
but DxeIpl will build identity mapped page tables that cover all
of the available processor physical address space.

Reported-by: Gary Ching-Pang Lin <glin@suse.com>
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Jordan Justen <jordan.l.justen@intel.com>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
Tested-by: Laszlo Ersek <lersek@redhat.com>

git-svn-id: svn://svn.code.sf.net/p/edk2/code/trunk/edk2/OvmfPkg@14715 6f19259b-4bc3-4df7-8a09-765794883524
OvmfPkg/ResetVector: enable caching in initial page tables

In UEFI X64 we use other mechanisms to disable caching.
(CD/NW in CR0 and MTRRs.)

This fixes a slow boot issue with SVM.

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Reviewed-by: Jordan Justen <jordan.l.justen@intel.com>

git-svn-id: svn://svn.code.sf.net/p/edk2/code/trunk/edk2/OvmfPkg@14716 6f19259b-4bc3-4df7-8a09-765794883524
OvmfPkg: For OvmfPkgX64, use OvmfPkg/ResetVector

This reset vector code will build page tables in RAM at address
0x80000, rather than relying on page tables to be present within
the flash image.

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Jordan Justen <jordan.l.justen@intel.com>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
Tested-by: Laszlo Ersek <lersek@redhat.com>

git-svn-id: svn://svn.code.sf.net/p/edk2/code/trunk/edk2/OvmfPkg@14717 6f19259b-4bc3-4df7-8a09-765794883524
OvmfPkg X64: Convert 24KB from uncompressed to compressed storage

Since we no longer require flash tables to be stored uncompressed
in the flash image, we can now give extra space to the main/compressed
storage area.

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Jordan Justen <jordan.l.justen@intel.com>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
Tested-by: Laszlo Ersek <lersek@redhat.com>

git-svn-id: svn://svn.code.sf.net/p/edk2/code/trunk/edk2/OvmfPkg@14718 6f19259b-4bc3-4df7-8a09-765794883524
OvmfPkg/Sec: Stop building identity mapped pages in SEC

Now for X64 we use a VTF0 ResetVector which puts the page
tables in RAM. Therefore SEC no longer needs to do this.

This reverts commit r14494.

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Jordan Justen <jordan.l.justen@intel.com>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
Tested-by: Laszlo Ersek <lersek@redhat.com>

git-svn-id: svn://svn.code.sf.net/p/edk2/code/trunk/edk2/OvmfPkg@14719 6f19259b-4bc3-4df7-8a09-765794883524
OvmfPkg: Remove IndustryStandard/X64Paging.h

Since we no longer building page tables in SEC C code, we no
longer need this file.

This reverts commit r14493.

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Jordan Justen <jordan.l.justen@intel.com>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
Tested-by: Laszlo Ersek <lersek@redhat.com>

git-svn-id: svn://svn.code.sf.net/p/edk2/code/trunk/edk2/OvmfPkg@14720 6f19259b-4bc3-4df7-8a09-765794883524
OvmfPkg: EFI handover flags are in Bp->hdr.xloadflags

LoadLinux() is looking at the wrong field for the kernel's EFI handover
protocol flags. It's not currently possible for JumpToUefiKernel() to
ever be called (even accidentally) because BIT2 and BIT3 of
Bp->hdr.load_flags are never set in modern kernels, which means that
control is always transferred to the kernel via the legacy entry point.

Look at the correct field so that the EFI handover protocol is used
whenever it's available.

Contributed-under: TianoCore Contribution Agreement 1.0
Cc: David Woodhouse <David.Woodhouse@intel.com>
Cc: Jordan Justen <jordan.l.justen@intel.com>
Cc: Borislav Petkov <bp@suse.de>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
Reviewed-by: Jordan Justen <jordan.l.justen@intel.com>

git-svn-id: svn://svn.code.sf.net/p/edk2/code/trunk/edk2/OvmfPkg@14721 6f19259b-4bc3-4df7-8a09-765794883524