Setup for 32bit PV userspace execution

* Implement hypercall_update_va_mapping().
* Walk the live pagetables setting _PAGE_USER.

For now, 32bit PV XTF guests need to be run on a hypervisor booted with
"smep=0 smap=0" to prevent Xen's %cr4 settings from interfering.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>

Setup for 64bit PV userspace execution

* Implement read_cr3(), HYPERCALL4() and hypercall_mmuext_op().
* Use FLAT_RING3_SS64 for __{KERN,USER}_DS.
* Set user %cr3.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>

Setup for common PV userspace execution

* Implement and use hypercall_stack_switch().
* Implement {read,write}_[cdefgs]s() wrappers.
* Use __USER_DS for the regular data segment selectors.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>

Setup for HVM userspace execution

* Introduce definitions for a task state segment and load one.
* Use __USER_DS for the regular data segment selectors.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>

Factor low level difference between PV and HVM into macros

to reduce code duplication when further entry/exit paths are added.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>

Common infrastructure for userspace execution

Introduce __USER_{CS,DS}, expand the boot stack to two pages, add some DPL3
GDT descriptors, and space in GDT for a TSS.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>

Introduce test_setup() to detect runtime support relevant for tests

Currently it just identifies whether the Forced Emulation Prefix is available.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>

Exception Logging support

Provide an interface whereby a test can log all exceptions which occur, and
query the log after the fact.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>

Alter pv64 kernel selectors to be rpl0

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>

Exception table infrastructure

To redirect control flow if a fault occurs.  Entries are registered with the
_ASM_EXTABLE() and placed in the .ex_table section, which is collected
together by the linker.

The .ex_table section is sorted on boot (to facilitate fast searching), and
searched in do_exception() when a fault or abort is encountered.  If a
matching entry is found, control flow is redirected and the exception returned
from.

Some of the changes are to make the two asm_macros.h files safe to include in
C code.  In addition, an extra selftest is added, making use of the exception
table infrastructure.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>

Provide a heapsort() implementation

Modelled after qsort() in the C standard library.  Sorts in place.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>

Avoid __always_inline conflicting with cdef.h

Fixes build issues with the build-time selftests.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>

XTF Selftests

Provide a sanity test of the environment and infrastructure provided by the
test framework itself.  These are all expected to pass.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>

Modify entry points to be able to return from exceptions

Trap and Interrupt exceptions will now return, while Fault and Abort
exceptions are still fatal.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>

Represent exception frames in C

Introduce struct cpu_regs, and make the entry points create the expected
layout.

As part of this, split the very x86 bits of asm_macros.h into a new header
file.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>

PV exception entry points

Infrastructure to register the virtual IDT with Xen and get execution back
into C when an exception occurs.  The existing 32 and 64bit entry points are
mostly reused, with small adjustments for PV guests.

Most of this change is importing and implementing Xen ABI bits for PV guests.

Exceptions are currently fatal.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>

HVM exception entry points

Infrastructure to set up the IDT and get execution back into C when an
exception occurs.

Exceptions are currently fatal.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>

Refactor architectural trap setup

The setup of entry points is very different between PV and HVM guests.
Introduce two new traps.c to accommodate, a stub arch_init_traps(), and a stub
do_trap() as the C entry point for traps.

Adjust the single arch_crash_hard() into the relevant arch traps.c to reduce
the #ifdef'ary

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>

x86 architectural infrastructure for exception handling

Unlike the GDT which PV guests might have a legitimate interest in, a PV guest
genuinely has no interest in an x86 architectural IDT.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>

Move build system into build/

In hindsight, config/ was not the best choice of names.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>

Import and declare all hypercall entry points

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>

Reduce the quantity of token concatenation with hypercall declarations

Allows better indexing from tools such as cscope

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>

Avoid a constantly rebooting domain when triple faults occur

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>

Fix booting the HVM tests on hardware without hap support

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>

Introduce __noinline and __always_inline annotations

Additionally, switch to uniformly use of the double-underscore variants of
attribute names.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>

Pull all definitions from stddef.h, including bits like offsetof()

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>

Add to clean/distclean rules

Remove generated configuration files, and delete cscope files in any
directory.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>

Adjust linker script to avoid having a PT_LOAD header all the way from zero

Previously, the generated binaries had a single PT_LOAD header all the
way from 0 to the end of the generated code.

When building, the domain builder maps the entire region and
zeroes/copies the data as appropriate.  This causes a failure to build
when the header overlaps with unmapped addresses such as the HVM legacy
VGA range.

Link all binaries to load and run at 1MB to avoid the legacy VGA hole in
HVM guests.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>

Create hvm64 test binaries as elf32, take 2

Experimentally, gcc/binutils from Debian Jessie (4.9.2/2.25) and CentOS
7.1 (4.8.3/2.23) don't make valid binaries when linking x86-64 object
files as elf32-x86-64.

Issues include corrupt DWARF debugging information (as confirmed by
gdb/readelf), and erroneously merged strings in .rodata (as confirmed by
strings).

Instead, link all binaries in their natural width, and objcopy hvm64
binaries to elf32-x86-64 after the fact.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>

Provide memset() and memcmp()

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>

Undo previous change to link.lds.S

1MB != 0x10000, and while this shouldn't actually matter, it causes the
domain builder to choke for HVM guests.

Revert for now, until the domain builders' behaviour is understood.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>

Introduce macros for basic number manipulation

And sprinkle them through the existing code.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>

Avoid failing to build if the last directory lacks a Makefile

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>

Automatically include config.h for all per-arch translation units

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>

Create hvm64 test binaries as elf32

New improvements to the HVM domain building logic actually sanity check the
binary for being 32bit, as all HVM domains start in 32bit mode.

Previously, elf64 binaries were erroneously accepted.

In addition, drop the big/little endian bits.  x86 is unlikely to ever have a
big endian variant.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>

Expose the GDT to C code

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>

Fix per-arch .S generation rule to properly pass $AFLAGS

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>

Modify default xl cfg files to name the VM identically to the kernel used

Suggested-by: Anshul Makkar <anshul.makkar@citrix.com>
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>

Generate xl configuration files for tests

For now just the default configuration, which gets slightly customised
for each generated environment.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>

Only recurse into directories with a Makefile

Git will leave directories around by default when switching branches,
which causes unnecessary build failures.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>

Disable LTO for now

It clearly isn't wired up correctly at the moment, and causes build
issues on Debian Jessie.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>

Default CC to gcc

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>

Short summary of execution environment

Interface for test reports

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>

HVM 32 and 64bit environment

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>

HVM basic setup

 * Hypercalls
 * PV and Qemu console
 * Memory management
 * Pagetables

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>

LDT/GDT infrastructure

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>

x86 architectural MSR/CR constants and instruction wrappers

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>

Xen ABI bits for HVM guests

 - HVMOP_get_param
 - HVM PV Console parameters
 - Xen CPUID leaves

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>

Introduce and use a boot stack (one page)

HVM guests don't have one provided by the domain builder.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>

Introduce panic() and use it to cover some exceptional cases

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>

Use vsnprintf() to provide full formatting capabilities to the console

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>

Integer subset of vsnprintf(), including 64bit types in 32bit build

Also a test binary which compares this implementation to the local libc's
implementation.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>

Implement strnlen()

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>

Provide 64bit division in 32bit environments

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>

PV Console driver.  Synchronous output only

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>

Ordering primitives, suitable for a shared ring

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>

Basic memory management for PV guests, sufficient to obtain the console ring virtual address

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>

Hypercall infrastructure needed for writing to a PV console

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>

Write to the hypervisor console

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>

Basic console and printk() infrastructure

printk() can currently only deal with a plain string, and the output goes
nowhere.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>

Architecture specific setup, obtaining the PV start_info page

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>

Basic hypercall infrastructure.  Tests now shut down as opposed to spinning in a loop

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>

Basic build system and pv32/64 stubs.  They currently spin in a loop

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>

Doxygen configuration

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>

Some introductory text files

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>

Initial commit

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>