arm64: Add arm64 SVE tests

[andrew]

Summary

Add the tests/sys/arch directory for architecture-specific tests and
use it to add arm64 SVE tests. These test the kernel is managing the
SVE state in a way we expect.

These tests require SVE hardware support to run so will skip when they
can't detect it.

Sponsored by: Arm Ltd

[imp]

So would you also need a getcontext/setcontext test with SVE state changing in between test too?

[andrew]

Needs an update to the appropriate mtree file

[andrew]

• Add an mtree entry
• Check the headder type
• Use a brk instruction to stop execution as a syscall may drop the SVE context

[markj]

tests/sys/Makefile

7

Can we use the same layout as the kernel sources? i.e., no arch/ and aarch64->arm64. All else being equal, having the same layout makes tests a bit easier to find.

tests/sys/arch/Makefile

2

Extra newline.

[andrew]

tests/sys/Makefile

7

I put them in arch so we don't need to list all the architectures in the mtree file

[markj]

tests/sys/Makefile

7

I don't follow. The mtree update in this patch is incomplete, it's missing the aarch64 entry under arch. You have to list them either way, as, e.g., BSD.usr.dist does for user man pages. But this patch only needs to add an arm64 entry.

[andrew]

tests/sys/Makefile

7

The tests are installed into /usr/tests/sys/arch

[andrew]

Remove extra lines at the start of Makefiles