On Fri, Jul 02, 2021 at 01:48:14PM +0200, Varad Gautam wrote:

This series brings EFI support to a reduced subset of kvm-unit-tests
on x86_64. I'm sending it out for early review since it covers enough
ground to allow adding KVM testcases for EFI-only environments.

EFI support works by changing the test entrypoint to a stub entry
point for the EFI loader to jump to in long mode, where the test binary
exits EFI boot services, performs the remaining CPU bootstrapping,
and then calls the testcase main().

Since the EFI loader only understands PE objects, the first commit
introduces a `configure --efi` mode which builds each test as a shared
lib. This shared lib is repackaged into a PE via objdump.

Commit 2-4 take a trip from the asm entrypoint to C to exit EFI and
relocate ELF .dynamic contents.

Commit 5 adds post-EFI long mode x86_64 setup and calls the testcase.

Commit 6 patches out some broken tests for EFI. Testcases that refuse
to build as shared libs are also left disabled, these need some massaging.

git tree: https://github.com/varadgautam/kvm-unit-tests/commits/efi-stub

Hi Varad,

Thanks for this. I haven't reviewed it in detail yet (I just got back from
vacation), but this looks like the right approach. In fact, I had started
going down the efi stub approach for AArch64 a while back as well, but the
effort got preempted by other work [again]. I'll try to allocate time to
play with this for x86 and to build on it for AArch64 in the coming weeks.

drew

Varad Gautam (6):
  x86: Build tests as PE objects for the EFI loader
  x86: Call efi_main from _efi_pe_entry
  x86: efi_main: Get EFI memory map and exit boot services
  x86: efi_main: Self-relocate ELF .dynamic addresses
  cstart64.S: x86_64 bootstrapping after exiting EFI
  x86: Disable some breaking tests for EFI and modify vmexit test

 .gitignore          |   2 +
 Makefile            |  16 ++-
 configure           |  11 ++
 lib/linux/uefi.h    | 337 ++++++++++++++++++++++++++++++++++++++++++++
 x86/Makefile.common |  45 ++++--
 x86/Makefile.x86_64 |  43 +++---
 x86/cstart64.S      |  78 ++++++++++
 x86/efi.lds         |  67 +++++++++
 x86/efi_main.c      | 167 ++++++++++++++++++++++
 x86/vmexit.c        |   7 +
 10 files changed, 741 insertions(+), 32 deletions(-)
 create mode 100644 lib/linux/uefi.h
 create mode 100644 x86/efi.lds
 create mode 100644 x86/efi_main.c

-- 
2.30.2

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