Re: [kvm-unit-tests PATCH 0/6] Initial x86_64 UEFI support

[Andrew Jones <drjones@redhat.com>]

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
>