Re: [PATCH v9 0/7] Basic recovery for machine checks inside SGX

[Jarkko Sakkinen <jarkko@kernel.org>]

On Mon, 2021-10-11 at 11:59 -0700, Tony Luck wrote:
> Posting latest version to a slightly wider audience.
> 
> The big picture is that SGX uses some memory pages that are walled off
> from access by the OS. This means they:
> 1) Don't have "struct page" describing them
> 2) Don't appear in the kernel 1:1 map
> 
> But they are still backed by normal DDR memory, so errors can occur.
> 
> Parts 1-4 of this series handle the internal SGX bits to keep track of
> these pages in an error context. They've had a fair amount of review
> on the linux-sgx list (but if any of the 37 subscribers to that list
> not named Jarkko or Reinette want to chime in with extra comments and
> {Acked,Reviewed,Tested}-by that would be great).
> 
> Linux-mm reviewers can (if they like) skip to part 5 where two changes are
> made: 1) Hook into memory_failure() in the same spot as device mapping 2)
> Skip trying to change 1:1 map (since SGX pages aren't there).
> 
> The hooks have generic looking names rather than specifically saying
> "sgx" at the suggestion of Dave Hansen. I'm not wedded to the names,
> so better suggestions welcome.  I could also change to using some
> "ARCH_HAS_PLATFORM_PAGES" config bits if that's the current fashion.
> 
> Rafael (and other ACPI list readers) can skip to parts 6 & 7 where there
> are hooks into error injection and reporting to simply say "these odd
> looking physical addresses are actually ok to use). I added some extra
> notes to the einj.rst documentation on how to inject into SGX memory.
> 
> Tony Luck (7):
>   x86/sgx: Add new sgx_epc_page flag bit to mark in-use pages
>   x86/sgx: Add infrastructure to identify SGX EPC pages
>   x86/sgx: Initial poison handling for dirty and free pages
>   x86/sgx: Add SGX infrastructure to recover from poison
>   x86/sgx: Hook arch_memory_failure() into mainline code
>   x86/sgx: Add hook to error injection address validation
>   x86/sgx: Add check for SGX pages to ghes_do_memory_failure()
> 
>  .../firmware-guide/acpi/apei/einj.rst         |  19 ++++
>  arch/x86/include/asm/processor.h              |   8 ++
>  arch/x86/include/asm/set_memory.h             |   4 +
>  arch/x86/kernel/cpu/sgx/main.c                | 104 +++++++++++++++++-
>  arch/x86/kernel/cpu/sgx/sgx.h                 |   6 +-
>  drivers/acpi/apei/einj.c                      |   3 +-
>  drivers/acpi/apei/ghes.c                      |   2 +-
>  include/linux/mm.h                            |  14 +++
>  mm/memory-failure.c                           |  19 +++-
>  9 files changed, 168 insertions(+), 11 deletions(-)
> 
> 
> base-commit: 64570fbc14f8d7cb3fe3995f20e26bc25ce4b2cc

I think you instructed me on this before but I've forgot it:
how do I simulate this and test how it works?

/Jarkko