Re: [RFC PATCH 0/4] x86/boot/KASLR: Parse ACPI table and limit kaslr in immovable memory.

[Baoquan He]

On 07/03/18 at 09:32am, Chao Fan wrote:
> On Mon, Jul 02, 2018 at 08:18:55PM +0800, Baoquan He wrote:
> >Hi Chao,
> >
> >On 06/12/18 at 04:10pm, Chao Fan wrote:
> >> *** Issues need be discussed
> >> There are several issues I am not quite sure, please help review and
> >> give suggestions:
> >> 
> >> 1) In PATCH 1, I copy the structures and functions from ACPI head file,
> >>    so that ACPI head file will never been used here. I am not sure
> >>    whether it's good to include ACPI head file or use the method in
> >>    PATCH 1. If people think we can use ACPI head files directely, I
> >>    will remove the PATCH 1.
> >
> >Usaully we try to reuse code even though they are located in different
> >life space. I think it applies to this SRAT handling. Copying ACPI codes
> 
> Yes, you are right. But as you said, they are in different life space,
> so I don't have a better method to dig the SRAT table.
> If anyone have a good way or suggestion, please tell me.

I think someone has told a good way, please check
arch/x86/boot/compressed/eboot.c and see what uefi has done.

> 
> >to kernel decompressing looks messy. Is there better way to reuse ACPI
> >code and read SRAT table, then get what we need in a simple way?
> >
> >Thanks
> >Baoquan
> >> 
> >> ***Test results:
> >>  - I did a very simple test, and it can get the memory information in
> >>    bios and efi KVM guest machine, and put it by early printk. But no
> >>    more tests, so it's with RFC tag.
> >> 
> >> Any comments will be welcome.
> >> 
> >> 
> >> Chao Fan (4):
> >>   x86/boot: Add acpitb.h to help parse acpi tables
> >>   x86/boot: Add acpitb.c to parse acpi tables
> >>   x86/boot/KASLR: Walk srat tables to filter immovable memory
> >>   x86/boot/KASLR: Limit kaslr to choosing the immovable memory
> >> 
> >>  arch/x86/boot/compressed/Makefile |   1 +
> >>  arch/x86/boot/compressed/acpitb.c | 245 ++++++++++++++++++++++++++++++
> >>  arch/x86/boot/compressed/acpitb.h | 175 +++++++++++++++++++++
> >>  arch/x86/boot/compressed/kaslr.c  | 120 +++++++++++++--
> >>  4 files changed, 530 insertions(+), 11 deletions(-)
> >>  create mode 100644 arch/x86/boot/compressed/acpitb.c
> >>  create mode 100644 arch/x86/boot/compressed/acpitb.h
> >> 
> >> -- 
> >> 2.17.0
> >> 
> >> 
> >> 
> >
> >
> 
>