[edk2-devel] [PATCH v8 0/2] UefiCpuPkg/PiSmmCpuDxeSmm: Reflect page table depth with page table address

[Laszlo Ersek]

On 11/16/20 04:18, Sheng Wei wrote:
> When trying to get page table base, if mInternalCr3 is zero, it will use
>  the page table from CR3, and reflect the page table depth by CR4 LA57 bit.
> If mInternalCr3 is non zero, it will use the page table from mInternalCr3
>  and reflect the page table depth of mInternalCr3 at same time.
> In the case of X64, we use m5LevelPagingNeeded to reflect the depth of
>  the page table. And in the case of IA32, it will not the page table depth
>  information.
> 
> This patch is a bug fix when enable CET feature with 5 level paging.
> The SMM page tables are allocated / initialized in PiCpuSmmEntry().
> When CET is enabled, PiCpuSmmEntry() must further modify the attribute of
>  shadow stack pages. This page table is not set to CR3 in PiCpuSmmEntry().
>  So the page table base address is set to mInternalCr3 for modifty the
>  page table attribute. It could not use CR4 LA57 bit to reflect the
>  page table depth for mInternalCr3.
> So we create a architecture-specific implementation GetPageTable() with
>  2 output parameters. One parameter is used to output the page table
>  address. Another parameter is used to reflect if it is 5 level paging
>  or not.
> 
> Correct the Cr3 typo
> 
> REF: https://bugzilla.tianocore.org/show_bug.cgi?id=3015
> 
> Signed-off-by: Sheng Wei <w.sheng at intel.com>
> Cc: Eric Dong <eric.dong at intel.com>
> Cc: Ray Ni <ray.ni at intel.com>
> Cc: Laszlo Ersek <lersek at redhat.com>
> Cc: Rahul Kumar <rahul1.kumar at intel.com>
> Cc: Jiewen Yao <jiewen.yao at intel.com>
> 
> Sheng Wei (2):
>   UefiCpuPkg/PiSmmCpuDxeSmm: Correct the Cr3 typo
>   UefiCpuPkg/PiSmmCpuDxeSmm: Reflect page table depth with page table
>     address
> 
>  UefiCpuPkg/PiSmmCpuDxeSmm/Ia32/PageTbl.c           | 26 ++++++++++++-
>  UefiCpuPkg/PiSmmCpuDxeSmm/PiSmmCpuDxeSmm.h         | 13 ++++---
>  UefiCpuPkg/PiSmmCpuDxeSmm/SmmCpuMemoryManagement.c | 35 +++++-------------
>  UefiCpuPkg/PiSmmCpuDxeSmm/X64/PageTbl.c            | 43 ++++++++++++++++++----
>  4 files changed, 77 insertions(+), 40 deletions(-)
> 

series
Reviewed-by: Laszlo Ersek <lersek at redhat.com>

The 2nd patch needs an ACK from Eric or Ray; then we can merge this series.

(It is a bugfix so it can go in even during the hard feature freeze. But
we should merge it as soon as we can.)

Thanks,
Laszlo



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