OvmfPkg/Sec/X64: seed the temporary RAM with PcdInitValueInTempStack

This allows the PEI core to report the maximum temporary SEC/PEI stack
usage on the DEBUG_INFO level, in the PeiCheckAndSwitchStack() function
[MdeModulePkg/Core/Pei/Dispatcher/Dispatcher.c]:

* Normal boot:

> Temp Stack : BaseAddress=0x814000 Length=0x4000
> Temp Heap  : BaseAddress=0x810000 Length=0x4000
> Total temporary memory:    32768 bytes.
>   temporary memory stack ever used:       5080 bytes. <----
>   temporary memory heap used for HobList: 8080 bytes.
>   temporary memory heap occupied by memory pages: 0 bytes.

* S3 resume (no SMM / PEI decompression)

> Temp Stack : BaseAddress=0x814000 Length=0x4000
> Temp Heap  : BaseAddress=0x810000 Length=0x4000
> Total temporary memory:    32768 bytes.
>   temporary memory stack ever used:       5048 bytes. <----
>   temporary memory heap used for HobList: 7112 bytes.
>   temporary memory heap occupied by memory pages: 0 bytes.

I unit-tested this change by transitorily adding an infinite loop right
after the "rep stosq", and dumping the guest's temp SEC/PEI RAM (32KB
currently) while the guest was stuck in the loop. The dump includes one
dword from before and after the temp SEC/PEI RAM:

> $ virsh qemu-monitor-command GUEST_NAME --hmp 'xp /8194wx 0x80FFFC'
>
> 000000000080fffc: 0x00000000 0x5aa55aa5 0x5aa55aa5 0x5aa55aa5
> 000000000081000c: 0x5aa55aa5 0x5aa55aa5 0x5aa55aa5 0x5aa55aa5
> ...
> 0000000000817fec: 0x5aa55aa5 0x5aa55aa5 0x5aa55aa5 0x5aa55aa5
> 0000000000817ffc: 0x5aa55aa5 0x00000000

Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Jordan Justen <jordan.l.justen@intel.com>
Ref: https://bugzilla.tianocore.org/show_bug.cgi?id=747
Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Jordan Justen <jordan.l.justen@intel.com>
This commit is contained in:
Laszlo Ersek 2017-11-08 20:32:30 +01:00
parent 9d9350a579
commit 2278b8a82e
1 changed files with 21 additions and 0 deletions

View File

@ -30,12 +30,33 @@ extern ASM_PFX(SecCoreStartupWithStack)
; @param[in] RAX Initial value of the EAX register (BIST: Built-in Self Test)
; @param[in] DI 'BP': boot-strap processor, or 'AP': application processor
; @param[in] RBP Pointer to the start of the Boot Firmware Volume
; @param[in] DS Selector allowing flat access to all addresses
; @param[in] ES Selector allowing flat access to all addresses
; @param[in] FS Selector allowing flat access to all addresses
; @param[in] GS Selector allowing flat access to all addresses
; @param[in] SS Selector allowing flat access to all addresses
;
; @return None This routine does not return
;
global ASM_PFX(_ModuleEntryPoint)
ASM_PFX(_ModuleEntryPoint):
;
; Fill the temporary RAM with the initial stack value.
; The loop below will seed the heap as well, but that's harmless.
;
mov rax, (FixedPcdGet32 ( \
PcdInitValueInTempStack \
) << 32) | \
FixedPcdGet32 (PcdInitValueInTempStack) ; qword to store
mov rdi, FixedPcdGet32 (PcdOvmfSecPeiTempRamBase) ; base address,
; relative to
; ES
mov rcx, FixedPcdGet32 (PcdOvmfSecPeiTempRamSize) / 8 ; qword count
cld ; store from base
; up
rep stosq
;
; Load temporary RAM stack based on PCDs
;