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 <[email protected]> Cc: Jordan Justen <[email protected]> Ref: https://bugzilla.tianocore.org/show_bug.cgi?id=747 Contributed-under: TianoCore Contribution Agreement 1.1 Signed-off-by: Laszlo Ersek <[email protected]> --- Notes: v2: - update comment on ES [Jordan] - document the other segment registers too [Jordan] - move seeding to top of routine, for consistency with the IA32 version - replace runtime right shift with compile-time division [Jordan] - compose qword-to-write at compile-time, not at runtime - drop Ard's Reviewed-by OvmfPkg/Sec/X64/SecEntry.nasm | 21 ++++++++++++++++++++ 1 file changed, 21 insertions(+) diff --git a/OvmfPkg/Sec/X64/SecEntry.nasm b/OvmfPkg/Sec/X64/SecEntry.nasm index f40427aa8e04..7c55032ac962 100644 --- a/OvmfPkg/Sec/X64/SecEntry.nasm +++ b/OvmfPkg/Sec/X64/SecEntry.nasm @@ -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 ; -- 2.14.1.3.gb7cf6e02401b _______________________________________________ edk2-devel mailing list [email protected] https://lists.01.org/mailman/listinfo/edk2-devel
