From 68e37f457881d222c68834920f4ffd6f668a2b77 Mon Sep 17 00:00:00 2001 From: Ceping Sun Date: Wed, 8 Nov 2023 19:38:25 +0800 Subject: MdePkg/BaseLib: Update TdVmcall to always output the value in R11 REF: https://bugzilla.tianocore.org/show_bug.cgi?id=4572 According to section 3.2 of the [GHCI] spec, if the return status of MapGPA is "TDG.VP.VMCALL_RETRY", TD must retry this operation for the pages in the region starting at the GPA specified in R11. Currently, TDVF has not handled the retry results and always clears the R11 on unsuccessful return status. For this, the TdVmcall needs to output the value of R11 on unsuccessful return status to handle the retry results of MapGPA. Reference: [GHCI]: TDX Guest-Host-Communication Interface v1.0 https://cdrdv2.intel.com/v1/dl/getContent/726790 Cc: Liming Gao Cc: Michael D Kinney Cc: Erdem Aktas Cc: James Bottomley Cc: Min Xu Cc: Tom Lendacky Cc: Michael Roth Acked-by: Gerd Hoffmann Reviewed-by: Jiewen Yao Reviewed-by: Liming Gao Signed-off-by: Ceping Sun --- MdePkg/Library/BaseLib/X64/TdVmcall.nasm | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-) (limited to 'MdePkg') diff --git a/MdePkg/Library/BaseLib/X64/TdVmcall.nasm b/MdePkg/Library/BaseLib/X64/TdVmcall.nasm index 5ecc10b..8dd9bfc 100644 --- a/MdePkg/Library/BaseLib/X64/TdVmcall.nasm +++ b/MdePkg/Library/BaseLib/X64/TdVmcall.nasm @@ -133,9 +133,7 @@ ASM_PFX(TdVmCall): test r9, r9 jz .no_return_data - ; On success, propagate TDVMCALL output value to output param - test rax, rax - jnz .no_return_data + ; Propagate TDVMCALL output value to output param mov [r9], r11 .no_return_data: tdcall_regs_postamble -- cgit v1.1