diff options
| author | Tom Lendacky <thomas.lendacky@amd.com> | 2020-08-12 15:21:36 -0500 |
|---|---|---|
| committer | mergify[bot] <37929162+mergify[bot]@users.noreply.github.com> | 2020-08-17 02:46:39 +0000 |
| commit | 5277540e37e88a1a69f9517c4ad895051b4b3ed3 (patch) | |
| tree | 2395bf622ff3af9ca7c5fa92c5d570e2c1eda63f /UefiCpuPkg/Library/CpuExceptionHandlerLib/X64 | |
| parent | 3a4a6ead323feb6f021c0daf93a974464a9eeeec (diff) | |
| download | edk2-5277540e37e88a1a69f9517c4ad895051b4b3ed3.tar.gz edk2-5277540e37e88a1a69f9517c4ad895051b4b3ed3.tar.bz2 edk2-5277540e37e88a1a69f9517c4ad895051b4b3ed3.zip | |
UefiCpuPkg/CpuExceptionHandler: Add base support for the #VC exception
BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=2198
Add base support to handle #VC exceptions. Update the common exception
handlers to invoke the VmgExitHandleVc () function of the VmgExitLib
library when a #VC is encountered. A non-zero return code will propagate
to the targeted exception handler.
Under SEV-ES, a DR7 read or write intercept generates a #VC exception.
To avoid exception recursion, a #VC exception will not try to read and
push the actual debug registers into the EFI_SYSTEM_CONTEXT_X64 struct
and instead push zeroes. The #VC exception handler does not make use of
the debug registers from the saved context and the exception processing
exit code does not attempt to restore the debug register values.
Cc: Eric Dong <eric.dong@intel.com>
Cc: Ray Ni <ray.ni@intel.com>
Cc: Laszlo Ersek <lersek@redhat.com>
Reviewed-by: Eric Dong <eric.dong@intel.com>
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Regression-tested-by: Laszlo Ersek <lersek@redhat.com>
Diffstat (limited to 'UefiCpuPkg/Library/CpuExceptionHandlerLib/X64')
| -rw-r--r-- | UefiCpuPkg/Library/CpuExceptionHandlerLib/X64/ExceptionHandlerAsm.nasm | 17 | ||||
| -rw-r--r-- | UefiCpuPkg/Library/CpuExceptionHandlerLib/X64/Xcode5ExceptionHandlerAsm.nasm | 17 |
2 files changed, 34 insertions, 0 deletions
diff --git a/UefiCpuPkg/Library/CpuExceptionHandlerLib/X64/ExceptionHandlerAsm.nasm b/UefiCpuPkg/Library/CpuExceptionHandlerLib/X64/ExceptionHandlerAsm.nasm index 3814f9de37..2a5545ecfd 100644 --- a/UefiCpuPkg/Library/CpuExceptionHandlerLib/X64/ExceptionHandlerAsm.nasm +++ b/UefiCpuPkg/Library/CpuExceptionHandlerLib/X64/ExceptionHandlerAsm.nasm @@ -18,6 +18,8 @@ ; CommonExceptionHandler()
;
+%define VC_EXCEPTION 29
+
extern ASM_PFX(mErrorCodeFlag) ; Error code flags for exceptions
extern ASM_PFX(mDoFarReturnFlag) ; Do far return flag
extern ASM_PFX(CommonExceptionHandler)
@@ -224,6 +226,9 @@ HasErrorCode: push rax
;; UINT64 Dr0, Dr1, Dr2, Dr3, Dr6, Dr7;
+ cmp qword [rbp + 8], VC_EXCEPTION
+ je VcDebugRegs ; For SEV-ES (#VC) Debug registers ignored
+
mov rax, dr7
push rax
mov rax, dr6
@@ -236,7 +241,19 @@ HasErrorCode: push rax
mov rax, dr0
push rax
+ jmp DrFinish
+
+VcDebugRegs:
+;; UINT64 Dr0, Dr1, Dr2, Dr3, Dr6, Dr7 are skipped for #VC to avoid exception recursion
+ xor rax, rax
+ push rax
+ push rax
+ push rax
+ push rax
+ push rax
+ push rax
+DrFinish:
;; FX_SAVE_STATE_X64 FxSaveState;
sub rsp, 512
mov rdi, rsp
diff --git a/UefiCpuPkg/Library/CpuExceptionHandlerLib/X64/Xcode5ExceptionHandlerAsm.nasm b/UefiCpuPkg/Library/CpuExceptionHandlerLib/X64/Xcode5ExceptionHandlerAsm.nasm index 19198f2731..26cae56cc5 100644 --- a/UefiCpuPkg/Library/CpuExceptionHandlerLib/X64/Xcode5ExceptionHandlerAsm.nasm +++ b/UefiCpuPkg/Library/CpuExceptionHandlerLib/X64/Xcode5ExceptionHandlerAsm.nasm @@ -18,6 +18,8 @@ ; CommonExceptionHandler()
;
+%define VC_EXCEPTION 29
+
extern ASM_PFX(mErrorCodeFlag) ; Error code flags for exceptions
extern ASM_PFX(mDoFarReturnFlag) ; Do far return flag
extern ASM_PFX(CommonExceptionHandler)
@@ -225,6 +227,9 @@ HasErrorCode: push rax
;; UINT64 Dr0, Dr1, Dr2, Dr3, Dr6, Dr7;
+ cmp qword [rbp + 8], VC_EXCEPTION
+ je VcDebugRegs ; For SEV-ES (#VC) Debug registers ignored
+
mov rax, dr7
push rax
mov rax, dr6
@@ -237,7 +242,19 @@ HasErrorCode: push rax
mov rax, dr0
push rax
+ jmp DrFinish
+
+VcDebugRegs:
+;; UINT64 Dr0, Dr1, Dr2, Dr3, Dr6, Dr7 are skipped for #VC to avoid exception recursion
+ xor rax, rax
+ push rax
+ push rax
+ push rax
+ push rax
+ push rax
+ push rax
+DrFinish:
;; FX_SAVE_STATE_X64 FxSaveState;
sub rsp, 512
mov rdi, rsp
|