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UefiCpuPkg/CpuExceptionHandler: Add base support for the #VC exception

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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>
This commit is contained in:
Tom Lendacky
2020-08-12 15:21:36 -05:00
committed by mergify[bot]
parent 3a4a6ead32
commit 5277540e37
10 changed files with 86 additions and 2 deletions
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10
UefiCpuPkg/Library/CpuExceptionHandlerLib/CpuExceptionCommon.c
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@ -14,7 +14,7 @@
//
// 1 means an error code will be pushed, otherwise 0
//
CONST UINT32 mErrorCodeFlag = 0x00227d00;
CONST UINT32 mErrorCodeFlag = 0x20227d00;
//
// Define the maximum message length
@ -45,6 +45,14 @@ CONST CHAR8 *mExceptionNameStr[] = {
"#XM - SIMD floating-point",
"#VE - Virtualization",
"#CP - Control Protection"
"Reserved",
"Reserved",
"Reserved",
"Reserved",
"Reserved",
"Reserved",
"Reserved",
"#VC - VMM Communication",
};
#define EXCEPTION_KNOWN_NAME_NUM (sizeof (mExceptionNameStr) / sizeof (CHAR8 *))