On 12/21/22 10:06, Michael Roth wrote:
Currently OVMF tries to rely on the base size advertised via the CPUID
table entries corresponding to leaf 0xD, sub-leafs 0x0/0x1. This will
generally work for KVM guests, but might not for other SEV-SNP
hypervisor implementations. Make the handling more robust by simply
using the base area size documented by the APM.
Signed-off-by: Michael Roth <michael.r...@amd.com>
Reviewed-by: Tom Lendacky <thomas.lenda...@amd.com>
---
OvmfPkg/Library/CcExitLib/CcExitVcHandler.c | 9 ++++-----
1 file changed, 4 insertions(+), 5 deletions(-)
diff --git a/OvmfPkg/Library/CcExitLib/CcExitVcHandler.c
b/OvmfPkg/Library/CcExitLib/CcExitVcHandler.c
index cd117d5a31..f985dcff8d 100644
--- a/OvmfPkg/Library/CcExitLib/CcExitVcHandler.c
+++ b/OvmfPkg/Library/CcExitLib/CcExitVcHandler.c
@@ -1647,8 +1647,6 @@ SnpEnabled (
@param[in] XFeaturesEnabled Bit-mask of enabled XSAVE features/areas as
indicated by XCR0/MSR_IA32_XSS bits
- @param[in] XSaveBaseSize Base/legacy XSAVE area size (e.g. when
- XCR0 is 1)
@param[in, out] XSaveSize Pointer to storage for calculated XSAVE
area
size
@param[in] Compacted Whether or not the calculation is for the
@@ -1663,7 +1661,6 @@ STATIC
BOOLEAN
GetCpuidXSaveSize (
IN UINT64 XFeaturesEnabled,
- IN UINT32 XSaveBaseSize,
IN OUT UINT32 *XSaveSize,
IN BOOLEAN Compacted
)
@@ -1672,7 +1669,10 @@ GetCpuidXSaveSize (
UINT64 XFeaturesFound = 0;
UINT32 Idx;
- *XSaveSize = XSaveBaseSize;
+ //
+ // The base/legacy XSave size is documented to be 0x240 in the APM.
+ //
+ *XSaveSize = 0x240;
CpuidInfo = (SEV_SNP_CPUID_INFO *)(UINT64)PcdGet32 (PcdOvmfCpuidBase);
for (Idx = 0; Idx < CpuidInfo->Count; Idx++) {
@@ -1888,7 +1888,6 @@ GetCpuidFw (
if (!GetCpuidXSaveSize (
XCr0 | XssMsr.Uint64,
- *Ebx,
&XSaveSize,
Compacted
))
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