BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=4654
The RMPADJUST instruction is used to alter the VMSA attribute of a page,
but the VMSA attribute can only be changed when running at VMPL0. When
an SVSM is present, use the SVSM_CORE_CREATE_VCPU and SVSM_CORE_DELTE_VCPU
calls to add or remove the VMSA attribute on a page instead of issuing
the RMPADJUST instruction directly.
Implement the CcExitSnpVmsaRmpAdjust() API to perform the proper operation
to update the VMSA attribute.
Signed-off-by: Tom Lendacky <thomas.lenda...@amd.com>
---
OvmfPkg/Library/CcExitLib/CcExitSvsm.c | 100 +++++++++++++++++++-
1 file changed, 99 insertions(+), 1 deletion(-)
diff --git a/OvmfPkg/Library/CcExitLib/CcExitSvsm.c
b/OvmfPkg/Library/CcExitLib/CcExitSvsm.c
index 43e0a357efa5..3459338b2033 100644
--- a/OvmfPkg/Library/CcExitLib/CcExitSvsm.c
+++ b/OvmfPkg/Library/CcExitLib/CcExitSvsm.c
@@ -137,6 +137,103 @@ SvsmMsrProtocol (
return Ret;
}
+/**
+ Perform an RMPADJUST operation to alter the VMSA setting of a page.
+
+ Add or remove the VMSA attribute for a page.
+
+ @param[in] Vmsa Pointer to an SEV-ES save area page
+ @param[in] ApicId APIC ID associated with the VMSA
+ @param[in] SetVmsa Boolean indicator as to whether to set or
+ or clear the VMSA setting for the page
+
+ @retval EFI_SUCCESS RMPADJUST operation successful
+ @retval EFI_UNSUPPORTED Operation is not supported
+ @retval EFI_INVALID_PARAMETER RMPADJUST operation failed, an invalid
+ parameter was supplied
+
+**/
+EFI_STATUS
+EFIAPI
+SvsmVmsaRmpAdjust (
+ IN SEV_ES_SAVE_AREA *Vmsa,
+ IN UINT32 ApicId,
+ IN BOOLEAN SetVmsa
+ )
+{
+ SVSM_CALL_DATA SvsmCallData;
+ SVSM_FUNCTION Function;
+ UINTN Ret;
+
+ SvsmCallData.Caa = SvsmGetCaa ();
+
+ Function.Id.Protocol = 0;
+
+ if (SetVmsa) {
+ Function.Id.CallId = 2;
+
+ SvsmCallData.RaxIn = Function.Uint64;
+ SvsmCallData.RcxIn = (UINT64)(UINTN)Vmsa;
+ SvsmCallData.RdxIn = (UINT64)(UINTN)Vmsa + SIZE_4KB;
+ SvsmCallData.R8In = ApicId;
+ } else {
+ Function.Id.CallId = 3;
+
+ SvsmCallData.RaxIn = Function.Uint64;
+ SvsmCallData.RcxIn = (UINT64)(UINTN)Vmsa;
+ }
+
+ Ret = SvsmMsrProtocol (&SvsmCallData);
+
+ return (Ret == 0) ? EFI_SUCCESS : EFI_INVALID_PARAMETER;
+}
+
+/**
+ Perform an RMPADJUST operation to alter the VMSA setting of a page.
+
+ Add or remove the VMSA attribute for a page.
+
+ @param[in] Vmsa Pointer to an SEV-ES save area page
+ @param[in] ApicId APIC ID associated with the VMSA
+ @param[in] SetVmsa Boolean indicator as to whether to set or
+ or clear the VMSA setting for the page
+
+ @retval EFI_SUCCESS RMPADJUST operation successful
+ @retval EFI_UNSUPPORTED Operation is not supported
+ @retval EFI_INVALID_PARAMETER RMPADJUST operation failed, an invalid
+ parameter was supplied
+
+**/
+EFI_STATUS
+EFIAPI
+BaseVmsaRmpAdjust (
+ IN SEV_ES_SAVE_AREA *Vmsa,
+ IN UINT32 ApicId,
+ IN BOOLEAN SetVmsa
+ )
+{
+ UINT64 Rdx;
+ UINT32 Ret;
+
+ //
+ // The RMPADJUST instruction is used to set or clear the VMSA bit for a
+ // page. The VMSA change is only made when running at VMPL0 and is ignored
+ // otherwise. If too low a target VMPL is specified, the instruction can
+ // succeed without changing the VMSA bit when not running at VMPL0. Using a
+ // target VMPL level of 1, RMPADJUST will return a FAIL_PERMISSION error if
+ // not running at VMPL0, thus ensuring that the VMSA bit is set appropriately
+ // when no error is returned.
+ //
+ Rdx = 1;
+ if (SetVmsa) {
+ Rdx |= RMPADJUST_VMSA_PAGE_BIT;
+ }
+
+ Ret = AsmRmpAdjust ((UINT64)(UINTN)Vmsa, 0, Rdx);
+
+ return (Ret == 0) ? EFI_SUCCESS : EFI_INVALID_PARAMETER;
+}
+
/**
Issue an SVSM request to perform the PVALIDATE instruction.
@@ -409,5 +506,6 @@ CcExitSnpVmsaRmpAdjust (
IN BOOLEAN SetVmsa
)
{
- return EFI_UNSUPPORTED;
+ return CcExitSnpSvsmPresent () ? SvsmVmsaRmpAdjust (Vmsa, ApicId, SetVmsa)
+ : BaseVmsaRmpAdjust (Vmsa, ApicId, SetVmsa);
}
--
2.42.0
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