BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=4654
The RMPADJUST instruction is used to change 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 change the VMSA attribute on a page instead of issuing the
RMPADJUST instruction directly.
Implement the CcExitSnpVmsaRmpAdjust() API to perform the appropriate
operation to change the VMSA attribute based on the presence of an SVSM.
Signed-off-by: Tom Lendacky <thomas.lenda...@amd.com>
---
UefiCpuPkg/Library/MpInitLib/MpLib.h | 14 ------
UefiCpuPkg/Library/MpInitLib/Ia32/AmdSev.c | 20 --------
UefiCpuPkg/Library/MpInitLib/X64/AmdSev.c | 53 +++-----------------
3 files changed, 6 insertions(+), 81 deletions(-)
diff --git a/UefiCpuPkg/Library/MpInitLib/MpLib.h
b/UefiCpuPkg/Library/MpInitLib/MpLib.h
index a96a6389c17d..6e2137cb17cd 100644
--- a/UefiCpuPkg/Library/MpInitLib/MpLib.h
+++ b/UefiCpuPkg/Library/MpInitLib/MpLib.h
@@ -870,20 +870,6 @@ FillExchangeInfoDataSevEs (
IN volatile MP_CPU_EXCHANGE_INFO *ExchangeInfo
);
-/**
- Issue RMPADJUST to adjust the VMSA attribute of an SEV-SNP page.
-
- @param[in] PageAddress
- @param[in] VmsaPage
-
- @return RMPADJUST return value
-**/
-UINT32
-SevSnpRmpAdjust (
- IN EFI_PHYSICAL_ADDRESS PageAddress,
- IN BOOLEAN VmsaPage
- );
-
/**
Create an SEV-SNP AP save area (VMSA) for use in running the vCPU.
diff --git a/UefiCpuPkg/Library/MpInitLib/Ia32/AmdSev.c
b/UefiCpuPkg/Library/MpInitLib/Ia32/AmdSev.c
index c83144285b68..a2b8a5b3f516 100644
--- a/UefiCpuPkg/Library/MpInitLib/Ia32/AmdSev.c
+++ b/UefiCpuPkg/Library/MpInitLib/Ia32/AmdSev.c
@@ -48,23 +48,3 @@ SevSnpCreateAP (
//
ASSERT (FALSE);
}
-
-/**
- Issue RMPADJUST to adjust the VMSA attribute of an SEV-SNP page.
-
- @param[in] PageAddress
- @param[in] VmsaPage
-
- @return RMPADJUST return value
-**/
-UINT32
-SevSnpRmpAdjust (
- IN EFI_PHYSICAL_ADDRESS PageAddress,
- IN BOOLEAN VmsaPage
- )
-{
- //
- // RMPADJUST is not supported in 32-bit mode
- //
- return RETURN_UNSUPPORTED;
-}
diff --git a/UefiCpuPkg/Library/MpInitLib/X64/AmdSev.c
b/UefiCpuPkg/Library/MpInitLib/X64/AmdSev.c
index c9f0984f41a2..db9a37fbbd19 100644
--- a/UefiCpuPkg/Library/MpInitLib/X64/AmdSev.c
+++ b/UefiCpuPkg/Library/MpInitLib/X64/AmdSev.c
@@ -38,20 +38,15 @@ SevSnpPerformApAction (
BOOLEAN InterruptState;
UINT64 ExitInfo1;
UINT64 ExitInfo2;
- UINT32 RmpAdjustStatus;
UINT64 VmgExitStatus;
+ EFI_STATUS VmsaStatus;
if (Action == SVM_VMGEXIT_SNP_AP_CREATE) {
//
- // To turn the page into a recognized VMSA page, issue RMPADJUST:
- // Target VMPL but numerically higher than current VMPL
- // Target PermissionMask is not used
+ // Turn the page into a recognized VMSA page.
//
- RmpAdjustStatus = SevSnpRmpAdjust (
- (EFI_PHYSICAL_ADDRESS)(UINTN)SaveArea,
- TRUE
- );
- if (RmpAdjustStatus != 0) {
+ VmsaStatus = CcExitSnpVmsaRmpAdjust (SaveArea, ApicId, TRUE);
+ if (EFI_ERROR (VmsaStatus)) {
DEBUG ((DEBUG_INFO, "SEV-SNP: RMPADJUST failed for VMSA creation\n"));
ASSERT (FALSE);
@@ -94,11 +89,8 @@ SevSnpPerformApAction (
// Make the current VMSA not runnable and accessible to be
// reprogrammed.
//
- RmpAdjustStatus = SevSnpRmpAdjust (
- (EFI_PHYSICAL_ADDRESS)(UINTN)SaveArea,
- FALSE
- );
- if (RmpAdjustStatus != 0) {
+ VmsaStatus = CcExitSnpVmsaRmpAdjust (SaveArea, ApicId, FALSE);
+ if (EFI_ERROR (VmsaStatus)) {
DEBUG ((DEBUG_INFO, "SEV-SNP: RMPADJUST failed for VMSA reset\n"));
ASSERT (FALSE);
@@ -292,36 +284,3 @@ SevSnpCreateAP (
SevSnpCreateSaveArea (CpuMpData, CpuData, ApicId);
}
}
-
-/**
- Issue RMPADJUST to adjust the VMSA attribute of an SEV-SNP page.
-
- @param[in] PageAddress
- @param[in] VmsaPage
-
- @return RMPADJUST return value
-**/
-UINT32
-SevSnpRmpAdjust (
- IN EFI_PHYSICAL_ADDRESS PageAddress,
- IN BOOLEAN VmsaPage
- )
-{
- UINT64 Rdx;
-
- //
- // 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 (VmsaPage) {
- Rdx |= RMPADJUST_VMSA_PAGE_BIT;
- }
-
- return AsmRmpAdjust ((UINT64)PageAddress, 0, Rdx);
-}
--
2.42.0
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