From c1dd400a13d1a5e862809c55f6760ba3a944a609 Mon Sep 17 00:00:00 2001 From: "Mikolaj Lisik via groups.io" Date: Thu, 26 Jan 2023 20:26:40 +0000 Subject: OvmfPkg: Create additional PML1 entries for large SEV-SNP VMs Edk2 was failing, rather than creating more PML4 entries, when they weren't present in the initial memory acceptance flow. Because of that VMs with more than 512G memory were crashing. This code fixes that. This change affects only SEV-SNP VMs. The code was tested by successfully booting a 512G SEV-SNP VM. Signed-off-by: Mikolaj Lisik Acked-by: Gerd Hoffmann Acked-by: Tom Lendacky --- .../BaseMemEncryptSevLib/X64/PeiDxeVirtualMemory.c | 27 ++++++++++++++-------- 1 file changed, 18 insertions(+), 9 deletions(-) diff --git a/OvmfPkg/Library/BaseMemEncryptSevLib/X64/PeiDxeVirtualMemory.c b/OvmfPkg/Library/BaseMemEncryptSevLib/X64/PeiDxeVirtualMemory.c index a1f6e61c1e..cf2441b551 100644 --- a/OvmfPkg/Library/BaseMemEncryptSevLib/X64/PeiDxeVirtualMemory.c +++ b/OvmfPkg/Library/BaseMemEncryptSevLib/X64/PeiDxeVirtualMemory.c @@ -548,6 +548,7 @@ InternalMemEncryptSevCreateIdentityMap1G ( PAGE_MAP_AND_DIRECTORY_POINTER *PageMapLevel4Entry; PAGE_TABLE_1G_ENTRY *PageDirectory1GEntry; UINT64 PgTableMask; + UINT64 *NewPageTable; UINT64 AddressEncMask; BOOLEAN IsWpEnabled; RETURN_STATUS Status; @@ -602,15 +603,23 @@ InternalMemEncryptSevCreateIdentityMap1G ( PageMapLevel4Entry = (VOID *)(Cr3BaseAddress & ~PgTableMask); PageMapLevel4Entry += PML4_OFFSET (PhysicalAddress); if (!PageMapLevel4Entry->Bits.Present) { - DEBUG (( - DEBUG_ERROR, - "%a:%a: bad PML4 for Physical=0x%Lx\n", - gEfiCallerBaseName, - __func__, - PhysicalAddress - )); - Status = RETURN_NO_MAPPING; - goto Done; + NewPageTable = AllocatePageTableMemory (1); + if (NewPageTable == NULL) { + DEBUG (( + DEBUG_ERROR, + "%a:%a: failed to allocate a new PML4 entry\n", + gEfiCallerBaseName, + __func__ + )); + Status = RETURN_NO_MAPPING; + goto Done; + } + + SetMem (NewPageTable, EFI_PAGE_SIZE, 0); + PageMapLevel4Entry->Uint64 = (UINT64)(UINTN)NewPageTable | AddressEncMask; + PageMapLevel4Entry->Bits.MustBeZero = 0; + PageMapLevel4Entry->Bits.ReadWrite = 1; + PageMapLevel4Entry->Bits.Present = 1; } PageDirectory1GEntry = (VOID *)( -- cgit v1.2.3