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From: "Lendacky, Thomas" <thomas.lendacky@amd.com>
To: devel@edk2.groups.io
Cc: Brijesh Singh <brijesh.singh@amd.com>,
	Ard Biesheuvel <ard.biesheuvel@arm.com>,
	Eric Dong <eric.dong@intel.com>,
	Jordan Justen <jordan.l.justen@intel.com>,
	Laszlo Ersek <lersek@redhat.com>,
	Liming Gao <liming.gao@intel.com>,
	Michael D Kinney <michael.d.kinney@intel.com>,
	Ray Ni <ray.ni@intel.com>
Subject: [PATCH v11 29/46] OvmfPkg: Create a GHCB page for use during Sec phase
Date: Tue, 21 Jul 2020 16:19:06 -0500	[thread overview]
Message-ID: <5076b2a43303c175d80794e3305393c3f0fa5228.1595366363.git.thomas.lendacky@amd.com> (raw)
In-Reply-To: <cover.1595366363.git.thomas.lendacky@amd.com>

From: Tom Lendacky <thomas.lendacky@amd.com>

BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=2198

A GHCB page is needed during the Sec phase, so this new page must be
created. Since the #VC exception handler routines assume that a per-CPU
variable area is immediately after the GHCB, this per-CPU variable area
must also be created. Since the GHCB must be marked as an un-encrypted,
or shared, page, an additional pagetable page is required to break down
the 2MB region where the GHCB page lives into 4K pagetable entries.

Create a new entry in the OVMF memory layout for the new page table
page and for the SEC GHCB and per-CPU variable pages. After breaking down
the 2MB page, update the GHCB page table entry to remove the encryption
mask.

The GHCB page will be used by the SEC #VC exception handler. The #VC
exception handler will fill in the necessary fields of the GHCB and exit
to the hypervisor using the VMGEXIT instruction. The hypervisor then
accesses the GHCB in order to perform the requested function.

Four new fixed PCDs are needed to support the SEC GHCB page:
  - PcdOvmfSecGhcbBase  UINT32 value that is the base address of the
                        GHCB used during the SEC phase.
  - PcdOvmfSecGhcbSize  UINT32 value that is the size, in bytes, of the
                        GHCB area used during the SEC phase.

  - PcdOvmfSecGhcbPageTableBase  UINT32 value that is address of a page
                        table page used to break down the 2MB page into
                        512 4K pages.
  - PcdOvmfSecGhcbPageTableSize  UINT32 value that is the size, in bytes,
                        of the page table page.

Cc: Jordan Justen <jordan.l.justen@intel.com>
Cc: Laszlo Ersek <lersek@redhat.com>
Cc: Ard Biesheuvel <ard.biesheuvel@arm.com>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
---
 OvmfPkg/OvmfPkg.dec                       |  9 +++
 OvmfPkg/OvmfPkgX64.fdf                    |  6 ++
 OvmfPkg/ResetVector/ResetVector.inf       |  5 ++
 OvmfPkg/ResetVector/Ia32/PageTables64.asm | 76 +++++++++++++++++++++++
 OvmfPkg/ResetVector/ResetVector.nasmb     | 17 +++++
 5 files changed, 113 insertions(+)

diff --git a/OvmfPkg/OvmfPkg.dec b/OvmfPkg/OvmfPkg.dec
index f16c00ad5b99..74d88f61617c 100644
--- a/OvmfPkg/OvmfPkg.dec
+++ b/OvmfPkg/OvmfPkg.dec
@@ -289,6 +289,15 @@ [PcdsFixedAtBuild]
   ## Number of page frames to use for storing grant table entries.
   gUefiOvmfPkgTokenSpaceGuid.PcdXenGrantFrames|4|UINT32|0x33
 
+  ## Specify the extra page table needed to mark the GHCB as unencrypted.
+  #  The value should be a multiple of 4KB for each.
+  gUefiOvmfPkgTokenSpaceGuid.PcdOvmfSecGhcbPageTableBase|0x0|UINT32|0x3e
+  gUefiOvmfPkgTokenSpaceGuid.PcdOvmfSecGhcbPageTableSize|0x0|UINT32|0x3f
+
+  ## The base address of the SEC GHCB page used by SEV-ES.
+  gUefiOvmfPkgTokenSpaceGuid.PcdOvmfSecGhcbBase|0|UINT32|0x40
+  gUefiOvmfPkgTokenSpaceGuid.PcdOvmfSecGhcbSize|0|UINT32|0x41
+
 [PcdsDynamic, PcdsDynamicEx]
   gUefiOvmfPkgTokenSpaceGuid.PcdEmuVariableEvent|0|UINT64|2
   gUefiOvmfPkgTokenSpaceGuid.PcdOvmfFlashVariablesEnable|FALSE|BOOLEAN|0x10
diff --git a/OvmfPkg/OvmfPkgX64.fdf b/OvmfPkg/OvmfPkgX64.fdf
index 83ff6aef2e8c..edb03b5464d4 100644
--- a/OvmfPkg/OvmfPkgX64.fdf
+++ b/OvmfPkg/OvmfPkgX64.fdf
@@ -76,6 +76,12 @@ [FD.MEMFD]
 0x007000|0x001000
 gEfiMdePkgTokenSpaceGuid.PcdGuidedExtractHandlerTableAddress|gUefiOvmfPkgTokenSpaceGuid.PcdGuidedExtractHandlerTableSize
 
+0x008000|0x001000
+gUefiOvmfPkgTokenSpaceGuid.PcdOvmfSecGhcbPageTableBase|gUefiOvmfPkgTokenSpaceGuid.PcdOvmfSecGhcbPageTableSize
+
+0x009000|0x002000
+gUefiOvmfPkgTokenSpaceGuid.PcdOvmfSecGhcbBase|gUefiOvmfPkgTokenSpaceGuid.PcdOvmfSecGhcbSize
+
 0x010000|0x010000
 gUefiOvmfPkgTokenSpaceGuid.PcdOvmfSecPeiTempRamBase|gUefiOvmfPkgTokenSpaceGuid.PcdOvmfSecPeiTempRamSize
 
diff --git a/OvmfPkg/ResetVector/ResetVector.inf b/OvmfPkg/ResetVector/ResetVector.inf
index b0ddfa5832a2..483fd90fe785 100644
--- a/OvmfPkg/ResetVector/ResetVector.inf
+++ b/OvmfPkg/ResetVector/ResetVector.inf
@@ -26,6 +26,7 @@ [Sources]
 [Packages]
   OvmfPkg/OvmfPkg.dec
   MdePkg/MdePkg.dec
+  MdeModulePkg/MdeModulePkg.dec
   UefiCpuPkg/UefiCpuPkg.dec
 
 [BuildOptions]
@@ -33,5 +34,9 @@ [BuildOptions]
    *_*_X64_NASMB_FLAGS = -I$(WORKSPACE)/UefiCpuPkg/ResetVector/Vtf0/
 
 [Pcd]
+  gUefiOvmfPkgTokenSpaceGuid.PcdOvmfSecGhcbBase
+  gUefiOvmfPkgTokenSpaceGuid.PcdOvmfSecGhcbSize
+  gUefiOvmfPkgTokenSpaceGuid.PcdOvmfSecGhcbPageTableBase
+  gUefiOvmfPkgTokenSpaceGuid.PcdOvmfSecGhcbPageTableSize
   gUefiOvmfPkgTokenSpaceGuid.PcdOvmfSecPageTablesBase
   gUefiOvmfPkgTokenSpaceGuid.PcdOvmfSecPageTablesSize
diff --git a/OvmfPkg/ResetVector/Ia32/PageTables64.asm b/OvmfPkg/ResetVector/Ia32/PageTables64.asm
index abad009f20f5..9f86ddf6f08f 100644
--- a/OvmfPkg/ResetVector/Ia32/PageTables64.asm
+++ b/OvmfPkg/ResetVector/Ia32/PageTables64.asm
@@ -21,6 +21,11 @@ BITS    32
 %define PAGE_2M_MBO            0x080
 %define PAGE_2M_PAT          0x01000
 
+%define PAGE_4K_PDE_ATTR (PAGE_ACCESSED + \
+                          PAGE_DIRTY + \
+                          PAGE_READ_WRITE + \
+                          PAGE_PRESENT)
+
 %define PAGE_2M_PDE_ATTR (PAGE_2M_MBO + \
                           PAGE_ACCESSED + \
                           PAGE_DIRTY + \
@@ -75,6 +80,37 @@ NoSev:
 SevExit:
     OneTimeCallRet CheckSevFeature
 
+; Check if Secure Encrypted Virtualization - Encrypted State (SEV-ES) feature
+; is enabled.
+;
+; Modified:  EAX, EBX, ECX
+;
+; If SEV-ES is enabled then EAX will be non-zero.
+; If SEV-ES is disabled then EAX will be zero.
+;
+CheckSevEsFeature:
+    xor       eax, eax
+
+    ; SEV-ES can't be enabled if SEV isn't, so first check the encryption
+    ; mask.
+    test      edx, edx
+    jz        NoSevEs
+
+    ; Save current value of encryption mask
+    mov       ebx, edx
+
+    ; Check if SEV-ES is enabled
+    ;  MSR_0xC0010131 - Bit 1 (SEV-ES enabled)
+    mov       ecx, 0xc0010131
+    rdmsr
+    and       eax, 2
+
+    ; Restore encryption mask
+    mov       edx, ebx
+
+NoSevEs:
+    OneTimeCallRet CheckSevEsFeature
+
 ;
 ; Modified:  EAX, EBX, ECX, EDX
 ;
@@ -139,6 +175,46 @@ pageTableEntriesLoop:
     mov     [(ecx * 8 + PT_ADDR (0x2000 - 8)) + 4], edx
     loop    pageTableEntriesLoop
 
+    OneTimeCall   CheckSevEsFeature
+    test    eax, eax
+    jz      SetCr3
+
+    ;
+    ; The initial GHCB will live at GHCB_BASE and needs to be un-encrypted.
+    ; This requires the 2MB page for this range be broken down into 512 4KB
+    ; pages.  All will be marked encrypted, except for the GHCB.
+    ;
+    mov     ecx, (GHCB_BASE >> 21)
+    mov     eax, GHCB_PT_ADDR + PAGE_PDP_ATTR
+    mov     [ecx * 8 + PT_ADDR (0x2000)], eax
+
+    ;
+    ; Page Table Entries (512 * 4KB entries => 2MB)
+    ;
+    mov     ecx, 512
+pageTableEntries4kLoop:
+    mov     eax, ecx
+    dec     eax
+    shl     eax, 12
+    add     eax, GHCB_BASE & 0xFFE0_0000
+    add     eax, PAGE_4K_PDE_ATTR
+    mov     [ecx * 8 + GHCB_PT_ADDR - 8], eax
+    mov     [(ecx * 8 + GHCB_PT_ADDR - 8) + 4], edx
+    loop    pageTableEntries4kLoop
+
+    ;
+    ; Clear the encryption bit from the GHCB entry
+    ;
+    mov     ecx, (GHCB_BASE & 0x1F_FFFF) >> 12
+    mov     [ecx * 8 + GHCB_PT_ADDR + 4], strict dword 0
+
+    mov     ecx, GHCB_SIZE / 4
+    xor     eax, eax
+clearGhcbMemoryLoop:
+    mov     dword[ecx * 4 + GHCB_BASE - 4], eax
+    loop    clearGhcbMemoryLoop
+
+SetCr3:
     ;
     ; Set CR3 now that the paging structures are available
     ;
diff --git a/OvmfPkg/ResetVector/ResetVector.nasmb b/OvmfPkg/ResetVector/ResetVector.nasmb
index 75cfe16654b1..bfb77e439105 100644
--- a/OvmfPkg/ResetVector/ResetVector.nasmb
+++ b/OvmfPkg/ResetVector/ResetVector.nasmb
@@ -53,8 +53,25 @@
     %error "This implementation inherently depends on PcdOvmfSecPageTablesSize"
   %endif
 
+  %if (FixedPcdGet32 (PcdOvmfSecGhcbPageTableSize) != 0x1000)
+    %error "This implementation inherently depends on PcdOvmfSecGhcbPageTableSize"
+  %endif
+
+  %if (FixedPcdGet32 (PcdOvmfSecGhcbSize) != 0x2000)
+    %error "This implementation inherently depends on PcdOvmfSecGhcbSize"
+  %endif
+
+  %if ((FixedPcdGet32 (PcdOvmfSecGhcbBase) >> 21) != \
+       ((FixedPcdGet32 (PcdOvmfSecGhcbBase) + FixedPcdGet32 (PcdOvmfSecGhcbSize) - 1) >> 21))
+    %error "This implementation inherently depends on PcdOvmfSecGhcbBase not straddling a 2MB boundary"
+  %endif
+
   %define PT_ADDR(Offset) (FixedPcdGet32 (PcdOvmfSecPageTablesBase) + (Offset))
 %include "Ia32/Flat32ToFlat64.asm"
+
+  %define GHCB_PT_ADDR (FixedPcdGet32 (PcdOvmfSecGhcbPageTableBase))
+  %define GHCB_BASE (FixedPcdGet32 (PcdOvmfSecGhcbBase))
+  %define GHCB_SIZE (FixedPcdGet32 (PcdOvmfSecGhcbSize))
 %include "Ia32/PageTables64.asm"
 %endif
 
-- 
2.27.0


  parent reply	other threads:[~2020-07-21 21:23 UTC|newest]

Thread overview: 58+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-07-21 21:18 [PATCH v11 00/46] SEV-ES guest support Lendacky, Thomas
2020-07-21 21:18 ` [PATCH v11 01/46] MdeModulePkg: Create PCDs to be used in support of SEV-ES Lendacky, Thomas
2020-07-21 21:18 ` [PATCH v11 02/46] UefiCpuPkg: Create PCD " Lendacky, Thomas
2020-07-21 21:18 ` [PATCH v11 03/46] MdePkg: Add the MSR definition for the GHCB register Lendacky, Thomas
2020-07-23  8:33   ` [edk2-devel] " Liming Gao
2020-07-21 21:18 ` [PATCH v11 04/46] MdePkg: Add a structure definition for the GHCB Lendacky, Thomas
2020-07-23  8:33   ` Liming Gao
2020-07-21 21:18 ` [PATCH v11 05/46] MdeModulePkg/DxeIplPeim: Support GHCB pages when creating page tables Lendacky, Thomas
2020-07-21 21:18 ` [PATCH v11 06/46] MdePkg/BaseLib: Add support for the XGETBV instruction Lendacky, Thomas
2020-07-22  0:55   ` [edk2-devel] " Zhiguang Liu
2020-07-22 20:27     ` Laszlo Ersek
2020-07-22 20:48       ` Lendacky, Thomas
2020-07-23  1:16       ` Liming Gao
2020-07-23 14:18         ` Lendacky, Thomas
2020-07-23 14:59           ` Liming Gao
2020-07-23 18:35             ` Lendacky, Thomas
2020-07-21 21:18 ` [PATCH v11 07/46] MdePkg/BaseLib: Add support for the VMGEXIT instruction Lendacky, Thomas
2020-07-21 21:18 ` [PATCH v11 08/46] UefiCpuPkg: Implement library support for VMGEXIT Lendacky, Thomas
2020-07-21 21:18 ` [PATCH v11 09/46] OvmfPkg: Prepare OvmfPkg to use the VmgExitLib library Lendacky, Thomas
2020-07-21 21:18 ` [PATCH v11 10/46] UefiPayloadPkg: Prepare UefiPayloadPkg " Lendacky, Thomas
2020-07-21 21:18 ` [PATCH v11 11/46] UefiCpuPkg/CpuExceptionHandler: Add base support for the #VC exception Lendacky, Thomas
2020-07-21 21:18 ` [PATCH v11 12/46] OvmfPkg/VmgExitLib: Implement library support for VmgExitLib in OVMF Lendacky, Thomas
2020-07-21 21:18 ` [PATCH v11 13/46] OvmfPkg/VmgExitLib: Add support for IOIO_PROT NAE events Lendacky, Thomas
2020-07-21 21:18 ` [PATCH v11 14/46] OvmfPkg/VmgExitLib: Support string IO " Lendacky, Thomas
2020-07-21 21:18 ` [PATCH v11 15/46] OvmfPkg/VmgExitLib: Add support for CPUID " Lendacky, Thomas
2020-07-21 21:18 ` [PATCH v11 16/46] OvmfPkg/VmgExitLib: Add support for MSR_PROT " Lendacky, Thomas
2020-07-21 21:18 ` [PATCH v11 17/46] OvmfPkg/VmgExitLib: Add support for NPF NAE events (MMIO) Lendacky, Thomas
2020-07-21 21:18 ` [PATCH v11 18/46] OvmfPkg/VmgExitLib: Add support for WBINVD NAE events Lendacky, Thomas
2020-07-21 21:18 ` [PATCH v11 19/46] OvmfPkg/VmgExitLib: Add support for RDTSC " Lendacky, Thomas
2020-07-21 21:18 ` [PATCH v11 20/46] OvmfPkg/VmgExitLib: Add support for RDPMC " Lendacky, Thomas
2020-07-21 21:18 ` [PATCH v11 21/46] OvmfPkg/VmgExitLib: Add support for INVD " Lendacky, Thomas
2020-07-21 21:18 ` [PATCH v11 22/46] OvmfPkg/VmgExitLib: Add support for VMMCALL " Lendacky, Thomas
2020-07-21 21:19 ` [PATCH v11 23/46] OvmfPkg/VmgExitLib: Add support for RDTSCP " Lendacky, Thomas
2020-07-21 21:19 ` [PATCH v11 24/46] OvmfPkg/VmgExitLib: Add support for MONITOR/MONITORX " Lendacky, Thomas
2020-07-21 21:19 ` [PATCH v11 25/46] OvmfPkg/VmgExitLib: Add support for MWAIT/MWAITX " Lendacky, Thomas
2020-07-21 21:19 ` [PATCH v11 26/46] OvmfPkg/VmgExitLib: Add support for DR7 Read/Write " Lendacky, Thomas
2020-07-21 21:19 ` [PATCH v11 27/46] OvmfPkg/MemEncryptSevLib: Add an SEV-ES guest indicator function Lendacky, Thomas
2020-07-21 21:19 ` [PATCH v11 28/46] OvmfPkg: Add support to perform SEV-ES initialization Lendacky, Thomas
2020-07-21 21:19 ` Lendacky, Thomas [this message]
2020-07-21 21:19 ` [PATCH v11 30/46] OvmfPkg/PlatformPei: Reserve GHCB-related areas if S3 is supported Lendacky, Thomas
2020-07-21 21:19 ` [PATCH v11 31/46] OvmfPkg: Create GHCB pages for use during Pei and Dxe phase Lendacky, Thomas
2020-07-21 21:19 ` [PATCH v11 32/46] OvmfPkg/PlatformPei: Move early GDT into ram when SEV-ES is enabled Lendacky, Thomas
2020-07-21 21:19 ` [PATCH v11 33/46] UefiCpuPkg: Create an SEV-ES workarea PCD Lendacky, Thomas
2020-07-21 21:19 ` [PATCH v11 34/46] OvmfPkg: Reserve a page in memory for the SEV-ES usage Lendacky, Thomas
2020-07-21 21:19 ` [PATCH v11 35/46] OvmfPkg/PlatformPei: Reserve SEV-ES work area if S3 is supported Lendacky, Thomas
2020-07-21 21:19 ` [PATCH v11 36/46] OvmfPkg/ResetVector: Add support for a 32-bit SEV check Lendacky, Thomas
2020-07-21 21:19 ` [PATCH v11 37/46] OvmfPkg/Sec: Add #VC exception handling for Sec phase Lendacky, Thomas
2020-07-21 21:19 ` [PATCH v11 38/46] OvmfPkg/Sec: Enable cache early to speed up booting Lendacky, Thomas
2020-07-21 21:19 ` [PATCH v11 39/46] OvmfPkg/QemuFlashFvbServicesRuntimeDxe: Bypass flash detection with SEV-ES Lendacky, Thomas
2020-07-22  4:05 ` [PATCH v11 40/46] UefiCpuPkg: Add a 16-bit protected mode code segment descriptor Lendacky, Thomas
2020-07-22  4:05 ` [PATCH v11 41/46] UefiCpuPkg/MpInitLib: Add CPU MP data flag to indicate if SEV-ES is enabled Lendacky, Thomas
2020-07-22  4:05 ` [PATCH v11 42/46] UefiCpuPkg: Allow AP booting under SEV-ES Lendacky, Thomas
2020-07-22  4:05 ` [PATCH v11 43/46] OvmfPkg: Use the SEV-ES work area for the SEV-ES AP reset vector Lendacky, Thomas
2020-07-22  4:05 ` [PATCH v11 44/46] OvmfPkg: Move the GHCB allocations into reserved memory Lendacky, Thomas
2020-07-22  4:05 ` [PATCH v11 45/46] UefiCpuPkg/MpInitLib: Prepare SEV-ES guest APs for OS use Lendacky, Thomas
2020-07-22  4:05 ` [PATCH v11 46/46] Maintainers.txt: Add reviewers for the OvmfPkg SEV-related files Lendacky, Thomas
2020-07-22 20:13 ` [PATCH v11 00/46] SEV-ES guest support Laszlo Ersek
2020-07-22 20:39   ` Lendacky, Thomas

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