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From: "Brijesh Singh" <brijesh.singh@amd.com>
To: devel@edk2.groups.io
Cc: Brijesh Singh <brijesh.singh@amd.com>,
	James Bottomley <jejb@linux.ibm.com>, Min Xu <min.m.xu@intel.com>,
	Jiewen Yao <jiewen.yao@intel.com>,
	Tom Lendacky <thomas.lendacky@amd.com>,
	Jordan Justen <jordan.l.justen@intel.com>,
	Ard Biesheuvel <ardb+tianocore@kernel.org>,
	Laszlo Ersek <lersek@redhat.com>
Subject: [RFC PATCH 09/19] MdePkg: Add AsmPvalidate() support
Date: Wed, 24 Mar 2021 10:32:05 -0500	[thread overview]
Message-ID: <20210324153215.17971-10-brijesh.singh@amd.com> (raw)
In-Reply-To: <20210324153215.17971-1-brijesh.singh@amd.com>

BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=3275

The PVALIDATE instruction validates or rescinds validation of a guest
page RMP entry. Upon completion, a return code is stored in EAX, rFLAGS
bits OF, ZF, AF, PF and SF are set based on this return code. If the
instruction completed succesfully, the rFLAGS bit CF indicates if the
contents of the RMP entry were changed or not.

For more information about the instruction see AMD APM volume 3.

Cc: James Bottomley <jejb@linux.ibm.com>
Cc: Min Xu <min.m.xu@intel.com>
Cc: Jiewen Yao <jiewen.yao@intel.com>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: Jordan Justen <jordan.l.justen@intel.com>
Cc: Ard Biesheuvel <ardb+tianocore@kernel.org>
Cc: Laszlo Ersek <lersek@redhat.com>
Signed-off-by: Brijesh Singh <brijesh.singh@amd.com>
---
 MdePkg/Include/Library/BaseLib.h          | 37 +++++++++++++++++
 MdePkg/Library/BaseLib/BaseLib.inf        |  1 +
 MdePkg/Library/BaseLib/X64/Pvalidate.nasm | 43 ++++++++++++++++++++
 3 files changed, 81 insertions(+)

diff --git a/MdePkg/Include/Library/BaseLib.h b/MdePkg/Include/Library/BaseLib.h
index 1171a0ffb5..fee27e9a1b 100644
--- a/MdePkg/Include/Library/BaseLib.h
+++ b/MdePkg/Include/Library/BaseLib.h
@@ -7495,5 +7495,42 @@ PatchInstructionX86 (
   IN  UINTN                    ValueSize
   );
 
+/**
+ Execute a PVALIDATE instruction to validate or rescnids validation of a guest
+ page's RMP entry.
+
+ Upon completion, in addition to the return value the instruction also updates
+ the eFlags. A caller must check both the return code as well as eFlags to
+ determine if the RMP entry has been updated.
+
+ The function is available on x64.
+
+ @param[in]    Address        The guest virtual address to validate.
+ @param[in]    PageSize       The page size to use.
+ @param[i]     Validate       Validate or rescinds.
+ @param[out]   Eflags         The value of Eflags after PVALIDATE completion.
+
+ @retval       PvalidateRetValue  The return value from the PVALIDATE instruction.
+**/
+typedef enum {
+  PVALIDATE_PAGE_SIZE_4K = 0,
+  PVALIDATE_PAGE_SIZE_2M,
+} PvalidatePageSize;
+
+typedef enum {
+  PVALIDATE_RET_SUCCESS = 0,
+  PVALIDATE_RET_FAIL_INPUT = 1,
+  PVALIDATE_RET_FAIL_SIZEMISMATCH = 6,
+} PvalidateRetValue;
+
+PvalidateRetValue
+EFIAPI
+AsmPvalidate (
+  IN   PvalidatePageSize       PageSize,
+  IN   BOOLEAN                 Validate,
+  IN   UINTN                   Address,
+  OUT  IA32_EFLAGS32           *Eflags
+  );
+
 #endif // defined (MDE_CPU_IA32) || defined (MDE_CPU_X64)
 #endif // !defined (__BASE_LIB__)
diff --git a/MdePkg/Library/BaseLib/BaseLib.inf b/MdePkg/Library/BaseLib/BaseLib.inf
index 3b85c56c3c..01aa5cc7a4 100644
--- a/MdePkg/Library/BaseLib/BaseLib.inf
+++ b/MdePkg/Library/BaseLib/BaseLib.inf
@@ -319,6 +319,7 @@
   X64/RdRand.nasm
   X64/XGetBv.nasm
   X64/VmgExit.nasm
+  X64/Pvalidate.nasm
   ChkStkGcc.c  | GCC
 
 [Sources.EBC]
diff --git a/MdePkg/Library/BaseLib/X64/Pvalidate.nasm b/MdePkg/Library/BaseLib/X64/Pvalidate.nasm
new file mode 100644
index 0000000000..f2aba114ac
--- /dev/null
+++ b/MdePkg/Library/BaseLib/X64/Pvalidate.nasm
@@ -0,0 +1,43 @@
+;-----------------------------------------------------------------------------
+;
+; Copyright (c) 2020-2021, AMD. All rights reserved.<BR>
+; SPDX-License-Identifier: BSD-2-Clause-Patent
+;
+; Module Name:
+;
+;   Pvalidate.Asm
+;
+; Abstract:
+;
+;   AsmPvalidate function
+;
+; Notes:
+;
+;-----------------------------------------------------------------------------
+
+    SECTION .text
+
+;-----------------------------------------------------------------------------
+;  PvalidateRetValue
+;  EFIAPI
+;  AsmPvalidate (
+;    IN   UINT32  RmpPageSize
+;    IN   UINT32  Validate,
+;    IN   UINTN   Address,
+;    OUT  UINTN  *Eflags,
+;    )
+;-----------------------------------------------------------------------------
+global ASM_PFX(AsmPvalidate)
+ASM_PFX(AsmPvalidate):
+  mov     rax, r8
+
+  ; PVALIDATE instruction opcode
+  DB      0xF2, 0x0F, 0x01, 0xFF
+
+  ; Read the Eflags
+  pushfq
+  pop     r8
+  mov     [r9], r8
+
+  ; The PVALIDATE instruction returns the status in rax register.
+  ret
-- 
2.17.1


  parent reply	other threads:[~2021-03-24 15:32 UTC|newest]

Thread overview: 68+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-03-24 15:31 [RFC PATCH 00/19] Add AMD Secure Nested Paging (SEV-SNP) support brijesh.singh
2021-03-24 15:31 ` [RFC PATCH 01/19] OvmfPkg: Reserve the Secrets and Cpuid page for the SEV-SNP guest Brijesh Singh
2021-04-06  8:11   ` Min Xu
2021-04-06 12:16     ` Laszlo Ersek
2021-04-07  0:21       ` Min Xu
2021-04-07  0:44         ` James Bottomley
2021-04-07 15:02           ` Laszlo Ersek
2021-04-07 15:12             ` James Bottomley
2021-04-08  6:24             ` [edk2-devel] " Min Xu
2021-04-08 13:31               ` Lendacky, Thomas
2021-04-09 12:29                 ` Laszlo Ersek
2021-04-09 13:32                 ` Laszlo Ersek
2021-04-09 13:44                   ` Yao, Jiewen
2021-04-09 14:11                     ` separate OVMF binary for TDX? [was: OvmfPkg: Reserve the Secrets and Cpuid page for the SEV-SNP guest] Laszlo Ersek
2021-04-12  8:35                       ` Dr. David Alan Gilbert
2021-04-12 11:54                         ` [edk2-devel] " Yao, Jiewen
2021-04-12 14:33                           ` James Bottomley
2021-04-14 23:34                             ` erdemaktas
2021-04-15  7:59                               ` Paolo Bonzini
2021-04-15 19:42                                 ` Erdem Aktas
2021-04-21  0:38                                   ` Yao, Jiewen
2021-04-21 10:44                                     ` Laszlo Ersek
2021-04-21 17:07                                       ` Erdem Aktas
2021-04-22 14:20                                         ` Laszlo Ersek
2021-04-07 13:22         ` [RFC PATCH 01/19] OvmfPkg: Reserve the Secrets and Cpuid page for the SEV-SNP guest Laszlo Ersek
2021-04-07 13:24           ` Laszlo Ersek
2021-04-08  0:45           ` Min Xu
2021-04-07  0:31       ` James Bottomley
2021-04-12 14:52   ` Brijesh Singh
2021-04-13  9:49     ` Laszlo Ersek
2021-04-13 11:29       ` Brijesh Singh
2021-04-13 13:13         ` Laszlo Ersek
2021-04-19 21:42       ` Brijesh Singh
2021-04-20  8:14         ` Laszlo Ersek
2021-03-24 15:31 ` [RFC PATCH 02/19] OvmfPkg: validate the data pages used in the SEC phase Brijesh Singh
2021-03-24 15:31 ` [RFC PATCH 03/19] MdePkg: Expand the SEV MSR to include the SNP definition Brijesh Singh
2021-03-24 15:32 ` [RFC PATCH 04/19] OvmfPkg/MemEncryptSevLib: add MemEncryptSevSnpEnabled() Brijesh Singh
2021-03-24 15:32 ` [RFC PATCH 05/19] MdePkg: Define the GHCB GPA structure Brijesh Singh
2021-03-24 15:32 ` [RFC PATCH 06/19] UefiCpuPkg/MpLib: add support to register GHCB GPA when SEV-SNP is enabled Brijesh Singh
2021-03-24 15:32 ` [RFC PATCH 07/19] OvmfPkg: Add a library to support registering GHCB GPA Brijesh Singh
2021-03-24 15:32 ` [RFC PATCH 08/19] OvmfPkg: register GHCB gpa for the SEV-SNP guest Brijesh Singh
2021-03-24 15:32 ` Brijesh Singh [this message]
2021-03-25  2:49   ` 回复: [edk2-devel] [RFC PATCH 09/19] MdePkg: Add AsmPvalidate() support gaoliming
2021-03-25 10:54     ` Brijesh Singh
2021-03-26 20:02       ` Andrew Fish
2021-03-24 15:32 ` [RFC PATCH 10/19] OvmfPkg: Define the Page State Change VMGEXIT structures Brijesh Singh
2021-03-24 15:32 ` [RFC PATCH 11/19] OvmfPkg/ResetVector: Invalidate the GHCB page Brijesh Singh
2021-03-24 15:32 ` [RFC PATCH 12/19] OvmfPkg/MemEncryptSevLib: Add support to validate system RAM Brijesh Singh
2021-04-01  6:37   ` Yao, Jiewen
2021-04-01 13:07     ` Brijesh Singh
2021-03-24 15:32 ` [RFC PATCH 13/19] OvmfPkg/SecMain: Validate the data/code pages used for the PEI phase Brijesh Singh
2021-03-24 15:32 ` [RFC PATCH 14/19] OvmfPkg/MemEncryptSevLib: Add support to validate RAM in " Brijesh Singh
2021-03-24 15:32 ` [RFC PATCH 15/19] OvmfPkg/PlatformPei: Validate the system RAM when SNP is active Brijesh Singh
2021-03-24 15:32 ` [RFC PATCH 16/19] OvmfPkg/MemEncryptSevLib: Add support to validate > 4GB memory in PEI phase Brijesh Singh
2021-04-01  6:43   ` Yao, Jiewen
2021-03-24 15:32 ` [RFC PATCH 17/19] OvmfPkg/VmgExitLib: Allow PMBASE register access in Dxe phase Brijesh Singh
2021-03-24 15:32 ` [RFC PATCH 18/19] OvmfPkg/MemEncryptSevLib: Validate the memory during set or clear enc attribute Brijesh Singh
2021-03-24 20:07   ` Brijesh Singh
2021-03-24 15:32 ` [RFC PATCH 19/19] OvmfPkg/MemEncryptSevLib: Skip page state change for non RAM region Brijesh Singh
2021-03-24 19:14 ` [edk2-devel] [RFC PATCH 00/19] Add AMD Secure Nested Paging (SEV-SNP) support Laszlo Ersek
2021-04-08  9:58 ` Laszlo Ersek
2021-04-08 11:59   ` Brijesh Singh
2021-04-09 12:24     ` Laszlo Ersek
2021-04-09 22:43       ` Brijesh Singh
2021-04-12 16:23         ` Laszlo Ersek
2021-04-12 20:14           ` Brijesh Singh
2021-04-13 13:00             ` Laszlo Ersek
2021-04-14 11:18               ` Brijesh Singh

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