From: "Lendacky, Thomas" <thomas.lendacky@amd.com>
To: devel@edk2.groups.io
Cc: Jordan Justen <jordan.l.justen@intel.com>,
Laszlo Ersek <lersek@redhat.com>,
Ard Biesheuvel <ard.biesheuvel@linaro.org>,
Michael D Kinney <michael.d.kinney@intel.com>,
Liming Gao <liming.gao@intel.com>,
Eric Dong <eric.dong@intel.com>, Ray Ni <ray.ni@intel.com>,
Brijesh Singh <brijesh.singh@amd.com>
Subject: [RFC PATCH v3 22/43] UefiCpuPkg/CpuExceptionHandler: Add support for DR7 Read/Write NAE events
Date: Wed, 20 Nov 2019 14:06:44 -0600 [thread overview]
Message-ID: <a94e704d716abe630b6ce2c7d7aebc4bf02f4ea1.1574280425.git.thomas.lendacky@amd.com> (raw)
In-Reply-To: <cover.1574280425.git.thomas.lendacky@amd.com>
BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=2198
Under SEV-ES, a DR7 read or write intercept generates a #VC exception.
The #VC handler must provide special support to the guest for this. On
a DR7 write, the #VC handler must cache the value and issue a VMGEXIT
to notify the hypervisor of the write. However, the #VC handler must
not actually set the value of the DR7 register. On a DR7 read, the #VC
handler must return the cached value of the DR7 register to the guest.
VMGEXIT is not invoked for a DR7 register read.
To avoid exception recursion, a #VC exception will not try to read and
push the actual debug registers into the EFI_SYSTEM_CONTEXT_X64 struct
and instead push zeroes. The #VC exception handler does not make use of
the debug registers from saved context.
Cc: Eric Dong <eric.dong@intel.com>
Cc: Ray Ni <ray.ni@intel.com>
Cc: Laszlo Ersek <lersek@redhat.com>
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
---
.../X64/AMDSevVcCommon.c | 68 +++++++++++++++++++
.../X64/ExceptionHandlerAsm.nasm | 15 ++++
2 files changed, 83 insertions(+)
diff --git a/UefiCpuPkg/Library/CpuExceptionHandlerLib/X64/AMDSevVcCommon.c b/UefiCpuPkg/Library/CpuExceptionHandlerLib/X64/AMDSevVcCommon.c
index 1d7c34e7e442..22393f72d795 100644
--- a/UefiCpuPkg/Library/CpuExceptionHandlerLib/X64/AMDSevVcCommon.c
+++ b/UefiCpuPkg/Library/CpuExceptionHandlerLib/X64/AMDSevVcCommon.c
@@ -13,6 +13,12 @@
#define CR4_OSXSAVE (1 << 18)
+#define DR7_RESET_VALUE 0x400
+typedef struct {
+ BOOLEAN Dr7Cached;
+ UINT64 Dr7;
+} SEV_ES_PER_CPU_DATA;
+
typedef enum {
LongMode64Bit = 0,
LongModeCompat32Bit,
@@ -1081,6 +1087,60 @@ RdtscExit (
return 0;
}
+STATIC
+UINTN
+Dr7WriteExit (
+ GHCB *Ghcb,
+ EFI_SYSTEM_CONTEXT_X64 *Regs,
+ SEV_ES_INSTRUCTION_DATA *InstructionData
+ )
+{
+ SEV_ES_INSTRUCTION_OPCODE_EXT *Ext = &InstructionData->Ext;
+ SEV_ES_PER_CPU_DATA *SevEsData = (SEV_ES_PER_CPU_DATA *) (Ghcb + 1);
+ INTN *Register;
+ UINTN Status;
+
+ DecodeModRm (Regs, InstructionData);
+
+ /* MOV DRn always treats MOD == 3 no matter how encoded */
+ Register = GetRegisterPointer (Regs, Ext->ModRm.Rm);
+
+ /* Using a value of 0 for ExitInfo1 means RAX holds the value */
+ Ghcb->SaveArea.Rax = *Register;
+ GhcbSetRegValid (Ghcb, GhcbRax);
+
+ Status = VmgExit (Ghcb, SvmExitDr7Write, 0, 0);
+ if (Status) {
+ return Status;
+ }
+
+ SevEsData->Dr7 = *Register;
+ SevEsData->Dr7Cached = TRUE;
+
+ return 0;
+}
+
+STATIC
+UINTN
+Dr7ReadExit (
+ GHCB *Ghcb,
+ EFI_SYSTEM_CONTEXT_X64 *Regs,
+ SEV_ES_INSTRUCTION_DATA *InstructionData
+ )
+{
+ SEV_ES_INSTRUCTION_OPCODE_EXT *Ext = &InstructionData->Ext;
+ SEV_ES_PER_CPU_DATA *SevEsData = (SEV_ES_PER_CPU_DATA *) (Ghcb + 1);
+ INTN *Register;
+
+ DecodeModRm (Regs, InstructionData);
+
+ /* MOV DRn always treats MOD == 3 no matter how encoded */
+ Register = GetRegisterPointer (Regs, Ext->ModRm.Rm);
+ *Register = (SevEsData->Dr7Cached) ? SevEsData->Dr7 : DR7_RESET_VALUE;
+
+ return 0;
+}
+
UINTN
DoVcCommon (
GHCB *Ghcb,
@@ -1097,6 +1157,14 @@ DoVcCommon (
ExitCode = Regs->ExceptionData;
switch (ExitCode) {
+ case SvmExitDr7Read:
+ NaeExit = Dr7ReadExit;
+ break;
+
+ case SvmExitDr7Write:
+ NaeExit = Dr7WriteExit;
+ break;
+
case SvmExitRdtsc:
NaeExit = RdtscExit;
break;
diff --git a/UefiCpuPkg/Library/CpuExceptionHandlerLib/X64/ExceptionHandlerAsm.nasm b/UefiCpuPkg/Library/CpuExceptionHandlerLib/X64/ExceptionHandlerAsm.nasm
index 19198f273137..a0549f7ae6bd 100644
--- a/UefiCpuPkg/Library/CpuExceptionHandlerLib/X64/ExceptionHandlerAsm.nasm
+++ b/UefiCpuPkg/Library/CpuExceptionHandlerLib/X64/ExceptionHandlerAsm.nasm
@@ -225,6 +225,9 @@ HasErrorCode:
push rax
;; UINT64 Dr0, Dr1, Dr2, Dr3, Dr6, Dr7;
+ cmp qword [rbp + 8], 29
+ je VcDebugRegs ; For SEV-ES (#VC) Debug registers ignored
+
mov rax, dr7
push rax
mov rax, dr6
@@ -237,7 +240,19 @@ HasErrorCode:
push rax
mov rax, dr0
push rax
+ jmp DrFinish
+VcDebugRegs:
+;; UINT64 Dr0, Dr1, Dr2, Dr3, Dr6, Dr7 are skipped for #VC to avoid exception recursion
+ xor rax, rax
+ push rax
+ push rax
+ push rax
+ push rax
+ push rax
+ push rax
+
+DrFinish:
;; FX_SAVE_STATE_X64 FxSaveState;
sub rsp, 512
mov rdi, rsp
--
2.17.1
next prev parent reply other threads:[~2019-11-20 20:07 UTC|newest]
Thread overview: 82+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-11-20 20:06 [RFC PATCH v3 00/43] SEV-ES guest support Lendacky, Thomas
2019-11-20 20:06 ` [RFC PATCH v3 01/43] MdePkg: Create PCDs to be used in support of SEV-ES Lendacky, Thomas
2019-12-12 6:53 ` Ni, Ray
2019-12-12 20:48 ` Lendacky, Thomas
2019-12-13 1:21 ` Ni, Ray
2019-11-20 20:06 ` [RFC PATCH v3 02/43] MdePkg: Add the MSR definition for the GHCB register Lendacky, Thomas
2019-11-20 20:06 ` [RFC PATCH v3 03/43] MdePkg: Add a structure definition for the GHCB Lendacky, Thomas
2019-11-20 20:06 ` [RFC PATCH v3 04/43] MdeModulePkg/DxeIplPeim: Support GHCB pages when creating page tables Lendacky, Thomas
2019-12-12 6:53 ` [edk2-devel] " Ni, Ray
2019-12-12 20:58 ` Lendacky, Thomas
2019-11-20 20:06 ` [RFC PATCH v3 05/43] MdePkg/BaseLib: Add support for the XGETBV instruction Lendacky, Thomas
2019-11-20 20:06 ` [RFC PATCH v3 06/43] MdePkg/BaseLib: Add support for the VMGEXIT instruction Lendacky, Thomas
2019-11-20 20:06 ` [RFC PATCH v3 07/43] UefiCpuPkg: Implement library support for VMGEXIT Lendacky, Thomas
2019-11-21 11:15 ` [edk2-devel] " Laszlo Ersek
2019-11-21 16:48 ` Lendacky, Thomas
2019-11-20 20:06 ` [RFC PATCH v3 08/43] UefiCpuPkg/CpuExceptionHandler: Add base support for the #VC exception Lendacky, Thomas
2019-11-20 20:06 ` [RFC PATCH v3 09/43] UefiCpuPkg/CpuExceptionHandler: Add support for IOIO_PROT NAE events Lendacky, Thomas
2019-11-20 20:06 ` [RFC PATCH v3 10/43] UefiCpuPkg/CpuExceptionHandler: Support string IO " Lendacky, Thomas
2019-11-20 20:06 ` [RFC PATCH v3 11/43] UefiCpuPkg/CpuExceptionHandler: Add support for CPUID " Lendacky, Thomas
2019-11-20 20:06 ` [RFC PATCH v3 12/43] UefiCpuPkg/CpuExceptionHandler: Add support for MSR_PROT " Lendacky, Thomas
2019-11-20 20:06 ` [RFC PATCH v3 13/43] UefiCpuPkg/CpuExceptionHandler: Add support for NPF NAE events (MMIO) Lendacky, Thomas
2019-11-20 20:06 ` [RFC PATCH v3 14/43] UefiCpuPkg/CpuExceptionHandler: Add support for WBINVD NAE events Lendacky, Thomas
2019-11-20 20:06 ` [RFC PATCH v3 15/43] UefiCpuPkg/CpuExceptionHandler: Add support for RDTSC " Lendacky, Thomas
2019-11-20 20:06 ` [RFC PATCH v3 16/43] UefiCpuPkg/CpuExceptionHandler: Add support for RDPMC " Lendacky, Thomas
2019-11-20 20:06 ` [RFC PATCH v3 17/43] UefiCpuPkg/CpuExceptionHandler: Add support for INVD " Lendacky, Thomas
2019-11-20 20:06 ` [RFC PATCH v3 18/43] UefiCpuPkg/CpuExceptionHandler: Add support for VMMCALL " Lendacky, Thomas
2019-11-20 20:06 ` [RFC PATCH v3 19/43] UefiCpuPkg/CpuExceptionHandler: Add support for RDTSCP " Lendacky, Thomas
2019-11-20 20:06 ` [RFC PATCH v3 20/43] UefiCpuPkg/CpuExceptionHandler: Add support for MONITOR/MONITORX " Lendacky, Thomas
2019-11-20 20:06 ` [RFC PATCH v3 21/43] UefiCpuPkg/CpuExceptionHandler: Add support for MWAIT/MWAITX " Lendacky, Thomas
2019-11-20 20:06 ` Lendacky, Thomas [this message]
2019-12-12 6:53 ` [RFC PATCH v3 22/43] UefiCpuPkg/CpuExceptionHandler: Add support for DR7 Read/Write " Ni, Ray
2019-12-12 20:27 ` Lendacky, Thomas
2019-12-12 6:53 ` Ni, Ray
2019-12-12 20:39 ` Lendacky, Thomas
2019-11-20 20:06 ` [RFC PATCH v3 23/43] OvmfPkg/MemEncryptSevLib: Add an SEV-ES guest indicator function Lendacky, Thomas
2019-11-20 20:06 ` [RFC PATCH v3 24/43] OvmfPkg: Add support to perform SEV-ES initialization Lendacky, Thomas
2019-11-20 20:06 ` [RFC PATCH v3 25/43] OvmfPkg/ResetVector: Add support for a 32-bit SEV check Lendacky, Thomas
2019-11-21 11:02 ` [edk2-devel] " Laszlo Ersek
2019-11-20 20:06 ` [RFC PATCH v3 26/43] OvmfPkg: Create a GHCB page for use during Sec phase Lendacky, Thomas
2019-11-21 11:29 ` [edk2-devel] " Laszlo Ersek
2019-11-20 20:06 ` [RFC PATCH v3 27/43] OvmfPkg/PlatformPei: Reserve GHCB-related areas if S3 is supported Lendacky, Thomas
2019-11-20 20:06 ` [RFC PATCH v3 28/43] OvmfPkg: Create GHCB pages for use during Pei and Dxe phase Lendacky, Thomas
2019-12-12 6:54 ` Ni, Ray
2019-12-12 21:03 ` Lendacky, Thomas
2019-11-20 20:06 ` [RFC PATCH v3 29/43] OvmfPkg/PlatformPei: Move early GDT into ram when SEV-ES is enabled Lendacky, Thomas
2019-11-20 20:06 ` [RFC PATCH v3 30/43] OvmfPkg/Sec: Add #VC exception handling for Sec phase Lendacky, Thomas
2019-11-21 12:06 ` [edk2-devel] " Laszlo Ersek
2019-11-21 20:46 ` Lendacky, Thomas
2019-11-22 12:52 ` Laszlo Ersek
2019-11-22 16:30 ` Lendacky, Thomas
2019-11-22 21:10 ` Laszlo Ersek
2019-11-22 22:48 ` Lendacky, Thomas
2019-11-20 20:06 ` [RFC PATCH v3 31/43] OvmfPkg/Sec: Enable cache early to speed up booting Lendacky, Thomas
2019-11-21 12:08 ` [edk2-devel] " Laszlo Ersek
2019-11-20 20:06 ` [RFC PATCH v3 32/43] OvmfPkg/QemuFlashFvbServicesRuntimeDxe: Bypass flash detection with SEV-ES is enabled Lendacky, Thomas
2019-11-21 12:31 ` [edk2-devel] " Laszlo Ersek
2019-11-21 21:11 ` Lendacky, Thomas
2019-11-22 12:20 ` Laszlo Ersek
2019-11-20 20:06 ` [RFC PATCH v3 33/43] MdeModulePkg: Reserve a 16-bit protected mode code segment descriptor Lendacky, Thomas
2019-12-12 6:57 ` Ni, Ray
2019-12-12 21:19 ` [edk2-devel] " Lendacky, Thomas
2019-12-13 1:20 ` Ni, Ray
2019-11-20 20:06 ` [RFC PATCH v3 34/43] UefiCpuPkg: Add " Lendacky, Thomas
2019-11-20 20:06 ` [RFC PATCH v3 35/43] UefiCpuPkg/MpInitLib: Add a CPU MP data flag to indicate if SEV-ES is enabled Lendacky, Thomas
2019-12-12 7:01 ` Ni, Ray
2019-12-12 21:21 ` Lendacky, Thomas
2019-11-20 20:06 ` [RFC PATCH v3 36/43] UefiCpuPkg: Allow AP booting under SEV-ES Lendacky, Thomas
2019-11-20 20:06 ` [RFC PATCH v3 37/43] OvmfPkg: Reserve a page in memory for the SEV-ES AP reset vector Lendacky, Thomas
2019-11-21 19:27 ` [edk2-devel] " Laszlo Ersek
2019-11-21 22:49 ` Lendacky, Thomas
2019-11-22 16:06 ` Laszlo Ersek
2019-11-22 16:40 ` Lendacky, Thomas
2019-11-20 20:07 ` [RFC PATCH v3 38/43] OvmfPkg: Move the GHCB allocations into reserved memory Lendacky, Thomas
2019-11-20 20:07 ` [RFC PATCH v3 39/43] MdePkg: Add a finalization function to the CPU protocol Lendacky, Thomas
2019-11-20 21:32 ` [RFC PATCH v3 40/43] UefiCpuPkg/MpInitLib: Add MP finalization interface to MpInitLib Lendacky, Thomas
2019-11-20 21:32 ` [RFC PATCH v3 41/43] UefiCpuPkg/MpInitLib: Prepare SEV-ES guest APs for OS use Lendacky, Thomas
2019-11-20 21:32 ` [RFC PATCH v3 42/43] UefiCpuPkg/CpuDxe: Provide an DXE MP finalization routine to support SEV-ES Lendacky, Thomas
2019-11-20 21:32 ` [RFC PATCH v3 43/43] MdeModulePkg/DxeCore: Perform the CPU protocol finalization support Lendacky, Thomas
2019-11-21 1:53 ` [edk2-devel] [RFC PATCH v3 00/43] SEV-ES guest support Nate DeSimone
2019-11-21 15:50 ` Lendacky, Thomas
2019-11-21 9:45 ` Laszlo Ersek
2019-11-21 9:48 ` Laszlo Ersek
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