From: "Gerd Hoffmann" <kraxel@redhat.com>
To: devel@edk2.groups.io
Cc: Tom Lendacky <thomas.lendacky@amd.com>,
Jiewen Yao <jiewen.yao@intel.com>,
Oliver Steffen <osteffen@redhat.com>,
Laszlo Ersek <lersek@redhat.com>,
Erdem Aktas <erdemaktas@google.com>,
Michael Roth <michael.roth@amd.com>,
Ard Biesheuvel <ardb+tianocore@kernel.org>,
Gerd Hoffmann <kraxel@redhat.com>, Min Xu <min.m.xu@intel.com>
Subject: [edk2-devel] [PATCH 09/10] OvmfPkg/ResetVector: leave SEV VC handler installed longer
Date: Thu, 22 Feb 2024 12:54:34 +0100 [thread overview]
Message-ID: <20240222115435.85794-10-kraxel@redhat.com> (raw)
In-Reply-To: <20240222115435.85794-1-kraxel@redhat.com>
When running in SEV mode keep the VC handler installed.
Add a function to uninstall it later.
This allows using the cpuid instruction in SetCr3ForPageTables64,
which is needed to check for la57 & 1G page support.
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
---
OvmfPkg/ResetVector/Ia32/AmdSev.asm | 12 ++++++++++--
OvmfPkg/ResetVector/Ia32/PageTables64.asm | 1 +
OvmfPkg/ResetVector/Main.asm | 4 ++++
3 files changed, 15 insertions(+), 2 deletions(-)
diff --git a/OvmfPkg/ResetVector/Ia32/AmdSev.asm b/OvmfPkg/ResetVector/Ia32/AmdSev.asm
index ed94f1dc668f..9063ce1080d3 100644
--- a/OvmfPkg/ResetVector/Ia32/AmdSev.asm
+++ b/OvmfPkg/ResetVector/Ia32/AmdSev.asm
@@ -320,9 +320,9 @@ NoSevEsVcHlt:
NoSevPass:
xor eax, eax
-SevExit:
;
- ; Clear exception handlers and stack
+ ; When NOT running in SEV mode: clear exception handlers and stack here.
+ ; Otherwise: SevClearVcHandlerAndStack must be called later.
;
push eax
mov eax, ADDR_OF(IdtrClear)
@@ -330,8 +330,16 @@ SevExit:
pop eax
mov esp, 0
+SevExit:
OneTimeCallRet CheckSevFeatures
+SevClearVcHandlerAndStack:
+ ; Clear exception handlers and stack
+ mov eax, ADDR_OF(IdtrClear)
+ lidt [cs:eax]
+ mov esp, 0
+ OneTimeCallRet SevClearVcHandlerAndStack
+
; Start of #VC exception handling routines
;
diff --git a/OvmfPkg/ResetVector/Ia32/PageTables64.asm b/OvmfPkg/ResetVector/Ia32/PageTables64.asm
index ada3dc0ffbe0..6e2063430802 100644
--- a/OvmfPkg/ResetVector/Ia32/PageTables64.asm
+++ b/OvmfPkg/ResetVector/Ia32/PageTables64.asm
@@ -250,6 +250,7 @@ SevInit:
CreatePageTables4Level edx
; Clear the C-bit from the GHCB page if the SEV-ES is enabled.
OneTimeCall SevClearPageEncMaskForGhcbPage
+ OneTimeCall SevClearVcHandlerAndStack
jmp SetCr3
TdxBspInit:
diff --git a/OvmfPkg/ResetVector/Main.asm b/OvmfPkg/ResetVector/Main.asm
index 46cfa87c4c0a..88b25db3bc9e 100644
--- a/OvmfPkg/ResetVector/Main.asm
+++ b/OvmfPkg/ResetVector/Main.asm
@@ -80,7 +80,11 @@ SearchBfv:
; Set the OVMF/SEV work area as appropriate.
;
OneTimeCall CheckSevFeatures
+ cmp byte[WORK_AREA_GUEST_TYPE], 1
+ jnz NoSevIa32
+ OneTimeCall SevClearVcHandlerAndStack
+NoSevIa32:
;
; Restore initial EAX value into the EAX register
;
--
2.43.2
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next prev parent reply other threads:[~2024-02-22 11:54 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-02-22 11:54 [edk2-devel] [PATCH 00/10] OvmfPkg/ResetVector: cleanup and add 5-level paging support Gerd Hoffmann
2024-02-22 11:54 ` [edk2-devel] [PATCH 01/10] OvmfPkg/ResetVector: improve page table flag names Gerd Hoffmann
2024-02-22 11:54 ` [edk2-devel] [PATCH 02/10] OvmfPkg/ResetVector: add ClearOvmfPageTables macro Gerd Hoffmann
2024-02-28 4:09 ` Laszlo Ersek
2024-02-28 8:22 ` Gerd Hoffmann
2024-02-29 7:42 ` Laszlo Ersek
2024-02-22 11:54 ` [edk2-devel] [PATCH 03/10] OvmfPkg/ResetVector: add CreatePageTables4Level macro Gerd Hoffmann
2024-02-28 4:14 ` Laszlo Ersek
2024-02-22 11:54 ` [edk2-devel] [PATCH 04/10] OvmfPkg/ResetVector: split TDX BSP workflow Gerd Hoffmann
2024-02-28 4:34 ` Laszlo Ersek
2024-02-22 11:54 ` [edk2-devel] [PATCH 05/10] OvmfPkg/ResetVector: split SEV and non-CoCo workflows Gerd Hoffmann
2024-02-28 4:51 ` Laszlo Ersek
2024-02-22 11:54 ` [edk2-devel] [PATCH 06/10] OvmfPkg/ResetVector: add 5-level paging support Gerd Hoffmann
2024-02-28 5:33 ` Laszlo Ersek
2024-02-22 11:54 ` [edk2-devel] [PATCH 07/10] OvmfPkg/ResetVector: print post codes for 4/5 level paging Gerd Hoffmann
2024-02-28 5:35 ` Laszlo Ersek
2024-02-22 11:54 ` [edk2-devel] [PATCH 08/10] OvmfPkg/ResetVector: wire up 5-level paging for TDX Gerd Hoffmann
2024-02-28 5:44 ` Laszlo Ersek
2024-02-22 11:54 ` Gerd Hoffmann [this message]
2024-02-28 5:52 ` [edk2-devel] [PATCH 09/10] OvmfPkg/ResetVector: leave SEV VC handler installed longer Laszlo Ersek
2024-02-29 15:47 ` Lendacky, Thomas via groups.io
2024-02-22 11:54 ` [edk2-devel] [PATCH 10/10] OvmfPkg/ResetVector: wire up 5-level paging for SEV Gerd Hoffmann
2024-02-28 5:51 ` Laszlo Ersek
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