From 1227418989346af3af179742cf42ce842e0ad484 Mon Sep 17 00:00:00 2001
From: Dov Murik <dovmurik@linux.ibm.com>
Date: Tue, 12 Apr 2022 21:21:24 +0000
Subject: efi: Save location of EFI confidential computing area
Confidential computing (coco) hardware such as AMD SEV (Secure Encrypted
Virtualization) allows a guest owner to inject secrets into the VMs
memory without the host/hypervisor being able to read them.
Firmware support for secret injection is available in OVMF, which
reserves a memory area for secret injection and includes a pointer to it
the in EFI config table entry LINUX_EFI_COCO_SECRET_TABLE_GUID.
If EFI exposes such a table entry, uefi_init() will keep a pointer to
the EFI config table entry in efi.coco_secret, so it can be used later
by the kernel (specifically drivers/virt/coco/efi_secret). It will also
appear in the kernel log as "CocoSecret=ADDRESS"; for example:
[ 0.000000] efi: EFI v2.70 by EDK II
[ 0.000000] efi: CocoSecret=0x7f22e680 SMBIOS=0x7f541000 ACPI=0x7f77e000 ACPI 2.0=0x7f77e014 MEMATTR=0x7ea0c018
The new functionality can be enabled with CONFIG_EFI_COCO_SECRET=y.
Signed-off-by: Dov Murik <dovmurik@linux.ibm.com>
Reviewed-by: Gerd Hoffmann <kraxel@redhat.com>
Link: https://lore.kernel.org/r/20220412212127.154182-2-dovmurik@linux.ibm.com
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
---
arch/x86/platform/efi/efi.c | 3 +++
1 file changed, 3 insertions(+)
(limited to 'arch/x86')
diff --git a/arch/x86/platform/efi/efi.c b/arch/x86/platform/efi/efi.c
index 147c30a81f15..1591d67e0bcd 100644
--- a/arch/x86/platform/efi/efi.c
+++ b/arch/x86/platform/efi/efi.c
@@ -93,6 +93,9 @@ static const unsigned long * const efi_tables[] = {
#ifdef CONFIG_LOAD_UEFI_KEYS
&efi.mokvar_table,
#endif
+#ifdef CONFIG_EFI_COCO_SECRET
+ &efi.coco_secret,
+#endif
};
u64 efi_setup; /* efi setup_data physical address */
--
cgit
From 3ba75c1316390b2bc39c19cb8f0f85922ab3f9ed Mon Sep 17 00:00:00 2001
From: Baskov Evgeniy <baskov@ispras.ru>
Date: Thu, 3 Mar 2022 17:21:19 +0300
Subject: efi: libstub: declare DXE services table
UEFI DXE services are not yet used in kernel code
but are required to manipulate page table memory
protection flags.
Add required declarations to use DXE services functions.
Signed-off-by: Baskov Evgeniy <baskov@ispras.ru>
Link: https://lore.kernel.org/r/20220303142120.1975-2-baskov@ispras.ru
[ardb: ignore absent DXE table but warn if the signature check fails]
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
---
arch/x86/include/asm/efi.h | 5 +++++
1 file changed, 5 insertions(+)
(limited to 'arch/x86')
diff --git a/arch/x86/include/asm/efi.h b/arch/x86/include/asm/efi.h
index 98938a68251c..bed74a0f2932 100644
--- a/arch/x86/include/asm/efi.h
+++ b/arch/x86/include/asm/efi.h
@@ -357,6 +357,11 @@ static inline u32 efi64_convert_status(efi_status_t status)
runtime), \
func, __VA_ARGS__))
+#define efi_dxe_call(func, ...) \
+ (efi_is_native() \
+ ? efi_dxe_table->func(__VA_ARGS__) \
+ : __efi64_thunk_map(efi_dxe_table, func, __VA_ARGS__))
+
#else /* CONFIG_EFI_MIXED */
static inline bool efi_is_64bit(void)
--
cgit
From 24b72bb12e84c75e297a5a81f24b921d7a011575 Mon Sep 17 00:00:00 2001
From: Peter Jones <pjones@redhat.com>
Date: Tue, 29 Mar 2022 14:47:43 -0400
Subject: efi: x86: Set the NX-compatibility flag in the PE header
Following Baskov Evgeniy's "Handle UEFI NX-restricted page tables"
patches, it's safe to set this compatibility flag to let loaders know
they don't need to make special accommodations for kernel to load if
pre-boot NX is enabled.
Signed-off-by: Peter Jones <pjones@redhat.com>
Link: https://lore.kernel.org/all/20220329184743.798513-1-pjones@redhat.com/
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
---
arch/x86/boot/header.S | 4 ++++
1 file changed, 4 insertions(+)
(limited to 'arch/x86')
diff --git a/arch/x86/boot/header.S b/arch/x86/boot/header.S
index 6dbd7e9f74c9..0352e4589efa 100644
--- a/arch/x86/boot/header.S
+++ b/arch/x86/boot/header.S
@@ -163,7 +163,11 @@ extra_header_fields:
.long 0x200 # SizeOfHeaders
.long 0 # CheckSum
.word IMAGE_SUBSYSTEM_EFI_APPLICATION # Subsystem (EFI application)
+#ifdef CONFIG_DXE_MEM_ATTRIBUTES
+ .word IMAGE_DLL_CHARACTERISTICS_NX_COMPAT # DllCharacteristics
+#else
.word 0 # DllCharacteristics
+#endif
#ifdef CONFIG_X86_32
.long 0 # SizeOfStackReserve
.long 0 # SizeOfStackCommit
--
cgit