tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
arm64: mm: Add top-level dispatcher for internal mem_encrypt API
Implementing the internal mem_encrypt API for arm64 depends entirely on
the Confidential Computing environment in which the kernel is running.
Introduce a simple dispatcher so that backend hooks can be registered
depending upon the environment in which the kernel finds itself.
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Steven Price <steven.price@arm.com>
Acked-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20240830130150.8568-4-will@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>
+68
-1
+1
arch/arm64/Kconfig
+1
arch/arm64/Kconfig
···
34
34
select ARCH_HAS_KERNEL_FPU_SUPPORT if KERNEL_MODE_NEON
35
35
select ARCH_HAS_KEEPINITRD
36
36
select ARCH_HAS_MEMBARRIER_SYNC_CORE
37
+
select ARCH_HAS_MEM_ENCRYPT
37
38
select ARCH_HAS_NMI_SAFE_THIS_CPU_OPS
38
39
select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
39
40
select ARCH_HAS_PTE_DEVMAP
+15
arch/arm64/include/asm/mem_encrypt.h
+15
arch/arm64/include/asm/mem_encrypt.h
···
1
+
/* SPDX-License-Identifier: GPL-2.0-only */
2
+
#ifndef __ASM_MEM_ENCRYPT_H
3
+
#define __ASM_MEM_ENCRYPT_H
4
+
5
+
struct arm64_mem_crypt_ops {
6
+
int (*encrypt)(unsigned long addr, int numpages);
7
+
int (*decrypt)(unsigned long addr, int numpages);
8
+
};
9
+
10
+
int arm64_mem_crypt_ops_register(const struct arm64_mem_crypt_ops *ops);
11
+
12
+
int set_memory_encrypted(unsigned long addr, int numpages);
13
+
int set_memory_decrypted(unsigned long addr, int numpages);
14
+
15
+
#endif /* __ASM_MEM_ENCRYPT_H */
+1
arch/arm64/include/asm/set_memory.h
+1
arch/arm64/include/asm/set_memory.h
+1
-1
arch/arm64/mm/Makefile
+1
-1
arch/arm64/mm/Makefile
···
1
1
# SPDX-License-Identifier: GPL-2.0
2
2
obj-y := dma-mapping.o extable.o fault.o init.o \
3
3
cache.o copypage.o flush.o \
4
-
ioremap.o mmap.o pgd.o mmu.o \
4
+
ioremap.o mmap.o pgd.o mem_encrypt.o mmu.o \
5
5
context.o proc.o pageattr.o fixmap.o
6
6
obj-$(CONFIG_ARM64_CONTPTE) += contpte.o
7
7
obj-$(CONFIG_HUGETLB_PAGE) += hugetlbpage.o
+50
arch/arm64/mm/mem_encrypt.c
+50
arch/arm64/mm/mem_encrypt.c
···
1
+
// SPDX-License-Identifier: GPL-2.0-only
2
+
/*
3
+
* Implementation of the memory encryption/decryption API.
4
+
*
5
+
* Since the low-level details of the operation depend on the
6
+
* Confidential Computing environment (e.g. pKVM, CCA, ...), this just
7
+
* acts as a top-level dispatcher to whatever hooks may have been
8
+
* registered.
9
+
*
10
+
* Author: Will Deacon <will@kernel.org>
11
+
* Copyright (C) 2024 Google LLC
12
+
*
13
+
* "Hello, boils and ghouls!"
14
+
*/
15
+
16
+
#include <linux/bug.h>
17
+
#include <linux/compiler.h>
18
+
#include <linux/err.h>
19
+
#include <linux/mm.h>
20
+
21
+
#include <asm/mem_encrypt.h>
22
+
23
+
static const struct arm64_mem_crypt_ops *crypt_ops;
24
+
25
+
int arm64_mem_crypt_ops_register(const struct arm64_mem_crypt_ops *ops)
26
+
{
27
+
if (WARN_ON(crypt_ops))
28
+
return -EBUSY;
29
+
30
+
crypt_ops = ops;
31
+
return 0;
32
+
}
33
+
34
+
int set_memory_encrypted(unsigned long addr, int numpages)
35
+
{
36
+
if (likely(!crypt_ops) || WARN_ON(!PAGE_ALIGNED(addr)))
37
+
return 0;
38
+
39
+
return crypt_ops->encrypt(addr, numpages);
40
+
}
41
+
EXPORT_SYMBOL_GPL(set_memory_encrypted);
42
+
43
+
int set_memory_decrypted(unsigned long addr, int numpages)
44
+
{
45
+
if (likely(!crypt_ops) || WARN_ON(!PAGE_ALIGNED(addr)))
46
+
return 0;
47
+
48
+
return crypt_ops->decrypt(addr, numpages);
49
+
}
50
+
EXPORT_SYMBOL_GPL(set_memory_decrypted);