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authorLinus Torvalds <torvalds@linux-foundation.org>2022-01-10 09:33:40 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2022-01-10 09:33:40 -0800
commit01d5e7872c1c2c04f4fd419c9a4968e148efc5a0 (patch)
treed6fcd96823ceb11aa0baff08b890a5c065b6cd78
parentcd36722d74733b748ae812e37dcfe035b420de67 (diff)
parent20f07a044a76aebaaa0603038857229b5c460d69 (diff)
Merge tag 'x86_sev_for_v5.17_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 SEV updates from Borislav Petkov: "The accumulated pile of x86/sev generalizations and cleanups: - Share the SEV string unrolling logic with TDX as TDX guests need it too - Cleanups and generalzation of code shared by SEV and TDX" * tag 'x86_sev_for_v5.17_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/sev: Move common memory encryption code to mem_encrypt.c x86/sev: Rename mem_encrypt.c to mem_encrypt_amd.c x86/sev: Use CC_ATTR attribute to generalize string I/O unroll x86/sev: Remove do_early_exception() forward declarations x86/head64: Carve out the guest encryption postprocessing into a helper x86/sev: Get rid of excessive use of defines x86/sev: Shorten GHCB terminate macro names
-rw-r--r--arch/x86/Kconfig10
-rw-r--r--arch/x86/boot/compressed/sev.c6
-rw-r--r--arch/x86/include/asm/io.h20
-rw-r--r--arch/x86/include/asm/sev-common.h55
-rw-r--r--arch/x86/kernel/cc_platform.c8
-rw-r--r--arch/x86/kernel/head64.c60
-rw-r--r--arch/x86/kernel/sev-shared.c2
-rw-r--r--arch/x86/kernel/sev.c11
-rw-r--r--arch/x86/mm/Makefile7
-rw-r--r--arch/x86/mm/mem_encrypt.c441
-rw-r--r--arch/x86/mm/mem_encrypt_amd.c438
-rw-r--r--include/linux/cc_platform.h11
12 files changed, 545 insertions, 524 deletions
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 5c2ccb85f2ef..4e0fb37cee16 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -1523,16 +1523,20 @@ config X86_CPA_STATISTICS
helps to determine the effectiveness of preserving large and huge
page mappings when mapping protections are changed.
+config X86_MEM_ENCRYPT
+ select ARCH_HAS_FORCE_DMA_UNENCRYPTED
+ select DYNAMIC_PHYSICAL_MASK
+ select ARCH_HAS_RESTRICTED_VIRTIO_MEMORY_ACCESS
+ def_bool n
+
config AMD_MEM_ENCRYPT
bool "AMD Secure Memory Encryption (SME) support"
depends on X86_64 && CPU_SUP_AMD
select DMA_COHERENT_POOL
- select DYNAMIC_PHYSICAL_MASK
select ARCH_USE_MEMREMAP_PROT
- select ARCH_HAS_FORCE_DMA_UNENCRYPTED
select INSTRUCTION_DECODER
- select ARCH_HAS_RESTRICTED_VIRTIO_MEMORY_ACCESS
select ARCH_HAS_CC_PLATFORM
+ select X86_MEM_ENCRYPT
help
Say yes to enable support for the encryption of system memory.
This requires an AMD processor that supports Secure Memory
diff --git a/arch/x86/boot/compressed/sev.c b/arch/x86/boot/compressed/sev.c
index 670e998fe930..28bcf04c022e 100644
--- a/arch/x86/boot/compressed/sev.c
+++ b/arch/x86/boot/compressed/sev.c
@@ -122,7 +122,7 @@ static enum es_result vc_read_mem(struct es_em_ctxt *ctxt,
static bool early_setup_sev_es(void)
{
if (!sev_es_negotiate_protocol())
- sev_es_terminate(GHCB_SEV_ES_REASON_PROTOCOL_UNSUPPORTED);
+ sev_es_terminate(GHCB_SEV_ES_PROT_UNSUPPORTED);
if (set_page_decrypted((unsigned long)&boot_ghcb_page))
return false;
@@ -175,7 +175,7 @@ void do_boot_stage2_vc(struct pt_regs *regs, unsigned long exit_code)
enum es_result result;
if (!boot_ghcb && !early_setup_sev_es())
- sev_es_terminate(GHCB_SEV_ES_REASON_GENERAL_REQUEST);
+ sev_es_terminate(GHCB_SEV_ES_GEN_REQ);
vc_ghcb_invalidate(boot_ghcb);
result = vc_init_em_ctxt(&ctxt, regs, exit_code);
@@ -202,5 +202,5 @@ finish:
if (result == ES_OK)
vc_finish_insn(&ctxt);
else if (result != ES_RETRY)
- sev_es_terminate(GHCB_SEV_ES_REASON_GENERAL_REQUEST);
+ sev_es_terminate(GHCB_SEV_ES_GEN_REQ);
}
diff --git a/arch/x86/include/asm/io.h b/arch/x86/include/asm/io.h
index 5c6a4af0b911..f6d91ecb8026 100644
--- a/arch/x86/include/asm/io.h
+++ b/arch/x86/include/asm/io.h
@@ -40,6 +40,7 @@
#include <linux/string.h>
#include <linux/compiler.h>
+#include <linux/cc_platform.h>
#include <asm/page.h>
#include <asm/early_ioremap.h>
#include <asm/pgtable_types.h>
@@ -256,21 +257,6 @@ static inline void slow_down_io(void)
#endif
-#ifdef CONFIG_AMD_MEM_ENCRYPT
-#include <linux/jump_label.h>
-
-extern struct static_key_false sev_enable_key;
-static inline bool sev_key_active(void)
-{
- return static_branch_unlikely(&sev_enable_key);
-}
-
-#else /* !CONFIG_AMD_MEM_ENCRYPT */
-
-static inline bool sev_key_active(void) { return false; }
-
-#endif /* CONFIG_AMD_MEM_ENCRYPT */
-
#define BUILDIO(bwl, bw, type) \
static inline void out##bwl(unsigned type value, int port) \
{ \
@@ -301,7 +287,7 @@ static inline unsigned type in##bwl##_p(int port) \
\
static inline void outs##bwl(int port, const void *addr, unsigned long count) \
{ \
- if (sev_key_active()) { \
+ if (cc_platform_has(CC_ATTR_GUEST_UNROLL_STRING_IO)) { \
unsigned type *value = (unsigned type *)addr; \
while (count) { \
out##bwl(*value, port); \
@@ -317,7 +303,7 @@ static inline void outs##bwl(int port, const void *addr, unsigned long count) \
\
static inline void ins##bwl(int port, void *addr, unsigned long count) \
{ \
- if (sev_key_active()) { \
+ if (cc_platform_has(CC_ATTR_GUEST_UNROLL_STRING_IO)) { \
unsigned type *value = (unsigned type *)addr; \
while (count) { \
*value = in##bwl(port); \
diff --git a/arch/x86/include/asm/sev-common.h b/arch/x86/include/asm/sev-common.h
index 6acaf5af0a3d..1b2fd32b42fe 100644
--- a/arch/x86/include/asm/sev-common.h
+++ b/arch/x86/include/asm/sev-common.h
@@ -18,20 +18,19 @@
/* SEV Information Request/Response */
#define GHCB_MSR_SEV_INFO_RESP 0x001
#define GHCB_MSR_SEV_INFO_REQ 0x002
-#define GHCB_MSR_VER_MAX_POS 48
-#define GHCB_MSR_VER_MAX_MASK 0xffff
-#define GHCB_MSR_VER_MIN_POS 32
-#define GHCB_MSR_VER_MIN_MASK 0xffff
-#define GHCB_MSR_CBIT_POS 24
-#define GHCB_MSR_CBIT_MASK 0xff
-#define GHCB_MSR_SEV_INFO(_max, _min, _cbit) \
- ((((_max) & GHCB_MSR_VER_MAX_MASK) << GHCB_MSR_VER_MAX_POS) | \
- (((_min) & GHCB_MSR_VER_MIN_MASK) << GHCB_MSR_VER_MIN_POS) | \
- (((_cbit) & GHCB_MSR_CBIT_MASK) << GHCB_MSR_CBIT_POS) | \
+
+#define GHCB_MSR_SEV_INFO(_max, _min, _cbit) \
+ /* GHCBData[63:48] */ \
+ ((((_max) & 0xffff) << 48) | \
+ /* GHCBData[47:32] */ \
+ (((_min) & 0xffff) << 32) | \
+ /* GHCBData[31:24] */ \
+ (((_cbit) & 0xff) << 24) | \
GHCB_MSR_SEV_INFO_RESP)
+
#define GHCB_MSR_INFO(v) ((v) & 0xfffUL)
-#define GHCB_MSR_PROTO_MAX(v) (((v) >> GHCB_MSR_VER_MAX_POS) & GHCB_MSR_VER_MAX_MASK)
-#define GHCB_MSR_PROTO_MIN(v) (((v) >> GHCB_MSR_VER_MIN_POS) & GHCB_MSR_VER_MIN_MASK)
+#define GHCB_MSR_PROTO_MAX(v) (((v) >> 48) & 0xffff)
+#define GHCB_MSR_PROTO_MIN(v) (((v) >> 32) & 0xffff)
/* CPUID Request/Response */
#define GHCB_MSR_CPUID_REQ 0x004
@@ -46,30 +45,36 @@
#define GHCB_CPUID_REQ_EBX 1
#define GHCB_CPUID_REQ_ECX 2
#define GHCB_CPUID_REQ_EDX 3
-#define GHCB_CPUID_REQ(fn, reg) \
- (GHCB_MSR_CPUID_REQ | \
- (((unsigned long)reg & GHCB_MSR_CPUID_REG_MASK) << GHCB_MSR_CPUID_REG_POS) | \
- (((unsigned long)fn) << GHCB_MSR_CPUID_FUNC_POS))
+#define GHCB_CPUID_REQ(fn, reg) \
+ /* GHCBData[11:0] */ \
+ (GHCB_MSR_CPUID_REQ | \
+ /* GHCBData[31:12] */ \
+ (((unsigned long)(reg) & 0x3) << 30) | \
+ /* GHCBData[63:32] */ \
+ (((unsigned long)fn) << 32))
/* AP Reset Hold */
-#define GHCB_MSR_AP_RESET_HOLD_REQ 0x006
-#define GHCB_MSR_AP_RESET_HOLD_RESP 0x007
+#define GHCB_MSR_AP_RESET_HOLD_REQ 0x006
+#define GHCB_MSR_AP_RESET_HOLD_RESP 0x007
/* GHCB Hypervisor Feature Request/Response */
-#define GHCB_MSR_HV_FT_REQ 0x080
-#define GHCB_MSR_HV_FT_RESP 0x081
+#define GHCB_MSR_HV_FT_REQ 0x080
+#define GHCB_MSR_HV_FT_RESP 0x081
#define GHCB_MSR_TERM_REQ 0x100
#define GHCB_MSR_TERM_REASON_SET_POS 12
#define GHCB_MSR_TERM_REASON_SET_MASK 0xf
#define GHCB_MSR_TERM_REASON_POS 16
#define GHCB_MSR_TERM_REASON_MASK 0xff
-#define GHCB_SEV_TERM_REASON(reason_set, reason_val) \
- (((((u64)reason_set) & GHCB_MSR_TERM_REASON_SET_MASK) << GHCB_MSR_TERM_REASON_SET_POS) | \
- ((((u64)reason_val) & GHCB_MSR_TERM_REASON_MASK) << GHCB_MSR_TERM_REASON_POS))
-#define GHCB_SEV_ES_REASON_GENERAL_REQUEST 0
-#define GHCB_SEV_ES_REASON_PROTOCOL_UNSUPPORTED 1
+#define GHCB_SEV_TERM_REASON(reason_set, reason_val) \
+ /* GHCBData[15:12] */ \
+ (((((u64)reason_set) & 0xf) << 12) | \
+ /* GHCBData[23:16] */ \
+ ((((u64)reason_val) & 0xff) << 16))
+
+#define GHCB_SEV_ES_GEN_REQ 0
+#define GHCB_SEV_ES_PROT_UNSUPPORTED 1
#define GHCB_RESP_CODE(v) ((v) & GHCB_MSR_INFO_MASK)
diff --git a/arch/x86/kernel/cc_platform.c b/arch/x86/kernel/cc_platform.c
index 03bb2f343ddb..8a25b1c0d480 100644
--- a/arch/x86/kernel/cc_platform.c
+++ b/arch/x86/kernel/cc_platform.c
@@ -50,6 +50,14 @@ static bool amd_cc_platform_has(enum cc_attr attr)
case CC_ATTR_GUEST_STATE_ENCRYPT:
return sev_status & MSR_AMD64_SEV_ES_ENABLED;
+ /*
+ * With SEV, the rep string I/O instructions need to be unrolled
+ * but SEV-ES supports them through the #VC handler.
+ */
+ case CC_ATTR_GUEST_UNROLL_STRING_IO:
+ return (sev_status & MSR_AMD64_SEV_ENABLED) &&
+ !(sev_status & MSR_AMD64_SEV_ES_ENABLED);
+
default:
return false;
}
diff --git a/arch/x86/kernel/head64.c b/arch/x86/kernel/head64.c
index fc5371a7e9d1..3be9dd213dad 100644
--- a/arch/x86/kernel/head64.c
+++ b/arch/x86/kernel/head64.c
@@ -126,6 +126,36 @@ static bool __head check_la57_support(unsigned long physaddr)
}
#endif
+static unsigned long sme_postprocess_startup(struct boot_params *bp, pmdval_t *pmd)
+{
+ unsigned long vaddr, vaddr_end;
+ int i;
+
+ /* Encrypt the kernel and related (if SME is active) */
+ sme_encrypt_kernel(bp);
+
+ /*
+ * Clear the memory encryption mask from the .bss..decrypted section.
+ * The bss section will be memset to zero later in the initialization so
+ * there is no need to zero it after changing the memory encryption
+ * attribute.
+ */
+ if (sme_get_me_mask()) {
+ vaddr = (unsigned long)__start_bss_decrypted;
+ vaddr_end = (unsigned long)__end_bss_decrypted;
+ for (; vaddr < vaddr_end; vaddr += PMD_SIZE) {
+ i = pmd_index(vaddr);
+ pmd[i] -= sme_get_me_mask();
+ }
+ }
+
+ /*
+ * Return the SME encryption mask (if SME is active) to be used as a
+ * modifier for the initial pgdir entry programmed into CR3.
+ */
+ return sme_get_me_mask();
+}
+
/* Code in __startup_64() can be relocated during execution, but the compiler
* doesn't have to generate PC-relative relocations when accessing globals from
* that function. Clang actually does not generate them, which leads to
@@ -135,7 +165,6 @@ static bool __head check_la57_support(unsigned long physaddr)
unsigned long __head __startup_64(unsigned long physaddr,
struct boot_params *bp)
{
- unsigned long vaddr, vaddr_end;
unsigned long load_delta, *p;
unsigned long pgtable_flags;
pgdval_t *pgd;
@@ -276,34 +305,7 @@ unsigned long __head __startup_64(unsigned long physaddr,
*/
*fixup_long(&phys_base, physaddr) += load_delta - sme_get_me_mask();
- /* Encrypt the kernel and related (if SME is active) */
- sme_encrypt_kernel(bp);
-
- /*
- * Clear the memory encryption mask from the .bss..decrypted section.
- * The bss section will be memset to zero later in the initialization so
- * there is no need to zero it after changing the memory encryption
- * attribute.
- *
- * This is early code, use an open coded check for SME instead of
- * using cc_platform_has(). This eliminates worries about removing
- * instrumentation or checking boot_cpu_data in the cc_platform_has()
- * function.
- */
- if (sme_get_me_mask()) {
- vaddr = (unsigned long)__start_bss_decrypted;
- vaddr_end = (unsigned long)__end_bss_decrypted;
- for (; vaddr < vaddr_end; vaddr += PMD_SIZE) {
- i = pmd_index(vaddr);
- pmd[i] -= sme_get_me_mask();
- }
- }
-
- /*
- * Return the SME encryption mask (if SME is active) to be used as a
- * modifier for the initial pgdir entry programmed into CR3.
- */
- return sme_get_me_mask();
+ return sme_postprocess_startup(bp, pmd);
}
unsigned long __startup_secondary_64(void)
diff --git a/arch/x86/kernel/sev-shared.c b/arch/x86/kernel/sev-shared.c
index 787dc5f568b5..ce987688bbc0 100644
--- a/arch/x86/kernel/sev-shared.c
+++ b/arch/x86/kernel/sev-shared.c
@@ -221,7 +221,7 @@ void __init do_vc_no_ghcb(struct pt_regs *regs, unsigned long exit_code)
fail:
/* Terminate the guest */
- sev_es_terminate(GHCB_SEV_ES_REASON_GENERAL_REQUEST);
+ sev_es_terminate(GHCB_SEV_ES_GEN_REQ);
}
static enum es_result vc_insn_string_read(struct es_em_ctxt *ctxt,
diff --git a/arch/x86/kernel/sev.c b/arch/x86/kernel/sev.c
index a9fc2ac7a8bd..c9482f472ab6 100644
--- a/arch/x86/kernel/sev.c
+++ b/arch/x86/kernel/sev.c
@@ -26,6 +26,7 @@
#include <asm/fpu/xcr.h>
#include <asm/processor.h>
#include <asm/realmode.h>
+#include <asm/setup.h>
#include <asm/traps.h>
#include <asm/svm.h>
#include <asm/smp.h>
@@ -86,9 +87,6 @@ struct ghcb_state {
static DEFINE_PER_CPU(struct sev_es_runtime_data*, runtime_data);
DEFINE_STATIC_KEY_FALSE(sev_es_enable_key);
-/* Needed in vc_early_forward_exception */
-void do_early_exception(struct pt_regs *regs, int trapnr);
-
static __always_inline bool on_vc_stack(struct pt_regs *regs)
{
unsigned long sp = regs->sp;
@@ -209,9 +207,6 @@ static noinstr struct ghcb *__sev_get_ghcb(struct ghcb_state *state)
return ghcb;
}
-/* Needed in vc_early_forward_exception */
-void do_early_exception(struct pt_regs *regs, int trapnr);
-
static inline u64 sev_es_rd_ghcb_msr(void)
{
return __rdmsr(MSR_AMD64_SEV_ES_GHCB);
@@ -1432,7 +1427,7 @@ DEFINE_IDTENTRY_VC_KERNEL(exc_vmm_communication)
show_regs(regs);
/* Ask hypervisor to sev_es_terminate */
- sev_es_terminate(GHCB_SEV_ES_REASON_GENERAL_REQUEST);
+ sev_es_terminate(GHCB_SEV_ES_GEN_REQ);
/* If that fails and we get here - just panic */
panic("Returned from Terminate-Request to Hypervisor\n");
@@ -1480,7 +1475,7 @@ bool __init handle_vc_boot_ghcb(struct pt_regs *regs)
/* Do initial setup or terminate the guest */
if (unlikely(boot_ghcb == NULL && !sev_es_setup_ghcb()))
- sev_es_terminate(GHCB_SEV_ES_REASON_GENERAL_REQUEST);
+ sev_es_terminate(GHCB_SEV_ES_GEN_REQ);
vc_ghcb_invalidate(boot_ghcb);
diff --git a/arch/x86/mm/Makefile b/arch/x86/mm/Makefile
index 5864219221ca..fe3d3061fc11 100644
--- a/arch/x86/mm/Makefile
+++ b/arch/x86/mm/Makefile
@@ -2,9 +2,11 @@
# Kernel does not boot with instrumentation of tlb.c and mem_encrypt*.c
KCOV_INSTRUMENT_tlb.o := n
KCOV_INSTRUMENT_mem_encrypt.o := n
+KCOV_INSTRUMENT_mem_encrypt_amd.o := n
KCOV_INSTRUMENT_mem_encrypt_identity.o := n
KASAN_SANITIZE_mem_encrypt.o := n
+KASAN_SANITIZE_mem_encrypt_amd.o := n
KASAN_SANITIZE_mem_encrypt_identity.o := n
# Disable KCSAN entirely, because otherwise we get warnings that some functions
@@ -13,6 +15,7 @@ KCSAN_SANITIZE := n
ifdef CONFIG_FUNCTION_TRACER
CFLAGS_REMOVE_mem_encrypt.o = -pg
+CFLAGS_REMOVE_mem_encrypt_amd.o = -pg
CFLAGS_REMOVE_mem_encrypt_identity.o = -pg
endif
@@ -52,6 +55,8 @@ obj-$(CONFIG_X86_INTEL_MEMORY_PROTECTION_KEYS) += pkeys.o
obj-$(CONFIG_RANDOMIZE_MEMORY) += kaslr.o
obj-$(CONFIG_PAGE_TABLE_ISOLATION) += pti.o
-obj-$(CONFIG_AMD_MEM_ENCRYPT) += mem_encrypt.o
+obj-$(CONFIG_X86_MEM_ENCRYPT) += mem_encrypt.o
+obj-$(CONFIG_AMD_MEM_ENCRYPT) += mem_encrypt_amd.o
+
obj-$(CONFIG_AMD_MEM_ENCRYPT) += mem_encrypt_identity.o
obj-$(CONFIG_AMD_MEM_ENCRYPT) += mem_encrypt_boot.o
diff --git a/arch/x86/mm/mem_encrypt.c b/arch/x86/mm/mem_encrypt.c
index 35487305d8af..50d209939c66 100644
--- a/arch/x86/mm/mem_encrypt.c
+++ b/arch/x86/mm/mem_encrypt.c
@@ -1,419 +1,18 @@
// SPDX-License-Identifier: GPL-2.0-only
/*
- * AMD Memory Encryption Support
+ * Memory Encryption Support Common Code
*
* Copyright (C) 2016 Advanced Micro Devices, Inc.
*
* Author: Tom Lendacky <thomas.lendacky@amd.com>
*/
-#define DISABLE_BRANCH_PROFILING
-
-#include <linux/linkage.h>
-#include <linux/init.h>
-#include <linux/mm.h>
#include <linux/dma-direct.h>
+#include <linux/dma-mapping.h>
#include <linux/swiotlb.h>
+#include <linux/cc_platform.h>
#include <linux/mem_encrypt.h>
-#include <linux/device.h>
-#include <linux/kernel.h>
-#include <linux/bitops.h>
-#include <linux/dma-mapping.h>
#include <linux/virtio_config.h>
-#include <linux/cc_platform.h>
-
-#include <asm/tlbflush.h>
-#include <asm/fixmap.h>
-#include <asm/setup.h>
-#include <asm/bootparam.h>
-#include <asm/set_memory.h>
-#include <asm/cacheflush.h>
-#include <asm/processor-flags.h>
-#include <asm/msr.h>
-#include <asm/cmdline.h>
-
-#include "mm_internal.h"
-
-/*
- * Since SME related variables are set early in the boot process they must
- * reside in the .data section so as not to be zeroed out when the .bss
- * section is later cleared.
- */
-u64 sme_me_mask __section(".data") = 0;
-u64 sev_status __section(".data") = 0;
-u64 sev_check_data __section(".data") = 0;
-EXPORT_SYMBOL(sme_me_mask);
-DEFINE_STATIC_KEY_FALSE(sev_enable_key);
-EXPORT_SYMBOL_GPL(sev_enable_key);
-
-/* Buffer used for early in-place encryption by BSP, no locking needed */
-static char sme_early_buffer[PAGE_SIZE] __initdata __aligned(PAGE_SIZE);
-
-/*
- * This routine does not change the underlying encryption setting of the
- * page(s) that map this memory. It assumes that eventually the memory is
- * meant to be accessed as either encrypted or decrypted but the contents
- * are currently not in the desired state.
- *
- * This routine follows the steps outlined in the AMD64 Architecture
- * Programmer's Manual Volume 2, Section 7.10.8 Encrypt-in-Place.
- */
-static void __init __sme_early_enc_dec(resource_size_t paddr,
- unsigned long size, bool enc)
-{
- void *src, *dst;
- size_t len;
-
- if (!sme_me_mask)
- return;
-
- wbinvd();
-
- /*
- * There are limited number of early mapping slots, so map (at most)
- * one page at time.
- */
- while (size) {
- len = min_t(size_t, sizeof(sme_early_buffer), size);
-
- /*
- * Create mappings for the current and desired format of
- * the memory. Use a write-protected mapping for the source.
- */
- src = enc ? early_memremap_decrypted_wp(paddr, len) :
- early_memremap_encrypted_wp(paddr, len);
-
- dst = enc ? early_memremap_encrypted(paddr, len) :
- early_memremap_decrypted(paddr, len);
-
- /*
- * If a mapping can't be obtained to perform the operation,
- * then eventual access of that area in the desired mode
- * will cause a crash.
- */
- BUG_ON(!src || !dst);
-
- /*
- * Use a temporary buffer, of cache-line multiple size, to
- * avoid data corruption as documented in the APM.
- */
- memcpy(sme_early_buffer, src, len);
- memcpy(dst, sme_early_buffer, len);
-
- early_memunmap(dst, len);
- early_memunmap(src, len);
-
- paddr += len;
- size -= len;
- }
-}
-
-void __init sme_early_encrypt(resource_size_t paddr, unsigned long size)
-{
- __sme_early_enc_dec(paddr, size, true);
-}
-
-void __init sme_early_decrypt(resource_size_t paddr, unsigned long size)
-{
- __sme_early_enc_dec(paddr, size, false);
-}
-
-static void __init __sme_early_map_unmap_mem(void *vaddr, unsigned long size,
- bool map)
-{
- unsigned long paddr = (unsigned long)vaddr - __PAGE_OFFSET;
- pmdval_t pmd_flags, pmd;
-
- /* Use early_pmd_flags but remove the encryption mask */
- pmd_flags = __sme_clr(early_pmd_flags);
-
- do {
- pmd = map ? (paddr & PMD_MASK) + pmd_flags : 0;
- __early_make_pgtable((unsigned long)vaddr, pmd);
-
- vaddr += PMD_SIZE;
- paddr += PMD_SIZE;
- size = (size <= PMD_SIZE) ? 0 : size - PMD_SIZE;
- } while (size);
-
- flush_tlb_local();
-}
-
-void __init sme_unmap_bootdata(char *real_mode_data)
-{
- struct boot_params *boot_data;
- unsigned long cmdline_paddr;
-
- if (!cc_platform_has(CC_ATTR_HOST_MEM_ENCRYPT))
- return;
-
- /* Get the command line address before unmapping the real_mode_data */
- boot_data = (struct boot_params *)real_mode_data;
- cmdline_paddr = boot_data->hdr.cmd_line_ptr | ((u64)boot_data->ext_cmd_line_ptr << 32);
-
- __sme_early_map_unmap_mem(real_mode_data, sizeof(boot_params), false);
-
- if (!cmdline_paddr)
- return;
-
- __sme_early_map_unmap_mem(__va(cmdline_paddr), COMMAND_LINE_SIZE, false);
-}
-
-void __init sme_map_bootdata(char *real_mode_data)
-{
- struct boot_params *boot_data;
- unsigned long cmdline_paddr;
-
- if (!cc_platform_has(CC_ATTR_HOST_MEM_ENCRYPT))
- return;
-
- __sme_early_map_unmap_mem(real_mode_data, sizeof(boot_params), true);
-
- /* Get the command line address after mapping the real_mode_data */
- boot_data = (struct boot_params *)real_mode_data;
- cmdline_paddr = boot_data->hdr.cmd_line_ptr | ((u64)boot_data->ext_cmd_line_ptr << 32);
-
- if (!cmdline_paddr)
- return;
-
- __sme_early_map_unmap_mem(__va(cmdline_paddr), COMMAND_LINE_SIZE, true);
-}
-
-void __init sme_early_init(void)
-{
- unsigned int i;
-
- if (!sme_me_mask)
- return;
-
- early_pmd_flags = __sme_set(early_pmd_flags);
-
- __supported_pte_mask = __sme_set(__supported_pte_mask);
-
- /* Update the protection map with memory encryption mask */
- for (i = 0; i < ARRAY_SIZE(protection_map); i++)
- protection_map[i] = pgprot_encrypted(protection_map[i]);
-
- if (cc_platform_has(CC_ATTR_GUEST_MEM_ENCRYPT))
- swiotlb_force = SWIOTLB_FORCE;
-}
-
-void __init sev_setup_arch(void)
-{
- phys_addr_t total_mem = memblock_phys_mem_size();
- unsigned long size;
-
- if (!cc_platform_has(CC_ATTR_GUEST_MEM_ENCRYPT))
- return;
-
- /*
- * For SEV, all DMA has to occur via shared/unencrypted pages.
- * SEV uses SWIOTLB to make this happen without changing device
- * drivers. However, depending on the workload being run, the
- * default 64MB of SWIOTLB may not be enough and SWIOTLB may
- * run out of buffers for DMA, resulting in I/O errors and/or
- * performance degradation especially with high I/O workloads.
- *
- * Adjust the default size of SWIOTLB for SEV guests using
- * a percentage of guest memory for SWIOTLB buffers.
- * Also, as the SWIOTLB bounce buffer memory is allocated
- * from low memory, ensure that the adjusted size is within
- * the limits of low available memory.
- *
- * The percentage of guest memory used here for SWIOTLB buffers
- * is more of an approximation of the static adjustment which
- * 64MB for <1G, and ~128M to 256M for 1G-to-4G, i.e., the 6%
- */
- size = total_mem * 6 / 100;
- size = clamp_val(size, IO_TLB_DEFAULT_SIZE, SZ_1G);
- swiotlb_adjust_size(size);
-}
-
-static unsigned long pg_level_to_pfn(int level, pte_t *kpte, pgprot_t *ret_prot)
-{
- unsigned long pfn = 0;
- pgprot_t prot;
-
- switch (level) {
- case PG_LEVEL_4K:
- pfn = pte_pfn(*kpte);
- prot = pte_pgprot(*kpte);
- break;
- case PG_LEVEL_2M:
- pfn = pmd_pfn(*(pmd_t *)kpte);
- prot = pmd_pgprot(*(pmd_t *)kpte);
- break;
- case PG_LEVEL_1G:
- pfn = pud_pfn(*(pud_t *)kpte);
- prot = pud_pgprot(*(pud_t *)kpte);
- break;
- default:
- WARN_ONCE(1, "Invalid level for kpte\n");
- return 0;
- }
-
- if (ret_prot)
- *ret_prot = prot;
-
- return pfn;
-}
-
-void notify_range_enc_status_changed(unsigned long vaddr, int npages, bool enc)
-{
-#ifdef CONFIG_PARAVIRT
- unsigned long sz = npages << PAGE_SHIFT;
- unsigned long vaddr_end = vaddr + sz;
-
- while (vaddr < vaddr_end) {
- int psize, pmask, level;
- unsigned long pfn;
- pte_t *kpte;
-
- kpte = lookup_address(vaddr, &level);
- if (!kpte || pte_none(*kpte)) {
- WARN_ONCE(1, "kpte lookup for vaddr\n");
- return;
- }
-
- pfn = pg_level_to_pfn(level, kpte, NULL);
- if (!pfn)
- continue;
-
- psize = page_level_size(level);
- pmask = page_level_mask(level);
-
- notify_page_enc_status_changed(pfn, psize >> PAGE_SHIFT, enc);
-
- vaddr = (vaddr & pmask) + psize;
- }
-#endif
-}
-
-static void __init __set_clr_pte_enc(pte_t *kpte, int level, bool enc)
-{
- pgprot_t old_prot, new_prot;
- unsigned long pfn, pa, size;
- pte_t new_pte;
-
- pfn = pg_level_to_pfn(level, kpte, &old_prot);
- if (!pfn)
- return;
-
- new_prot = old_prot;
- if (enc)
- pgprot_val(new_prot) |= _PAGE_ENC;
- else
- pgprot_val(new_prot) &= ~_PAGE_ENC;
-
- /* If prot is same then do nothing. */
- if (pgprot_val(old_prot) == pgprot_val(new_prot))
- return;
-
- pa = pfn << PAGE_SHIFT;
- size = page_level_size(level);
-
- /*
- * We are going to perform in-place en-/decryption and change the
- * physical page attribute from C=1 to C=0 or vice versa. Flush the
- * caches to ensure that data gets accessed with the correct C-bit.
- */
- clflush_cache_range(__va(pa), size);
-
- /* Encrypt/decrypt the contents in-place */
- if (enc)
- sme_early_encrypt(pa, size);
- else
- sme_early_decrypt(pa, size);
-
- /* Change the page encryption mask. */
- new_pte = pfn_pte(pfn, new_prot);
- set_pte_atomic(kpte, new_pte);
-}
-
-static int __init early_set_memory_enc_dec(unsigned long vaddr,
- unsigned long size, bool enc)
-{
- unsigned long vaddr_end, vaddr_next, start;
- unsigned long psize, pmask;
- int split_page_size_mask;
- int level, ret;
- pte_t *kpte;
-
- start = vaddr;
- vaddr_next = vaddr;
- vaddr_end = vaddr + size;
-
- for (; vaddr < vaddr_end; vaddr = vaddr_next) {
- kpte = lookup_address(vaddr, &level);
- if (!kpte || pte_none(*kpte)) {
- ret = 1;
- goto out;
- }
-
- if (level == PG_LEVEL_4K) {
- __set_clr_pte_enc(kpte, level, enc);
- vaddr_next = (vaddr & PAGE_MASK) + PAGE_SIZE;
- continue;
- }
-
- psize = page_level_size(level);
- pmask = page_level_mask(level);
-
- /*
- * Check whether we can change the large page in one go.
- * We request a split when the address is not aligned and
- * the number of pages to set/clear encryption bit is smaller
- * than the number of pages in the large page.
- */
- if (vaddr == (vaddr & pmask) &&
- ((vaddr_end - vaddr) >= psize)) {
- __set_clr_pte_enc(kpte, level, enc);
- vaddr_next = (vaddr & pmask) + psize;
- continue;
- }
-
- /*
- * The virtual address is part of a larger page, create the next
- * level page table mapping (4K or 2M). If it is part of a 2M
- * page then we request a split of the large page into 4K
- * chunks. A 1GB large page is split into 2M pages, resp.
- */
- if (level == PG_LEVEL_2M)
- split_page_size_mask = 0;
- else
- split_page_size_mask = 1 << PG_LEVEL_2M;
-
- /*
- * kernel_physical_mapping_change() does not flush the TLBs, so
- * a TLB flush is required after we exit from the for loop.
- */
- kernel_physical_mapping_change(__pa(vaddr & pmask),
- __pa((vaddr_end & pmask) + psize),
- split_page_size_mask);
- }
-
- ret = 0;
-
- notify_range_enc_status_changed(start, PAGE_ALIGN(size) >> PAGE_SHIFT, enc);
-out:
- __flush_tlb_all();
- return ret;
-}
-
-int __init early_set_memory_decrypted(unsigned long vaddr, unsigned long size)
-{
- return early_set_memory_enc_dec(vaddr, size, false);
-}
-
-int __init early_set_memory_encrypted(unsigned long vaddr, unsigned long size)
-{
- return early_set_memory_enc_dec(vaddr, size, true);
-}
-
-void __init early_set_mem_enc_dec_hypercall(unsigned long vaddr, int npages, bool enc)
-{
- notify_range_enc_status_changed(vaddr, npages, enc);
-}
/* Override for DMA direct allocation check - ARCH_HAS_FORCE_DMA_UNENCRYPTED */
bool force_dma_unencrypted(struct device *dev)
@@ -441,30 +40,6 @@ bool force_dma_unencrypted(struct device *dev)
return false;
}
-void __init mem_encrypt_free_decrypted_mem(void)
-{
- unsigned long vaddr, vaddr_end, npages;
- int r;
-
- vaddr = (unsigned long)__start_bss_decrypted_unused;
- vaddr_end = (unsigned long)__end_bss_decrypted;
- npages = (vaddr_end - vaddr) >> PAGE_SHIFT;
-
- /*
- * The unused memory range was mapped decrypted, change the encryption
- * attribute from decrypted to encrypted before freeing it.
- */
- if (cc_platform_has(CC_ATTR_MEM_ENCRYPT)) {
- r = set_memory_encrypted(vaddr, npages);
- if (r) {
- pr_warn("failed to free unused decrypted pages\n");
- return;
- }
- }
-
- free_init_pages("unused decrypted", vaddr, vaddr_end);
-}
-
static void print_mem_encrypt_feature_info(void)
{
pr_info("AMD Memory Encryption Features active:");
@@ -493,20 +68,12 @@ static void print_mem_encrypt_feature_info(void)
/* Architecture __weak replacement functions */
void __init mem_encrypt_init(void)
{
- if (!sme_me_mask)
+ if (!cc_platform_has(CC_ATTR_MEM_ENCRYPT))
return;
/* Call into SWIOTLB to update the SWIOTLB DMA buffers */
swiotlb_update_mem_attributes();
- /*
- * With SEV, we need to unroll the rep string I/O instructions,
- * but SEV-ES supports them through the #VC handler.
- */
- if (cc_platform_has(CC_ATTR_GUEST_MEM_ENCRYPT) &&
- !cc_platform_has(CC_ATTR_GUEST_STATE_ENCRYPT))
- static_branch_enable(&sev_enable_key);
-
print_mem_encrypt_feature_info();
}
diff --git a/arch/x86/mm/mem_encrypt_amd.c b/arch/x86/mm/mem_encrypt_amd.c
new file mode 100644
index 000000000000..2b2d018ea345
--- /dev/null
+++ b/arch/x86/mm/mem_encrypt_amd.c
@@ -0,0 +1,438 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * AMD Memory Encryption Support
+ *
+ * Copyright (C) 2016 Advanced Micro Devices, Inc.
+ *
+ * Author: Tom Lendacky <thomas.lendacky@amd.com>
+ */
+
+#define DISABLE_BRANCH_PROFILING
+
+#include <linux/linkage.h>
+#include <linux/init.h>
+#include <linux/mm.h>
+#include <linux/dma-direct.h>
+#include <linux/swiotlb.h>
+#include <linux/mem_encrypt.h>
+#include <linux/device.h>
+#include <linux/kernel.h>
+#include <linux/bitops.h>
+#include <linux/dma-mapping.h>
+#include <linux/virtio_config.h>
+#include <linux/cc_platform.h>
+
+#include <asm/tlbflush.h>
+#include <asm/fixmap.h>
+#include <asm/setup.h>
+#include <asm/bootparam.h>
+#include <asm/set_memory.h>
+#include <asm/cacheflush.h>
+#include <asm/processor-flags.h>
+#include <asm/msr.h>
+#include <asm/cmdline.h>
+
+#include "mm_internal.h"
+
+/*
+ * Since SME related variables are set early in the boot process they must
+ * reside in the .data section so as not to be zeroed out when the .bss
+ * section is later cleared.
+ */
+u64 sme_me_mask __section(".data") = 0;
+u64 sev_status __section(".data") = 0;
+u64 sev_check_data __section(".data") = 0;
+EXPORT_SYMBOL(sme_me_mask);
+
+/* Buffer used for early in-place encryption by BSP, no locking needed */
+static char sme_early_buffer[PAGE_SIZE] __initdata __aligned(PAGE_SIZE);
+
+/*
+ * This routine does not change the underlying encryption setting of the
+ * page(s) that map this memory. It assumes that eventually the memory is
+ * meant to be accessed as either encrypted or decrypted but the contents
+ * are currently not in the desired state.
+ *
+ * This routine follows the steps outlined in the AMD64 Architecture
+ * Programmer's Manual Volume 2, Section 7.10.8 Encrypt-in-Place.
+ */
+static void __init __sme_early_enc_dec(resource_size_t paddr,
+ unsigned long size, bool enc)
+{
+ void *src, *dst;
+ size_t len;
+
+ if (!sme_me_mask)
+ return;
+
+ wbinvd();
+
+ /*
+ * There are limited number of early mapping slots, so map (at most)
+ * one page at time.
+ */
+ while (size) {
+ len = min_t(size_t, sizeof(sme_early_buffer), size);
+
+ /*
+ * Create mappings for the current and desired format of
+ * the memory. Use a write-protected mapping for the source.
+ */
+ src = enc ? early_memremap_decrypted_wp(paddr, len) :
+ early_memremap_encrypted_wp(paddr, len);
+
+ dst = enc ? early_memremap_encrypted(paddr, len) :
+ early_memremap_decrypted(paddr, len);
+
+ /*
+ * If a mapping can't be obtained to perform the operation,
+ * then eventual access of that area in the desired mode
+ * will cause a crash.
+ */
+ BUG_ON(!src || !dst);
+
+ /*
+ * Use a temporary buffer, of cache-line multiple size, to
+ * avoid data corruption as documented in the APM.
+ */
+ memcpy(sme_early_buffer, src, len);
+ memcpy(dst, sme_early_buffer, len);
+
+ early_memunmap(dst, len);
+ early_memunmap(src, len);
+
+ paddr += len;
+ size -= len;
+ }
+}
+
+void __init sme_early_encrypt(resource_size_t paddr, unsigned long size)
+{
+ __sme_early_enc_dec(paddr, size, true);
+}
+
+void __init sme_early_decrypt(resource_size_t paddr, unsigned long size)
+{
+ __sme_early_enc_dec(paddr, size, false);
+}
+
+static void __init __sme_early_map_unmap_mem(void *vaddr, unsigned long size,
+ bool map)
+{
+ unsigned long paddr = (unsigned long)vaddr - __PAGE_OFFSET;
+ pmdval_t pmd_flags, pmd;
+
+ /* Use early_pmd_flags but remove the encryption mask */
+ pmd_flags = __sme_clr(early_pmd_flags);
+
+ do {
+ pmd = map ? (paddr & PMD_MASK) + pmd_flags : 0;
+ __early_make_pgtable((unsigned long)vaddr, pmd);
+
+ vaddr += PMD_SIZE;
+ paddr += PMD_SIZE;
+ size = (size <= PMD_SIZE) ? 0 : size - PMD_SIZE;
+ } while (size);
+
+ flush_tlb_local();
+}
+
+void __init sme_unmap_bootdata(char *real_mode_data)
+{
+ struct boot_params *boot_data;
+ unsigned long cmdline_paddr;
+
+ if (!cc_platform_has(CC_ATTR_HOST_MEM_ENCRYPT))
+ return;
+
+ /* Get the command line address before unmapping the real_mode_data */
+ boot_data = (struct boot_params *)real_mode_data;
+ cmdline_paddr = boot_data->hdr.cmd_line_ptr | ((u64)boot_data->ext_cmd_line_ptr << 32);
+
+ __sme_early_map_unmap_mem(real_mode_data, sizeof(boot_params), false);
+
+ if (!cmdline_paddr)
+ return;
+
+ __sme_early_map_unmap_mem(__va(cmdline_paddr), COMMAND_LINE_SIZE, false);
+}
+
+void __init sme_map_bootdata(char *real_mode_data)
+{
+ struct boot_params *boot_data;
+ unsigned long cmdline_paddr;
+
+ if (!cc_platform_has(CC_ATTR_HOST_MEM_ENCRYPT))
+ return;
+
+ __sme_early_map_unmap_mem(real_mode_data, sizeof(boot_params), true);
+
+ /* Get the command line address after mapping the real_mode_data */
+ boot_data = (struct boot_params *)real_mode_data;
+ cmdline_paddr = boot_data->hdr.cmd_line_ptr | ((u64)boot_data->ext_cmd_line_ptr << 32);
+
+ if (!cmdline_paddr)
+ return;
+
+ __sme_early_map_unmap_mem(__va(cmdline_paddr), COMMAND_LINE_SIZE, true);
+}
+
+void __init sme_early_init(void)
+{
+ unsigned int i;
+
+ if (!sme_me_mask)
+ return;
+
+ early_pmd_flags = __sme_set(early_pmd_flags);
+
+ __supported_pte_mask = __sme_set(__supported_pte_mask);
+
+ /* Update the protection map with memory encryption mask */
+ for (i = 0; i < ARRAY_SIZE(protection_map); i++)
+ protection_map[i] = pgprot_encrypted(protection_map[i]);
+
+ if (cc_platform_has(CC_ATTR_GUEST_MEM_ENCRYPT))
+ swiotlb_force = SWIOTLB_FORCE;
+}
+
+void __init sev_setup_arch(void)
+{
+ phys_addr_t total_mem = memblock_phys_mem_size();
+ unsigned long size;
+
+ if (!cc_platform_has(CC_ATTR_GUEST_MEM_ENCRYPT))
+ return;
+
+ /*
+ * For SEV, all DMA has to occur via shared/unencrypted pages.
+ * SEV uses SWIOTLB to make this happen without changing device
+ * drivers. However, depending on the workload being run, the
+ * default 64MB of SWIOTLB may not be enough and SWIOTLB may
+ * run out of buffers for DMA, resulting in I/O errors and/or
+ * performance degradation especially with high I/O workloads.
+ *
+ * Adjust the default size of SWIOTLB for SEV guests using
+ * a percentage of guest memory for SWIOTLB buffers.
+ * Also, as the SWIOTLB bounce buffer memory is allocated
+ * from low memory, ensure that the adjusted size is within
+ * the limits of low available memory.
+ *
+ * The percentage of guest memory used here for SWIOTLB buffers
+ * is more of an approximation of the static adjustment which
+ * 64MB for <1G, and ~128M to 256M for 1G-to-4G, i.e., the 6%
+ */
+ size = total_mem * 6 / 100;
+ size = clamp_val(size, IO_TLB_DEFAULT_SIZE, SZ_1G);
+ swiotlb_adjust_size(size);
+}
+
+static unsigned long pg_level_to_pfn(int level, pte_t *kpte, pgprot_t *ret_prot)
+{
+ unsigned long pfn = 0;
+ pgprot_t prot;
+
+ switch (level) {
+ case PG_LEVEL_4K:
+ pfn = pte_pfn(*kpte);
+ prot = pte_pgprot(*kpte);
+ break;
+ case PG_LEVEL_2M:
+ pfn = pmd_pfn(*(pmd_t *)kpte);
+ prot = pmd_pgprot(*(pmd_t *)kpte);
+ break;
+ case PG_LEVEL_1G:
+ pfn = pud_pfn(*(pud_t *)kpte);
+ prot = pud_pgprot(*(pud_t *)kpte);
+ break;
+ default:
+ WARN_ONCE(1, "Invalid level for kpte\n");
+ return 0;
+ }
+
+ if (ret_prot)
+ *ret_prot = prot;
+
+ return pfn;
+}
+
+void notify_range_enc_status_changed(unsigned long vaddr, int npages, bool enc)
+{
+#ifdef CONFIG_PARAVIRT
+ unsigned long sz = npages << PAGE_SHIFT;
+ unsigned long vaddr_end = vaddr + sz;
+
+ while (vaddr < vaddr_end) {
+ int psize, pmask, level;
+ unsigned long pfn;
+ pte_t *kpte;
+
+ kpte = lookup_address(vaddr, &level);
+ if (!kpte || pte_none(*kpte)) {
+ WARN_ONCE(1, "kpte lookup for vaddr\n");
+ return;
+ }
+
+ pfn = pg_level_to_pfn(level, kpte, NULL);
+ if (!pfn)
+ continue;
+
+ psize = page_level_size(level);
+ pmask = page_level_mask(level);
+
+ notify_page_enc_status_changed(pfn, psize >> PAGE_SHIFT, enc);
+
+ vaddr = (vaddr & pmask) + psize;
+ }
+#endif
+}
+
+static void __init __set_clr_pte_enc(pte_t *kpte, int level, bool enc)
+{
+ pgprot_t old_prot, new_prot;
+ unsigned long pfn, pa, size;
+ pte_t new_pte;
+
+ pfn = pg_level_to_pfn(level, kpte, &old_prot);
+ if (!pfn)
+ return;
+
+ new_prot = old_prot;
+ if (enc)
+ pgprot_val(new_prot) |= _PAGE_ENC;
+ else
+ pgprot_val(new_prot) &= ~_PAGE_ENC;
+
+ /* If prot is same then do nothing. */
+ if (pgprot_val(old_prot) == pgprot_val(new_prot))
+ return;
+
+ pa = pfn << PAGE_SHIFT;
+ size = page_level_size(level);
+
+ /*
+ * We are going to perform in-place en-/decryption and change the
+ * physical page attribute from C=1 to C=0 or vice versa. Flush the
+ * caches to ensure that data gets accessed with the correct C-bit.
+ */
+ clflush_cache_range(__va(pa), size);
+
+ /* Encrypt/decrypt the contents in-place */
+ if (enc)
+ sme_early_encrypt(pa, size);
+ else
+ sme_early_decrypt(pa, size);
+
+ /* Change the page encryption mask. */
+ new_pte = pfn_pte(pfn, new_prot);
+ set_pte_atomic(kpte, new_pte);
+}
+
+static int __init early_set_memory_enc_dec(unsigned long vaddr,
+ unsigned long size, bool enc)
+{
+ unsigned long vaddr_end, vaddr_next, start;
+ unsigned long psize, pmask;
+ int split_page_size_mask;
+ int level, ret;
+ pte_t *kpte;
+
+ start = vaddr;
+ vaddr_next = vaddr;
+ vaddr_end = vaddr + size;
+
+ for (; vaddr < vaddr_end; vaddr = vaddr_next) {
+ kpte = lookup_address(vaddr, &level);
+ if (!kpte || pte_none(*kpte)) {
+ ret = 1;
+ goto out;
+ }
+
+ if (level == PG_LEVEL_4K) {
+ __set_clr_pte_enc(kpte, level, enc);
+ vaddr_next = (vaddr & PAGE_MASK) + PAGE_SIZE;
+ continue;
+ }
+
+ psize = page_level_size(level);
+ pmask = page_level_mask(level);
+
+ /*
+ * Check whether we can change the large page in one go.
+ * We request a split when the address is not aligned and
+ * the number of pages to set/clear encryption bit is smaller
+ * than the number of pages in the large page.
+ */
+ if (vaddr == (vaddr & pmask) &&
+ ((vaddr_end - vaddr) >= psize)) {
+ __set_clr_pte_enc(kpte, level, enc);
+ vaddr_next = (vaddr & pmask) + psize;
+ continue;
+ }
+
+ /*
+ * The virtual address is part of a larger page, create the next
+ * level page table mapping (4K or 2M). If it is part of a 2M
+ * page then we request a split of the large page into 4K
+ * chunks. A 1GB large page is split into 2M pages, resp.
+ */
+ if (level == PG_LEVEL_2M)
+ split_page_size_mask = 0;
+ else
+ split_page_size_mask = 1 << PG_LEVEL_2M;
+
+ /*
+ * kernel_physical_mapping_change() does not flush the TLBs, so
+ * a TLB flush is required after we exit from the for loop.
+ */
+ kernel_physical_mapping_change(__pa(vaddr & pmask),
+ __pa((vaddr_end & pmask) + psize),
+ split_page_size_mask);
+ }
+
+ ret = 0;
+
+ notify_range_enc_status_changed(start, PAGE_ALIGN(size) >> PAGE_SHIFT, enc);
+out:
+ __flush_tlb_all();
+ return ret;
+}
+
+int __init early_set_memory_decrypted(unsigned long vaddr, unsigned long size)
+{
+ return early_set_memory_enc_dec(vaddr, size, false);
+}
+
+int __init early_set_memory_encrypted(unsigned long vaddr, unsigned long size)
+{
+ return early_set_memory_enc_dec(vaddr, size, true);
+}
+
+void __init early_set_mem_enc_dec_hypercall(unsigned long vaddr, int npages, bool enc)
+{
+ notify_range_enc_status_changed(vaddr, npages, enc);
+}
+
+void __init mem_encrypt_free_decrypted_mem(void)
+{
+ unsigned long vaddr, vaddr_end, npages;
+ int r;
+
+ vaddr = (unsigned long)__start_bss_decrypted_unused;
+ vaddr_end = (unsigned long)__end_bss_decrypted;
+ npages = (vaddr_end - vaddr) >> PAGE_SHIFT;
+
+ /*
+ * The unused memory range was mapped decrypted, change the encryption
+ * attribute from decrypted to encrypted before freeing it.
+ */
+ if (cc_platform_has(CC_ATTR_MEM_ENCRYPT)) {
+ r = set_memory_encrypted(vaddr, npages);
+ if (r) {
+ pr_warn("failed to free unused decrypted pages\n");
+ return;
+ }
+ }
+
+ free_init_pages("unused decrypted", vaddr, vaddr_end);
+}
diff --git a/include/linux/cc_platform.h b/include/linux/cc_platform.h
index a075b70b9a70..efd8205282da 100644
--- a/include/linux/cc_platform.h
+++ b/include/linux/cc_platform.h
@@ -61,6 +61,17 @@ enum cc_attr {
* Examples include SEV-ES.
*/
CC_ATTR_GUEST_STATE_ENCRYPT,
+
+ /**
+ * @CC_ATTR_GUEST_UNROLL_STRING_IO: String I/O is implemented with
+ * IN/OUT instructions
+ *
+ * The platform/OS is running as a guest/virtual machine and uses
+ * IN/OUT instructions in place of string I/O.
+ *
+ * Examples include TDX guest & SEV.
+ */
+ CC_ATTR_GUEST_UNROLL_STRING_IO,
};
#ifdef CONFIG_ARCH_HAS_CC_PLATFORM