diff options
author | Linus Torvalds <torvalds@linux-foundation.org> | 2022-01-10 09:33:40 -0800 |
---|---|---|
committer | Linus Torvalds <torvalds@linux-foundation.org> | 2022-01-10 09:33:40 -0800 |
commit | 01d5e7872c1c2c04f4fd419c9a4968e148efc5a0 (patch) | |
tree | d6fcd96823ceb11aa0baff08b890a5c065b6cd78 | |
parent | cd36722d74733b748ae812e37dcfe035b420de67 (diff) | |
parent | 20f07a044a76aebaaa0603038857229b5c460d69 (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/Kconfig | 10 | ||||
-rw-r--r-- | arch/x86/boot/compressed/sev.c | 6 | ||||
-rw-r--r-- | arch/x86/include/asm/io.h | 20 | ||||
-rw-r--r-- | arch/x86/include/asm/sev-common.h | 55 | ||||
-rw-r--r-- | arch/x86/kernel/cc_platform.c | 8 | ||||
-rw-r--r-- | arch/x86/kernel/head64.c | 60 | ||||
-rw-r--r-- | arch/x86/kernel/sev-shared.c | 2 | ||||
-rw-r--r-- | arch/x86/kernel/sev.c | 11 | ||||
-rw-r--r-- | arch/x86/mm/Makefile | 7 | ||||
-rw-r--r-- | arch/x86/mm/mem_encrypt.c | 441 | ||||
-rw-r--r-- | arch/x86/mm/mem_encrypt_amd.c | 438 | ||||
-rw-r--r-- | include/linux/cc_platform.h | 11 |
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 |