x86/sev: Rename mem_encrypt.c to mem_encrypt_amd.c
authorKuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
Mon, 6 Dec 2021 13:55:04 +0000 (16:55 +0300)
committerBorislav Petkov <bp@suse.de>
Wed, 8 Dec 2021 15:49:47 +0000 (16:49 +0100)
Both Intel TDX and AMD SEV implement memory encryption features. But the
bulk of the code in mem_encrypt.c is AMD-specific. Rename the file to
mem_encrypt_amd.c. A subsequent patch will extract the parts that can be
shared by both TDX and AMD SEV/SME into a generic file.

No functional changes.

Signed-off-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Tony Luck <tony.luck@intel.com>
Reviewed-by: Tom Lendacky <thomas.lendacky@amd.com>
Tested-by: Tom Lendacky <thomas.lendacky@amd.com>
Link: https://lore.kernel.org/r/20211206135505.75045-3-kirill.shutemov@linux.intel.com
arch/x86/mm/Makefile
arch/x86/mm/mem_encrypt.c [deleted file]
arch/x86/mm/mem_encrypt_amd.c [new file with mode: 0644]

index 5864219221ca8991dfb21baab0bd7a353cbdeff1..c9c48064115367e067d99fb64c55ef222aa25ba6 100644 (file)
@@ -1,10 +1,10 @@
 # SPDX-License-Identifier: GPL-2.0
 # 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
@@ -12,7 +12,7 @@ KASAN_SANITIZE_mem_encrypt_identity.o := n
 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 +52,6 @@ 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_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
deleted file mode 100644 (file)
index b520021..0000000
+++ /dev/null
@@ -1,507 +0,0 @@
-// 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);
-}
-
-/* Override for DMA direct allocation check - ARCH_HAS_FORCE_DMA_UNENCRYPTED */
-bool force_dma_unencrypted(struct device *dev)
-{
-       /*
-        * For SEV, all DMA must be to unencrypted addresses.
-        */
-       if (cc_platform_has(CC_ATTR_GUEST_MEM_ENCRYPT))
-               return true;
-
-       /*
-        * For SME, all DMA must be to unencrypted addresses if the
-        * device does not support DMA to addresses that include the
-        * encryption mask.
-        */
-       if (cc_platform_has(CC_ATTR_HOST_MEM_ENCRYPT)) {
-               u64 dma_enc_mask = DMA_BIT_MASK(__ffs64(sme_me_mask));
-               u64 dma_dev_mask = min_not_zero(dev->coherent_dma_mask,
-                                               dev->bus_dma_limit);
-
-               if (dma_dev_mask <= dma_enc_mask)
-                       return true;
-       }
-
-       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:");
-
-       /* Secure Memory Encryption */
-       if (cc_platform_has(CC_ATTR_HOST_MEM_ENCRYPT)) {
-               /*
-                * SME is mutually exclusive with any of the SEV
-                * features below.
-                */
-               pr_cont(" SME\n");
-               return;
-       }
-
-       /* Secure Encrypted Virtualization */
-       if (cc_platform_has(CC_ATTR_GUEST_MEM_ENCRYPT))
-               pr_cont(" SEV");
-
-       /* Encrypted Register State */
-       if (cc_platform_has(CC_ATTR_GUEST_STATE_ENCRYPT))
-               pr_cont(" SEV-ES");
-
-       pr_cont("\n");
-}
-
-/* Architecture __weak replacement functions */
-void __init mem_encrypt_init(void)
-{
-       if (!sme_me_mask)
-               return;
-
-       /* Call into SWIOTLB to update the SWIOTLB DMA buffers */
-       swiotlb_update_mem_attributes();
-
-       print_mem_encrypt_feature_info();
-}
-
-int arch_has_restricted_virtio_memory_access(void)
-{
-       return cc_platform_has(CC_ATTR_GUEST_MEM_ENCRYPT);
-}
-EXPORT_SYMBOL_GPL(arch_has_restricted_virtio_memory_access);
diff --git a/arch/x86/mm/mem_encrypt_amd.c b/arch/x86/mm/mem_encrypt_amd.c
new file mode 100644 (file)
index 0000000..b520021
--- /dev/null
@@ -0,0 +1,507 @@
+// 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);
+}
+
+/* Override for DMA direct allocation check - ARCH_HAS_FORCE_DMA_UNENCRYPTED */
+bool force_dma_unencrypted(struct device *dev)
+{
+       /*
+        * For SEV, all DMA must be to unencrypted addresses.
+        */
+       if (cc_platform_has(CC_ATTR_GUEST_MEM_ENCRYPT))
+               return true;
+
+       /*
+        * For SME, all DMA must be to unencrypted addresses if the
+        * device does not support DMA to addresses that include the
+        * encryption mask.
+        */
+       if (cc_platform_has(CC_ATTR_HOST_MEM_ENCRYPT)) {
+               u64 dma_enc_mask = DMA_BIT_MASK(__ffs64(sme_me_mask));
+               u64 dma_dev_mask = min_not_zero(dev->coherent_dma_mask,
+                                               dev->bus_dma_limit);
+
+               if (dma_dev_mask <= dma_enc_mask)
+                       return true;
+       }
+
+       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:");
+
+       /* Secure Memory Encryption */
+       if (cc_platform_has(CC_ATTR_HOST_MEM_ENCRYPT)) {
+               /*
+                * SME is mutually exclusive with any of the SEV
+                * features below.
+                */
+               pr_cont(" SME\n");
+               return;
+       }
+
+       /* Secure Encrypted Virtualization */
+       if (cc_platform_has(CC_ATTR_GUEST_MEM_ENCRYPT))
+               pr_cont(" SEV");
+
+       /* Encrypted Register State */
+       if (cc_platform_has(CC_ATTR_GUEST_STATE_ENCRYPT))
+               pr_cont(" SEV-ES");
+
+       pr_cont("\n");
+}
+
+/* Architecture __weak replacement functions */
+void __init mem_encrypt_init(void)
+{
+       if (!sme_me_mask)
+               return;
+
+       /* Call into SWIOTLB to update the SWIOTLB DMA buffers */
+       swiotlb_update_mem_attributes();
+
+       print_mem_encrypt_feature_info();
+}
+
+int arch_has_restricted_virtio_memory_access(void)
+{
+       return cc_platform_has(CC_ATTR_GUEST_MEM_ENCRYPT);
+}
+EXPORT_SYMBOL_GPL(arch_has_restricted_virtio_memory_access);