#ifdef CONFIG_AMD_MEM_ENCRYPT
 
 extern u64 sme_me_mask;
+extern bool sev_enabled;
 
 void sme_encrypt_execute(unsigned long encrypted_kernel_vaddr,
                         unsigned long decrypted_kernel_vaddr,
 
 # 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
+# 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_identity.o := n
 
-KASAN_SANITIZE_mem_encrypt.o   := n
+KASAN_SANITIZE_mem_encrypt.o           := n
+KASAN_SANITIZE_mem_encrypt_identity.o  := n
 
 ifdef CONFIG_FUNCTION_TRACER
-CFLAGS_REMOVE_mem_encrypt.o    = -pg
+CFLAGS_REMOVE_mem_encrypt.o            = -pg
+CFLAGS_REMOVE_mem_encrypt_identity.o   = -pg
 endif
 
 obj-y  :=  init.o init_$(BITS).o fault.o ioremap.o extable.o pageattr.o mmap.o \
 obj-$(CONFIG_PAGE_TABLE_ISOLATION)             += pti.o
 
 obj-$(CONFIG_AMD_MEM_ENCRYPT)  += mem_encrypt.o
+obj-$(CONFIG_AMD_MEM_ENCRYPT)  += mem_encrypt_identity.o
 obj-$(CONFIG_AMD_MEM_ENCRYPT)  += mem_encrypt_boot.o
 
 #include <asm/bootparam.h>
 #include <asm/set_memory.h>
 #include <asm/cacheflush.h>
-#include <asm/sections.h>
 #include <asm/processor-flags.h>
 #include <asm/msr.h>
 #include <asm/cmdline.h>
 
 #include "mm_internal.h"
 
-static char sme_cmdline_arg[] __initdata = "mem_encrypt";
-static char sme_cmdline_on[]  __initdata = "on";
-static char sme_cmdline_off[] __initdata = "off";
-
 /*
  * 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
 DEFINE_STATIC_KEY_FALSE(sev_enable_key);
 EXPORT_SYMBOL_GPL(sev_enable_key);
 
-static bool sev_enabled __section(.data);
+bool sev_enabled __section(.data);
 
 /* Buffer used for early in-place encryption by BSP, no locking needed */
 static char sme_early_buffer[PAGE_SIZE] __aligned(PAGE_SIZE);
        /* Make the SWIOTLB buffer area decrypted */
        set_memory_decrypted((unsigned long)vaddr, size >> PAGE_SHIFT);
 }
-
-struct sme_populate_pgd_data {
-       void    *pgtable_area;
-       pgd_t   *pgd;
-
-       pmdval_t pmd_flags;
-       pteval_t pte_flags;
-       unsigned long paddr;
-
-       unsigned long vaddr;
-       unsigned long vaddr_end;
-};
-
-static void __init sme_clear_pgd(struct sme_populate_pgd_data *ppd)
-{
-       unsigned long pgd_start, pgd_end, pgd_size;
-       pgd_t *pgd_p;
-
-       pgd_start = ppd->vaddr & PGDIR_MASK;
-       pgd_end = ppd->vaddr_end & PGDIR_MASK;
-
-       pgd_size = (((pgd_end - pgd_start) / PGDIR_SIZE) + 1) * sizeof(pgd_t);
-
-       pgd_p = ppd->pgd + pgd_index(ppd->vaddr);
-
-       memset(pgd_p, 0, pgd_size);
-}
-
-#define PGD_FLAGS              _KERNPG_TABLE_NOENC
-#define P4D_FLAGS              _KERNPG_TABLE_NOENC
-#define PUD_FLAGS              _KERNPG_TABLE_NOENC
-#define PMD_FLAGS              _KERNPG_TABLE_NOENC
-
-#define PMD_FLAGS_LARGE                (__PAGE_KERNEL_LARGE_EXEC & ~_PAGE_GLOBAL)
-
-#define PMD_FLAGS_DEC          PMD_FLAGS_LARGE
-#define PMD_FLAGS_DEC_WP       ((PMD_FLAGS_DEC & ~_PAGE_CACHE_MASK) | \
-                                (_PAGE_PAT | _PAGE_PWT))
-
-#define PMD_FLAGS_ENC          (PMD_FLAGS_LARGE | _PAGE_ENC)
-
-#define PTE_FLAGS              (__PAGE_KERNEL_EXEC & ~_PAGE_GLOBAL)
-
-#define PTE_FLAGS_DEC          PTE_FLAGS
-#define PTE_FLAGS_DEC_WP       ((PTE_FLAGS_DEC & ~_PAGE_CACHE_MASK) | \
-                                (_PAGE_PAT | _PAGE_PWT))
-
-#define PTE_FLAGS_ENC          (PTE_FLAGS | _PAGE_ENC)
-
-static pmd_t __init *sme_prepare_pgd(struct sme_populate_pgd_data *ppd)
-{
-       pgd_t *pgd_p;
-       p4d_t *p4d_p;
-       pud_t *pud_p;
-       pmd_t *pmd_p;
-
-       pgd_p = ppd->pgd + pgd_index(ppd->vaddr);
-       if (native_pgd_val(*pgd_p)) {
-               if (IS_ENABLED(CONFIG_X86_5LEVEL))
-                       p4d_p = (p4d_t *)(native_pgd_val(*pgd_p) & ~PTE_FLAGS_MASK);
-               else
-                       pud_p = (pud_t *)(native_pgd_val(*pgd_p) & ~PTE_FLAGS_MASK);
-       } else {
-               pgd_t pgd;
-
-               if (IS_ENABLED(CONFIG_X86_5LEVEL)) {
-                       p4d_p = ppd->pgtable_area;
-                       memset(p4d_p, 0, sizeof(*p4d_p) * PTRS_PER_P4D);
-                       ppd->pgtable_area += sizeof(*p4d_p) * PTRS_PER_P4D;
-
-                       pgd = native_make_pgd((pgdval_t)p4d_p + PGD_FLAGS);
-               } else {
-                       pud_p = ppd->pgtable_area;
-                       memset(pud_p, 0, sizeof(*pud_p) * PTRS_PER_PUD);
-                       ppd->pgtable_area += sizeof(*pud_p) * PTRS_PER_PUD;
-
-                       pgd = native_make_pgd((pgdval_t)pud_p + PGD_FLAGS);
-               }
-               native_set_pgd(pgd_p, pgd);
-       }
-
-       if (IS_ENABLED(CONFIG_X86_5LEVEL)) {
-               p4d_p += p4d_index(ppd->vaddr);
-               if (native_p4d_val(*p4d_p)) {
-                       pud_p = (pud_t *)(native_p4d_val(*p4d_p) & ~PTE_FLAGS_MASK);
-               } else {
-                       p4d_t p4d;
-
-                       pud_p = ppd->pgtable_area;
-                       memset(pud_p, 0, sizeof(*pud_p) * PTRS_PER_PUD);
-                       ppd->pgtable_area += sizeof(*pud_p) * PTRS_PER_PUD;
-
-                       p4d = native_make_p4d((pudval_t)pud_p + P4D_FLAGS);
-                       native_set_p4d(p4d_p, p4d);
-               }
-       }
-
-       pud_p += pud_index(ppd->vaddr);
-       if (native_pud_val(*pud_p)) {
-               if (native_pud_val(*pud_p) & _PAGE_PSE)
-                       return NULL;
-
-               pmd_p = (pmd_t *)(native_pud_val(*pud_p) & ~PTE_FLAGS_MASK);
-       } else {
-               pud_t pud;
-
-               pmd_p = ppd->pgtable_area;
-               memset(pmd_p, 0, sizeof(*pmd_p) * PTRS_PER_PMD);
-               ppd->pgtable_area += sizeof(*pmd_p) * PTRS_PER_PMD;
-
-               pud = native_make_pud((pmdval_t)pmd_p + PUD_FLAGS);
-               native_set_pud(pud_p, pud);
-       }
-
-       return pmd_p;
-}
-
-static void __init sme_populate_pgd_large(struct sme_populate_pgd_data *ppd)
-{
-       pmd_t *pmd_p;
-
-       pmd_p = sme_prepare_pgd(ppd);
-       if (!pmd_p)
-               return;
-
-       pmd_p += pmd_index(ppd->vaddr);
-       if (!native_pmd_val(*pmd_p) || !(native_pmd_val(*pmd_p) & _PAGE_PSE))
-               native_set_pmd(pmd_p, native_make_pmd(ppd->paddr | ppd->pmd_flags));
-}
-
-static void __init sme_populate_pgd(struct sme_populate_pgd_data *ppd)
-{
-       pmd_t *pmd_p;
-       pte_t *pte_p;
-
-       pmd_p = sme_prepare_pgd(ppd);
-       if (!pmd_p)
-               return;
-
-       pmd_p += pmd_index(ppd->vaddr);
-       if (native_pmd_val(*pmd_p)) {
-               if (native_pmd_val(*pmd_p) & _PAGE_PSE)
-                       return;
-
-               pte_p = (pte_t *)(native_pmd_val(*pmd_p) & ~PTE_FLAGS_MASK);
-       } else {
-               pmd_t pmd;
-
-               pte_p = ppd->pgtable_area;
-               memset(pte_p, 0, sizeof(*pte_p) * PTRS_PER_PTE);
-               ppd->pgtable_area += sizeof(*pte_p) * PTRS_PER_PTE;
-
-               pmd = native_make_pmd((pteval_t)pte_p + PMD_FLAGS);
-               native_set_pmd(pmd_p, pmd);
-       }
-
-       pte_p += pte_index(ppd->vaddr);
-       if (!native_pte_val(*pte_p))
-               native_set_pte(pte_p, native_make_pte(ppd->paddr | ppd->pte_flags));
-}
-
-static void __init __sme_map_range_pmd(struct sme_populate_pgd_data *ppd)
-{
-       while (ppd->vaddr < ppd->vaddr_end) {
-               sme_populate_pgd_large(ppd);
-
-               ppd->vaddr += PMD_PAGE_SIZE;
-               ppd->paddr += PMD_PAGE_SIZE;
-       }
-}
-
-static void __init __sme_map_range_pte(struct sme_populate_pgd_data *ppd)
-{
-       while (ppd->vaddr < ppd->vaddr_end) {
-               sme_populate_pgd(ppd);
-
-               ppd->vaddr += PAGE_SIZE;
-               ppd->paddr += PAGE_SIZE;
-       }
-}
-
-static void __init __sme_map_range(struct sme_populate_pgd_data *ppd,
-                                  pmdval_t pmd_flags, pteval_t pte_flags)
-{
-       unsigned long vaddr_end;
-
-       ppd->pmd_flags = pmd_flags;
-       ppd->pte_flags = pte_flags;
-
-       /* Save original end value since we modify the struct value */
-       vaddr_end = ppd->vaddr_end;
-
-       /* If start is not 2MB aligned, create PTE entries */
-       ppd->vaddr_end = ALIGN(ppd->vaddr, PMD_PAGE_SIZE);
-       __sme_map_range_pte(ppd);
-
-       /* Create PMD entries */
-       ppd->vaddr_end = vaddr_end & PMD_PAGE_MASK;
-       __sme_map_range_pmd(ppd);
-
-       /* If end is not 2MB aligned, create PTE entries */
-       ppd->vaddr_end = vaddr_end;
-       __sme_map_range_pte(ppd);
-}
-
-static void __init sme_map_range_encrypted(struct sme_populate_pgd_data *ppd)
-{
-       __sme_map_range(ppd, PMD_FLAGS_ENC, PTE_FLAGS_ENC);
-}
-
-static void __init sme_map_range_decrypted(struct sme_populate_pgd_data *ppd)
-{
-       __sme_map_range(ppd, PMD_FLAGS_DEC, PTE_FLAGS_DEC);
-}
-
-static void __init sme_map_range_decrypted_wp(struct sme_populate_pgd_data *ppd)
-{
-       __sme_map_range(ppd, PMD_FLAGS_DEC_WP, PTE_FLAGS_DEC_WP);
-}
-
-static unsigned long __init sme_pgtable_calc(unsigned long len)
-{
-       unsigned long p4d_size, pud_size, pmd_size, pte_size;
-       unsigned long total;
-
-       /*
-        * Perform a relatively simplistic calculation of the pagetable
-        * entries that are needed. Those mappings will be covered mostly
-        * by 2MB PMD entries so we can conservatively calculate the required
-        * number of P4D, PUD and PMD structures needed to perform the
-        * mappings.  For mappings that are not 2MB aligned, PTE mappings
-        * would be needed for the start and end portion of the address range
-        * that fall outside of the 2MB alignment.  This results in, at most,
-        * two extra pages to hold PTE entries for each range that is mapped.
-        * Incrementing the count for each covers the case where the addresses
-        * cross entries.
-        */
-       if (IS_ENABLED(CONFIG_X86_5LEVEL)) {
-               p4d_size = (ALIGN(len, PGDIR_SIZE) / PGDIR_SIZE) + 1;
-               p4d_size *= sizeof(p4d_t) * PTRS_PER_P4D;
-               pud_size = (ALIGN(len, P4D_SIZE) / P4D_SIZE) + 1;
-               pud_size *= sizeof(pud_t) * PTRS_PER_PUD;
-       } else {
-               p4d_size = 0;
-               pud_size = (ALIGN(len, PGDIR_SIZE) / PGDIR_SIZE) + 1;
-               pud_size *= sizeof(pud_t) * PTRS_PER_PUD;
-       }
-       pmd_size = (ALIGN(len, PUD_SIZE) / PUD_SIZE) + 1;
-       pmd_size *= sizeof(pmd_t) * PTRS_PER_PMD;
-       pte_size = 2 * sizeof(pte_t) * PTRS_PER_PTE;
-
-       total = p4d_size + pud_size + pmd_size + pte_size;
-
-       /*
-        * Now calculate the added pagetable structures needed to populate
-        * the new pagetables.
-        */
-       if (IS_ENABLED(CONFIG_X86_5LEVEL)) {
-               p4d_size = ALIGN(total, PGDIR_SIZE) / PGDIR_SIZE;
-               p4d_size *= sizeof(p4d_t) * PTRS_PER_P4D;
-               pud_size = ALIGN(total, P4D_SIZE) / P4D_SIZE;
-               pud_size *= sizeof(pud_t) * PTRS_PER_PUD;
-       } else {
-               p4d_size = 0;
-               pud_size = ALIGN(total, PGDIR_SIZE) / PGDIR_SIZE;
-               pud_size *= sizeof(pud_t) * PTRS_PER_PUD;
-       }
-       pmd_size = ALIGN(total, PUD_SIZE) / PUD_SIZE;
-       pmd_size *= sizeof(pmd_t) * PTRS_PER_PMD;
-
-       total += p4d_size + pud_size + pmd_size;
-
-       return total;
-}
-
-void __init __nostackprotector sme_encrypt_kernel(struct boot_params *bp)
-{
-       unsigned long workarea_start, workarea_end, workarea_len;
-       unsigned long execute_start, execute_end, execute_len;
-       unsigned long kernel_start, kernel_end, kernel_len;
-       unsigned long initrd_start, initrd_end, initrd_len;
-       struct sme_populate_pgd_data ppd;
-       unsigned long pgtable_area_len;
-       unsigned long decrypted_base;
-
-       if (!sme_active())
-               return;
-
-       /*
-        * Prepare for encrypting the kernel and initrd by building new
-        * pagetables with the necessary attributes needed to encrypt the
-        * kernel in place.
-        *
-        *   One range of virtual addresses will map the memory occupied
-        *   by the kernel and initrd as encrypted.
-        *
-        *   Another range of virtual addresses will map the memory occupied
-        *   by the kernel and initrd as decrypted and write-protected.
-        *
-        *     The use of write-protect attribute will prevent any of the
-        *     memory from being cached.
-        */
-
-       /* Physical addresses gives us the identity mapped virtual addresses */
-       kernel_start = __pa_symbol(_text);
-       kernel_end = ALIGN(__pa_symbol(_end), PMD_PAGE_SIZE);
-       kernel_len = kernel_end - kernel_start;
-
-       initrd_start = 0;
-       initrd_end = 0;
-       initrd_len = 0;
-#ifdef CONFIG_BLK_DEV_INITRD
-       initrd_len = (unsigned long)bp->hdr.ramdisk_size |
-                    ((unsigned long)bp->ext_ramdisk_size << 32);
-       if (initrd_len) {
-               initrd_start = (unsigned long)bp->hdr.ramdisk_image |
-                              ((unsigned long)bp->ext_ramdisk_image << 32);
-               initrd_end = PAGE_ALIGN(initrd_start + initrd_len);
-               initrd_len = initrd_end - initrd_start;
-       }
-#endif
-
-       /* Set the encryption workarea to be immediately after the kernel */
-       workarea_start = kernel_end;
-
-       /*
-        * Calculate required number of workarea bytes needed:
-        *   executable encryption area size:
-        *     stack page (PAGE_SIZE)
-        *     encryption routine page (PAGE_SIZE)
-        *     intermediate copy buffer (PMD_PAGE_SIZE)
-        *   pagetable structures for the encryption of the kernel
-        *   pagetable structures for workarea (in case not currently mapped)
-        */
-       execute_start = workarea_start;
-       execute_end = execute_start + (PAGE_SIZE * 2) + PMD_PAGE_SIZE;
-       execute_len = execute_end - execute_start;
-
-       /*
-        * One PGD for both encrypted and decrypted mappings and a set of
-        * PUDs and PMDs for each of the encrypted and decrypted mappings.
-        */
-       pgtable_area_len = sizeof(pgd_t) * PTRS_PER_PGD;
-       pgtable_area_len += sme_pgtable_calc(execute_end - kernel_start) * 2;
-       if (initrd_len)
-               pgtable_area_len += sme_pgtable_calc(initrd_len) * 2;
-
-       /* PUDs and PMDs needed in the current pagetables for the workarea */
-       pgtable_area_len += sme_pgtable_calc(execute_len + pgtable_area_len);
-
-       /*
-        * The total workarea includes the executable encryption area and
-        * the pagetable area. The start of the workarea is already 2MB
-        * aligned, align the end of the workarea on a 2MB boundary so that
-        * we don't try to create/allocate PTE entries from the workarea
-        * before it is mapped.
-        */
-       workarea_len = execute_len + pgtable_area_len;
-       workarea_end = ALIGN(workarea_start + workarea_len, PMD_PAGE_SIZE);
-
-       /*
-        * Set the address to the start of where newly created pagetable
-        * structures (PGDs, PUDs and PMDs) will be allocated. New pagetable
-        * structures are created when the workarea is added to the current
-        * pagetables and when the new encrypted and decrypted kernel
-        * mappings are populated.
-        */
-       ppd.pgtable_area = (void *)execute_end;
-
-       /*
-        * Make sure the current pagetable structure has entries for
-        * addressing the workarea.
-        */
-       ppd.pgd = (pgd_t *)native_read_cr3_pa();
-       ppd.paddr = workarea_start;
-       ppd.vaddr = workarea_start;
-       ppd.vaddr_end = workarea_end;
-       sme_map_range_decrypted(&ppd);
-
-       /* Flush the TLB - no globals so cr3 is enough */
-       native_write_cr3(__native_read_cr3());
-
-       /*
-        * A new pagetable structure is being built to allow for the kernel
-        * and initrd to be encrypted. It starts with an empty PGD that will
-        * then be populated with new PUDs and PMDs as the encrypted and
-        * decrypted kernel mappings are created.
-        */
-       ppd.pgd = ppd.pgtable_area;
-       memset(ppd.pgd, 0, sizeof(pgd_t) * PTRS_PER_PGD);
-       ppd.pgtable_area += sizeof(pgd_t) * PTRS_PER_PGD;
-
-       /*
-        * A different PGD index/entry must be used to get different
-        * pagetable entries for the decrypted mapping. Choose the next
-        * PGD index and convert it to a virtual address to be used as
-        * the base of the mapping.
-        */
-       decrypted_base = (pgd_index(workarea_end) + 1) & (PTRS_PER_PGD - 1);
-       if (initrd_len) {
-               unsigned long check_base;
-
-               check_base = (pgd_index(initrd_end) + 1) & (PTRS_PER_PGD - 1);
-               decrypted_base = max(decrypted_base, check_base);
-       }
-       decrypted_base <<= PGDIR_SHIFT;
-
-       /* Add encrypted kernel (identity) mappings */
-       ppd.paddr = kernel_start;
-       ppd.vaddr = kernel_start;
-       ppd.vaddr_end = kernel_end;
-       sme_map_range_encrypted(&ppd);
-
-       /* Add decrypted, write-protected kernel (non-identity) mappings */
-       ppd.paddr = kernel_start;
-       ppd.vaddr = kernel_start + decrypted_base;
-       ppd.vaddr_end = kernel_end + decrypted_base;
-       sme_map_range_decrypted_wp(&ppd);
-
-       if (initrd_len) {
-               /* Add encrypted initrd (identity) mappings */
-               ppd.paddr = initrd_start;
-               ppd.vaddr = initrd_start;
-               ppd.vaddr_end = initrd_end;
-               sme_map_range_encrypted(&ppd);
-               /*
-                * Add decrypted, write-protected initrd (non-identity) mappings
-                */
-               ppd.paddr = initrd_start;
-               ppd.vaddr = initrd_start + decrypted_base;
-               ppd.vaddr_end = initrd_end + decrypted_base;
-               sme_map_range_decrypted_wp(&ppd);
-       }
-
-       /* Add decrypted workarea mappings to both kernel mappings */
-       ppd.paddr = workarea_start;
-       ppd.vaddr = workarea_start;
-       ppd.vaddr_end = workarea_end;
-       sme_map_range_decrypted(&ppd);
-
-       ppd.paddr = workarea_start;
-       ppd.vaddr = workarea_start + decrypted_base;
-       ppd.vaddr_end = workarea_end + decrypted_base;
-       sme_map_range_decrypted(&ppd);
-
-       /* Perform the encryption */
-       sme_encrypt_execute(kernel_start, kernel_start + decrypted_base,
-                           kernel_len, workarea_start, (unsigned long)ppd.pgd);
-
-       if (initrd_len)
-               sme_encrypt_execute(initrd_start, initrd_start + decrypted_base,
-                                   initrd_len, workarea_start,
-                                   (unsigned long)ppd.pgd);
-
-       /*
-        * At this point we are running encrypted.  Remove the mappings for
-        * the decrypted areas - all that is needed for this is to remove
-        * the PGD entry/entries.
-        */
-       ppd.vaddr = kernel_start + decrypted_base;
-       ppd.vaddr_end = kernel_end + decrypted_base;
-       sme_clear_pgd(&ppd);
-
-       if (initrd_len) {
-               ppd.vaddr = initrd_start + decrypted_base;
-               ppd.vaddr_end = initrd_end + decrypted_base;
-               sme_clear_pgd(&ppd);
-       }
-
-       ppd.vaddr = workarea_start + decrypted_base;
-       ppd.vaddr_end = workarea_end + decrypted_base;
-       sme_clear_pgd(&ppd);
-
-       /* Flush the TLB - no globals so cr3 is enough */
-       native_write_cr3(__native_read_cr3());
-}
-
-void __init __nostackprotector sme_enable(struct boot_params *bp)
-{
-       const char *cmdline_ptr, *cmdline_arg, *cmdline_on, *cmdline_off;
-       unsigned int eax, ebx, ecx, edx;
-       unsigned long feature_mask;
-       bool active_by_default;
-       unsigned long me_mask;
-       char buffer[16];
-       u64 msr;
-
-       /* Check for the SME/SEV support leaf */
-       eax = 0x80000000;
-       ecx = 0;
-       native_cpuid(&eax, &ebx, &ecx, &edx);
-       if (eax < 0x8000001f)
-               return;
-
-#define AMD_SME_BIT    BIT(0)
-#define AMD_SEV_BIT    BIT(1)
-       /*
-        * Set the feature mask (SME or SEV) based on whether we are
-        * running under a hypervisor.
-        */
-       eax = 1;
-       ecx = 0;
-       native_cpuid(&eax, &ebx, &ecx, &edx);
-       feature_mask = (ecx & BIT(31)) ? AMD_SEV_BIT : AMD_SME_BIT;
-
-       /*
-        * Check for the SME/SEV feature:
-        *   CPUID Fn8000_001F[EAX]
-        *   - Bit 0 - Secure Memory Encryption support
-        *   - Bit 1 - Secure Encrypted Virtualization support
-        *   CPUID Fn8000_001F[EBX]
-        *   - Bits 5:0 - Pagetable bit position used to indicate encryption
-        */
-       eax = 0x8000001f;
-       ecx = 0;
-       native_cpuid(&eax, &ebx, &ecx, &edx);
-       if (!(eax & feature_mask))
-               return;
-
-       me_mask = 1UL << (ebx & 0x3f);
-
-       /* Check if memory encryption is enabled */
-       if (feature_mask == AMD_SME_BIT) {
-               /* For SME, check the SYSCFG MSR */
-               msr = __rdmsr(MSR_K8_SYSCFG);
-               if (!(msr & MSR_K8_SYSCFG_MEM_ENCRYPT))
-                       return;
-       } else {
-               /* For SEV, check the SEV MSR */
-               msr = __rdmsr(MSR_AMD64_SEV);
-               if (!(msr & MSR_AMD64_SEV_ENABLED))
-                       return;
-
-               /* SEV state cannot be controlled by a command line option */
-               sme_me_mask = me_mask;
-               sev_enabled = true;
-               return;
-       }
-
-       /*
-        * Fixups have not been applied to phys_base yet and we're running
-        * identity mapped, so we must obtain the address to the SME command
-        * line argument data using rip-relative addressing.
-        */
-       asm ("lea sme_cmdline_arg(%%rip), %0"
-            : "=r" (cmdline_arg)
-            : "p" (sme_cmdline_arg));
-       asm ("lea sme_cmdline_on(%%rip), %0"
-            : "=r" (cmdline_on)
-            : "p" (sme_cmdline_on));
-       asm ("lea sme_cmdline_off(%%rip), %0"
-            : "=r" (cmdline_off)
-            : "p" (sme_cmdline_off));
-
-       if (IS_ENABLED(CONFIG_AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT))
-               active_by_default = true;
-       else
-               active_by_default = false;
-
-       cmdline_ptr = (const char *)((u64)bp->hdr.cmd_line_ptr |
-                                    ((u64)bp->ext_cmd_line_ptr << 32));
-
-       cmdline_find_option(cmdline_ptr, cmdline_arg, buffer, sizeof(buffer));
-
-       if (!strncmp(buffer, cmdline_on, sizeof(buffer)))
-               sme_me_mask = me_mask;
-       else if (!strncmp(buffer, cmdline_off, sizeof(buffer)))
-               sme_me_mask = 0;
-       else
-               sme_me_mask = active_by_default ? me_mask : 0;
-}
 
--- /dev/null
+/*
+ * AMD Memory Encryption Support
+ *
+ * Copyright (C) 2016 Advanced Micro Devices, Inc.
+ *
+ * Author: Tom Lendacky <thomas.lendacky@amd.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#define DISABLE_BRANCH_PROFILING
+
+#include <linux/mm.h>
+#include <linux/mem_encrypt.h>
+
+#include <asm/setup.h>
+#include <asm/sections.h>
+#include <asm/cmdline.h>
+
+#include "mm_internal.h"
+
+#define PGD_FLAGS              _KERNPG_TABLE_NOENC
+#define P4D_FLAGS              _KERNPG_TABLE_NOENC
+#define PUD_FLAGS              _KERNPG_TABLE_NOENC
+#define PMD_FLAGS              _KERNPG_TABLE_NOENC
+
+#define PMD_FLAGS_LARGE                (__PAGE_KERNEL_LARGE_EXEC & ~_PAGE_GLOBAL)
+
+#define PMD_FLAGS_DEC          PMD_FLAGS_LARGE
+#define PMD_FLAGS_DEC_WP       ((PMD_FLAGS_DEC & ~_PAGE_CACHE_MASK) | \
+                                (_PAGE_PAT | _PAGE_PWT))
+
+#define PMD_FLAGS_ENC          (PMD_FLAGS_LARGE | _PAGE_ENC)
+
+#define PTE_FLAGS              (__PAGE_KERNEL_EXEC & ~_PAGE_GLOBAL)
+
+#define PTE_FLAGS_DEC          PTE_FLAGS
+#define PTE_FLAGS_DEC_WP       ((PTE_FLAGS_DEC & ~_PAGE_CACHE_MASK) | \
+                                (_PAGE_PAT | _PAGE_PWT))
+
+#define PTE_FLAGS_ENC          (PTE_FLAGS | _PAGE_ENC)
+
+struct sme_populate_pgd_data {
+       void    *pgtable_area;
+       pgd_t   *pgd;
+
+       pmdval_t pmd_flags;
+       pteval_t pte_flags;
+       unsigned long paddr;
+
+       unsigned long vaddr;
+       unsigned long vaddr_end;
+};
+
+static char sme_cmdline_arg[] __initdata = "mem_encrypt";
+static char sme_cmdline_on[]  __initdata = "on";
+static char sme_cmdline_off[] __initdata = "off";
+
+static void __init sme_clear_pgd(struct sme_populate_pgd_data *ppd)
+{
+       unsigned long pgd_start, pgd_end, pgd_size;
+       pgd_t *pgd_p;
+
+       pgd_start = ppd->vaddr & PGDIR_MASK;
+       pgd_end = ppd->vaddr_end & PGDIR_MASK;
+
+       pgd_size = (((pgd_end - pgd_start) / PGDIR_SIZE) + 1) * sizeof(pgd_t);
+
+       pgd_p = ppd->pgd + pgd_index(ppd->vaddr);
+
+       memset(pgd_p, 0, pgd_size);
+}
+
+static pmd_t __init *sme_prepare_pgd(struct sme_populate_pgd_data *ppd)
+{
+       pgd_t *pgd_p;
+       p4d_t *p4d_p;
+       pud_t *pud_p;
+       pmd_t *pmd_p;
+
+       pgd_p = ppd->pgd + pgd_index(ppd->vaddr);
+       if (native_pgd_val(*pgd_p)) {
+               if (IS_ENABLED(CONFIG_X86_5LEVEL))
+                       p4d_p = (p4d_t *)(native_pgd_val(*pgd_p) & ~PTE_FLAGS_MASK);
+               else
+                       pud_p = (pud_t *)(native_pgd_val(*pgd_p) & ~PTE_FLAGS_MASK);
+       } else {
+               pgd_t pgd;
+
+               if (IS_ENABLED(CONFIG_X86_5LEVEL)) {
+                       p4d_p = ppd->pgtable_area;
+                       memset(p4d_p, 0, sizeof(*p4d_p) * PTRS_PER_P4D);
+                       ppd->pgtable_area += sizeof(*p4d_p) * PTRS_PER_P4D;
+
+                       pgd = native_make_pgd((pgdval_t)p4d_p + PGD_FLAGS);
+               } else {
+                       pud_p = ppd->pgtable_area;
+                       memset(pud_p, 0, sizeof(*pud_p) * PTRS_PER_PUD);
+                       ppd->pgtable_area += sizeof(*pud_p) * PTRS_PER_PUD;
+
+                       pgd = native_make_pgd((pgdval_t)pud_p + PGD_FLAGS);
+               }
+               native_set_pgd(pgd_p, pgd);
+       }
+
+       if (IS_ENABLED(CONFIG_X86_5LEVEL)) {
+               p4d_p += p4d_index(ppd->vaddr);
+               if (native_p4d_val(*p4d_p)) {
+                       pud_p = (pud_t *)(native_p4d_val(*p4d_p) & ~PTE_FLAGS_MASK);
+               } else {
+                       p4d_t p4d;
+
+                       pud_p = ppd->pgtable_area;
+                       memset(pud_p, 0, sizeof(*pud_p) * PTRS_PER_PUD);
+                       ppd->pgtable_area += sizeof(*pud_p) * PTRS_PER_PUD;
+
+                       p4d = native_make_p4d((pudval_t)pud_p + P4D_FLAGS);
+                       native_set_p4d(p4d_p, p4d);
+               }
+       }
+
+       pud_p += pud_index(ppd->vaddr);
+       if (native_pud_val(*pud_p)) {
+               if (native_pud_val(*pud_p) & _PAGE_PSE)
+                       return NULL;
+
+               pmd_p = (pmd_t *)(native_pud_val(*pud_p) & ~PTE_FLAGS_MASK);
+       } else {
+               pud_t pud;
+
+               pmd_p = ppd->pgtable_area;
+               memset(pmd_p, 0, sizeof(*pmd_p) * PTRS_PER_PMD);
+               ppd->pgtable_area += sizeof(*pmd_p) * PTRS_PER_PMD;
+
+               pud = native_make_pud((pmdval_t)pmd_p + PUD_FLAGS);
+               native_set_pud(pud_p, pud);
+       }
+
+       return pmd_p;
+}
+
+static void __init sme_populate_pgd_large(struct sme_populate_pgd_data *ppd)
+{
+       pmd_t *pmd_p;
+
+       pmd_p = sme_prepare_pgd(ppd);
+       if (!pmd_p)
+               return;
+
+       pmd_p += pmd_index(ppd->vaddr);
+       if (!native_pmd_val(*pmd_p) || !(native_pmd_val(*pmd_p) & _PAGE_PSE))
+               native_set_pmd(pmd_p, native_make_pmd(ppd->paddr | ppd->pmd_flags));
+}
+
+static void __init sme_populate_pgd(struct sme_populate_pgd_data *ppd)
+{
+       pmd_t *pmd_p;
+       pte_t *pte_p;
+
+       pmd_p = sme_prepare_pgd(ppd);
+       if (!pmd_p)
+               return;
+
+       pmd_p += pmd_index(ppd->vaddr);
+       if (native_pmd_val(*pmd_p)) {
+               if (native_pmd_val(*pmd_p) & _PAGE_PSE)
+                       return;
+
+               pte_p = (pte_t *)(native_pmd_val(*pmd_p) & ~PTE_FLAGS_MASK);
+       } else {
+               pmd_t pmd;
+
+               pte_p = ppd->pgtable_area;
+               memset(pte_p, 0, sizeof(*pte_p) * PTRS_PER_PTE);
+               ppd->pgtable_area += sizeof(*pte_p) * PTRS_PER_PTE;
+
+               pmd = native_make_pmd((pteval_t)pte_p + PMD_FLAGS);
+               native_set_pmd(pmd_p, pmd);
+       }
+
+       pte_p += pte_index(ppd->vaddr);
+       if (!native_pte_val(*pte_p))
+               native_set_pte(pte_p, native_make_pte(ppd->paddr | ppd->pte_flags));
+}
+
+static void __init __sme_map_range_pmd(struct sme_populate_pgd_data *ppd)
+{
+       while (ppd->vaddr < ppd->vaddr_end) {
+               sme_populate_pgd_large(ppd);
+
+               ppd->vaddr += PMD_PAGE_SIZE;
+               ppd->paddr += PMD_PAGE_SIZE;
+       }
+}
+
+static void __init __sme_map_range_pte(struct sme_populate_pgd_data *ppd)
+{
+       while (ppd->vaddr < ppd->vaddr_end) {
+               sme_populate_pgd(ppd);
+
+               ppd->vaddr += PAGE_SIZE;
+               ppd->paddr += PAGE_SIZE;
+       }
+}
+
+static void __init __sme_map_range(struct sme_populate_pgd_data *ppd,
+                                  pmdval_t pmd_flags, pteval_t pte_flags)
+{
+       unsigned long vaddr_end;
+
+       ppd->pmd_flags = pmd_flags;
+       ppd->pte_flags = pte_flags;
+
+       /* Save original end value since we modify the struct value */
+       vaddr_end = ppd->vaddr_end;
+
+       /* If start is not 2MB aligned, create PTE entries */
+       ppd->vaddr_end = ALIGN(ppd->vaddr, PMD_PAGE_SIZE);
+       __sme_map_range_pte(ppd);
+
+       /* Create PMD entries */
+       ppd->vaddr_end = vaddr_end & PMD_PAGE_MASK;
+       __sme_map_range_pmd(ppd);
+
+       /* If end is not 2MB aligned, create PTE entries */
+       ppd->vaddr_end = vaddr_end;
+       __sme_map_range_pte(ppd);
+}
+
+static void __init sme_map_range_encrypted(struct sme_populate_pgd_data *ppd)
+{
+       __sme_map_range(ppd, PMD_FLAGS_ENC, PTE_FLAGS_ENC);
+}
+
+static void __init sme_map_range_decrypted(struct sme_populate_pgd_data *ppd)
+{
+       __sme_map_range(ppd, PMD_FLAGS_DEC, PTE_FLAGS_DEC);
+}
+
+static void __init sme_map_range_decrypted_wp(struct sme_populate_pgd_data *ppd)
+{
+       __sme_map_range(ppd, PMD_FLAGS_DEC_WP, PTE_FLAGS_DEC_WP);
+}
+
+static unsigned long __init sme_pgtable_calc(unsigned long len)
+{
+       unsigned long p4d_size, pud_size, pmd_size, pte_size;
+       unsigned long total;
+
+       /*
+        * Perform a relatively simplistic calculation of the pagetable
+        * entries that are needed. Those mappings will be covered mostly
+        * by 2MB PMD entries so we can conservatively calculate the required
+        * number of P4D, PUD and PMD structures needed to perform the
+        * mappings.  For mappings that are not 2MB aligned, PTE mappings
+        * would be needed for the start and end portion of the address range
+        * that fall outside of the 2MB alignment.  This results in, at most,
+        * two extra pages to hold PTE entries for each range that is mapped.
+        * Incrementing the count for each covers the case where the addresses
+        * cross entries.
+        */
+       if (IS_ENABLED(CONFIG_X86_5LEVEL)) {
+               p4d_size = (ALIGN(len, PGDIR_SIZE) / PGDIR_SIZE) + 1;
+               p4d_size *= sizeof(p4d_t) * PTRS_PER_P4D;
+               pud_size = (ALIGN(len, P4D_SIZE) / P4D_SIZE) + 1;
+               pud_size *= sizeof(pud_t) * PTRS_PER_PUD;
+       } else {
+               p4d_size = 0;
+               pud_size = (ALIGN(len, PGDIR_SIZE) / PGDIR_SIZE) + 1;
+               pud_size *= sizeof(pud_t) * PTRS_PER_PUD;
+       }
+       pmd_size = (ALIGN(len, PUD_SIZE) / PUD_SIZE) + 1;
+       pmd_size *= sizeof(pmd_t) * PTRS_PER_PMD;
+       pte_size = 2 * sizeof(pte_t) * PTRS_PER_PTE;
+
+       total = p4d_size + pud_size + pmd_size + pte_size;
+
+       /*
+        * Now calculate the added pagetable structures needed to populate
+        * the new pagetables.
+        */
+       if (IS_ENABLED(CONFIG_X86_5LEVEL)) {
+               p4d_size = ALIGN(total, PGDIR_SIZE) / PGDIR_SIZE;
+               p4d_size *= sizeof(p4d_t) * PTRS_PER_P4D;
+               pud_size = ALIGN(total, P4D_SIZE) / P4D_SIZE;
+               pud_size *= sizeof(pud_t) * PTRS_PER_PUD;
+       } else {
+               p4d_size = 0;
+               pud_size = ALIGN(total, PGDIR_SIZE) / PGDIR_SIZE;
+               pud_size *= sizeof(pud_t) * PTRS_PER_PUD;
+       }
+       pmd_size = ALIGN(total, PUD_SIZE) / PUD_SIZE;
+       pmd_size *= sizeof(pmd_t) * PTRS_PER_PMD;
+
+       total += p4d_size + pud_size + pmd_size;
+
+       return total;
+}
+
+void __init __nostackprotector sme_encrypt_kernel(struct boot_params *bp)
+{
+       unsigned long workarea_start, workarea_end, workarea_len;
+       unsigned long execute_start, execute_end, execute_len;
+       unsigned long kernel_start, kernel_end, kernel_len;
+       unsigned long initrd_start, initrd_end, initrd_len;
+       struct sme_populate_pgd_data ppd;
+       unsigned long pgtable_area_len;
+       unsigned long decrypted_base;
+
+       if (!sme_active())
+               return;
+
+       /*
+        * Prepare for encrypting the kernel and initrd by building new
+        * pagetables with the necessary attributes needed to encrypt the
+        * kernel in place.
+        *
+        *   One range of virtual addresses will map the memory occupied
+        *   by the kernel and initrd as encrypted.
+        *
+        *   Another range of virtual addresses will map the memory occupied
+        *   by the kernel and initrd as decrypted and write-protected.
+        *
+        *     The use of write-protect attribute will prevent any of the
+        *     memory from being cached.
+        */
+
+       /* Physical addresses gives us the identity mapped virtual addresses */
+       kernel_start = __pa_symbol(_text);
+       kernel_end = ALIGN(__pa_symbol(_end), PMD_PAGE_SIZE);
+       kernel_len = kernel_end - kernel_start;
+
+       initrd_start = 0;
+       initrd_end = 0;
+       initrd_len = 0;
+#ifdef CONFIG_BLK_DEV_INITRD
+       initrd_len = (unsigned long)bp->hdr.ramdisk_size |
+                    ((unsigned long)bp->ext_ramdisk_size << 32);
+       if (initrd_len) {
+               initrd_start = (unsigned long)bp->hdr.ramdisk_image |
+                              ((unsigned long)bp->ext_ramdisk_image << 32);
+               initrd_end = PAGE_ALIGN(initrd_start + initrd_len);
+               initrd_len = initrd_end - initrd_start;
+       }
+#endif
+
+       /* Set the encryption workarea to be immediately after the kernel */
+       workarea_start = kernel_end;
+
+       /*
+        * Calculate required number of workarea bytes needed:
+        *   executable encryption area size:
+        *     stack page (PAGE_SIZE)
+        *     encryption routine page (PAGE_SIZE)
+        *     intermediate copy buffer (PMD_PAGE_SIZE)
+        *   pagetable structures for the encryption of the kernel
+        *   pagetable structures for workarea (in case not currently mapped)
+        */
+       execute_start = workarea_start;
+       execute_end = execute_start + (PAGE_SIZE * 2) + PMD_PAGE_SIZE;
+       execute_len = execute_end - execute_start;
+
+       /*
+        * One PGD for both encrypted and decrypted mappings and a set of
+        * PUDs and PMDs for each of the encrypted and decrypted mappings.
+        */
+       pgtable_area_len = sizeof(pgd_t) * PTRS_PER_PGD;
+       pgtable_area_len += sme_pgtable_calc(execute_end - kernel_start) * 2;
+       if (initrd_len)
+               pgtable_area_len += sme_pgtable_calc(initrd_len) * 2;
+
+       /* PUDs and PMDs needed in the current pagetables for the workarea */
+       pgtable_area_len += sme_pgtable_calc(execute_len + pgtable_area_len);
+
+       /*
+        * The total workarea includes the executable encryption area and
+        * the pagetable area. The start of the workarea is already 2MB
+        * aligned, align the end of the workarea on a 2MB boundary so that
+        * we don't try to create/allocate PTE entries from the workarea
+        * before it is mapped.
+        */
+       workarea_len = execute_len + pgtable_area_len;
+       workarea_end = ALIGN(workarea_start + workarea_len, PMD_PAGE_SIZE);
+
+       /*
+        * Set the address to the start of where newly created pagetable
+        * structures (PGDs, PUDs and PMDs) will be allocated. New pagetable
+        * structures are created when the workarea is added to the current
+        * pagetables and when the new encrypted and decrypted kernel
+        * mappings are populated.
+        */
+       ppd.pgtable_area = (void *)execute_end;
+
+       /*
+        * Make sure the current pagetable structure has entries for
+        * addressing the workarea.
+        */
+       ppd.pgd = (pgd_t *)native_read_cr3_pa();
+       ppd.paddr = workarea_start;
+       ppd.vaddr = workarea_start;
+       ppd.vaddr_end = workarea_end;
+       sme_map_range_decrypted(&ppd);
+
+       /* Flush the TLB - no globals so cr3 is enough */
+       native_write_cr3(__native_read_cr3());
+
+       /*
+        * A new pagetable structure is being built to allow for the kernel
+        * and initrd to be encrypted. It starts with an empty PGD that will
+        * then be populated with new PUDs and PMDs as the encrypted and
+        * decrypted kernel mappings are created.
+        */
+       ppd.pgd = ppd.pgtable_area;
+       memset(ppd.pgd, 0, sizeof(pgd_t) * PTRS_PER_PGD);
+       ppd.pgtable_area += sizeof(pgd_t) * PTRS_PER_PGD;
+
+       /*
+        * A different PGD index/entry must be used to get different
+        * pagetable entries for the decrypted mapping. Choose the next
+        * PGD index and convert it to a virtual address to be used as
+        * the base of the mapping.
+        */
+       decrypted_base = (pgd_index(workarea_end) + 1) & (PTRS_PER_PGD - 1);
+       if (initrd_len) {
+               unsigned long check_base;
+
+               check_base = (pgd_index(initrd_end) + 1) & (PTRS_PER_PGD - 1);
+               decrypted_base = max(decrypted_base, check_base);
+       }
+       decrypted_base <<= PGDIR_SHIFT;
+
+       /* Add encrypted kernel (identity) mappings */
+       ppd.paddr = kernel_start;
+       ppd.vaddr = kernel_start;
+       ppd.vaddr_end = kernel_end;
+       sme_map_range_encrypted(&ppd);
+
+       /* Add decrypted, write-protected kernel (non-identity) mappings */
+       ppd.paddr = kernel_start;
+       ppd.vaddr = kernel_start + decrypted_base;
+       ppd.vaddr_end = kernel_end + decrypted_base;
+       sme_map_range_decrypted_wp(&ppd);
+
+       if (initrd_len) {
+               /* Add encrypted initrd (identity) mappings */
+               ppd.paddr = initrd_start;
+               ppd.vaddr = initrd_start;
+               ppd.vaddr_end = initrd_end;
+               sme_map_range_encrypted(&ppd);
+               /*
+                * Add decrypted, write-protected initrd (non-identity) mappings
+                */
+               ppd.paddr = initrd_start;
+               ppd.vaddr = initrd_start + decrypted_base;
+               ppd.vaddr_end = initrd_end + decrypted_base;
+               sme_map_range_decrypted_wp(&ppd);
+       }
+
+       /* Add decrypted workarea mappings to both kernel mappings */
+       ppd.paddr = workarea_start;
+       ppd.vaddr = workarea_start;
+       ppd.vaddr_end = workarea_end;
+       sme_map_range_decrypted(&ppd);
+
+       ppd.paddr = workarea_start;
+       ppd.vaddr = workarea_start + decrypted_base;
+       ppd.vaddr_end = workarea_end + decrypted_base;
+       sme_map_range_decrypted(&ppd);
+
+       /* Perform the encryption */
+       sme_encrypt_execute(kernel_start, kernel_start + decrypted_base,
+                           kernel_len, workarea_start, (unsigned long)ppd.pgd);
+
+       if (initrd_len)
+               sme_encrypt_execute(initrd_start, initrd_start + decrypted_base,
+                                   initrd_len, workarea_start,
+                                   (unsigned long)ppd.pgd);
+
+       /*
+        * At this point we are running encrypted.  Remove the mappings for
+        * the decrypted areas - all that is needed for this is to remove
+        * the PGD entry/entries.
+        */
+       ppd.vaddr = kernel_start + decrypted_base;
+       ppd.vaddr_end = kernel_end + decrypted_base;
+       sme_clear_pgd(&ppd);
+
+       if (initrd_len) {
+               ppd.vaddr = initrd_start + decrypted_base;
+               ppd.vaddr_end = initrd_end + decrypted_base;
+               sme_clear_pgd(&ppd);
+       }
+
+       ppd.vaddr = workarea_start + decrypted_base;
+       ppd.vaddr_end = workarea_end + decrypted_base;
+       sme_clear_pgd(&ppd);
+
+       /* Flush the TLB - no globals so cr3 is enough */
+       native_write_cr3(__native_read_cr3());
+}
+
+void __init __nostackprotector sme_enable(struct boot_params *bp)
+{
+       const char *cmdline_ptr, *cmdline_arg, *cmdline_on, *cmdline_off;
+       unsigned int eax, ebx, ecx, edx;
+       unsigned long feature_mask;
+       bool active_by_default;
+       unsigned long me_mask;
+       char buffer[16];
+       u64 msr;
+
+       /* Check for the SME/SEV support leaf */
+       eax = 0x80000000;
+       ecx = 0;
+       native_cpuid(&eax, &ebx, &ecx, &edx);
+       if (eax < 0x8000001f)
+               return;
+
+#define AMD_SME_BIT    BIT(0)
+#define AMD_SEV_BIT    BIT(1)
+       /*
+        * Set the feature mask (SME or SEV) based on whether we are
+        * running under a hypervisor.
+        */
+       eax = 1;
+       ecx = 0;
+       native_cpuid(&eax, &ebx, &ecx, &edx);
+       feature_mask = (ecx & BIT(31)) ? AMD_SEV_BIT : AMD_SME_BIT;
+
+       /*
+        * Check for the SME/SEV feature:
+        *   CPUID Fn8000_001F[EAX]
+        *   - Bit 0 - Secure Memory Encryption support
+        *   - Bit 1 - Secure Encrypted Virtualization support
+        *   CPUID Fn8000_001F[EBX]
+        *   - Bits 5:0 - Pagetable bit position used to indicate encryption
+        */
+       eax = 0x8000001f;
+       ecx = 0;
+       native_cpuid(&eax, &ebx, &ecx, &edx);
+       if (!(eax & feature_mask))
+               return;
+
+       me_mask = 1UL << (ebx & 0x3f);
+
+       /* Check if memory encryption is enabled */
+       if (feature_mask == AMD_SME_BIT) {
+               /* For SME, check the SYSCFG MSR */
+               msr = __rdmsr(MSR_K8_SYSCFG);
+               if (!(msr & MSR_K8_SYSCFG_MEM_ENCRYPT))
+                       return;
+       } else {
+               /* For SEV, check the SEV MSR */
+               msr = __rdmsr(MSR_AMD64_SEV);
+               if (!(msr & MSR_AMD64_SEV_ENABLED))
+                       return;
+
+               /* SEV state cannot be controlled by a command line option */
+               sme_me_mask = me_mask;
+               sev_enabled = true;
+               return;
+       }
+
+       /*
+        * Fixups have not been applied to phys_base yet and we're running
+        * identity mapped, so we must obtain the address to the SME command
+        * line argument data using rip-relative addressing.
+        */
+       asm ("lea sme_cmdline_arg(%%rip), %0"
+            : "=r" (cmdline_arg)
+            : "p" (sme_cmdline_arg));
+       asm ("lea sme_cmdline_on(%%rip), %0"
+            : "=r" (cmdline_on)
+            : "p" (sme_cmdline_on));
+       asm ("lea sme_cmdline_off(%%rip), %0"
+            : "=r" (cmdline_off)
+            : "p" (sme_cmdline_off));
+
+       if (IS_ENABLED(CONFIG_AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT))
+               active_by_default = true;
+       else
+               active_by_default = false;
+
+       cmdline_ptr = (const char *)((u64)bp->hdr.cmd_line_ptr |
+                                    ((u64)bp->ext_cmd_line_ptr << 32));
+
+       cmdline_find_option(cmdline_ptr, cmdline_arg, buffer, sizeof(buffer));
+
+       if (!strncmp(buffer, cmdline_on, sizeof(buffer)))
+               sme_me_mask = me_mask;
+       else if (!strncmp(buffer, cmdline_off, sizeof(buffer)))
+               sme_me_mask = 0;
+       else
+               sme_me_mask = active_by_default ? me_mask : 0;
+}