The following commit has been merged into the x86/sev branch of tip:
Commit-ID: dbca5e1a04f8b30aea4e2c91e5045ee6e7c3ef43
Gitweb: https://git.kernel.org/tip/dbca5e1a04f8b30aea4e2c91e5045ee6e7c3ef43
Author: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@xxxxxxxxxxxxxxx>
AuthorDate: Mon, 06 Dec 2021 16:55:04 +03:00
Committer: Borislav Petkov <bp@xxxxxxx>
CommitterDate: Wed, 08 Dec 2021 16:49:47 +01:00
x86/sev: Rename mem_encrypt.c to mem_encrypt_amd.c
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@xxxxxxxxxxxxxxx>
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx>
Signed-off-by: Borislav Petkov <bp@xxxxxxx>
Reviewed-by: Tony Luck <tony.luck@xxxxxxxxx>
Reviewed-by: Tom Lendacky <thomas.lendacky@xxxxxxx>
Tested-by: Tom Lendacky <thomas.lendacky@xxxxxxx>
Link: https://lore.kernel.org/r/20211206135505.75045-3-kirill.shutemov@xxxxxxxxxxxxxxx
---
arch/x86/mm/Makefile | 8 +-
arch/x86/mm/mem_encrypt.c | 507 +---------------------------------
arch/x86/mm/mem_encrypt_amd.c | 507 +++++++++++++++++++++++++++++++++-
3 files changed, 511 insertions(+), 511 deletions(-)
delete mode 100644 arch/x86/mm/mem_encrypt.c
create mode 100644 arch/x86/mm/mem_encrypt_amd.c
diff --git a/arch/x86/mm/Makefile b/arch/x86/mm/Makefile
index 5864219..c9c4806 100644
--- a/arch/x86/mm/Makefile
+++ b/arch/x86/mm/Makefile
@@ -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
index b520021..0000000
--- a/arch/x86/mm/mem_encrypt.c
+++ /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@xxxxxxx>
- */
-
-#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
index 0000000..b520021
--- /dev/null
+++ b/arch/x86/mm/mem_encrypt_amd.c
@@ -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@xxxxxxx>
+ */
+
+#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);
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