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Diffstat (limited to 'arch/x86/mm/mem_encrypt.c')
-rw-r--r--arch/x86/mm/mem_encrypt.c441
1 files changed, 4 insertions, 437 deletions
diff --git a/arch/x86/mm/mem_encrypt.c b/arch/x86/mm/mem_encrypt.c
index 35487305d8af..50d209939c66 100644
--- a/arch/x86/mm/mem_encrypt.c
+++ b/arch/x86/mm/mem_encrypt.c
@@ -1,419 +1,18 @@
// SPDX-License-Identifier: GPL-2.0-only
/*
- * AMD Memory Encryption Support
+ * Memory Encryption Support Common Code
*
* Copyright (C) 2016 Advanced Micro Devices, Inc.
*
* Author: Tom Lendacky <thomas.lendacky@amd.com>
*/
-#define DISABLE_BRANCH_PROFILING
-
-#include <linux/linkage.h>
-#include <linux/init.h>
-#include <linux/mm.h>
#include <linux/dma-direct.h>
+#include <linux/dma-mapping.h>
#include <linux/swiotlb.h>
+#include <linux/cc_platform.h>
#include <linux/mem_encrypt.h>
-#include <linux/device.h>
-#include <linux/kernel.h>
-#include <linux/bitops.h>
-#include <linux/dma-mapping.h>
#include <linux/virtio_config.h>
-#include <linux/cc_platform.h>
-
-#include <asm/tlbflush.h>
-#include <asm/fixmap.h>
-#include <asm/setup.h>
-#include <asm/bootparam.h>
-#include <asm/set_memory.h>
-#include <asm/cacheflush.h>
-#include <asm/processor-flags.h>
-#include <asm/msr.h>
-#include <asm/cmdline.h>
-
-#include "mm_internal.h"
-
-/*
- * Since SME related variables are set early in the boot process they must
- * reside in the .data section so as not to be zeroed out when the .bss
- * section is later cleared.
- */
-u64 sme_me_mask __section(".data") = 0;
-u64 sev_status __section(".data") = 0;
-u64 sev_check_data __section(".data") = 0;
-EXPORT_SYMBOL(sme_me_mask);
-DEFINE_STATIC_KEY_FALSE(sev_enable_key);
-EXPORT_SYMBOL_GPL(sev_enable_key);
-
-/* Buffer used for early in-place encryption by BSP, no locking needed */
-static char sme_early_buffer[PAGE_SIZE] __initdata __aligned(PAGE_SIZE);
-
-/*
- * This routine does not change the underlying encryption setting of the
- * page(s) that map this memory. It assumes that eventually the memory is
- * meant to be accessed as either encrypted or decrypted but the contents
- * are currently not in the desired state.
- *
- * This routine follows the steps outlined in the AMD64 Architecture
- * Programmer's Manual Volume 2, Section 7.10.8 Encrypt-in-Place.
- */
-static void __init __sme_early_enc_dec(resource_size_t paddr,
- unsigned long size, bool enc)
-{
- void *src, *dst;
- size_t len;
-
- if (!sme_me_mask)
- return;
-
- wbinvd();
-
- /*
- * There are limited number of early mapping slots, so map (at most)
- * one page at time.
- */
- while (size) {
- len = min_t(size_t, sizeof(sme_early_buffer), size);
-
- /*
- * Create mappings for the current and desired format of
- * the memory. Use a write-protected mapping for the source.
- */
- src = enc ? early_memremap_decrypted_wp(paddr, len) :
- early_memremap_encrypted_wp(paddr, len);
-
- dst = enc ? early_memremap_encrypted(paddr, len) :
- early_memremap_decrypted(paddr, len);
-
- /*
- * If a mapping can't be obtained to perform the operation,
- * then eventual access of that area in the desired mode
- * will cause a crash.
- */
- BUG_ON(!src || !dst);
-
- /*
- * Use a temporary buffer, of cache-line multiple size, to
- * avoid data corruption as documented in the APM.
- */
- memcpy(sme_early_buffer, src, len);
- memcpy(dst, sme_early_buffer, len);
-
- early_memunmap(dst, len);
- early_memunmap(src, len);
-
- paddr += len;
- size -= len;
- }
-}
-
-void __init sme_early_encrypt(resource_size_t paddr, unsigned long size)
-{
- __sme_early_enc_dec(paddr, size, true);
-}
-
-void __init sme_early_decrypt(resource_size_t paddr, unsigned long size)
-{
- __sme_early_enc_dec(paddr, size, false);
-}
-
-static void __init __sme_early_map_unmap_mem(void *vaddr, unsigned long size,
- bool map)
-{
- unsigned long paddr = (unsigned long)vaddr - __PAGE_OFFSET;
- pmdval_t pmd_flags, pmd;
-
- /* Use early_pmd_flags but remove the encryption mask */
- pmd_flags = __sme_clr(early_pmd_flags);
-
- do {
- pmd = map ? (paddr & PMD_MASK) + pmd_flags : 0;
- __early_make_pgtable((unsigned long)vaddr, pmd);
-
- vaddr += PMD_SIZE;
- paddr += PMD_SIZE;
- size = (size <= PMD_SIZE) ? 0 : size - PMD_SIZE;
- } while (size);
-
- flush_tlb_local();
-}
-
-void __init sme_unmap_bootdata(char *real_mode_data)
-{
- struct boot_params *boot_data;
- unsigned long cmdline_paddr;
-
- if (!cc_platform_has(CC_ATTR_HOST_MEM_ENCRYPT))
- return;
-
- /* Get the command line address before unmapping the real_mode_data */
- boot_data = (struct boot_params *)real_mode_data;
- cmdline_paddr = boot_data->hdr.cmd_line_ptr | ((u64)boot_data->ext_cmd_line_ptr << 32);
-
- __sme_early_map_unmap_mem(real_mode_data, sizeof(boot_params), false);
-
- if (!cmdline_paddr)
- return;
-
- __sme_early_map_unmap_mem(__va(cmdline_paddr), COMMAND_LINE_SIZE, false);
-}
-
-void __init sme_map_bootdata(char *real_mode_data)
-{
- struct boot_params *boot_data;
- unsigned long cmdline_paddr;
-
- if (!cc_platform_has(CC_ATTR_HOST_MEM_ENCRYPT))
- return;
-
- __sme_early_map_unmap_mem(real_mode_data, sizeof(boot_params), true);
-
- /* Get the command line address after mapping the real_mode_data */
- boot_data = (struct boot_params *)real_mode_data;
- cmdline_paddr = boot_data->hdr.cmd_line_ptr | ((u64)boot_data->ext_cmd_line_ptr << 32);
-
- if (!cmdline_paddr)
- return;
-
- __sme_early_map_unmap_mem(__va(cmdline_paddr), COMMAND_LINE_SIZE, true);
-}
-
-void __init sme_early_init(void)
-{
- unsigned int i;
-
- if (!sme_me_mask)
- return;
-
- early_pmd_flags = __sme_set(early_pmd_flags);
-
- __supported_pte_mask = __sme_set(__supported_pte_mask);
-
- /* Update the protection map with memory encryption mask */
- for (i = 0; i < ARRAY_SIZE(protection_map); i++)
- protection_map[i] = pgprot_encrypted(protection_map[i]);
-
- if (cc_platform_has(CC_ATTR_GUEST_MEM_ENCRYPT))
- swiotlb_force = SWIOTLB_FORCE;
-}
-
-void __init sev_setup_arch(void)
-{
- phys_addr_t total_mem = memblock_phys_mem_size();
- unsigned long size;
-
- if (!cc_platform_has(CC_ATTR_GUEST_MEM_ENCRYPT))
- return;
-
- /*
- * For SEV, all DMA has to occur via shared/unencrypted pages.
- * SEV uses SWIOTLB to make this happen without changing device
- * drivers. However, depending on the workload being run, the
- * default 64MB of SWIOTLB may not be enough and SWIOTLB may
- * run out of buffers for DMA, resulting in I/O errors and/or
- * performance degradation especially with high I/O workloads.
- *
- * Adjust the default size of SWIOTLB for SEV guests using
- * a percentage of guest memory for SWIOTLB buffers.
- * Also, as the SWIOTLB bounce buffer memory is allocated
- * from low memory, ensure that the adjusted size is within
- * the limits of low available memory.
- *
- * The percentage of guest memory used here for SWIOTLB buffers
- * is more of an approximation of the static adjustment which
- * 64MB for <1G, and ~128M to 256M for 1G-to-4G, i.e., the 6%
- */
- size = total_mem * 6 / 100;
- size = clamp_val(size, IO_TLB_DEFAULT_SIZE, SZ_1G);
- swiotlb_adjust_size(size);
-}
-
-static unsigned long pg_level_to_pfn(int level, pte_t *kpte, pgprot_t *ret_prot)
-{
- unsigned long pfn = 0;
- pgprot_t prot;
-
- switch (level) {
- case PG_LEVEL_4K:
- pfn = pte_pfn(*kpte);
- prot = pte_pgprot(*kpte);
- break;
- case PG_LEVEL_2M:
- pfn = pmd_pfn(*(pmd_t *)kpte);
- prot = pmd_pgprot(*(pmd_t *)kpte);
- break;
- case PG_LEVEL_1G:
- pfn = pud_pfn(*(pud_t *)kpte);
- prot = pud_pgprot(*(pud_t *)kpte);
- break;
- default:
- WARN_ONCE(1, "Invalid level for kpte\n");
- return 0;
- }
-
- if (ret_prot)
- *ret_prot = prot;
-
- return pfn;
-}
-
-void notify_range_enc_status_changed(unsigned long vaddr, int npages, bool enc)
-{
-#ifdef CONFIG_PARAVIRT
- unsigned long sz = npages << PAGE_SHIFT;
- unsigned long vaddr_end = vaddr + sz;
-
- while (vaddr < vaddr_end) {
- int psize, pmask, level;
- unsigned long pfn;
- pte_t *kpte;
-
- kpte = lookup_address(vaddr, &level);
- if (!kpte || pte_none(*kpte)) {
- WARN_ONCE(1, "kpte lookup for vaddr\n");
- return;
- }
-
- pfn = pg_level_to_pfn(level, kpte, NULL);
- if (!pfn)
- continue;
-
- psize = page_level_size(level);
- pmask = page_level_mask(level);
-
- notify_page_enc_status_changed(pfn, psize >> PAGE_SHIFT, enc);
-
- vaddr = (vaddr & pmask) + psize;
- }
-#endif
-}
-
-static void __init __set_clr_pte_enc(pte_t *kpte, int level, bool enc)
-{
- pgprot_t old_prot, new_prot;
- unsigned long pfn, pa, size;
- pte_t new_pte;
-
- pfn = pg_level_to_pfn(level, kpte, &old_prot);
- if (!pfn)
- return;
-
- new_prot = old_prot;
- if (enc)
- pgprot_val(new_prot) |= _PAGE_ENC;
- else
- pgprot_val(new_prot) &= ~_PAGE_ENC;
-
- /* If prot is same then do nothing. */
- if (pgprot_val(old_prot) == pgprot_val(new_prot))
- return;
-
- pa = pfn << PAGE_SHIFT;
- size = page_level_size(level);
-
- /*
- * We are going to perform in-place en-/decryption and change the
- * physical page attribute from C=1 to C=0 or vice versa. Flush the
- * caches to ensure that data gets accessed with the correct C-bit.
- */
- clflush_cache_range(__va(pa), size);
-
- /* Encrypt/decrypt the contents in-place */
- if (enc)
- sme_early_encrypt(pa, size);
- else
- sme_early_decrypt(pa, size);
-
- /* Change the page encryption mask. */
- new_pte = pfn_pte(pfn, new_prot);
- set_pte_atomic(kpte, new_pte);
-}
-
-static int __init early_set_memory_enc_dec(unsigned long vaddr,
- unsigned long size, bool enc)
-{
- unsigned long vaddr_end, vaddr_next, start;
- unsigned long psize, pmask;
- int split_page_size_mask;
- int level, ret;
- pte_t *kpte;
-
- start = vaddr;
- vaddr_next = vaddr;
- vaddr_end = vaddr + size;
-
- for (; vaddr < vaddr_end; vaddr = vaddr_next) {
- kpte = lookup_address(vaddr, &level);
- if (!kpte || pte_none(*kpte)) {
- ret = 1;
- goto out;
- }
-
- if (level == PG_LEVEL_4K) {
- __set_clr_pte_enc(kpte, level, enc);
- vaddr_next = (vaddr & PAGE_MASK) + PAGE_SIZE;
- continue;
- }
-
- psize = page_level_size(level);
- pmask = page_level_mask(level);
-
- /*
- * Check whether we can change the large page in one go.
- * We request a split when the address is not aligned and
- * the number of pages to set/clear encryption bit is smaller
- * than the number of pages in the large page.
- */
- if (vaddr == (vaddr & pmask) &&
- ((vaddr_end - vaddr) >= psize)) {
- __set_clr_pte_enc(kpte, level, enc);
- vaddr_next = (vaddr & pmask) + psize;
- continue;
- }
-
- /*
- * The virtual address is part of a larger page, create the next
- * level page table mapping (4K or 2M). If it is part of a 2M
- * page then we request a split of the large page into 4K
- * chunks. A 1GB large page is split into 2M pages, resp.
- */
- if (level == PG_LEVEL_2M)
- split_page_size_mask = 0;
- else
- split_page_size_mask = 1 << PG_LEVEL_2M;
-
- /*
- * kernel_physical_mapping_change() does not flush the TLBs, so
- * a TLB flush is required after we exit from the for loop.
- */
- kernel_physical_mapping_change(__pa(vaddr & pmask),
- __pa((vaddr_end & pmask) + psize),
- split_page_size_mask);
- }
-
- ret = 0;
-
- notify_range_enc_status_changed(start, PAGE_ALIGN(size) >> PAGE_SHIFT, enc);
-out:
- __flush_tlb_all();
- return ret;
-}
-
-int __init early_set_memory_decrypted(unsigned long vaddr, unsigned long size)
-{
- return early_set_memory_enc_dec(vaddr, size, false);
-}
-
-int __init early_set_memory_encrypted(unsigned long vaddr, unsigned long size)
-{
- return early_set_memory_enc_dec(vaddr, size, true);
-}
-
-void __init early_set_mem_enc_dec_hypercall(unsigned long vaddr, int npages, bool enc)
-{
- notify_range_enc_status_changed(vaddr, npages, enc);
-}
/* Override for DMA direct allocation check - ARCH_HAS_FORCE_DMA_UNENCRYPTED */
bool force_dma_unencrypted(struct device *dev)
@@ -441,30 +40,6 @@ bool force_dma_unencrypted(struct device *dev)
return false;
}
-void __init mem_encrypt_free_decrypted_mem(void)
-{
- unsigned long vaddr, vaddr_end, npages;
- int r;
-
- vaddr = (unsigned long)__start_bss_decrypted_unused;
- vaddr_end = (unsigned long)__end_bss_decrypted;
- npages = (vaddr_end - vaddr) >> PAGE_SHIFT;
-
- /*
- * The unused memory range was mapped decrypted, change the encryption
- * attribute from decrypted to encrypted before freeing it.
- */
- if (cc_platform_has(CC_ATTR_MEM_ENCRYPT)) {
- r = set_memory_encrypted(vaddr, npages);
- if (r) {
- pr_warn("failed to free unused decrypted pages\n");
- return;
- }
- }
-
- free_init_pages("unused decrypted", vaddr, vaddr_end);
-}
-
static void print_mem_encrypt_feature_info(void)
{
pr_info("AMD Memory Encryption Features active:");
@@ -493,20 +68,12 @@ static void print_mem_encrypt_feature_info(void)
/* Architecture __weak replacement functions */
void __init mem_encrypt_init(void)
{
- if (!sme_me_mask)
+ if (!cc_platform_has(CC_ATTR_MEM_ENCRYPT))
return;
/* Call into SWIOTLB to update the SWIOTLB DMA buffers */
swiotlb_update_mem_attributes();
- /*
- * With SEV, we need to unroll the rep string I/O instructions,
- * but SEV-ES supports them through the #VC handler.
- */
- if (cc_platform_has(CC_ATTR_GUEST_MEM_ENCRYPT) &&
- !cc_platform_has(CC_ATTR_GUEST_STATE_ENCRYPT))
- static_branch_enable(&sev_enable_key);
-
print_mem_encrypt_feature_info();
}