1 files changed, 10 insertions, 416 deletions

diff --git a/arch/x86/mm/mem_encrypt.c b/arch/x86/mm/mem_encrypt.c
index ff08dc463634..50d209939c66 100644
--- a/arch/x86/mm/mem_encrypt.c
+++ b/arch/x86/mm/mem_encrypt.c
@@ -1,401 +1,26 @@
 // 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 <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 (!sme_active())
-		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 (!sme_active())
-		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 (sev_active())
-		swiotlb_force = SWIOTLB_FORCE;
-}
-
-void __init sev_setup_arch(void)
-{
-	phys_addr_t total_mem = memblock_phys_mem_size();
-	unsigned long size;
-
-	if (!sev_active())
-		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 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;
-
-	switch (level) {
-	case PG_LEVEL_4K:
-		pfn = pte_pfn(*kpte);
-		old_prot = pte_pgprot(*kpte);
-		break;
-	case PG_LEVEL_2M:
-		pfn = pmd_pfn(*(pmd_t *)kpte);
-		old_prot = pmd_pgprot(*(pmd_t *)kpte);
-		break;
-	case PG_LEVEL_1G:
-		pfn = pud_pfn(*(pud_t *)kpte);
-		old_prot = pud_pgprot(*(pud_t *)kpte);
-		break;
-	default:
-		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;
-	unsigned long psize, pmask;
-	int split_page_size_mask;
-	int level, ret;
-	pte_t *kpte;
-
-	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;
-
-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);
-}
-
-/*
- * SME and SEV are very similar but they are not the same, so there are
- * times that the kernel will need to distinguish between SME and SEV. The
- * sme_active() and sev_active() functions are used for this.  When a
- * distinction isn't needed, the mem_encrypt_active() function can be used.
- *
- * The trampoline code is a good example for this requirement.  Before
- * paging is activated, SME will access all memory as decrypted, but SEV
- * will access all memory as encrypted.  So, when APs are being brought
- * up under SME the trampoline area cannot be encrypted, whereas under SEV
- * the trampoline area must be encrypted.
- */
-bool sev_active(void)
-{
-	return sev_status & MSR_AMD64_SEV_ENABLED;
-}
-
-bool sme_active(void)
-{
-	return sme_me_mask && !sev_active();
-}
-EXPORT_SYMBOL_GPL(sev_active);
-
-/* Needs to be called from non-instrumentable code */
-bool noinstr sev_es_active(void)
-{
-	return sev_status & MSR_AMD64_SEV_ES_ENABLED;
-}
-
 /* 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 (sev_active())
+	if (cc_platform_has(CC_ATTR_GUEST_MEM_ENCRYPT))
 		return true;
 
 	/*
@@ -403,7 +28,7 @@ bool force_dma_unencrypted(struct device *dev)
 	 * device does not support DMA to addresses that include the
 	 * encryption mask.
 	 */
-	if (sme_active()) {
+	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);
@@ -415,36 +40,12 @@ 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 (mem_encrypt_active()) {
-		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 (sme_active()) {
+	if (cc_platform_has(CC_ATTR_HOST_MEM_ENCRYPT)) {
 		/*
 		 * SME is mutually exclusive with any of the SEV
 		 * features below.
@@ -454,11 +55,11 @@ static void print_mem_encrypt_feature_info(void)
 	}
 
 	/* Secure Encrypted Virtualization */
-	if (sev_active())
+	if (cc_platform_has(CC_ATTR_GUEST_MEM_ENCRYPT))
 		pr_cont(" SEV");
 
 	/* Encrypted Register State */
-	if (sev_es_active())
+	if (cc_platform_has(CC_ATTR_GUEST_STATE_ENCRYPT))
 		pr_cont(" SEV-ES");
 
 	pr_cont("\n");
@@ -467,24 +68,17 @@ 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 (sev_active() && !sev_es_active())
-		static_branch_enable(&sev_enable_key);
-
 	print_mem_encrypt_feature_info();
 }
 
 int arch_has_restricted_virtio_memory_access(void)
 {
-	return sev_active();
+	return cc_platform_has(CC_ATTR_GUEST_MEM_ENCRYPT);
 }
 EXPORT_SYMBOL_GPL(arch_has_restricted_virtio_memory_access);