Merge tag 'x86_cc_for_v5.16_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull generic confidential computing updates from Borislav Petkov:
 "Add an interface called cc_platform_has() which is supposed to be used
  by confidential computing solutions to query different aspects of the
  system.

  The intent behind it is to unify testing of such aspects instead of
  having each confidential computing solution add its own set of tests
  to code paths in the kernel, leading to an unwieldy mess"

* tag 'x86_cc_for_v5.16_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  treewide: Replace the use of mem_encrypt_active() with cc_platform_has()
  x86/sev: Replace occurrences of sev_es_active() with cc_platform_has()
  x86/sev: Replace occurrences of sev_active() with cc_platform_has()
  x86/sme: Replace occurrences of sme_active() with cc_platform_has()
  powerpc/pseries/svm: Add a powerpc version of cc_platform_has()
  x86/sev: Add an x86 version of cc_platform_has()
  arch/cc: Introduce a function to check for confidential computing features
  x86/ioremap: Selectively build arch override encryption functions

4 files changed, 33 insertions, 52 deletions

diff --git a/arch/x86/mm/ioremap.c b/arch/x86/mm/ioremap.c
index 60ade7dd71bd..026031b3b782 100644
--- a/arch/x86/mm/ioremap.c
+++ b/arch/x86/mm/ioremap.c
@@ -14,7 +14,7 @@
 #include <linux/slab.h>
 #include <linux/vmalloc.h>
 #include <linux/mmiotrace.h>
-#include <linux/mem_encrypt.h>
+#include <linux/cc_platform.h>
 #include <linux/efi.h>
 #include <linux/pgtable.h>
 
@@ -92,7 +92,7 @@ static unsigned int __ioremap_check_ram(struct resource *res)
  */
 static unsigned int __ioremap_check_encrypted(struct resource *res)
 {
-	if (!sev_active())
+	if (!cc_platform_has(CC_ATTR_GUEST_MEM_ENCRYPT))
 		return 0;
 
 	switch (res->desc) {
@@ -112,7 +112,7 @@ static unsigned int __ioremap_check_encrypted(struct resource *res)
  */
 static void __ioremap_check_other(resource_size_t addr, struct ioremap_desc *desc)
 {
-	if (!sev_active())
+	if (!cc_platform_has(CC_ATTR_GUEST_MEM_ENCRYPT))
 		return;
 
 	if (!IS_ENABLED(CONFIG_EFI))
@@ -508,6 +508,7 @@ void unxlate_dev_mem_ptr(phys_addr_t phys, void *addr)
 	memunmap((void *)((unsigned long)addr & PAGE_MASK));
 }
 
+#ifdef CONFIG_AMD_MEM_ENCRYPT
 /*
  * Examine the physical address to determine if it is an area of memory
  * that should be mapped decrypted.  If the memory is not part of the
@@ -555,7 +556,7 @@ static bool memremap_should_map_decrypted(resource_size_t phys_addr,
 	case E820_TYPE_NVS:
 	case E820_TYPE_UNUSABLE:
 		/* For SEV, these areas are encrypted */
-		if (sev_active())
+		if (cc_platform_has(CC_ATTR_GUEST_MEM_ENCRYPT))
 			break;
 		fallthrough;
 
@@ -693,7 +694,7 @@ static bool __init early_memremap_is_setup_data(resource_size_t phys_addr,
 bool arch_memremap_can_ram_remap(resource_size_t phys_addr, unsigned long size,
 				 unsigned long flags)
 {
-	if (!mem_encrypt_active())
+	if (!cc_platform_has(CC_ATTR_MEM_ENCRYPT))
 		return true;
 
 	if (flags & MEMREMAP_ENC)
@@ -702,7 +703,7 @@ bool arch_memremap_can_ram_remap(resource_size_t phys_addr, unsigned long size,
 	if (flags & MEMREMAP_DEC)
 		return false;
 
-	if (sme_active()) {
+	if (cc_platform_has(CC_ATTR_HOST_MEM_ENCRYPT)) {
 		if (memremap_is_setup_data(phys_addr, size) ||
 		    memremap_is_efi_data(phys_addr, size))
 			return false;
@@ -723,12 +724,12 @@ pgprot_t __init early_memremap_pgprot_adjust(resource_size_t phys_addr,
 {
 	bool encrypted_prot;
 
-	if (!mem_encrypt_active())
+	if (!cc_platform_has(CC_ATTR_MEM_ENCRYPT))
 		return prot;
 
 	encrypted_prot = true;
 
-	if (sme_active()) {
+	if (cc_platform_has(CC_ATTR_HOST_MEM_ENCRYPT)) {
 		if (early_memremap_is_setup_data(phys_addr, size) ||
 		    memremap_is_efi_data(phys_addr, size))
 			encrypted_prot = false;
@@ -746,7 +747,6 @@ bool phys_mem_access_encrypted(unsigned long phys_addr, unsigned long size)
 	return arch_memremap_can_ram_remap(phys_addr, size, 0);
 }
 
-#ifdef CONFIG_AMD_MEM_ENCRYPT
 /* Remap memory with encryption */
 void __init *early_memremap_encrypted(resource_size_t phys_addr,
 				      unsigned long size)
diff --git a/arch/x86/mm/mem_encrypt.c b/arch/x86/mm/mem_encrypt.c
index ff08dc463634..23d54b810f08 100644
--- a/arch/x86/mm/mem_encrypt.c
+++ b/arch/x86/mm/mem_encrypt.c
@@ -20,6 +20,7 @@
 #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>
@@ -143,7 +144,7 @@ void __init sme_unmap_bootdata(char *real_mode_data)
 	struct boot_params *boot_data;
 	unsigned long cmdline_paddr;
 
-	if (!sme_active())
+	if (!cc_platform_has(CC_ATTR_HOST_MEM_ENCRYPT))
 		return;
 
 	/* Get the command line address before unmapping the real_mode_data */
@@ -163,7 +164,7 @@ void __init sme_map_bootdata(char *real_mode_data)
 	struct boot_params *boot_data;
 	unsigned long cmdline_paddr;
 
-	if (!sme_active())
+	if (!cc_platform_has(CC_ATTR_HOST_MEM_ENCRYPT))
 		return;
 
 	__sme_early_map_unmap_mem(real_mode_data, sizeof(boot_params), true);
@@ -193,7 +194,7 @@ void __init sme_early_init(void)
 	for (i = 0; i < ARRAY_SIZE(protection_map); i++)
 		protection_map[i] = pgprot_encrypted(protection_map[i]);
 
-	if (sev_active())
+	if (cc_platform_has(CC_ATTR_GUEST_MEM_ENCRYPT))
 		swiotlb_force = SWIOTLB_FORCE;
 }
 
@@ -202,7 +203,7 @@ void __init sev_setup_arch(void)
 	phys_addr_t total_mem = memblock_phys_mem_size();
 	unsigned long size;
 
-	if (!sev_active())
+	if (!cc_platform_has(CC_ATTR_GUEST_MEM_ENCRYPT))
 		return;
 
 	/*
@@ -360,42 +361,13 @@ 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 +375,7 @@ 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);
@@ -428,7 +400,7 @@ void __init mem_encrypt_free_decrypted_mem(void)
 	 * The unused memory range was mapped decrypted, change the encryption
 	 * attribute from decrypted to encrypted before freeing it.
 	 */
-	if (mem_encrypt_active()) {
+	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");
@@ -444,7 +416,7 @@ 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 +426,11 @@ 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");
@@ -477,7 +449,8 @@ void __init mem_encrypt_init(void)
 	 * 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())
+	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();
@@ -485,6 +458,6 @@ void __init mem_encrypt_init(void)
 
 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);
diff --git a/arch/x86/mm/mem_encrypt_identity.c b/arch/x86/mm/mem_encrypt_identity.c
index 470b20208430..f8c612902038 100644
--- a/arch/x86/mm/mem_encrypt_identity.c
+++ b/arch/x86/mm/mem_encrypt_identity.c
@@ -30,6 +30,7 @@
 #include <linux/kernel.h>
 #include <linux/mm.h>
 #include <linux/mem_encrypt.h>
+#include <linux/cc_platform.h>
 
 #include <asm/setup.h>
 #include <asm/sections.h>
@@ -287,7 +288,13 @@ void __init sme_encrypt_kernel(struct boot_params *bp)
 	unsigned long pgtable_area_len;
 	unsigned long decrypted_base;
 
-	if (!sme_active())
+	/*
+	 * This is early code, use an open coded check for SME instead of
+	 * using cc_platform_has(). This eliminates worries about removing
+	 * instrumentation or checking boot_cpu_data in the cc_platform_has()
+	 * function.
+	 */
+	if (!sme_get_me_mask() || sev_status & MSR_AMD64_SEV_ENABLED)
 		return;
 
 	/*
diff --git a/arch/x86/mm/pat/set_memory.c b/arch/x86/mm/pat/set_memory.c
index ad8a5c586a35..527957586f3c 100644
--- a/arch/x86/mm/pat/set_memory.c
+++ b/arch/x86/mm/pat/set_memory.c
@@ -18,6 +18,7 @@
 #include <linux/libnvdimm.h>
 #include <linux/vmstat.h>
 #include <linux/kernel.h>
+#include <linux/cc_platform.h>
 
 #include <asm/e820/api.h>
 #include <asm/processor.h>
@@ -1986,7 +1987,7 @@ static int __set_memory_enc_dec(unsigned long addr, int numpages, bool enc)
 	int ret;
 
 	/* Nothing to do if memory encryption is not active */
-	if (!mem_encrypt_active())
+	if (!cc_platform_has(CC_ATTR_MEM_ENCRYPT))
 		return 0;
 
 	/* Should not be working on unaligned addresses */