[PATCH v3 7/8] x86/sev: Replace occurrences of sev_es_active() with cc_platform_has()

[Tom Lendacky]

Replace uses of sev_es_active() with the more generic cc_platform_has()
using CC_ATTR_GUEST_STATE_ENCRYPT. If future support is added for other
memory encyrption techonologies, the use of CC_ATTR_GUEST_STATE_ENCRYPT
can be updated, as required.

Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: Borislav Petkov <bp@xxxxxxxxx>
Signed-off-by: Tom Lendacky <thomas.lendacky@xxxxxxx>
---
 arch/x86/include/asm/mem_encrypt.h |  2 --
 arch/x86/kernel/sev.c              |  6 +++---
 arch/x86/mm/mem_encrypt.c          | 14 ++++----------
 arch/x86/realmode/init.c           |  3 +--
 4 files changed, 8 insertions(+), 17 deletions(-)

diff --git a/arch/x86/include/asm/mem_encrypt.h b/arch/x86/include/asm/mem_encrypt.h
index f440eebeeb2c..499440781b39 100644
--- a/arch/x86/include/asm/mem_encrypt.h
+++ b/arch/x86/include/asm/mem_encrypt.h
@@ -51,7 +51,6 @@ void __init mem_encrypt_free_decrypted_mem(void);
 void __init mem_encrypt_init(void);
 
 void __init sev_es_init_vc_handling(void);
-bool sev_es_active(void);
 bool amd_cc_platform_has(enum cc_attr attr);
 
 #define __bss_decrypted __section(".bss..decrypted")
@@ -75,7 +74,6 @@ static inline void __init sme_encrypt_kernel(struct boot_params *bp) { }
 static inline void __init sme_enable(struct boot_params *bp) { }
 
 static inline void sev_es_init_vc_handling(void) { }
-static inline bool sev_es_active(void) { return false; }
 static inline bool amd_cc_platform_has(enum cc_attr attr) { return false; }
 
 static inline int __init
diff --git a/arch/x86/kernel/sev.c b/arch/x86/kernel/sev.c
index a6895e440bc3..53a6837d354b 100644
--- a/arch/x86/kernel/sev.c
+++ b/arch/x86/kernel/sev.c
@@ -11,7 +11,7 @@
 
 #include <linux/sched/debug.h>	/* For show_regs() */
 #include <linux/percpu-defs.h>
-#include <linux/mem_encrypt.h>
+#include <linux/cc_platform.h>
 #include <linux/printk.h>
 #include <linux/mm_types.h>
 #include <linux/set_memory.h>
@@ -615,7 +615,7 @@ int __init sev_es_efi_map_ghcbs(pgd_t *pgd)
 	int cpu;
 	u64 pfn;
 
-	if (!sev_es_active())
+	if (!cc_platform_has(CC_ATTR_GUEST_STATE_ENCRYPT))
 		return 0;
 
 	pflags = _PAGE_NX | _PAGE_RW;
@@ -774,7 +774,7 @@ void __init sev_es_init_vc_handling(void)
 
 	BUILD_BUG_ON(offsetof(struct sev_es_runtime_data, ghcb_page) % PAGE_SIZE);
 
-	if (!sev_es_active())
+	if (!cc_platform_has(CC_ATTR_GUEST_STATE_ENCRYPT))
 		return;
 
 	if (!sev_es_check_cpu_features())
diff --git a/arch/x86/mm/mem_encrypt.c b/arch/x86/mm/mem_encrypt.c
index 22d4e152a6de..47d571a2cd28 100644
--- a/arch/x86/mm/mem_encrypt.c
+++ b/arch/x86/mm/mem_encrypt.c
@@ -373,13 +373,6 @@ int __init early_set_memory_encrypted(unsigned long vaddr, unsigned long size)
  * up under SME the trampoline area cannot be encrypted, whereas under SEV
  * the trampoline area must be encrypted.
  */
-
-/* Needs to be called from non-instrumentable code */
-bool noinstr sev_es_active(void)
-{
-	return sev_status & MSR_AMD64_SEV_ES_ENABLED;
-}
-
 bool amd_cc_platform_has(enum cc_attr attr)
 {
 	switch (attr) {
@@ -393,7 +386,7 @@ bool amd_cc_platform_has(enum cc_attr attr)
 		return sev_status & MSR_AMD64_SEV_ENABLED;
 
 	case CC_ATTR_GUEST_STATE_ENCRYPT:
-		return sev_es_active();
+		return sev_status & MSR_AMD64_SEV_ES_ENABLED;
 
 	default:
 		return false;
@@ -469,7 +462,7 @@ static void print_mem_encrypt_feature_info(void)
 		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");
@@ -488,7 +481,8 @@ 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 (cc_platform_has(CC_ATTR_GUEST_MEM_ENCRYPT) && !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();
diff --git a/arch/x86/realmode/init.c b/arch/x86/realmode/init.c
index c878c5ee5a4c..4a3da7592b99 100644
--- a/arch/x86/realmode/init.c
+++ b/arch/x86/realmode/init.c
@@ -2,7 +2,6 @@
 #include <linux/io.h>
 #include <linux/slab.h>
 #include <linux/memblock.h>
-#include <linux/mem_encrypt.h>
 #include <linux/cc_platform.h>
 #include <linux/pgtable.h>
 
@@ -48,7 +47,7 @@ static void sme_sev_setup_real_mode(struct trampoline_header *th)
 	if (cc_platform_has(CC_ATTR_HOST_MEM_ENCRYPT))
 		th->flags |= TH_FLAGS_SME_ACTIVE;
 
-	if (sev_es_active()) {
+	if (cc_platform_has(CC_ATTR_GUEST_STATE_ENCRYPT)) {
 		/*
 		 * Skip the call to verify_cpu() in secondary_startup_64 as it
 		 * will cause #VC exceptions when the AP can't handle them yet.
-- 
2.33.0