[PATCH 06/11] x86/sev: Replace occurrences of sev_es_active() with prot_guest_has()

From: Tom Lendacky
Date: Tue Jul 27 2021 - 18:28:09 EST


Replace occurrences of sev_es_active() with the more generic
prot_guest_has() using PATTR_GUEST_PROT_STATE, except for in
arch/x86/kernel/sev*.c and arch/x86/mm/mem_encrypt*.c where PATTR_SEV_ES
will be used. If future support is added for other memory encyrption
techonologies, the use of PATTR_GUEST_PROT_STATE can be updated, as
required, to specifically use PATTR_SEV_ES.

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 | 7 +++----
arch/x86/realmode/init.c | 3 +--
4 files changed, 7 insertions(+), 11 deletions(-)

diff --git a/arch/x86/include/asm/mem_encrypt.h b/arch/x86/include/asm/mem_encrypt.h
index 7e25de37c148..797146e0cd6b 100644
--- a/arch/x86/include/asm/mem_encrypt.h
+++ b/arch/x86/include/asm/mem_encrypt.h
@@ -50,7 +50,6 @@ 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_prot_guest_has(unsigned int attr);

#define __bss_decrypted __section(".bss..decrypted")
@@ -74,7 +73,6 @@ 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_prot_guest_has(unsigned int attr) { return false; }

static inline int __init
diff --git a/arch/x86/kernel/sev.c b/arch/x86/kernel/sev.c
index a6895e440bc3..66a4ab9d95d7 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/protected_guest.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 (!prot_guest_has(PATTR_SEV_ES))
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 (!prot_guest_has(PATTR_SEV_ES))
return;

if (!sev_es_check_cpu_features())
diff --git a/arch/x86/mm/mem_encrypt.c b/arch/x86/mm/mem_encrypt.c
index eb5cae93b238..451de8e84fce 100644
--- a/arch/x86/mm/mem_encrypt.c
+++ b/arch/x86/mm/mem_encrypt.c
@@ -383,8 +383,7 @@ static bool sme_active(void)
return sme_me_mask && !sev_active();
}

-/* Needs to be called from non-instrumentable code */
-bool noinstr sev_es_active(void)
+static bool sev_es_active(void)
{
return sev_status & MSR_AMD64_SEV_ES_ENABLED;
}
@@ -482,7 +481,7 @@ static void print_mem_encrypt_feature_info(void)
pr_cont(" SEV");

/* Encrypted Register State */
- if (sev_es_active())
+ if (amd_prot_guest_has(PATTR_SEV_ES))
pr_cont(" SEV-ES");

pr_cont("\n");
@@ -501,7 +500,7 @@ 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 (amd_prot_guest_has(PATTR_SEV) && !sev_es_active())
+ if (amd_prot_guest_has(PATTR_SEV) && !amd_prot_guest_has(PATTR_SEV_ES))
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 2109ae569c67..7711d0071f41 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/protected_guest.h>
#include <linux/pgtable.h>

@@ -48,7 +47,7 @@ static void sme_sev_setup_real_mode(struct trampoline_header *th)
if (prot_guest_has(PATTR_HOST_MEM_ENCRYPT))
th->flags |= TH_FLAGS_SME_ACTIVE;

- if (sev_es_active()) {
+ if (prot_guest_has(PATTR_GUEST_PROT_STATE)) {
/*
* Skip the call to verify_cpu() in secondary_startup_64 as it
* will cause #VC exceptions when the AP can't handle them yet.
--
2.32.0