[RFC Part1 PATCH 12/13] x86/sev-es: make GHCB get and put helper accessible outside

[Brijesh Singh <brijesh.singh@xxxxxxx>]

The SEV-SNP support extended the GHCB specification with few SNP-specific
VMGEXITs. Those VMGEXITs will be implemented in sev-snp.c. Make the GHCB
get/put helper available outside the sev-es.c so that SNP VMGEXIT can
avoid duplicating the GHCB get/put logic..

Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: Borislav Petkov <bp@xxxxxxxxx>
Cc: Joerg Roedel <jroedel@xxxxxxx>
Cc: "H. Peter Anvin" <hpa@xxxxxxxxx>
Cc: Tony Luck <tony.luck@xxxxxxxxx>
Cc: Dave Hansen <dave.hansen@xxxxxxxxx>
Cc: "Peter Zijlstra (Intel)" <peterz@xxxxxxxxxxxxx>
Cc: Paolo Bonzini <pbonzini@xxxxxxxxxx>
Cc: Tom Lendacky <thomas.lendacky@xxxxxxx>
Cc: David Rientjes <rientjes@xxxxxxxxxx>
Cc: Sean Christopherson <seanjc@xxxxxxxxxx>
Cc: x86@xxxxxxxxxx
Cc: kvm@xxxxxxxxxxxxxxx
Signed-off-by: Brijesh Singh <brijesh.singh@xxxxxxx>
---
 arch/x86/include/asm/sev-es.h | 9 +++++++++
 arch/x86/kernel/sev-es.c      | 8 ++------
 2 files changed, 11 insertions(+), 6 deletions(-)

diff --git a/arch/x86/include/asm/sev-es.h b/arch/x86/include/asm/sev-es.h
index cf1d957c7091..33838a8f8495 100644
--- a/arch/x86/include/asm/sev-es.h
+++ b/arch/x86/include/asm/sev-es.h
@@ -81,6 +81,10 @@ extern void vc_no_ghcb(void);
 extern void vc_boot_ghcb(void);
 extern bool handle_vc_boot_ghcb(struct pt_regs *regs);
 
+struct ghcb_state {
+	struct ghcb *ghcb;
+};
+
 #ifdef CONFIG_AMD_MEM_ENCRYPT
 extern struct static_key_false sev_es_enable_key;
 extern void __sev_es_ist_enter(struct pt_regs *regs);
@@ -103,12 +107,17 @@ static __always_inline void sev_es_nmi_complete(void)
 		__sev_es_nmi_complete();
 }
 extern int __init sev_es_efi_map_ghcbs(pgd_t *pgd);
+extern struct ghcb *sev_es_get_ghcb(struct ghcb_state *state);
+extern void sev_es_put_ghcb(struct ghcb_state *state);
+
 #else
 static inline void sev_es_ist_enter(struct pt_regs *regs) { }
 static inline void sev_es_ist_exit(void) { }
 static inline int sev_es_setup_ap_jump_table(struct real_mode_header *rmh) { return 0; }
 static inline void sev_es_nmi_complete(void) { }
 static inline int sev_es_efi_map_ghcbs(pgd_t *pgd) { return 0; }
+static inline struct ghcb *sev_es_get_ghcb(struct ghcb_state *state) { return NULL; }
+static inline void sev_es_put_ghcb(struct ghcb_state *state) { }
 #endif
 
 #endif
diff --git a/arch/x86/kernel/sev-es.c b/arch/x86/kernel/sev-es.c
index 004bf1102dc1..d4957b3fc43f 100644
--- a/arch/x86/kernel/sev-es.c
+++ b/arch/x86/kernel/sev-es.c
@@ -98,10 +98,6 @@ struct sev_es_runtime_data {
 	bool ghcb_registered;
 };
 
-struct ghcb_state {
-	struct ghcb *ghcb;
-};
-
 static DEFINE_PER_CPU(struct sev_es_runtime_data*, runtime_data);
 DEFINE_STATIC_KEY_FALSE(sev_es_enable_key);
 
@@ -178,7 +174,7 @@ void noinstr __sev_es_ist_exit(void)
 	this_cpu_write(cpu_tss_rw.x86_tss.ist[IST_INDEX_VC], *(unsigned long *)ist);
 }
 
-static __always_inline struct ghcb *sev_es_get_ghcb(struct ghcb_state *state)
+struct ghcb *sev_es_get_ghcb(struct ghcb_state *state)
 {
 	struct sev_es_runtime_data *data;
 	struct ghcb *ghcb;
@@ -213,7 +209,7 @@ static __always_inline struct ghcb *sev_es_get_ghcb(struct ghcb_state *state)
 	return ghcb;
 }
 
-static __always_inline void sev_es_put_ghcb(struct ghcb_state *state)
+void sev_es_put_ghcb(struct ghcb_state *state)
 {
 	struct sev_es_runtime_data *data;
 	struct ghcb *ghcb;
-- 
2.17.1