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

Brijesh Singh
2021-03-24T16:45:30Z

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@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Joerg Roedel <jroedel@suse.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: "Peter Zijlstra (Intel)" <peterz@infradead.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Sean Christopherson <seanjc@google.com>
Cc: x86@kernel.org
Cc: kvm@vger.kernel.org
Signed-off-by: Brijesh Singh <brijesh.singh@amd.com>
---
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