[PATCH 6.18.y 4/5] x86/sev: Remove redundant ghcbs_initialized checks around __sev_{get,put}_ghcb()

[Sasha Levin <sashal@kernel.org>]

From: Nikunj A Dadhania <nikunj@amd.com>

[ Upstream commit 9d8460a1c7a6b0f2dc6302e5d0f31d4e8c2a7913 ]

After

  3645eb7e3915 ("x86/fred: Fix early boot failures on SEV-ES/SNP guests"),

__sev_{get,put}_ghcb() handle the early-boot GHCB fallback internally, making
the ghcbs_initialized guards in __set_pages_state() and
svsm_perform_call_protocol() redundant.

Remove them.

Also initialize state->ghcb to NULL in the early-boot path of
__sev_get_ghcb() so that the ghcb_state is well-defined for all callers,
even though __sev_put_ghcb() currently returns early before reading it.

No functional change intended.

Suggested-by: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Nikunj A Dadhania <nikunj@amd.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Tom Lendacky <thomas.lendacky@amd.com>
Link: https://patch.msgid.link/20260518102230.3394603-1-nikunj@amd.com
Stable-dep-of: 6c43c72748ff ("x86/sev: Make vTPM SVSM calls preemption-safe")
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 arch/x86/coco/sev/core.c    |  8 ++------
 arch/x86/coco/sev/noinstr.c |  4 +++-
 arch/x86/coco/sev/svsm.c    | 10 ++--------
 3 files changed, 7 insertions(+), 15 deletions(-)

diff --git a/arch/x86/coco/sev/core.c b/arch/x86/coco/sev/core.c
index 2415410e898ec..fefd7031be020 100644
--- a/arch/x86/coco/sev/core.c
+++ b/arch/x86/coco/sev/core.c
@@ -367,17 +367,13 @@ static unsigned long __set_pages_state(struct snp_psc_desc *data, unsigned long
 
 	local_irq_save(flags);
 
-	if (sev_cfg.ghcbs_initialized)
-		ghcb = __sev_get_ghcb(&state);
-	else
-		ghcb = boot_ghcb;
+	ghcb = __sev_get_ghcb(&state);
 
 	/* Invoke the hypervisor to perform the page state changes */
 	if (!ghcb || vmgexit_psc(ghcb, data))
 		sev_es_terminate(SEV_TERM_SET_LINUX, GHCB_TERM_PSC);
 
-	if (sev_cfg.ghcbs_initialized)
-		__sev_put_ghcb(&state);
+	__sev_put_ghcb(&state);
 
 	local_irq_restore(flags);
 
diff --git a/arch/x86/coco/sev/noinstr.c b/arch/x86/coco/sev/noinstr.c
index 5afd663a1c217..e1e03f12fc7bb 100644
--- a/arch/x86/coco/sev/noinstr.c
+++ b/arch/x86/coco/sev/noinstr.c
@@ -121,8 +121,10 @@ noinstr struct ghcb *__sev_get_ghcb(struct ghcb_state *state)
 
 	WARN_ON(!irqs_disabled());
 
-	if (!sev_cfg.ghcbs_initialized)
+	if (!sev_cfg.ghcbs_initialized) {
+		state->ghcb = NULL;
 		return boot_ghcb;
+	}
 
 	data = this_cpu_read(runtime_data);
 	ghcb = &data->ghcb_page;
diff --git a/arch/x86/coco/sev/svsm.c b/arch/x86/coco/sev/svsm.c
index 2acf4a76afe7a..916d62cd17dc7 100644
--- a/arch/x86/coco/sev/svsm.c
+++ b/arch/x86/coco/sev/svsm.c
@@ -74,20 +74,14 @@ int svsm_perform_call_protocol(struct svsm_call *call)
 
 	flags = native_local_irq_save();
 
-	if (sev_cfg.ghcbs_initialized)
-		ghcb = __sev_get_ghcb(&state);
-	else if (boot_ghcb)
-		ghcb = boot_ghcb;
-	else
-		ghcb = NULL;
+	ghcb = __sev_get_ghcb(&state);
 
 	do {
 		ret = ghcb ? svsm_perform_ghcb_protocol(ghcb, call)
 			   : __pi_svsm_perform_msr_protocol(call);
 	} while (ret == -EAGAIN);
 
-	if (sev_cfg.ghcbs_initialized)
-		__sev_put_ghcb(&state);
+	__sev_put_ghcb(&state);
 
 	native_local_irq_restore(flags);
 
-- 
2.53.0