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From:   gregkh@linuxfoundation.org
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org, Andy Lutomirski <luto@kernel.org>,
        Joerg Roedel <jroedel@suse.de>, Borislav Petkov <bp@suse.de>
Subject: [PATCH 5.10 273/290] x86/sev-es: Correctly track IRQ states in runtime #VC handler
Date:   Mon, 15 Mar 2021 14:56:06 +0100
Message-Id: <20210315135551.250398104@linuxfoundation.org>
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From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

From: Joerg Roedel <jroedel@suse.de>

commit 62441a1fb53263bda349b6e5997c3cc5c120d89e upstream.

Call irqentry_nmi_enter()/irqentry_nmi_exit() in the #VC handler to
correctly track the IRQ state during its execution.

Fixes: 0786138c78e79 ("x86/sev-es: Add a Runtime #VC Exception Handler")
Reported-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: stable@vger.kernel.org # v5.10+
Link: https://lkml.kernel.org/r/20210303141716.29223-5-joro@8bytes.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 arch/x86/kernel/sev-es.c |    6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

--- a/arch/x86/kernel/sev-es.c
+++ b/arch/x86/kernel/sev-es.c
@@ -1258,13 +1258,12 @@ static __always_inline bool on_vc_fallba
 DEFINE_IDTENTRY_VC_SAFE_STACK(exc_vmm_communication)
 {
 	struct sev_es_runtime_data *data = this_cpu_read(runtime_data);
+	irqentry_state_t irq_state;
 	struct ghcb_state state;
 	struct es_em_ctxt ctxt;
 	enum es_result result;
 	struct ghcb *ghcb;
 
-	lockdep_assert_irqs_disabled();
-
 	/*
 	 * Handle #DB before calling into !noinstr code to avoid recursive #DB.
 	 */
@@ -1273,6 +1272,8 @@ DEFINE_IDTENTRY_VC_SAFE_STACK(exc_vmm_co
 		return;
 	}
 
+	irq_state = irqentry_nmi_enter(regs);
+	lockdep_assert_irqs_disabled();
 	instrumentation_begin();
 
 	/*
@@ -1335,6 +1336,7 @@ DEFINE_IDTENTRY_VC_SAFE_STACK(exc_vmm_co
 
 out:
 	instrumentation_end();
+	irqentry_nmi_exit(regs, irq_state);
 
 	return;