[PATCH 5.11 289/306] x86/sev-es: Correctly track IRQ states in runtime #VC handler

[gregkh]

From: Greg Kroah-Hartman <gre...@linuxfoundation.org>

From: Joerg Roedel <jroe...@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 <l...@kernel.org>
Signed-off-by: Joerg Roedel <jroe...@suse.de>
Signed-off-by: Borislav Petkov <b...@suse.de>
Cc: sta...@vger.kernel.org # v5.10+
Link: https://lkml.kernel.org/r/20210303141716.29223-5-j...@8bytes.org
Signed-off-by: Greg Kroah-Hartman <gre...@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;