[tip: x86/urgent] x86/sev-es: Correctly track IRQ states in runtime #VC handler

[tip-bot2 for Joerg Roedel]

The following commit has been merged into the x86/urgent branch of tip:

Commit-ID:     62441a1fb53263bda349b6e5997c3cc5c120d89e
Gitweb:        https://git.kernel.org/tip/62441a1fb53263bda349b6e5997c3cc5c120d89e
Author:        Joerg Roedel <jroedel@xxxxxxx>
AuthorDate:    Wed, 03 Mar 2021 15:17:15 +01:00
Committer:     Borislav Petkov <bp@xxxxxxx>
CommitterDate: Tue, 09 Mar 2021 12:33:46 +01:00

x86/sev-es: Correctly track IRQ states in runtime #VC handler

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@xxxxxxxxxx>
Signed-off-by: Joerg Roedel <jroedel@xxxxxxx>
Signed-off-by: Borislav Petkov <bp@xxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx # v5.10+
Link: https://lkml.kernel.org/r/20210303141716.29223-5-joro@xxxxxxxxxx
---
 arch/x86/kernel/sev-es.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/arch/x86/kernel/sev-es.c b/arch/x86/kernel/sev-es.c
index 301f20f..c3fd8fa 100644
--- a/arch/x86/kernel/sev-es.c
+++ b/arch/x86/kernel/sev-es.c
@@ -1258,13 +1258,12 @@ static __always_inline bool on_vc_fallback_stack(struct pt_regs *regs)
 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_communication)
 		return;
 	}
 
+	irq_state = irqentry_nmi_enter(regs);
+	lockdep_assert_irqs_disabled();
 	instrumentation_begin();
 
 	/*
@@ -1335,6 +1336,7 @@ DEFINE_IDTENTRY_VC_SAFE_STACK(exc_vmm_communication)
 
 out:
 	instrumentation_end();
+	irqentry_nmi_exit(regs, irq_state);
 
 	return;